Newbie needing some help with distortion

 

New member
Username: Aberham

San Diego, CA USA

Post Number: 1
Registered: Sep-05
This is my first post here but I have been reading this form for a few months. I am a novice so most of my questions are going to be pretty basic to most of you, and I certainly appreciate any help from the experts out there. I realize that distortion in the speakers can be difficult to diagnose but hopefully this will help me understand better what is causing the problems.

My simple setup is an Onkyo TX-SR502 6.1 receiver, 2 tower speakers Sony SS-MF550H, and 2 surrounds and 1 center Sony SS-CN350. I have a Sony 100 watt subwoofer on the way. I realize this is far from being a top notch system but I think it will do me well especially since I live in an apartment.

Basically the problem is that my speakers, mainly the center channel speaker gets a lot of distortion from time to time. I can't control it, sometimes it seems like it is just a connection problem because I will pick up the speaker and move it around which seems to make it temporarly better but it eventually reverts to distorted sound which gets very annoying.

I was talking to someone at an audio store nearby that said it could be because my receiver is only 75 watts per channel and the speakers at 125 watts. Would that be part of the problem? I have tried to make sure the connections are good and I just bought some banana clips but it didn't seem to make much of a difference.

I am completely puzzled and am willing to spend some more money if needed to replace my speakers in order to get the right ones for the receiver that I have. I appreciate any suggestions. Thanks.
 

Varit
Unregistered guest
The max wattage rating of the speakers has nothing to do with it. But, it's possible the amp is distorting if you turn it up past 50%.
 

Bronze Member
Username: Uncle_fester

Transylvania

Post Number: 12
Registered: Apr-05
The maximum wattage rating of speakers is usually irrelevant. It indicates the maximum which the speaker can handle for a short period without blowing. A 75 WPC receiver is perfectly adequate to drive these speakers.

I would think that the problem lies within the centre speaker. It could well be that a wire in one of the 4.75" drivers is giving a poor connection. The small wires which connect the terminals of the drive units to the voice coil can sometimes give out partially and give intermittent contact. The symptom of the sound being sometimes okay after moving the unit is an indication of this.

You could confirm that the speaker is at fault by temporarily swapping it with one of the surrounds to see if the fault moves with the speaker.

If under guarantee then have have it exchanged, otherwise have it repaired or replace it - this will be cheaper than buying a whole new set.

Regards,
Fester
 

Gold Member
Username: Edster922

Abubala, Ababala The Occupation

Post Number: 2205
Registered: Mar-05
Dan,

Do you have an SPL meter? It's a very good $40 investment found at RadioShack and will be very helpful in calibrating your speakers. Also you can use it to figure out exactly when your speakers start distorting...I'd say if the distortion starts by 75db then it's definitely your speakers.

That Onkyo has gotten some very decent reviews, I would tend to blame it on the Sony speakers. The 75wpc vs. 125wpc argument you heard is BS, either the salesperson is a complete idiot or he just wants you to drop some more cash.

Now Onkyo does have a history of inflating its wpc numbers so it's possible that the 502 is closer to about 45 than 75wpc.

Probably best thing to do would be to test your speakers with a different receiver and see if they still distort. I'd borrow a friend's receiver if you can. Many receivers even though they are multichannel, put out significantly less than their claimed power when running multiple channels simultaneously.

If you do replace the speakers I would get bookshelves instead of towers, first because you live in an apartment and secondly because with a (probably) overrated RMS receiver like the 502 the smaller speakers would be easier to drive with less power. A great low-cost solution would be the Athena AS-B1 ($100/pr.) and AS-C1 center ($100) from audioadvisor.com
 

Gold Member
Username: Artk

Albany, Oregon USA

Post Number: 1766
Registered: Feb-05
Sounds like a processing problem. Onkyo processor's have been famous for doing that for quite a number of years. Unlikely to be the speakers.
 

Gold Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 5845
Registered: May-04


You don't mention at what volume level you experience this problem. Since you indicate apartment living, I'm going to assume you are not blasting the volume when this occurs. And, unfortunately, the concept of "distortion" is sometimes quite broad based and sweeping when used by someone unfamiliar with how to describe what they are hearing. I will guess the sound is breaking up and not having noises such as a buzz or hum introduced.

