Horizontal bi-amping - identical amps?
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1335 Registered: Feb-07 | If I were (hypothetically) interested in horizontally bi-amping my Sttafs, would it be preferable to use identical amplifiers? I believe I have the concept correct - horizontal is when you use one amp to drive the L/R low, and another to drive the L/R high, right? |
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Gold Member Username: Nickelbut10Post Number: 1781 Registered: Jun-07 | Thinking about Bi-Amping those suckers Dave? I never really understood the concept of using a separate amp just for the highs. The lows I can see, so therefore maybe it is worth it? I seem to remember a few threads where Jan Vigne had explained the proper technology on why it isn't to any benefit. But I could be wrong man, so I will let the experts answer this one. And learn from it as well. |
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Bronze Member Username: SoundgameRichmond Hill, Ontario Canada Post Number: 43 Registered: Jun-08 | Hey there Dave, You have the equipment right at hand to try a number of combos. You could try to one 2B to the high and one to the low horizontally. You could try a 2B to the high and a pair of Powerpack 120 to the low. You could even go quad with 2Bs bridged running the lows on each side and the two 120s running to top end on each side. Then you could bring in the Rotel setup to drive the highs and the 2B to drive the bass. I guess it would be easier to match the pace of the highs and lows if you used the same type of amp when bi-amping horizontally. Sounds like a Saturday of experimenting. |
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Gold Member Username: Stu_pittIrvington, New York USA Post Number: 2962 Registered: May-05 | "I never really understood the concept of using a separate amp just for the highs. The lows I can see, so therefore maybe it is worth it?" If you have a seperate amp for the lows, what would power the highs? You'd need another amp, hence the bi-amp. I believe most people do this to tighten up bass, or have an amp that's just not quite powerful enough. Maybe not though. "Sounds like a Saturday of experimenting." That's really the only way to know for sure which way will sound best. After everything else is sorted out though - room, source, etc. I'd imagine identicle amps would probably win out. |
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Platinum Member Username: NuckPost Number: 10675 Registered: Dec-04 | Using amps this way will change the load that the amp sees, certainly. However, the real benefit of multi-amping is enabling the use of active crossovers, which is most common in pro stuff. Marchand makes some of the best active units, but at a price, and generally a fixed configuration. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1338 Registered: Feb-07 | There's the part I was overlooking, Nuck - the active crossovers. So is there any point in bi-amping if I'm still using the speaker's internal crossovers? For sure, George - I have lots of gear on hand to experiment. What I eventually may do (when we move into our next house) is use the Power Pacs and 2Bs to bi-amp my RS6s. What I'm really interested in, though, is seeing how the Sttafs sound bi-amped, perhaps with another Rotel amp. |
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Gold Member Username: Nickelbut10Post Number: 1783 Registered: Jun-07 | "If you have a seperate amp for the lows, what would power the highs? You'd need another amp, hence the bi-amp. I believe most people do this to tighten up bass, or have an amp that's just not quite powerful enough. Maybe not though." No no, I understand that. Sorry I should had been more careful with the wording Stu. Technically speaking I can see why people would want to do it, based on tightening up the low end. But for any purpose in changing the high frequencies it would be useless IMO. What do you guys think? |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1339 Registered: Feb-07 | That's what I was thinking, Nick. It seems like sorta a waste to dedicate an entire amp to drive just one little tweeter. |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3184 Registered: Sep-04 | If you don't go active, the main improvement to be had by biamping is wrought through the extra power of the 2nd amplifier. Doing it horizontally ensures that both sides of each stereo amp gets used in a similar fashion. If you used them vertically - i.e. left for treble and right for bass on each amp - you're in danger of over-using one channel of each amplifier unless you rotate them frequently. So I tend to prefer the horizontal method. Of course, you should periodically rotate these power amps also. I used to biamp my Totem Mani-2s horizontally with my P7. I found that when I did this there was substantially improved grip and control. On the subject of whether the amps should be the same, this is one way to ensure that the gain between the amps is the same. Some manufacturers always guarantee the same gain on their amplifiers so you can mix and match but not all do this. Finally I saw a comment earlier: "I never really understood the concept of using a separate amp just for the highs. The lows I can see, so therefore maybe it is worth it?" Interestingly (I hope), Naim Audio suggest that when upgrading in the active scenario, always use your best amplifier on the treble followed by midrange and bass last, even though the power requirements are the opposite. I know several people who have tried it both ways and confirmed that Naim's advice is correct, so although the power requirements of the treble section are lower, it seems the perceived value of the upgrade is higher with the treble generally speaking, so don't discount this as being the right port of call. Cheers, Frank. |
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Gold Member Username: Nickelbut10Post Number: 1788 Registered: Jun-07 | Thanks for the input Frank. Good stuff. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1340 Registered: Feb-07 | Excellent information Frank. This is exactly what I was looking for. It seems counter-intuitive to use one's best amplifier to drive the highs. Just so my assumptions are correct, can you explain the difference between horizontal and vertical? I think I'm mixed up. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1341 Registered: Feb-07 | The gain is something else I'd forgotten about. I remember when I was running my Rotel and Bryston monos on the same system (the Brystons powering the 'A' channel and the Rotel driving the 'B' channel). The B channel was a fair bit louder due to the Rotel's higher gain. So mixing and matching these 2 amps for bi-amping would probably not be good. |
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Platinum Member Username: NuckPost Number: 10680 Registered: Dec-04 | David, I have a 5 channel Rotel power amp that you can also use to play with. |
