Why does my center speaker sound bassy?

_nerd

Hi all,

I have a Polk Audio LSiC center speaker. Whenever someone in a movie or TV show talks while the system is at a high volume, the center speaker emits quite a bit of bass at the lower frequencies of someone’s voice.

Speaker configuration:
80Hz front, center and rear
120Hz LFE
0dB front, center, rear, and sub
Sound mode: direct
No room calibration

I don’t use calibration because (to my ears) the speakers sound fuller without it. I’m using a Onkyo TX-NR809 for processing, and a Rotel RMB-1095 amplifier to drive the speakers.

F1nut

You absolutely need to run the calibration program.

Clipdat

Slide the center channel speaker forward so that it doesn't have the surfaces of the amplifier and receiver in front of it. Ideally you don't want any immediate surfaces right in front of it for the sound to reflect off of.

F1nut

A couple of things. Your center appears to be sitting on DVD cases instead of one solid shelf, not good. The gap between the AVR and the amp is acting like a megaphone for the sound coming out of the power ports.

Can you put the AVR and amp on the lower shelves? If so, put the center on the top shelf and lower the TV as it's too high anyway.

_nerd

F1nut wrote: »

You absolutely need to run the calibration program.

Oh alright, I’ll run it in a moment. I stopped using calibration years ago because the speakers sound canned and compressed with it enabled.

Clipdat

Agreed, bust out that mic, have the room as quiet as possible and run that calibration program.

There ought to be a fairly substantial difference/improvement afterwards.

_nerd

Ok I ran it. It set my front 3 speakers to 40Hz, detected that I didn’t have rear speakers (I don’t have any yet), set the center speaker to -3.0dB, sub to -2.0dB and other settings.

I had to set the 3 fronts back to 80Hz because my sub didn’t appear to output any bass. Setting the fronts to 80Hz brought the sub back to life, and I left the calibrated dB settings alone. I’m having the same experience with the center, having a strong bassy resonance during during vocal dialogues.

Should I go back to a dual 6.5” center speaker? Would adding sound treatment panels to the wall help? The center speaker is not in an enclosed area.

_nerd

Ok as I’m watching TV more post calibration with the center at -3.0dB, the center does sound less bassy but still it still has a significant resonance.

Would setting the center at a lower dB help some more? Is there a such thing as EQ per channel? I believe I had that type of granularity on a Marantz AV7704mkii I owned previously.

pitdogg2

Manually drop the bass some in the GUI EQ settings. It may make voices sound strange so be careful. You also may be able to up the center to 120hz setting. Some receiver/processors will allow this some not.

Like @Clipdat said and I cannot stress enough that you need a very dead quiet area while doing it. Things as unlikely as furnaces kicking on can affect the outcome. I chased my tail for days trying to figure out a problem once. Mine was a very low water trickle sound from my fish room (barely audible). Some of those mics are veerrry sensitive.

Dead quiet is best.

WLDock

You are for sure getting peaks in the response. Like others have said, run cals from as many locations as your software will allow. Run some a few inches to the right or left of the main mic position also.

_nerd

Thank you both for the tips. Setting the center channel floor to 120Hz and overall bass to -4.0dB, I still have a strong peaks from the center speaker.

This is driving me nuts. I’ve owned the Polk CSi5, CSi40, and CS400i center speakers and never experienced this “peak” effect before. I will run calibration again in several positions at and around my listening areas.

_nerd

Update:

Setting the center crossover to 150Hz made a bigger difference than 120Hz. I get the sense that the low end falls off sharply just before the the perceptible “peak” I experienced prior to setting it to 150Hz.

I’ve never had to set a crossover point above 80Hz before. Also, I just found a menu option for EQ settings and there is an EQ for each channel. Should I lower the crossover point for the center channel back to 80Hz and make adjustments to the EQ for that channel instead?

pitdogg2

could you be getting a reflection from in front from how you have it set up?

_nerd

Reflection from the wall? I was thinking this could be the case. Would putting sound treatment on the wall be a good troubleshooting step?

To rephrase something I’ve said earlier, I did have an issue like this in the past with another dual 5.25” center speaker many many years ago. It was a Polk CSi30. I hated that speaker so much - it was a temporary center between two of the bigger Polk center speakers I mentioned previously. I had a feeling in the back of my mind when I bought the LSiC after placing the CSi5 with a new owner that I would experience this “peak” problem again.

Maybe I should go back to a bigger center speaker. Is the LSiM706c any good?

pitdogg2

no I was thinking off the amp and receiver. Then you have that void in between those.