If that's the case, I would tend to go along with Fester in where the problem lies. Most connections are intermittent and they either work or they don't. They might be intermittent to the point of reconnecting when the speaker is moved; but I would guess a badly aligned voice coil is the problem. Possibly this could have occurred when you played the system at high levels once or have been a factory defect.

In either case, follow Fester's advice on swapping speakers (one at a time) to locate where the problem exists. If the problem remains in the same channel, the problem is in the amplifier. If the problem follows the speaker, the problem is in the speaker.


If noises and/or hum are the actual "distortion", I would make my guess the amplifier is at fault since speakers normally only reproduce the signal they are fed. Once again, the swap begins with the speakers to isolate the problem.


If there is a possibility you misunderstood what the "person" at the audio shop told you, you will eventually learn more and understand how the system works more completely. If, on the other hand, you did fully understand what this person said, I would avoid taking any further information from that individual ever again. If they were an employee of the store, I would even consider avoiding that store. Unless they were suggesting you were clippimg the amplifier, the amount of power you have will not cause the problem (and certainly not the relief) you describe.

If you are running the amplifier at loud levels (even though they may not seem loud to you), all bets are off. Turn the volume down and the problem probably won't exist unless you have damaged the speaker already.


 

Gold Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 5846
Registered: May-04


Art - Why would the processor be affected by moving the speaker? It's not clear what this phrase means; "I will pick up the speaker and move it around which seems to make it temporarily better but it eventually reverts to distorted sound". But, unless that "seems" is very important, moving the speaker should have no effect on the receiver's operation.


Also, ed, the difference in where clipping begins between 45 and 75 watts is hardly going to be noticeable. We're back to that 1.5 dB point on peaks. Are you assuming Dan is clipping the amplifier? And, the SPL meter is only going to indicate a volume level without reference to how efficient the speakers are or how far away from the speakers Dan sits. Both those numbers would change what Dan reads on the meter.





 

Gold Member
Username: Artk

Albany, Oregon USA

Post Number: 1767
Registered: Feb-05
I was guessing that was a coincidence. Could be a number of things.
 

New member
Username: Aberham

San Diego, CA USA

Post Number: 2
Registered: Sep-05
I am going to first try to test the center speaker in another channel to see if I am still getting distortion. Most of my friends find other ways of spending their money so most do not have any type of home audio setup so I am pretty much alone on this one. The distortion isn't the buzzing type of distortion it just sounds like choppy audio. I actually notice the distortion more when the volume is slightly lower than normal. The distortion doesn't come into play much when I turn the volume up loud. I sure hope it isn't the receiver that is causing the problems, I actually like the ease of use and the setup.

Are those Sony speakers pretty much garbage? I didn't spend that much on them so they are replaceable, maybe like $350 including subwoofer so I may end up replacing them altogether even if the problems do not lie within the speakers if it is worth it. I had been reading some rave reviews on the Flaunce speakers from people that have the same receiver as me. Also is it possible this could just be a connection problem with the speaker wires or something? I have tried to ensure that the connections are good and bought some dual banana plugs but I still have just the bare wire connecting into the speakers itself. I am using "12 gauge Monster XP speaker wire. I'll post back when I test out my speakers more, I certainly appreciate the help so far.
 

Gold Member
Username: Edster922

Abubala, Ababala The Occupation

Post Number: 2215
Registered: Mar-05
ooh, that does sound like it's more of a receiver problem than the speakers though yes, those Sonys are not very good.

For about the same or less money than the Onkyo 502 I'd get the all-digital Panasonic sa-xr55, see the huge thread in the "receivers" section.

If you go Fluance then I'd get the SV-6 bookshelves all the way around, I've been told those are the best speakers they make and that the packaged system is overly bright. But still would be a good couple of notches above the Sony though not quite as good as the Athenas.

As for Monster, that's the biggest scam in audio next to Bose. Any generic Home Depot 12 guage cable will be fine, ditto with the interconnects.
 

Gold Member
Username: Artk

Albany, Oregon USA

Post Number: 1778
Registered: Feb-05
Alright Eddie quit sellin' that Panny and give me a chnace to sell the Yammie...lol!
 

Gold Member
Username: Edster922

Abubala, Ababala The Occupation

Post Number: 2220
Registered: Mar-05
"selling" the Panny, Art???

I think of it as just spreading the Good Word!
 