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Gold Member Username: Arande2Rattle your ... Missouri Post Number: 2932 Registered: Dec-06 | How about quint-amping those 5-way speakers? (say an active crossover of 80, 200, 1500, 4000, 10000hz). |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1344 Registered: Feb-07 | Let's not get too carried away here Andre, lol. You are a gentleman and a scholar Nuck. Thanks. |
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Platinum Member Username: NuckPost Number: 10683 Registered: Dec-04 | Sent mail, David. |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3188 Registered: Sep-04 | David, I am assuming you're using stereo amps. Horizontal biamping: Power amp 1: left output to left speaker LF connections, right output to right speaker LF connections Power amp 2: left output to left speaker HF connections, right output to right speaker HF connections Horizontal mode uses standard wiring - i.e. preamp outputs, output 1 left to power amp 1 left, output 1 right to power amp 1 right. Output 2 left to power amp 2 left and output 2 right to power amp 2 right Vertical biamping: Power amp 1: left output to left speaker LF connections, right output to left speaker HF connections Power amp 2: left output to right speaker LF connections, right output to right speaker HF connections Vertical mode uses non-standard wiring - i.e. preamp outputs, output 1 left to power amp 1 left, output 1 right to power amp 2 right. Output 2 left to power amp 1 left and output 2 right to power amp 2 right. Note: You can use Y-leads in both cases, although the vertical configuration is possibly easier since each y-lead goes from the preamp to a single power amp (left y-lead to left power amp and right y-lead to right power amp) whereas in the horizontal case, the destination of the two ends of the lead is to a different box. Different amplifiers have different gain settings. This makes life a real pain in the neck if you try to mix and match power amps. You will almost definitely skew the presentation too with variable results. I only ever recommend biamping very rarely and then only with the same model of amplifier or with a brand which guarantees gain values (guess who?). |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1351 Registered: Feb-07 | Awesome! Thanks Frank. I think the problems with variable gain among amps makes bi-amping too much of a hassle. How do you feel about running amps in mono and using one amp for each speaker (assuming they're the same)? I have had good results doing this with 2 NAD C272s as well my my dual Bryston 2Bs. |
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Gold Member Username: Mike3Wylie, Tx USA Post Number: 1428 Registered: May-06 | Don't thank Frank yet David, I think he mis-spoke regarding the Vertical mode pre-amp output. I think it should state; Vertical mode uses non-standard wiring - i.e. preamp outputs, output 1 left to power amp 1 left, output 1 right to power amp 2 left. Output 2 left to power amp 1 right and output 2 right to power amp 2 right. If I messed up Frank can beat me with a stick. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1352 Registered: Feb-07 | Thanks Michael. You getting out the stick, Frank? |
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Silver Member Username: MagfanUSA Post Number: 333 Registered: Oct-07 | I heard Braun Tri-amps, many years ago. I looked them up and they were LV-1020s. Only a minor and maybe non-starter point when using different amps in a bi/tri amping situation. It is JUST possible that the signal will take longer to go thru one amp than another. It doesnt' have to be much. 1milisecond= .001 second. This latency will cause image problems at the very least. Matching amps should make this go away. |
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Platinum Member Username: NuckPost Number: 10687 Registered: Dec-04 | That is what active XO's are for. |
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New member Username: OddyoCanada Post Number: 1 Registered: Sep-08 | Hi folks - new to the forum and just thought I'd put my 2 cents in here. This is my experience with bi-amping: I had always been champing at the bit to do this, and was always told I should have identical amps. When I finally acquired them (Adcom GFA-5200's) and went to hook them up I realized that I wasn't quite sure how to do it. I was fortunate to be using a NAD 7240PE receiver at the time, which allowed for two pre-outs to go to the power amps, but how to hook up the speakers? As I was using Linn Helix speakers, I asked my local Linn dealer and he said I could either use one amp each to power one channel each or one amp to power the tweeters and one to power the woofers (he did not describe these as either "horizontal" or "vertical"). He also opined that it should be harder to drive the woofers so it mgiht create a little difference in the loads the amps see. In an effort to make things as even as possible, I asked him what he thought of the idea of running the R tweeter and L woofer from one amp and the remaining two drivers from the other and he thought that seemed a great idea. This I did for a number of years. When I replaced the Helix with a pair of Totem Sttaf I did the same at first, but then read a forum where it was highly UNrecommended, something about differing phases? Anyway, the idea of "horizontal" and "vertical" came up again (and I was confused by it, too!)and, not wanting that differing load idea, I simply went to one amp driving L and one amp driving R - I must say, a great improvement in clarity was realized! |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1392 Registered: Feb-07 | Thanks for the post Brian. So you were basically using each amp as a monoblock? Are you able to run your Adcoms in mono mode? I've done this with NAD C272s in the past (both in mono, each driving a speaker). The improvement was easily noticable. |
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Gold Member Username: Nickelbut10Post Number: 1831 Registered: Jun-07 | Brian- Well said. Good to see another good postie and Canuck on the forum. Stick around man. Cheers. |
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Platinum Member Username: NuckPost Number: 10739 Registered: Dec-04 | Brian, the 'old' way would destroy stereo seperation. Yoour new setup is considered vertical, or one amp for one channel. Vey simple, and usually very good. Great to see you here! |
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New member Username: OddyoCanada Post Number: 6 Registered: Sep-08 | Thanks, guys. David, I don't run my amps in mono mode (not sure that I can), I just run one set of L/R to the tweeter and one set to the woofer. |
