Dialogue Distortion in My Lsi9?

wingnut4772

Hi Guys. I am getting some distortion from my center channel especially on male voices for example when thy are yelling or their voice is at a certain range. I suspect that a bass management bug in my Sherwood sends a full signal to my center regardless of my crossover or my size setting on my speaker.

With my new Cinenova amp, I can high pass the center channel at the 60hz that I want.

My question is : do you guys think that the distortion is from the full range being sent to the center? (Picture WOTW at ref!) and if so ...what part would I actually need to replace? I am having some difficulty telling if its the tweeter or the woofer but wouldn't it be the woofer? TIA

audiobliss

I would say high pass the center channel at the amp at 60Hz and see if you still get that distortion.

Early B.

NM. \

First, isolate the problem. Trade out your center channel with another speaker and see if you still have distortion.

audiobliss

Based on the title of her post, I'm assuming she's using a sinlge LSi9 for the center channel.

wingnut4772

Hi. Yes I did high pass it at 60 through the amp and the distortion still exists. I am using the 9 as a center - sorry forgot to say. I did test out another speaker and it seems fine.

I think I may have done some overzealous demo-ing with my new Cinenova amp (awesome by the way!) with the center crossover (on the amp) bypassed. I was just so excited I forgot the bass management issue...

Early B.

If trading out the center channel speaker (hook one of your fronts to the center channel posts on your amp) doesn't work, trade out the center channel speaker cable. If that doesn't work, trade out the RCA cable from the center channel pre-out to the receiver/processor. If that doesn't work, then scratch your head and before you go to bed, pray the problem isn't the amp.

Ferres

I never got issues of distortion in crossovers. I always set all my speakers to 'large'. So I throw full range at them since they are 'y' connected with the subwoofers.

Try to unplugged the powercord from the mainline socket then plug them back in a little later.

In my experience, the distortions I get is rarely traced to the speakers. But then again, Iv'e never pushed my system too hard and stayed in moderation.

Yes, could be a broke tweeter

wingnut4772

Okay I also forgot to mention that I noticed this somewhat with the Outlaw 770 amp that I had before. That's why I think I may have overdone it with the Earthquake and exacerbated the problem . I have run all the switching comparisons. Issue remains.

It is not horrendous. The speaker actually sounds terrific with the exception of whatever range that distortion is in. It's a very small window and most people might not notice it but I do.

If it is a broken tweeter, would having a working high pass prevent it from going in the future?

Early B.

I doubt if you damaged anything. Sounds like a higher quality amp may have simply magnified the level of distortion you're hearing. I'll bet money it's the cables.

wingnut4772

I swtched out the speaker cable from Better Cables to Cobalt and it is the same. I am using Cobalt interconnects and I don't have another brand to test....

And...how would an interconnect or a cable effect that ..just a technical curiosity?

TroyD

Eh, I'd swap out another speaker into your center. If the distortion still exists, than the problem is upstream. If it doesn't, you've got a ganked up speaker (which is probably a easier, cheaper fix).


BDT

Ferres

If it is a broken tweeter, it won't be in such a small window. So I would agree with TroyD on the upstream part.

I would look into your 'power' situation with outlets and such, if they can handle the draw from the cinenova amp. A power conditioner can only do so much. Do you notice any 'harshness' issues when playing music on your mains?

With cables, I'd think to look at the 'powercables' rather than the interconnects.

McLoki

I am going to go out on a limb and say its the woofer. You have enough other LSi speakers that you could rob the woofers from one and transplant them into your LSi9 to see if it cleans up the distortion. (if it doesn't - try the tweeter)

You did already say that it sounds fine with another speaker didn't you?

I am guessing you stressed the woofer a little sending a full range signal at 3 times the rated power to it....

Anyway - if it is the speaker, at least it can be fixed. (I think the midrange drivers from Polk are around $45 or so)

Good Luck,

Michael

Early B.

Can you place your ear next to speaker and determine which driver is the culprit? if so, remove it and send it to Polk for a replacement. I had to do that for one of Rti10's a while ago and they sent a new one within a week.

wingnut4772

I think when I place my ear it is the woofer. Is it easy to remove to check it? I know the tweeters are really easy?

I would look into your 'power' situation with outlets and such, if they can handle the draw from the cinenova amp. A power conditioner can only do so much. Do you notice any 'harshness' issues when playing music on your mains?

I have a 20 amp dedicated circuit but right now I have the Cinenova plugged into my Panamax 4400 which is built for 20 amp circuits.

Do you notice any 'harshness' issues when playing music on your mains?

No actually.

wingnut4772

Okay. I actually removed the woofer from a 15 and replaced the one in the 9 with it. Distortion still there so I am beginning to think it's upstream. I am using Cobalt Cable interconnects ....any recommendation as to another brand to try?

polkatese

I highly doubt I/C will fix your issue, Darla. I know this is might not be the most practical thing to do, but can you borrow another pre/pro from a store? any brand will do. It seems that your three other areas to troubleshoot are: source (DVD player), different DVDs such as SPR, and pre/pro.

audiobliss

What about amp...that could be the problem...no?

McLoki

If you just swap the interconnect from your right channel to your center, what happens? (Stereo is now left and center, center channel is now played through your right speaker)

Is the distortion still there (now in your right LSi15)? Is there distortion now in the right channel (played through your LSi9)?

That will at least tell you if it is the speaker or not. Sorry - I thought you had already done that and isolated it to your LSi9.

