Why is my center channel so quiet?

dbaldus

I have calibrated my setup using Avia and an SPL meter and am currently running the setup in my signature. However, while watching movies, I have found it necessary to boost the center channel output on my receiver to 3dB higher than it was calibrated to be "balanced" at. Even after doing this, I am forced to crank the volume in dialog scenes and turn it down during action scenes while watching certain movies (off the top of my head, Transformers or 300).

I'm starting to wonder if maybe it has something to do with me using different speaker cable for my fronts versus my center? I'm using standard Radio Shack wire for both, but I believe the center channel's speaker wire is actually 10 or 11 gauge and the wire I'm using for my fronts is 12 gauge.

Does anyone else have any other ideas? Has anyone ever had this experience before? Its literally been bothering me for years but I figured it was time to get this resolved!

speakergeek

My old onkyo reciever forced me to do that all the time. Now I'm using a Pioneer 1015 and don't have the issue using the same speakers. My point is it could simply be your receiver. I doubt it's the speaker wire. Your center is very efficient at 91 db/w/m, actually moreso than your mains. What is your receiver?However, you could just change out the wire and see. It seems simple enough a thing to do.

Yardman 49

Hello dB:

I had the same issue with my previous Onkyo SR504. No matter what I did to the setup, it always left me wondering "what's wrong with these studios? Why do they record the center channel so weakly?" I even thought that I might have had a polarity reversal between my mains and my center.

But when I got my new Onkyo SR705, the difference was like night and day. I ran the Audyssey setup, and bam! Center channel presence was great right off the bat.

I'm finally hearing the dialog and center channel action that I always strained to hear.

One of the main differences may be the independent crossovers and EQs that the 705 has for every channel. The SR504 didn't have any channel EQs (just a bass and treble setting for the entire receiver). Also, the SR504 limited me to only one crossover setting for the entire system. This really hurt the center channel, I believe, as I couldn't run it as low as it should go, due to my small Polk RM10 satellites that I use for my mains and surrounds.

Anyway, that's my 2 cents.


Best wishes,

Frank

dfranks

I have the same problem with my setup. I have the same speakers wires for all three but I suspect that it is my receiver Yammy Rx-V861.
I am using Polk all around
Csi A6
Rti A5
RC85I

dbaldus

Yardman -

Thanks for the advice. I have independent crossovers for each channel, but only a single EQ for all channels. Did turning the crossover to a lower frequency help your center to sound better, or did I misunderstand you?

Ron Temple

It's probably a placement issue. You might have a null and the pink noise test tones are effected by it. I'd bump the channel so it sounds blended for HT and adjust downward for music as needed.

Yardman 49

dbaldus wrote: »

Yardman -

Thanks for the advice. I have independent crossovers for each channel, but only a single EQ for all channels. Did turning the crossover to a lower frequency help your center to sound better, or did I misunderstand you?

Hello db:

When I first bought my RM10 satellite system, it came with a matching center speaker with two drivers and one tweeter (model RM202). I also bought a Polk PSW10 sub.

Coupled with the aforementioned Onkyo SR504, the center channel presence was very weak, especially for vocals. No matter what I did with the group level balances, or the system crossover setting, I could make no real improvement.

I then replaced the Polk center with a Klipsch RC-10. Although the speaker voicings were definitely different, there was some improvement with the center channel (the RC-10 just moves a lot more air). However, I still could never get the center channel to sound the way that I thought it should.

Strangely, 2 channel sources with ProLogic II gave a much better center presence than true Dolby digital or DTS.

With either of these center speakers I could never find a crossover that would work for both my satellites and my center. The -3dB for the satellites (RM101s) is 130 Hz (with a low range of 95Hz). The -3db for the Polk 202 center is 100Hz (with a low of 80Hz. For the Klipsch center, the -3dB is 88Hz.