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Bronze Member Username: SoundgameRichmond Hill, Ontario Canada Post Number: 74 Registered: Jun-08 | Not a "true" biamp but go easy on me. With all the bi-amping talk I decided to see what would happen if I used my Onkyo 805 bi-amp option (Surround Back channel drive the low, while the main outputs drive the high). All I can tell you is the sound improved noticeably - soundstage grew, imaging more precise and everything sounds cleaner. What I don't know yet is whether the sound improvement is due to the biamp setup or because I'm not using the brass jumpers on the speakers - they seemed quite flimsy. Will need to do more testing but for now I'm sold on biamping. |
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New member Username: OddyoCanada Post Number: 8 Registered: Sep-08 | I know it might stir things up a bit, but I must say that I experienced a noticeable improvement with bi-wiring and even more so with bi-amping. And just for good measure, I'll throw in that I believe interconnects make a difference, too (Note that I said make a difference - not always an improvement, no matter what you spend!). |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1401 Registered: Feb-07 | I believe cables can make a difference too Brian. Sometimes good, sometimes not so good. As I mentioned before, my Audioquest cables between my CA receiver and CA CDP was absolutely terrible (grainy sounding). Some $10 RCAs I bought on ebay sounded 10x more smooth. |
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New member Username: OddyoCanada Post Number: 9 Registered: Sep-08 | Yeah, it's strange isn't it? It seems to be all about the combinations and interactions. JOOC, which Audioquests were you using? I've had good luck with them generally. Zu Warmouth is a great cable, too. I read once an opinion that all cables in a system should be the same make and model and, while I'm not sure that's necessary, I thought it might be a good way to start. Then, as you swap out different interconnects you can really know which one you're hearing! |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1402 Registered: Feb-07 | I think they were Audioquest Sidewinders? Can't quite recall... the green ones, if that helps - lol. |
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Gold Member Username: Stu_pittIrvington, New York USA Post Number: 2995 Registered: May-05 | Audioquest Green ICs are Copperheads. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1403 Registered: Feb-07 | That's it, Stu. |
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Bronze Member Username: SoundgameRichmond Hill, Ontario Canada Post Number: 78 Registered: Jun-08 | Dave, Do you find your PP120's run better on your Sttafs than your 2B's. The 2B's bridged would provide more power, would they not? For the Sttafs, how much of an improvement do you think you will get out of them with the 4B or for that matter with a Mc? In other words, where is the balance (diminishing marginal returns) on the Sttafs from an amplifier standpoint - the point where you would be better off moving up the Totem line to get the most out of the amp? Not sure if I'm being clear. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1411 Registered: Feb-07 | Hey George, Yes, I find the PPs control the Sttafs a little bit better than the 2Bs. The damping factor on the PPs is quite high, and I find this provides tighter bass. I think the 2B's I have (keep in mind these are the old ones rated a 60 watt per channel) are only pushing 100 watts bridged. The PP's are rated for 120 at 8 ohms. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1412 Registered: Feb-07 | Oh yeah, and I think anything I buy above and beyond the Bryston monoblocks definitely brings me into diminishing returns territory. What do you think? |
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Gold Member Username: Nickelbut10Post Number: 1842 Registered: Jun-07 | I agree David, I can't see the Sttafs needing much more. If you get the 4bsst or the MAC, what speaker will it be used with? |
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Bronze Member Username: SoundgameRichmond Hill, Ontario Canada Post Number: 81 Registered: Jun-08 | IMO, a new B100SST or 2BSST but no more than a 3BSST would be more than a match for the Sttafs - anything more and it would be probably be better to move up the Totem line. Another option could be the Naim Supernait. However, if this is the begining of future upgrades going with a 4B in expectation of upgrading your 2ch speakers might work out. Lots of decisions - but ain't they fun? |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3206 Registered: Sep-04 | Michael, Thanks for correcting me, I should've drawn out a diagram before typing it up! |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 130 Registered: Jun-08 | Question - excuse my ignorance. I'm biamping my fronts on my Onkyo. With the jumpers removed, when I have the speaker wires hooked into the low only, I can hear the music, though at very low level through my tweeters. For those technically inclined, how is it that the tweeter is getting any voltage without the jumpers present? Is it somehow creeping through the X-over? I called the manufacturers tech. support and they said it was normal. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1469 Registered: Feb-07 | That's an interesting question George. I have no idea. |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3216 Registered: Sep-04 | George, Simpler latter day crossovers slope at between 6db and 24db which means that if one drive unit fails, you may still get some sound from the other. However, typically, biwireable speakers don't use ordinary crossovers - they tend to use separate filters which should mean that the two networks are completely separate so there should be no sound from the 'other' part of the speaker. That said, it does rather depend on the speaker design and if the manufacturer says it's normal who am I to argue? |
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Platinum Member Username: NuckPost Number: 10943 Registered: Dec-04 | I think I have a lead on another ca300 amp to mono them. Need another mains source, however... |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3236 Registered: Sep-04 | I guess I should point out one thing - I'm not a big fan of biamping! I tend to prefer to use better amps in the first place. In a pre/power scenario this means either using a better preamp (often the most undervalued item in a system and in my experience usually the weak link), or through a simply more capable power amp. Biamping is mainly useful when you have speakers which are particularly difficult to drive. Splitting the load between amps helps drive and grip. In order to guarantee no phase problems, I always recommend that one uses the same interconnect from pre to both power amps, same speaker wire and even the same lengths of speaker wire for both amps. Different wire (especially if configured differently such as twisted pair versus paralleled pair) can cause phase problems between the drive units. Even different lengths of cable can do so. This is one reason why I am not a fan of biamping. By comparison, you could sell your preamp and with the money retained and the cost of the 2nd power amp, you could probably upgrade the pre. This will usually result in better results all round by improving the signal control on all your sources. (Sorry Dave!) Frank. |
