What subwoofer cable...??? Best setup for Sub???

 

AL
I just bought an AR-S108S subwoofer, a little sub for my apartment. Here are my questions:

1. What subwoofer cable should I buy? Preferably not too expensive, just good enough to drive the sub.

2. I have a Yamaha 5560 A/V Receiver. Subwoofer has a line level input and two speakers level input in the back. Which will give the best bass, line level or speakers level in?

3. How should I setup this? I've read about sub going to 2 front speakers on the receiver. I'm just confused.

4. Also, in the back of the sub it has a Phase switch 180 or 0. What is that for? What should I have it on 180 or 0?

5. Regarding speakers level in, what gauge should I get? I have all my other 5 speakers connect with gauge 16.

I'm fairly new at this HT stuffs. Any kind of help will greatly appreciated. Thanks in advance!

AL,
 

1. What subwoofer cable should I buy?
A standard RCA-to-RCA cable, the kind you use to connect a CD player to the reciever input (though not opitical, digital), will do the job. You only need one cable and they usually come as pairs for stereo. You can pull the two strands apart. Better would be a single, thicker coax cable. In stores here they have "video connector" on the packet. Mine cost equivalent of $10 for 10 metres. Then there are exotic sub cables costing a lot. I am skeptical about those. The line level is low current, and just carries a HF signal; it is not as critical as speaker cables which have to carry 100W of power or whatever. However, the cable should be coaxial and well made to prevent RF interference with other things around. It should be long enough to let you place the sub anywhere you like. 10 metres or so even for a medium room.

2. "Subwoofer has a line level input and two speakers level input in the back...".
Line level and speaker level are for two different jobs. The line level is best if your amp/receiver has a "subwoofer out" socket AND if you want to hear what the engineers decided to put on the ".1" channel on the DVD: it is a separate channel from left, right, center, etc. Dolby and DTS call it the LFE for Low Frequency Effects channel. The speaker level input (there are usually two, left and right) is where just add the sub to you stereo hi-fi. You connect your sub to the L and R outputs from the receiver. Then you connect your L and R speakers for stereo to the "speaker out" or "Satellite speakers" output from the subwoofer. This puts the subwoofer as a link between your receiver and your main speakers. The sub has a crossover filter which takes the low bass and gives it to its own internal speaker. The rest passes through to the main speakers. This is good for listening to music in stereo, because the sub probably goes much lower that the main speakers can. Furthermore, the sub will take the load off the main speakers, letting them give a better response at higher frequencies. DO NOT connect the line level and speakers level at the same time unless your sub has some sort of switch between them and the manual says it is OK.

3. "How should I setup this? I've read about sub going to 2 front speakers on the receiver".
Also see 2. The sub has speakers in and speakers out for when you want to use it to help your stereo speakers; you connect "in" to the receiver's speakers out, and "out" to your front L and R speakers. WIth line-level to the sub for DVD etc. you don't need the speakers connections at all.

4. "The back of the sub it has a Phase switch 180 or 0. What is that for?"
Bass is low frequency sound. Treble is high frequency. The wavelength gets bigger the deeper the bass, the lower the frequency, and can be up to several metres (yards). The waves from different speakers can be in phase - peaks at the same time - or out of phase - one gives a peak when the other gives a trough. In the latter case, the waves cancel each other out, and, at the particular frequency, you hear nothing. This is why you have to get the phasing right even with stereo; you do this by strictly observing + to + and - to - between the amp and both stereo speakers. You can hear the effect of being out of phase by connecting + to - on just one channel. It won't harm the system, but will sound really bad; you lose bass and also the stereo image gets screwed up. With a subwoofer if you use the line-level connection you're probably OK with zero, because the engineers have figured it all out on the recording. But on any case all you can really do is turn the knob and see if it sounds better. Zero is in phase. 180 is completely out of phase. In between is in between. The reason the control is there is that sound takes time to travel and reflects from walls etc., so even if the sub is theoritically in phase with the other speakers, your room might make it cancel out the other speakers by getting the sound to you a bit later, so peaks from one speaker (e.g. the sub) come at the same time as troughs from the other. So all you can do with that control is twiddle it and listen to see what sounds good.

5. Use the same gauge as the other speakers. Remember the higher fequencies are getting passed on to the L and R main speakers. If you have good cable for them it will not make up for losses in the link between the receiver and the sub. Use the line-level input and you don't need speaker cables for the sub at all.