Bronze Member
Username: Pbdr

Post Number: 55
Registered: Apr-05
While you may very well have gotten a defective receiver, I wouldn't immediately plan on replacing it (obviously other than to fix the distortion problem). I have the same SR-502 for over 6 months and am very impressed. Yes, many consider it an "entry level" receiver (and it sounds like you got it as such). It is part of my first forray into good home audio and I may replace it in a few years, but the sound is great for music and the dolby decoding is good for HT.

I'm not trying ot sell any other receiver short or suggest the panasonic or yamaha isn't good, just standing up for what is a decent piece of equipment.

If it is a problem with the receiever the company will most likely fix or replace it at no cost, as it should be under warranty.

It does sound like it may be a speaker problem and I would try the suggestion of temporarily switching the speakers to isolate the problem.

Also, regardless of where the problem lies, once you get it worked out, I would think about switching the speakers before the receiver. I have mirage OMNI 60s bookshelves and a Wharfedale Powerecube 10 subwoofer (adding center soon then replaceing the bose surrounds) and my system sounds great to me.
 

New member
Username: Aberham

San Diego, CA USA

Post Number: 3
Registered: Sep-05
I've tested my center channel speaker on another channel and it still sounded scratchy/distortion. So I am guessing it must be the speaker, the rest of the speakers work great but the darn center gets messed up from time to time. The warranty is expired on the speaker so I may as well just get a better center I suppose. What would be a good replacement?
 

Bronze Member
Username: Rysa4

Post Number: 53
Registered: Jul-05
I agree with jan on the usage of the term distortion. In any case, you may actually have a blown driver in these cheap part constructed speakers or a connection problem on binding posts at the speaker or receiver level. Lastly, just change the speaker wire although I doubt thats it. Its more likely that your receiver is more powerful than your speakers can handle than the receiver being underpowered for the speakers. I don't care for those speakers personally-- at all- for anything. Including the sub.
 

Gold Member
Username: Edster922

Abubala, Ababala The Occupation

Post Number: 2265
Registered: Mar-05
dan,

The Athena AS-C1 center speaker is $100 from audioadvisor.com

http://www.audioadvisor.com/store/productdetail.asp?sku=ATHASC1&product_name=Aud ition%20AS-C1%20Center%20Channel%20Speaker

Here's a more expensive option but one that would provide utmost clarity and performance:

http://www.ascendacoustics.com/pages/products/speakers/cmt340c/cmt340c.html
 

Gold Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 5863
Registered: May-04


Dan - I would think it prudent to also consider why this problem has occurred. It's quite possible the problem will resurface if the cause of the malfunction is you and not the speaker.

Did you notice this problem when you first got the speakers set up? Or, has this problem occurred after a session of high volume playback? You may have damaged the driver while listening too loud. One time is all it takes. Do you have the ability to set your speakers to "Large" and "Small" configurations? With a sub in the system, you should have the center speaker set to "Small". Running low frequencies through this speaker could have resulted in its premature failure; and this would be especially true if you played the system at high volumes.


You can replace just the defective driver in your current center speaker or you can purchase a new speaker. Either way, if you don't consider what might have caused the problem in this speaker, you might find yourself with a similar problem down the road.



 

Silver Member
Username: Cheapskate

Post Number: 393
Registered: Mar-04
hey... i'm going to get rid of my nice enough onkyo so i too can get a panny SA-XR55 or SA-XR70 and FINALLY be able to own magnepans. LOL

if you follow the buzz, panny class-d recievers (all SA-XR series) are getting alot of raves and comparisons to much higher priced gear.

if anyone reading this already owns a radioshack SPL meter... check this info out to get more accurate readings when using test tones:
Set the meter for "C" weighted, Slow. For best results, set the meter on a tripod to keep reflections at a minimum. Get a Test CD that has 1/3 octave warble tones like Stereophile Test CD #3. Start with the 1 kHz tone and set the meter at 80 dB and set the 1 kHz tone to show 0 dB on the meter. I would suggest setting the meter at you listening position to see what the response is there. Start the test tones and with the chart I am suppling below, mark the level beside the frequency on the chart. You can do the corrections after you finish. Stand as far from the meter as you can when doing this so reflections off of your body does not influence the reading. Also try not to have anything else to near the meter. This will give you a close approximation of what the frequency response is of your speakers at your listening postion. Below is the correction chart. Everything is added.