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Gold Member Username: DmitchellOttawa, Ontario Canada Post Number: 1568 Registered: Feb-07 | No need to be sorry Frank! Everything you just said there makes sense to me. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13052 Registered: May-04 | . "Simpler latter day crossovers slope at between 6db and 24db which means that if one drive unit fails, you may still get some sound from the other. However, typically, biwireable speakers don't use ordinary crossovers - they tend to use separate filters which should mean that the two networks are completely separate so there should be no sound from the 'other' part of the speaker. That said, it does rather depend on the speaker design and if the manufacturer says it's normal who am I to argue?" This has been an interesting thread with what would appear to have much misinformation and misunderstanding of bi-amping and biwiring. Let's take the above post to start. I don't want to pick on Frank here, but "simpler" means what? 24dB slopes are not "simple". http://sound.westhost.com/articles/derived-xovers.htm http://www.apicsllc.com/apics/Misc/filter2.html#fourth And, if anything has ocurred in the past two decades, the architecture of a "typical" crossover has shown an increased number of components and therefore complexity rather than having become simpler. Designers now insert notch filters and other correction type filters (baffle step) that are meant to compensate for what the driver designer cannot achieve or for the vagaries of user ignorance, placement restrictions and plain old preference - or just to make their product more saleable on the demonstration floor. While there are more types of filter architectures to choose from today than when I first began selling audio in the early 1970's, a first order (-6db) or a fourth order crossover filter (-24dB per octave) is still contructed with the same arrangement of capacitors, inductors and padding resistors as always. Crossover architecture has been largely the same for the last seventy years. Passive bi-amping and biwiring are relative new comers to the game but do not change the basic layout of the filter itself other than to separate the discrete (low/mid/high) filter parts and therefore any ground plane between drivers that might otherwise be shared in a more "conventional" crossover type. I don't know if that is what Frank meant by, " ... biwireable speakers don't use ordinary crossovers - they tend to use separate filters which should mean that the two networks are completely separate so there should be no sound from the 'other' part of the speaker", but the actual filter layout and filter action of a biwired crossover is the same as a "conventional" crossover and remains quite "ordinary" in most respects. I am confused by Frank's suggestion that "crossovers slope at between 6db and 24db which means that if one drive unit fails, you may still get some sound from the other." It is not the slope of the crossover that would allow for any shared information should one driver fail. Whether in a "conventional" crossover or a biwired crossover it is how the filters/drivers are connected that allows one driver to operate without the other working or stops the operation of all drivers. If the crossover were wired in series, all drivers would cease to operate should any driver fail since failure in one driver breaks the circuit between all drivers and the amplifier. It is true that with both drivers working a shallow first order filter (-6dB) will allow more overlap between drivers than a sharper fourth order filter (-24dB) would allow but that is another issue all together. If any one driver fails in a series connected crossover, all drivers will cease to operate. In a parallel connection all other drivers will continue to work if one or more drivers fail. A true bi-amped crossover would be a totally different matter since the bi-amped configuration does not draw distinctions between any drivers (connected to only one amplifier of the multiple required amplifiers) wired in series or parallel. Unfortunately, most passive crossovers in most budget oriented consumer loudspeakers are neither truly biwire capable and in most cases they certainly are not actually bi-amp capable. "I'm biamping my fronts on my Onkyo. With the jumpers removed, when I have the speaker wires hooked into the low only, I can hear the music, though at very low level through my tweeters. For those technically inclined, how is it that the tweeter is getting any voltage without the jumpers present? Is it somehow creeping through the X-over? I called the manufacturers tech. support and they said it was normal." I'm going to guess that you are not truly "bi-amping" your speakers. I don't remember if we've been through this with the Onkyo receivers since a few of their receivers had/have small secondary amplifiers which can be used for multi-zone operation distinct from the multichannel functioning. If you are using such a receiver, one with two distinct amplifiers - one multichannel and the other meant for multi-zone, then you could possibly harm your receiver with what I understand to be your "bi-amped" speaker arrangement. To step back just a bit, if you are using a receiver with one amplifier but two sets of speaker outputs (A+B), you are not bi-amping with both speaker output connections running to the same speaker. You are, at best, biwiring your speaker. Here's what I see from George in an earlier post, "Not a "true" biamp but go easy on me. With all the bi-amping talk I decided to see what would happen if I used my Onkyo 805 bi-amp option (Surround Back channel drive the low, while the main outputs drive the high)." I assume this means a Dolby Digital/DTS receiver with at least five discrete amplifiers in the receiver. One problem you could have in this set up would be you are not separating the signal before the surround processor. If the surround channels are still seeing information that exists in all channels, then you need to go back into your receiver's set up menu and make the appropriate changes to get to a discrete two channel, stereo only set up for all channels. This would remove any information from the surround channels that would otherwise get processed as ambient information. My guess as to what is more likely to be happening here is simply marketing of a speaker as one thing when