Hope that helps. Manuals ought to help and explain what all those features are for, in simple English. In my post "Comparing two subwoofer" the Audio Pro user guide was complete rubbish. AR ought to be OK, though.
 

When I try and give my sub any measure of volume, I get this awful vibration / reasonance in the walls of the room - I have a large open room with bare timber flooring, and cathederal ceilings.I have tried putting it on spikes and moving it about - without much success. . .any suggestions?
 

AL
Thank you, John. That really helps me clearing things out. I went to Radio Shack today and bought a 12' audio cable (Gold Plate) for $12. I couldn't find any length longer than 12'. I asked them, they said they don't have anything longer than 12' at that local store. I'm wondering if you know where I can get a decent cable w/ a length of 20' or so. I'm in Southern California.

Phill, sorry I don't know much about subwoofer stuffs. Hope someone here can help you.
 

timn8ter
Phil, Can you be more specific about what is vibrating? Is it the walls themselves, or stuff hanging on the walls? There are a number of things that can be done to improve room acoustics. Some are expensive, some are not. It depends on what exactly is causing the problem. Solutions are: dampening material, bass traps, rugs, tapestries, curtains, acoustical foam, false ceilings, acoustic panels and equalizers. My favorite tool for taming the wild sub is the Behringer Feedback Destroyer.
 

AL
After hooking my subwoofer w/ a RCA digital sub cable. I'm noticing that the main speakers sounded louder than my subwoofer. How can I integrate my subwoofer's bass with the sound of main speakers? Here is my setting. I have all 5 speakers set as small and yes on sub. center is -2db, main is normal or 0db, surround is at -1db, sub is at 0db (LFE). I have my sub sits next to my 2 main speakers (facing me), the surround speakers in behind me about 3ft above my head. From what I hear, seemed like the main produce all the bass unless I maxed my sub's volume or 75% of sub volume. Is there something that I'm missing??? Oh, Phase level is at 0 not 180. Cross-over is 80hz. I want to hear more bass from sub. Any help will be greatly appreciated. Thanks!

AL,
 

AL, If the sub crossover is variable, turn it up to maximum. Dolby and DTS claim the LFE channel carries stuff up to and beyond 120 Hz. At 80 Hz you are filtering out all frequencies above that, and therefore losing a lot of the sound the recording engineers intended you to get. This will be especially bad if you have all other speaker are "Small", or set to "small" on the amp/receiver Ð because the receiver will then be sending all low frequencies from the other channels, too, to the sub, and at 80 Hz crossover you are throwing a lot of that away.

Remember, too, that you can't hear where a good sub is located. It should just give bass extension throughout the room. So listening for what is coming out of the sub compared with the main speakers is not what matters.

Re cable I think Radio Shack is not the best (though can they order?) and a good hi-fi store will have longer cables. I am not in Southern California and cannot advise.
I think most LFE channels on DVDs carry exaggerated bass, especially DD. DTS in my experience is much better.
 

GT
You can buy regular RG59 or RG6 coax cable with the F connectors and then purchase 2 F connector to RCA adapters. Home Depot sells 25ft RG6 cable with the F connectors for $9.28. It's shielded and 75 ohm. You can buy the RCA adapters for about $4. Cheapest way to get a decent subwoofer cable.

AR makes a Pro Series 25 foot subwoofer cable that you can get from Accessories For Less for $17. Not sure if you can wait for the shipping, although they ship very fast.

http://accessories4less.com/aless4/Corporate/itemdesc.asp?CartId=13334-ACCWARE-332TWFMD14&ic=HT%2D153&cc=&tpc=
 

AL
Thank you, John and GT. I have my dvd cross over at 80hz and sub cross over knoat max. I can hear a lil more bass now. It seemed to me that the bass is coming out from the front 2 speakers, but when i turn off my subwoofer to try hear it. I've noticed it really the sub that produced all the bass. Somehow, i heard it from the fronts when i had the sub on. Is it normal like that? This is my first HT system, I'm still lil confused and lost. BTW, I went to the computer shows last weekend. Fortunately, I found a RCA brand subwoofer cable for $10 (30 ft brand new, gold plated). If you guys out there looking for cables, try the comp shows or those swapmeets, they might carry those cables for cheap. Thank you all for the help.

AL,
 

John K.
Al, I didn't read your question earlier, but your last post shows that you're beginning to get the right idea. You're not supposed to hear the bass as if it's coming directly from the sub; if you do, that means the sub is too loud(a lot of people have their subs set too loud). Yes, you should have the impression that the bass is coming from the other speakers, not the sub. Turn the sub level up until you can hear it as a separate sound source, then back it off a little until you don't hear it.
 