(unknown which model this chart is calibrated for. see below for another chart)
20 Hz. _________________20HZ 6.2DB...................+7.5db..........+6.85db (avg.)
25 ____________________25HZ=4.4DB..................+5db.............+4.7db (avg.)
31.5 ___________________31.5HZ=3DB.................+3db.............+3db (avg.) =
40 ____________________40HZ =2DB....................+2.5db..........+2.125db (avg.)
50 ____________________50 =1.3DB......................+1.5db..........+1.4db (avg.)
63 ____________________ 63HZ =.8DB..................+1.5db..........+1.15db (avg.)
80 ____________________ 80 HZ =.5DB.................+1.5db..........+1db (avg.)
100 ___________________100HZ =.3DB.................+2db.............+1.15db (avg.)
125 ___________________125HZ =.2DB.................+.5db............+.35db (avg.)
160 ___________________160 =.1DB......................-.5db.............-.2db (avg.)
200 _Start______________ Flat.................................-.5db.............-.25db (avg.)
250 ___________________ Flat
315 ___________________ Flat
400 ___________________ Flat
500 ___________________ Flat
630 ___________________ Flat
800 ___________________ Flat
1kH___________________ Flat
1.25___________________ Flat
1.6 ____________________1600HZ = .1DB
2 ______________________2000HZ =.2DB
2.5 _Start_______________ 2500HZ =.3DB
3.15____________________3150HZ =.5DB
4 ______________________4KHZ =.8DB
5 ______________________5KHZ =1.3DB
6.3 _____________________6.3KHZ =2DB
8 ______________________8KHZ =3DB
10 _____________________10KHZ =4.4DB
12.5____________________12.5KHZ =6.2DB
16 _____________________16KHZ =8.5DB
20 _____________________20KHZ =11.2DB

Clayton- are these corrections needed to make Radio Shack meter readings accurate? Do I add 6.2DB at 20 HZ and 11.2 DB at 20KHZ?

Yes, these make it pretty darn accurate. A lot of people have had their meter calibrated and this was the average correction. All corrections are added as you say. (AUDIO ASYLUM)

More compensation numbers from a subwoofer site for the ANALOGUE model.

At 10Hz add 20dBs to the meter's readings and at ...
12Hz add 16.5dB
16Hz add 11.5dB
20Hz add 7.5dB
25Hz add 5dB
31.5Hz add 3dB
40Hz add 2.5dB
50Hz add 1.5dB
63Hz add 1.5dB
80Hz add 1.5dB
100Hz add 2dB
125Hz add .5dB

another set of analogue meter compensation numbers:
Correction Values for Radio Shack SPL Meter.
10hz........+20db
12.5hz.....+16.5db
16hz........+11.5db
20hz........+7.5db
25hz........+5db
31.5hz.....+3db
40hz........+2.5db
50hz........+1.5db
63hz........+1.5db
80hz........+1.5db
100hz......+2db
125hz......+.5db
160hz......-.5db
200hz......-.5db
250hz......+.5db
315hz......-.5db
400hz......0db
500hz......-.5db
630hz......0db
800hz......0db
1k...........0db
1.25k......0db
1.6k........-.5db
2k...........-1.5db
2.5k........-1.5db
3.15k......-1.5db
4k...........-2db
5k...........-2db
6.3k........-2db
8k...........-2db
10k.........-1db
12.5k......+.5db
16k.........0db
20k.........+1db




 

New member
Username: Aberham

San Diego, CA USA

Post Number: 4
Registered: Sep-05
Thanks Edster. Hi Jan, I've owned those speakers for just about over a year and the first time I had them setup correctly was probably three weeks ago. I just used my two towers for the main sound for awhile. I noticed the problem probably right as the speakers were setup properly but it wasn't a big deal. After a day or two it became very annoying. I live in an apartment so I can't play my speakers loud at all so I doubt the speaker was damaged from playing too loud. My Onkyo receiver does have that setup and from what I had read earlier when setting the speakers up I had set them to small. I guess I am still not completely sure how the speaker failed but I am going to assume that the speaker was defective from the start since I had noticed the problem pretty much right away once everything was setup.
« Previous Thread Next Thread »



Main Forums

Today's Posts

Forum Help

Follow Us