it truly is not that thing. I suspect your speakers are not truly biwireable and defintiely not bi-amp capable. The tweeter is still seeing signal through the ground path - or through a more direct path - through a less than ideally laid out crossover. That the speaker manufacturer considers this "normal" operation would suggest they know what they have marketed. So, first, are you certain you have the system set up correctly for any sort of biwire configuration? If you are, and you are using two discrete amplifiers into a speaker that does not actually separate the signal path to each driver, you could be placing your system at risk by allowing multiple amplifiers to face one another at your speaker inputs. I would say this warrants some research and consideration before you continue with this set up. . |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 172 Registered: Jun-08 | Thanks Jan. Let me try to be as clear as possible with the setup. Amp: Onkyo 805 AVR 7.1 This AVR uses 7 different amplifiers within, connected to a single power supply. As advertised and explained in the manual, the AVR allows for a bi-amping option. In the menu, you need to change the option to Bi-amp, in which case the surround back amplifiers (L rear / R rear) are reconfigured by the AVR to output only the low frequencies of the typical front channels, while the normal front L/R amplifier will now only output the high frequencies of the typical front channel. The AVR will now be capable of driving only 5 amplified channels as the front has been split into low/high frequency output using the surround back amplifiers. This is all outlined in the manual. The only caution is that you use a bi-amp capable speaker. Speakers: Sinclair BT36, 4 driver, 3-way, with one tweeter, one midrange and two bass drivers. These speakers have two sets of binding posts on the rear, typically connected with brass jumpers. I have removed the jumpers and followed the instructions that are outlined with the speakers and the AVR "precisely" to hook them up in the bi-amp setup. They seem to be working fine with no overheating or amp shut-down. The question was, whether I use the AVR or some other amplifier, when I remove the brass jumpers and hook up only the binding post connected to the low-end, I get the expected output from the low-end but I also hear some weak high frequencies from the tweeter (not distorted but perfectly clear, just about 1/10 of the typical volume of the input power). My question was how can this be so? The manufacturer of the speakers has confirmed that with the binding posts removed, each set of binding posts will present a nominal load of 8 ohms and that some output from the tweeter when only the low frequency binding posts are hooked up, is normal. I can't understand how this would work itself out. How does the ohms remain a a nominal 8, when the jumpers are removed and how is there any sound coming from the tweeters? Any further light you can shed on this would be appreciated. Thanks. |
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Platinum Member Username: NuckPost Number: 10944 Registered: Dec-04 | That's all wrong, George. Somebody has their wires crossed, essentially. If there are independant XO's forfrequencies, then nothing is there. The speakers are not wired as you were told, and the factory is doing doublespeak. Open them up? First,one check. Grab a meter and check for continuity between posts, upper and lower. The speakers I use right now (PSB Silver) have independant XO's ( I had to upgrade them...do you smell smoke)? These are bi-ampable. Nor do I understand the description of your Onkyo's outputs. The rears become LF output, while the fronts are HF? This would indicate some sort of internal active XO, or at least a permanent XO frequency, which does no good(in theory of active/bi-amp)unless the frequency exactly matches that of the factory values, slope, knee and so on. Also, as a 3 way speaker, where does the mid get the power from? |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 173 Registered: Jun-08 | My man Nuck, I don't have a continuity tester and wouldn't know where to get started. The Onkyo 805 would have an internal X-over that would split the output of the front channels into hi and low and then output that signal to the corresponding amplifiers. In fact the Onkyo 875 and 905 are also bridgeable as well as bi-ampable. So I'm confident that the amp is outputing hi frequencies from the front channel amps and low freq. from the surround back channel amps. cause the music sounds right and in fact sounds better i.e. more open a clear with a larger soundstage than when I have it hooked up in the normal mode; however, I suspect that has more to do with not using the brass jumpers in the bi-amp setup. (Nick - your friend has an Onkyo AVR - has he tried doing this?). I'm hesitant to start taking my speaks apart, as they have a 5 year warranty and in fact, I can and have reached in the rear port and taken picture of the X-over from the inside. Can't say I know what to look for, though they are on circuit boards and not fully wired. Can someone explain how the X-over might work? It's 8 ohms when the jumpers are in place and when the jumpers are removed, each set of post (the hi and the low) provide an 8 ohm load independently and as such, when I hook up my AVR in the bi-amp setup, I leave the setting at 8 ohms. If when the jumpers are out and I've got only the low posts hooked up, can you explain in technical speak how the tweeter would get any power at all. If it were that it's all wired together, then the tweeters should play at normal volume i.e. it would sound as if the jumpers were not removed in the first place but this isn't what happens. What happens is that the hi frequencies are dramatically reduced and the lows are more dominant. How would the speakers be designed to produce these results? This is a test of your knowledge boys - not that I know the answer myself. If this doesn't work, can you give me some educated questions to go back to the manufacturer with, as I'm on a first name basis with the Marketing Director who sits next to the engineer/designer. |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3239 Registered: Sep-04 | Jan, I think I may have had my wires crossed! However, by 'simpler' I meant smaller number of components and usually lower order crossovers which remain prevalent in most designs as far as I can tell. That said, if one of the ranges (e.g. treble or midrange) has been disconnected then there should not be any signal going to it and there should be no sound from it. So if you disconnect the biwire links and connect to the midrange unit, you should get absolutely nothing from the treble unit. If you do, it's pretty strange - unless the biwire terminals are really just for show and a single crossover exists in the speaker. |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 174 Registered: Jun-08 | But Frank, if the biwire terminals were just for show, then there shouldn't be such a reduction in the output of the high frequencies, while the mid and base frequencies remain at full output. How could it be wired to explain this difference? Has anyone specifically tested their speakers to see if this happens? |