So if I set the system crossover at around 120Hz or higher, the overall sound for the left/right fronts improved, as the sub could handle more of the mid-bass frequencies. But then either the Polk or Klipsch centers would get very "thin" sounding, and vocal presence would suffer. Likewise, dropping the system crossover to 100 Hz would help the center channel, but then I'd lose too much mids from the left/right front channels, since the sub would then not be getting these frequencies, and the satellites could not handle them.

Also, running the satellites as "large" as the Polk manual suggested also did not work, even with double bass turned on.

So the Onkyo705 really fixed this for me to a large part, enabling discrete group crossovers. Also, the discrete group EQs really help to balance the speaker voicings. Of course, the Klipsch still sounds like a Klipsch, but it blends much better with the Polks. And the center presence is greatly improved.

What has also helped is the Audyssey EQ that is on the SR705. It seems to not only balance the EQs pretty well, but also adds some additional processing (time domain?) that really improve the open-ness and clarity of the entire spectrum. I am chief sound technician at my church, and we have to set up a decent size system every Sunday in an auditorium. I use a multitap delay on the system mains; this actually helps with the clarity and presence of our vocal mix. So maybe Audyssey does something similar.

Sorry for the long winded response.

Yardman 49

Ron Temple wrote: »

It's probably a placement issue. You might have a null and the pink noise test tones are effected by it. I'd bump the channel so it sounds blended for HT and adjust downward for music as needed.

Hello Ron:

With my old SR504 setup, I had the center channel presence bumped way up, and it still did not solve the problem with center channel vocal presence for HT. It just provided more a of a bad thing.

At least that was my experience.

dbaldus

Hmmm...

So I currently have the crossovers for both my center (with a -3dB frequency of 50Hz) and my fronts (with a -3dB frequency of 40Hz) set to 80Hz. I can't try it right now because I'm not at home, but I'm curious what you think I should set my crossovers to when I get home? I can set the crossovers for each separately, and I believe that my options are 40, 60, 80, 100, 120, etc. for the crossover points.

What do you think?

Yardman 49

dbaldus wrote: »

Thanks for the advice. I have independent crossovers for each channel, but only a single EQ for all channels. Did turning the crossover to a lower frequency help your center to sound better, or did I misunderstand you?

Hello db:

You also stated in your last reply:

dbaldus wrote: »

So I currently have the crossovers for both my center (with a -3dB frequency of 50Hz) and my fronts (with a -3dB frequency of 40Hz) set to 80Hz. I can't try it right now because I'm not at home, but I'm curious what you think I should set my crossovers to when I get home? I can set the crossovers for each separately, and I believe that my options are 40, 60, 80, 100, 120, etc. for the crossover points.

I really am a very green newbie on HT, although I've been doing sound reinforcement for many years (chief technician at my church). I've learned a lot of tricks this way, but I don't know how many of them are applicable to HT. But here's my guess:

- Although the speakers may have similar -3dB limits, if you could examine the actual frequency response curves, they would most likely not be identical. For instance, one model of speaker may start to slowly roll off at a much higher frequency than another. So you may want to experiment. Set the crossovers differently for the front mains and the center. I'd heard that the rule of thumb is about 10-15Hz above the listed limit. So maybe the mains at 60, and the center at 80. Then maybe try the center at 100Hz.

- Or reverse this and set the center at 60, and the mains much higher (maybe at 100Hz), letting your sub carry the low frequencies for the mains. This may work well if you have your mains close to your center speaker. In that way, the center would carry more of the lower frequencies, which may have the effect of the increasing the presence of the center channel for both vocals and center channel effects, versus the mains. If the mains were physically too close to the center channel I could see where the center may get lost if the crossovers were identical.

- An additional approach: set the system wide EQs to optimize the sound for the center channel, rather than for the mains. Although this may hurt music played in stereo, it may still sound acceptable for "all channel stereo", and may indeed improve the center channel performance for HT surround.

- And of course I would then re-adjust the center channel level versus the mains after I'd optimized everything else.


Best wishes,

Frank