Michael

wingnut4772

You know what? Yes- it is somewhat there when I swap the interconnect positions. I think that my amp may be on the brighter edge and revealing some upstream issues that I may have not noticed as much with the Outlaw. I ordered some Kimber interconnects to try and see if there will be any difference. If not, I will just return them. The amp is still breaking in and is pretty new so maybe it will mellow out a little. I did notice this issue with the center before though with the Outlaw 770. It just was not enough for me to really bother me.

TroyD

Can you swap out an entire speaker? Do that before you start pulling wires and stuff.

Once you do THAT, start isolating things one at a time. IC's, amps and so forth.

Audible distortion means, to me anyway, something is broken. An IC, if broken in my experience, will shut the channel down (no connectivity). If it's an amp, swap it to a different channel and see if the problem follows. One step at a time and find the culprit.

BDT

wingnut4772

I highly doubt I/C will fix your issue, Darla. I know this is might not be the most practical thing to do, but can you borrow another pre/pro from a store? any brand will do. It seems that your three other areas to troubleshoot are: source (DVD player), different DVDs such as SPR, and pre/pro.

I don't notice it as much with the DVD player. In fact things are much smoother there. My Pioneer sounds really great. Is it possible it could be the Dish DVR or the optical cable? It is the worst when watching TV. I have never noticed it during music. I will have to try some DVDs again but I don't think it is there so much....?
__________________

polkatese

wingnut4772 wrote:

Is it possible it could be the Dish DVR or the optical cable? It is the worst when watching TV. I have never noticed it during music. I will have to try some DVDs again but I don't think it is there so much....?
__________________

hmmm..I am even more suspecting it's your Sherwood. I would rule out optical cable, and Dish DVR. If it's prevalent during watching TV, then I would look into switching the input, unless it's one of those assignable optical input assignment (I am not familiar with your Sherwood's features). How harsh the distortion? is it only at loud(er) volume or there at any volume?

wingnut4772

I think it is upstream also....I can switch inputs. The disotortion is not that bad and I am probably being obsessively anal but it is consistent at low and high volumes. I am going to try some different interconnect brands tonight and see if that affects it. I am also going to try out some material in analog only and see if that makes a difference.

wingnut4772

Okay. I tried the analog setting for movies and no real change that I notice. So I bought some Audioquest Diamondbacks at Tweeter just to see if there is any difference and then I put in 'Greg The Bunny' which stars Eugene Levy. His voice is the perfect example of the frequency that sets off the edginess. The monkey and Dracula are very good also. I noticed a definite improvement but .....I will keep listening. I wonder how the Kimbers will do?

wingnut4772

Okay improvement but still there

Ferres

'Harshness' can be mistaken for brightness. To be sure, listen the the 's' with female vocalists like 'Nora Jones'. If her 's' sounds really annoying, then you have harshness.

I just saw the specs on the panamax 4400. It looks kinda inadequate for your system regardless of the 20amp claim. Is it possible to plug the cinenova directly to a wall outlet? How about your pre-amp?

To be honest, I have no personal experience with Panamax products, I use Isotek and their cheapest powerconditioner is in the $400 price range but I can vouche for their quality. They also recommend the use of only one amplifier to be connected to the 'conditioner' and it has a similar ratings(2300w) to the 4400. Their powercords as well are very good, cleaned up a lot of the noise in the system. Noise that I did not notice before until they were gone.

Is it possible for you to demo Isotek powercords on the pre-amp side?

I think we can rule out any problems with the speakers as well as with the I/C cables and players. My hunch is still somewhere related to 'power'. Sorry if I seem anal about this.

wingnut4772

I don't have the harsh 's' thing going on . That I know for sure because I can't stand that.

I did plug the Cinenova right into the wall.

Isotek into my Sherwood? Ok.I am willing to try...how would that affect the particular problem do you think? I am not doubtful just learning. Should there still be a power issue if I have a dedicated 20 amp circuit?

Wouldn't plugging the Sherwood into the Panamax effectively be the same as using a fancy power cord?

I also have a Monster 2500 . I plugged the Sherwood into that as well and there is no change.

Also, with a special power cord..would that just go in the wall or into my Panamax? I have a surge protector to protect my equipment and I would like to actually be able to use it.

Ferres

Audiophile grade 'Powercords' help clean up noise and you can plug it via wall socket or thru the conditioner. They are shielded so they don't become rf antennas. This is for noise reduction not sure if it will help with distortions. Actually, quality powercords can be cheaper alternatives to conditioners at the start.

Yes, try Isotek powercords for the Sherwood if that is your pre-amp. There should be a noticable audio improvement with bass getting an extra boost.

Can you swap out a different pre-amp instead of the Sherwood so we can rule that out as a cause?

If there is no 'harshness', then you are getting enough power but you may have a less reliable wall outlet. If this is the case, the Panamax won't be able to do much about it.

How many wall outlets do you have near your system? Where they installed specific for an AV system? You could try testing with bare minimum setup (audio only) in another part of the house.

I'm not sure if you have a plasma TV, but one of the symptoms of bad outlets is if the image on a plasma tv inexplicably brightens(flicker) a little for a second or so during viewing dark scenes.

Ferres

Btw, regarding Wotw. When the tripod first appears and emits their horn sound, there will be an audible distortion sound at the center. It is in the dvd since this has been reported in the forums consistently regardless of system.

VR3

I didnt hear any.