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Platinum Member Username: NuckPost Number: 10950 Registered: Dec-04 | George, your speakers might be using a split reference, with one leg going through a passive device to ref. XO's can get ugly, I think yours are a bastardd concoction that work well, as you say. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13053 Registered: May-04 | . "In the menu, you need to change the option to Bi-amp, in which case the surround back amplifiers (L rear / R rear) are reconfigured by the AVR to output only the low frequencies of the typical front channels, while the normal front L/R amplifier will now only output the high frequencies of the typical front channel." I'm not a designer nor an engineer so I can only make a guess here. My first guess would be that if you were to apply a 9Volt battery to the low frequency terminals, you would get some movement of the higher frequency drivers - at least the midrange. Unfortunately, your speakers are not well described in the company's online literature and that leaves me truly guessing at what could be happening. Are you certain you are hearing the tweeters? Or are you just hearing what you perceive as rolled off high frequencies? You have a supposed "three way" speaker that is "bi-amp" capable. That means the three "ways" of the system are capable of being split into two sections when you try to bi-amp the speaker system. Probably the bi-amp split occurs between the midrange and the high frequency driver. Therefore, when you remove the jumper, the low frequency connection still drives the woofers and the midrange. Is it possible you are hearing rolled off high frequencies being emitted by the midrange? Are you certain the tweeter is actually responding to signal when the jumper is removed? Connecting the terminals of a battery to the LF inputs of the speaker would be instructional here. Do all drivers respond or only a certain group? If the tweeter actually responds to the battery input, then I would say the bi-amp capacity of your speaker is more a marketing department's dream than a designer's reality. It's quite possible the midrange and tweeter share a common ground path and the tweeter is seeing the back EMF of the midrange or a weak signal path resulting from an the out of phase connection applied to the tweeter to compensate for phase shift within the crossover. There are too many possibilites but I would think Sinclair is the place to find your answers. Without any sort of technical explanation to go on, it is really impossible to guess much more than the above. I don't know where the three way splits occur in the crossovers or their type and slope. I suspect there are some shallow first order filters in the crossover but how the signal can exist in the tweeter - if that's the case- with the jumper removed would simply be a question to ask the tech support guy. It would be important to know since this could allow multiple amplifiers to see one another across the speaker input. That would be my other question to Sinclair's tech support, are the amplifiers sharing a common connection with each other?. Part of the problem might be where Onkyo has placed their internal crossover point - I assume they do roll frequencies in and out when you set the receiver to "bi-amp" mode - and that there isn't much of a roll out of high frequencies being removed from the LF section of the bi-amped system. Unfortunately once again, the Japanese mass market designers have some very odd ideas about how to design for marketability with buzz words and not really deliver the goods internally, so it's possible Onkyo's "bi-amp" capacity isn't all it's written up to be. Then again it might be since Onkyo is capable of building a decent product. The reason for the situation might be within the crossover of the speakers. I would think the Sinclair support person could be a bit more forthcoming than just to say it's normal to hear high frequencies when driving just the LF input of their speaker. That isn't how a bi-amp capable speaker typically operates. My real concern is the speaker is biwire capable and bi-amping is a real stretch of merketing that could place your amplifier in some amount of danger. Specifically, you are driving the speaker from a common power supply and therefore a common ground shared by both amplifier sections so the danger here probably isn't too severe though this would still be a marketing tool that could place another client's components at risk. Do you know what happens when you connect to only the HF input of the speaker? "The manufacturer of the speakers has confirmed that with the binding posts removed, each set of binding posts will present a nominal load of 8 ohms and that some output from the tweeter when only the low frequency binding posts are hooked up, is normal. I can't understand how this would work itself out. How does the ohms remain a a nominal 8, when the jumpers are removed and how is there any sound coming from the tweeters?" To speak of an eight Ohm speaker system is a vast simplification of reality. The speaker might represent a nominal impedance of eight Ohms and that is typically what is meant when a manufacturer says their product is "eight Ohm" impedance - when driving the whole speaker system with the jumpers in place the amplifier will see a nominal eight Ohm impedance. When driving the speaker as two sections, the impedance can easily remain eight Ohms either because one driver - the tweeter(?) - is a nominal eight ohm load or the individual sections represent a nominal eight Ohm load. This shouldn't be too difficult to understand if you grasp the loose manner in which speaker manufacturers describe their products in terms that say overly much without really describing anything. Remember, along with nominal impedance (which means so little as to be virtually useless) the actual impedance of a speaker system is the cumulative impedance of the drivers and the crossover components combined. Talking about nominal impedance ratings is a bit like describing a car as 200 MPH capable because if it ran into another object that was going 150MPH in the opposite direction, the cumulative impact would be the equivalent of two hundred MPH. Pay no real attention to the man behind the screen. |
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Platinum Member Username: NuckPost Number: 10951 Registered: Dec-04 | I wish my brother George was here... |