_nerd

There is 7.5” of space between the back of the center speaker and the wall, and equipment under 4” of space in front of the center speaker, as shown in the photo.

ericv

Try setting the center to “small”. It will throw a little more of the soundstage out to the fronts and the bass will go to your subs. It’s worth a shot.

ericv

Also, if your center channel is a ported speaker, try inserting some foam into the port. It will tighten up the bass.

_nerd

Thank you very much for the tips, @ericv. I can’t find the setting to set any speakers to large/small. I only have crossover & EQ options for each channel. The speaker does have two PowerPorts in the back. I will look into inserting foam into the ports from the inside.

BlueFox

_nerd wrote: »

Ok I ran it. It set my front 3 speakers to 40Hz, detected that I didn’t have rear speakers (I don’t have any yet), set the center speaker to -3.0dB, sub to -2.0dB and other settings.

I had to set the 3 fronts back to 80Hz because my sub didn’t appear to output any bass. Setting the fronts to 80Hz brought the sub back to life, and I left the calibrated dB settings alone. I’m having the same experience with the center, having a strong bassy resonance during during vocal dialogues.

Should I go back to a dual 6.5” center speaker? Would adding sound treatment panels to the wall help? The center speaker is not in an enclosed area.

Your center is equal to both your L/R channel speakers combined. Get some full range floor standing speakers for the L/R, calibrate the setup, and then report how it sounds.

I had that center for years along with LSi15s for the L/R front, and never had an issue.

_nerd

Done. Thank you for the tip. I have lowered the crossover to 120Hz for testing at this placement point.

Edit: this response is for @Clipdat

_nerd

@BlueFox: I’m working on getting a pair of LSi9 speakers locally. I’ve been fascinated by those speakers for many years. I could obtain a pair of LSi15 but I don’t care for the built in subs.

@F1nut: the amp weighs almost 80lbd. There is clearance for it on the shelf right underneath its current placement. I do feel I mounted the TV too high. I mounted it in a way that the horizontal center of the TV is eye level when I am standing up. Is that too high? I don’t mind relocating the components away from the top shelf, but I don’t think the lower shelves can handle 100+ pounds of equipment. When I had a SVS SB16 Ultra subwoofer, I had the amp sitting on top of it.

FestYboy

Center of screen should be just above eye level while seated.

F1nut

If the top shelf will handle the load, so will the others. Try what I suggested as it will solve a lot of your issues.

I like the screen with the center line just below eye level when seated. Either Arty's or my preference would be considerably better than what you have now.

FestYboy

Jesse, do you run multi channel for your TV, or strictly 2 ch?

F1nut

Multi

_nerd

@FestYboy: many thanks to you as well for the tip. I can get the middle TV just above eye level when seated.


@F1nut: I am looking forward to moving things around tonight and lowering the TV.


To everyone: Would the center speaker be too low in proportion to the L/R mains if I relocated it to the middle shelf of the TV stand? When the TV lowered to the more desirable height, there won’t be room on the top shelf for the center speaker. The wall mount doubles as the mounting plate for the TV + a square neck/stem to attach it directly to the TV stand, allowing the TV to swivel. Would it be better to attach the TV to the TV stand again?

BlueFox

The center should be at the bottom of the TV. Mine is actually a bit higher since a lot of movies are letter boxed, and for those that are full screen I rarely notice the top of the center in the picture.

_nerd

@BlueFox: I agree. What I mean to ask is if it is ok for the center speaker to be below the L/R speakers. I tried to raise the center speaker to be as close to level with the mains as possible.

Edit: corrected one incorrect word.

BlueFox

Since my L/R speakers are towers, and on maple speaker stands, they are definitely higher than the center. The center is 99% for movie audio, so adjust it for the TV, not the other speakers.

_nerd

I was able to raise the middle shelf by removing 4 screws & so on. The equipment fits perfectly on the bottom shelf and is fully supported by the 4 thick machine screws holding the bottom shelf in place. Many thanks for the tips offered tonight. I will likely re-attach the TV to the TV stand with the neck piece tomorrow instead of tonight. It looks so pretty and I remember how difficult it was to get the tv on the wall, I don’t want to pull the tv stand away from the wall tonight.

@BlueFox: killer speakers you have there. I wanted that subwoofer for a minute. I currently have a Polk DSW microPRO 3000 & a Klipsch RSW-10 which sounds better than the 3000 despite having less than 1/3 the RMS output. I don’t use the Polk sub at all anymore.