My Centre Channel Is Louder Than My Main Speakers ???

My centre channel speaker always seems to be so much louder than my two main front speakers, why ? I know you can use the processor to alter the output to compensate, but I just want to know why it does this !

I have tried different processors but they all seem to have the same effect. Is it due to using different power amps with different outputs

Mains – Kef Reference 2: Biamped by 2 Rega Maias which are 85Wpc, therefore each speaker, effectively sees 170W

Centre – Kef 200c: Biamped by a Rotel RB991, which is 200Wpc, therefore the speaker, effectively sees 400W

Is this difference of 400W against 170W the reason why the centre channel is so much louder ?

Sorry if it sounds complicated !

 

Yes the amplifiers will make a difference. But if you're talking about it being loder when watching a film, or TV, then a high proportion of the sound is directed to the centre channel, making it appear louder. Has your processor got a test tone, as this is the only safe way to check relative loudness, using an spl if possible. Then compensate on the processor as you mentioned. One final thought is that the speakers may differ in efficiency, which will also create variations in loudness.
I have the opposite problem, if youcall it that, in that my LR speakers are highly efficient and need the output attenuating to match my less efficient centre channel. For music, I only use the L/R anyway, so it doesn't matter

 

Yes it is louder even with just the test tone.

I would not have thought the speakers would differ much, as they all use the same drivers, and come from the same family.

I was thinking about replacing the Hi Fi Pre Power Amp setup, now is my excuse !

 

Not sure if this is relevant to you but I've read in several places that when setting up a surround sound system the centre channel, and rears, benefit from being a decibel or two louder than the main speakers.

Both my Sony manual and a friend's Denon mention this. You should be able to alter this through the processor and balance them out a bit more.

 

Alter the processor balance until they all sound the same loudness with the test tone. Preferably use a sound level meter, but you can do pretty well by ear, if the test signal is noise or hiss not a pure tone. If you prefer a slightly more spacey effect do as griffo says IMHO.

How the loudness is achieved (efficiency of speakers, amp wattage or whatever) doesn't matter so long as the channel balance is as the theatre spec intended. Analogy: if all cars travel 30mph in a 30mph zone, it doesn't matter whether they have a 2l or 1 l engine, more or less efficient electric or gas guzzlers, or whatever.

BTW, it doesn't matter in itself that one amp has more watts than the other - within a given manuafcturer the gain as expressed by the ratio of output relative to unit input - will be likely be the same and can be expressed in dB - Linn are usually 28.5 dB whether its a 50 or 200W amp. Remember, an amp is just like a multiplier: 1 x 10 is 10 whatever amp from the range does it. It's just the bigger amp can go to 25 x 250 and a little amp runs out of steam at 10 x 100, lets say.

 

Erm, stupid question, but do the Rega and Rotel power amps have the same gain factor? If the Rotel has a higher gain this might not help - or am I being dumb?

 

Sorry - I edited my post twice, Dom. BTW, another factor is the crossover components, so even if the speaker elements are the same, it's possible that the centre sounds a different loudness because of the difference in power lost in the centre speaker vs. the stereos.

 

Guys, this is the reason you should run the test tone and check with an SPL: the whole idea of doing this is to overcome the differences you talk about!
Those who reckon it is easy to calibrate by ear are mistaken. I did a "by ear" calibration and the checked this against my SPL meter: a mere 6dB difference between all channels... (sarcasm, sorry)
I then did a training course at work (in a hi-fi shop) for my colleagues and showed them how to use an SPL meter, then got them to set up a system using the meter.
Needless to say, one clever individual tried to use his "golden" ears, ie. set up without the SPL meter.
It was immediately apparent that this was what had been done: the sound was uneven and disjointed by comparison to everyone else's efforts.
Don't kid yourselves: if you are gonna set up an A/V or multi-channel music system, you NEED an SPL meter: Maplins will probably be able to supply one for the cost of a couple of DVDs...
End of rant...