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Silver Member Username: Jazzman71Phoenix, AZ USA Post Number: 307 Registered: Dec-07 | "I guess I should point out one thing - I'm not a big fan of biamping! I tend to prefer to use better amps in the first place." You have my vote, Frank. |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 176 Registered: Jun-08 | Jan - I'll try the 9 volt out, re-test and give it a clinical listen and report back - hopefully this weekend. Frank/Neil - I would never personally invest in a bi-amp setup but my AVR came with the option so I figured I'd try it. And as it turns out it does sound noticeably better but again, it could be the fact that I've removed those brass jumpers. I wonder if I used some high quality jumpers whether I would really notice a difference between standard vs. bi-amp setup. Once I do the testing, I will go back to the tech support at Sinclair. My contact there has been very forthcoming. They provide great customer service. For example, my centre channel was an older Sinclair model so they mailed out a new badge for it to match my newer model towers - no charge. I had questions about the sound insulation and he sent me pictures of the construction at the factory, where I could see the placement of the dampening material. I also know that the tech support contact owns the prototype of my towers and claims to love them. |
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Platinum Member Username: NuckPost Number: 10953 Registered: Dec-04 | Excellent support George! Replace the brass jumpers with short bits of your speaker wire, George, and connect the + lead to the high post, the - lead to the lower  |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3240 Registered: Sep-04 | Although I'm not a fan, I should point out I used biamping for a couple of years with my processor because my speakers are so hard to drive, so even though not a fan, I used the method... |
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Silver Member Username: Jazzman71Phoenix, AZ USA Post Number: 308 Registered: Dec-07 | George, I did not mean to imply that you avoid trying it, with the necessary precautions. Bi-amping is just not something I want to get involved with. It is hard enough for me to match up a straight 2-channel setup. Processors are another matter entirely, and figuring out how they work tends to make my eyes glaze over. Good luck with the explorations. Cheers. |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 196 Registered: Jun-08 | Ok. The latest on this. I listened again to the amp just driving the LF posts and there are definitely HF coming from the tweeters but not anything I can perceive from the mid. range driver. Again, the HF are weak from the tweeter 1/10 of their volume when the amp is driving the LF posts, with the LF from the woofers working at normal volumes. The tweeters emitting anything when just the LF posts are hooked up seems illogical. When I hook the amp to only the HF posts, the tweeters and the midrange output at expected levels and the LF drivers emit no output whatsoever - so this seems totally logical. Now, given my former explaination on how my AVR runs in bi-amp mode, I tried hooking up the HF amp speaker connection to the LF posts, at low volume level - what supprised me is that the woofers emitted LF. When I did the exact opposite, the tweeters and midrange emitted HF. So whatever crossover is built into the AVR it does not seem to be suppressing or truncating the frequencies as expected. My concern then is that if the low frequencies are still present in the HF amp output, then when I hook this up to the tweeters with the jumpers removed, the tweeters would still be fed with LF. If removing the jumpers by-passes the X-over then would my tweeters be susceptible to damage based on the LF exposure? Now, again, I did not try this at higher volumes and it could be that the HF output from the AVR is sloped so that LF might still be passed but at a reduced level; however, at lower volume levels, I could not determine if there was any kind of slope of reduction in the amount of LF passed through the HF output. I think I need to send a question to ONKYO to get clarity on what the AVR actually does. Jan / Frank - any words of wisdom on all this? Again, any specific questions I can go back to Sinclair (speakers) or Onkyo (AVR) with? Thanks. |
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Platinum Member Username: NuckPost Number: 10969 Registered: Dec-04 | George, no matter how you connect to the posts, you WILL NOT bypass any of the passive XO in the speaker, LF or HF. |
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Gold Member Username: Mike3Wylie, Tx USA Post Number: 1491 Registered: May-06 | George, If you only had some Rogers LS3/5a's you would not have these headaches.  You're more than welcome Frank. |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 198 Registered: Jun-08 | Not to worry. Cheaper to not bi-amp and from what I've read no real improvement. I still need to make or obtain a high quality jumper set to see if I get the same/improved results. Oh, BTW Nuck, I am to bypass the X-overs in the speakers going through the HF posts - as mentioned when I connect to the HF posts, I do not get any LF emissions, hence, the HF posts are not connected to the LF drivers but for some reason the LF posts do send some minimal power to the HF drivers. It's weird having these different results depending on the posts you choose. |
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Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13061 Registered: May-04 | . "If removing the jumpers by-passes the X-over then would my tweeters be susceptible to damage based on the LF exposure?" You're asking a question about two products I know nothing about and the manufacturers are strangely shy about providing information on their web pages. Your speakers seem to do things they should not do and I don't know enough about your receiver to say anything is certain. I think it's safe to assume, though, that the crossover is still intact between the midrange and the low frequency drivers when you connect to the HF posts. This would roll out any low frequency information and negate the chance you might damage the tweeter with low frequency signals. If you have access to a test CD with a frequency sweep, you should try running it when the connections are made to the various posts. The idea the tweeter receives information when the connection is to the LF post is strange enough. The idea the midrange does not also receive those same signals is extremely odd. . |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3247 Registered: Sep-04 | George, The Onkyo sends out fullrange signals from all its amplifier outputs, except in stereo mode if you've set it up as sub+sat. The fact is the crossover in the speaker is meant to break down the fullrange signal for the treble, mid and bass units. It's not the job of the amplifier to do