AL
Thank you, John. I'm busy working all day, didn't have the chance to play w/ it. Will mess around w/ it in the weekend. Thanks for all the help.

AL,

(Unfortunately, HT is not a cheap hobby. I'm sensing an upgrade coming up really soon... My ears are graving for an acurate/pure sound...)
 

J. Pickles
I have a Marantz SR5200 receiver and a Definitive PF15TL+ subwoofer. I saw some of the earlier posts about how to properly hook up the sub, receiver, and the front speakers. There is still something I don't understand. I currently have the subwoofer cable for the LFE going from my receiver into the line in socket on the back of the sub. The two front speakers go right into the receiver. This sounds great with movies, but not with music. I would like to hook up the pre amp left and right outs from the receiver to the left and right in on the sub, and then connect the left and right outs on the sub to the left and right front speakers. This way music will sound better, but my question is will this mess up my movie watching? Can I keep this configuration for movies, or will I have to unhook and reconnect all the speakers to go back and forth? Please help.
 

Shapour P.
I was wondering, what is the best way to setup 3 subs to one amp?? And if the subs have an RMS of 300 max, what size amp should i get??
 

timn8ter
First of all I'd recommend reading "Getting the Bass Right" by F. Toole which can be found on the Harman.com website in their White Papers area. In my case I'm running two subs. I use the Sub out on the back of the receiver with a splitter. The two lines then go to a parametric equalizer and then to my 1000W two channel amp. I have my subs placed in the corners of the front wall. Another popular configuration is to stack the subs in the same corner. There is a lot of evidence to support this configuration as the best way to go.
 

timn8ter
As for how for your amp size it depends on their sensitivity.
 

Allan M.
What about connecting a powered sub to an HT system that does not have a separate "subwoofer out"? I may have the option to upgrade my HT receiver to a system with a passive sub but I currently have a powered sub. Will I be loosing bass response using the passive over the powered sub? Thanks for any advice.
 

timn8ter
Does your sub have a line-in connection that by-passes the amp? Trying to run an amplified speaker wire into another amplifier is going to cause problems.
 

timn8ter
Another thought, since powered subs have a crossover in them anyway, try running a cable from your Tape Monitor out connection.
 

John Allen
J. Pickles; " I would like to hook up the pre amp left and right outs from the receiver to the left and right in on the sub, and then connect the left and right outs on the sub to the left and right front speakers. This way music will sound better, but my question is will this mess up my movie watching?"

-No, this is a good configuration for movies, too. Polk and REL recommend this way of doing it for their fine subs (there is another thread on this). Try it and see. On my system Dolby Digital sounds much better if the sub is connected at the speaker level (see thread "DTS vs. Dolby Digital...") instead of at line level.

Allan M: "What about connecting a powered sub to an HT system that does not have a separate "subwoofer out"?"

-It is OK, and maybe even preferable, see above.

Allan M: " I may have the option to upgrade my HT receiver to a system with a passive sub but I currently have a powered sub. Will I be loosing bass response using the passive over the powered sub?"

-That is not necessarily an upgrade at all. Passive subs are a different question. If good, they are usually (1) old, what they call "legacy" stuff in the computer world, and (2) made with particular partner speakers in mind, usually by the same maker. I have a system like this. My front L and R speakers are KEF C15s (small, on stands), each one getting its signal through a KEF SW2000, which is a KEF passive sub with a built-in cross-over designed to work with the KEF C15. The combined effect is great. The -3 dB low frequency limit is 40 Hz. It gives a good full-range stereo system, and is OK for movies, too. I have recently added an active sub to take the whole system down to 25 Hz. There are benefits, even in stereo, though there are not many musical instruments that actually go much below 40 Hz. The main benefit is in movies where the low bass is used so much for special effects. My KEF SW2000s come from about 1990. I don't feel I need an upgrade. But you would not go that route today. A modern, active sub (or two, like timn8er) is usually a better choice than a passive one. If you already have a good passive sub it makes sense to give it its own single power amplifier channel. This may be part of the receiver, of course. But why not use the amp built-in to an active sub; the manufacturer probably thought about a making a good match.

Today, I personally would think about getting a KEF KTS 2005 system, which is an active sub with five small, egg-shaped speakers (I have just one, for the center channel) But I doubt it would be a real improvement.
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