this. (Well, there's an exception called active operation, but that's not what's going on here - you're running passive.) |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 199 Registered: Jun-08 | Frank, Since I know you're familiar with Onkyo, could you respond to the following: Onkyo in their manual outlines he procedure for bi-amping the front two channels on the 805. The procedure involves hooking the Sur.Rear speaker outputs to the LF speaker posts and the Front channel speaker outputs to the HF speaker posts (on a speaker that is equiped to handle bi-amping i.e. two bining posts)and finally setting the Onkyo's menu to Bi-amp mode. They indicate quite specifically how this is to be done and speak to there being the advantage of increased clarity. If a normal speaker with bi-amp hookups circumvents it's internal crossover when the jumpers are removed and the speaker is hooked up in a bi-amp fashion, then would not the Onkyo outputing a full spectrum through both the speaker outputs do possible damage to the speaker. In other words, if the Onkyo does not use an active crossover internally when it is hooked up in bi-amp mode (and the menu selection chosen on the ONKYO for Bi-Amp) and is outputting full spectrum through the speaker outputs while the speaker's internal crossover has been by-passed with the jumpers being removed, then could the tweeters not be overloaded with low frequencies? |
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Platinum Member Username: NuckPost Number: 10971 Registered: Dec-04 | George, active XO's, in in the speakers are identified with an external power supply, usually a 110v plug for the speaker, and largely internal amplification. These are powered monitors. Thers is no way to bypass your speakers internal passive XO's, short of opening them up and performing mods. Removing the jumpers does make the speaker capable of reacting to 2different sources of power, being biamp or biwire, which was likely the intention of the manufacturer. |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 202 Registered: Jun-08 | So Nuck, are there any speakers without active XO that you can bypass the XO by removing jumpers. Say Totem's for example? If you remove the jumper on a Totem that has HF and LF posts would the HF and LF drivers operate 100% independently i.e. would there be any HF transfer to the tweeters when only the LF posts are hooked up? If not, what is different in my speakers? |
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Gold Member Username: Frank_abelaBerkshire UK Post Number: 3252 Registered: Sep-04 | George, This is the right question, and to be honest I don't know the answer. In typical biwireable speakers with two sets of binding posts on the back, if one set of binding posts is not connected then the driver associated with that set will not make a sound. By disconnecting the link between the two sets of terminals you are not disconnecting the crossover, you're merely disconnecting one filter from the other (the HF filter from the LF filter). The filter feeds whichever drive units it feeds. In a 2 way speaker, one filter feeds one drive unit and the other filter feeds the other drive unit. It's the responsibility if the filter to cut out the frequencies that are not required for its drive unit(s). There is one example of a speaker where you can reconfigure the jumpers on the back to bypass the internal passive crossover (or filters) completely. Linn's Katan (and Ninka), allowed you to swap around a panel on the back which could take you from connected, through biamp, triamp (in the Ninka case) and finally active mode. This approach is unique as far as I know. In answer to your question on Totems, yes, the drivers would act completely independently. The tweeter would not be in operation if only the bass/midrange LF posts are connected. No idea what is going on with your speakers. There was one brand that has shut down called Royd. Their last set of speakers were internally configurable for single or biwiring and you had to know what had been ordered to know whether what you'd got was one or the other. Perhaps your speakers are the same? No idea... Incidentally, active crossovers are distinct from active speakers. Nuck has described an active speaker. This would not just contain an active crossover but also amplifiers, one per drive unit, hence the need to power the speaker. An active crossover can be placed between pre and power amps and in this case the power amps would be connected directly to the drive units on the speakers which would not contain a crossover or filters. The simplest case is of course the single driver speaker (e.g. Aurousal A1, MJ Acoustics Subliminal S1R) which has no need for a crossover at all! |
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Silver Member Username: SoundgameRichmond Hill Toronto ..., Ontario Canada Post Number: 213 Registered: Jun-08 | Thanks Frank. I've got some greater clarity but I think this requires that I go back to the manufacturer and see if they can outline to me the internal wiring and current path for these speakers. Not that it really matter because I'm happy with the sound but this is an interesting problem I would like to solve. Cheers. |
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Platinum Member Username: NuckPost Number: 11044 Registered: Dec-04 | I am very close to aquiring a second Classe ca300 amp now. Unfortunately, I am also soon moving to a rathervery small house as well. I have in mind to change to standmounts, to be able to move the speakers in and out of position as the listening arises. I am still bent on trying Totem Mani-2's, I think the Classe amps can deal with the speakers need for grip and control quite well. The room will be a crapshoot, BUT, I will not be constraing by any other opinions, nor will interior walls be an issue...the can move, but the listening area will still be small, think 13x15 ft. Thoughts? |
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Gold Member Username: ArtkAlbany, Oregon USA Post Number: 7977 Registered: Feb-05 | 13 x 15 is plenty big for good listening. My biggest listening space is at max 17.5 x 13.5 with a big corner fireplace taking up a bunch of space and I have plenty of space. |
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Platinum Member Username: NuckPost Number: 11050 Registered: Dec-04 | The space will grow after a year or so Art, so I am thinking ahead and thinking with my guts right now. |
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Silver Member Username: MagfanUSA Post Number: 360 Registered: Oct-07 | Attached, please find sketchomatic for Magnepan MG1.6s.....very simple and when jumpers are removed, 2 separate circuits. Also, what about amp Timbre? I didn't see that mentioned above. I could see (hear, actually) problems with say.....a NAD / ROTEL matchup.  |
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