How to improve center channel intelligibility

[Johns Naim]

Greetings all

I'm relatively new to HT, but with a strong background in 2 channel, and am seeking some thoughts from other experienced users re setup options etc, as I ponder the integration and or separation of my 2 channel plus AV setup.

I am presently running centreless, i.e. in phantom mode for DD/DTS 5.1, as I have a rather expensive pair of 2 channel stereo speakers doing double duty for AV usage, and a matching centre speaker is somewhat out of reach $$ wise at the present time.

I do notice sometimes that dialogue is not quite as clear as i would like, re the leading edges of transients of voice etc, and am wondering if a center channel speaker would help improve intelligibility. As it would of necessity be an unmatched brand, would I be likely to lose as much as I could possibly gain, as regards left to right channel pans etc through the center, i.e. different tonal balances etc. I am under the impression this is important for music surround, but less so for HT, as the center is supposedly mostly dialogue.

I would like to improve the intelligibility of the center, if possible, with the least possible tradeoffs re mismatches of tonal balance etc.

Many thanks,

All comments appreciated.

Cheers

John.

 

[wolfgang]

This is my personal humble opinion. The choice of centre channel is influence a lot by the practical aspect of where to put it. I suspect if you could hear the different timbre between makes of speakers them it will be very difficult to match all front channels into a homogenous panoramic sound fields. If you think the 2 front channels resolution is not of high enough quality then the additional centre have to be of superior quality since it is now required to reproduce most of the imformation during AV. If it is only in AV reproduction that you notice this maybe it is the DVDP and AV processor that is holding back the main speakers. One for you tries alone to sees if it provides the solution you required.

 

[lowrider]

I find a good center speaker indispensable for DD and DTS...

I had the same problem as you, there is no center to match my Sonus Faber EAII, Merlin, another member of this forum, recomended the Proac CC2, I tested it, along with plenty others, and bought it, it is fantastic and should match almost any front speakers...

I realized it is not a must to perfectely match that speaker, as long as it is not brighter than the fronts, but it must be very clear and powerful, there is as much as 80% info on the center channel...

 

[rodrat]

It's really worth waiting until you can afford a centre that matches your main speakers. It makes a huge difference to not just the dialogue but also carries a lot of the mid and bass. Prior to getting a matching PMC centre to match my main PMC speakers, I used a mission 77c (i think) they can be bought new for about £100. It did a very creditable job.

Rod

 

[MO!]

I've only ever tried 3 centers.

I've since replaced my main speakers and find my center isn't much of a match.

I wasn't aware that as much info as that stated above goes into the center. I found mine dominates things, and though voices are clear, the background noise, music, effects etc all seem to suffer badly. Though vocals don't quite have that locked to the screen feel, I find that putting the center in fantom MOde gives a nicer, MOre dynamic and rich sound.

Like I said, my center's not the "match" for my main speakers. And I'm sure the matching center would improve things. I'd make sure you deffo deMO and not just assume it will improve things though.

 

[Tenson]

Originally posted by rodrat
Prior to getting a matching PMC centre to match my main PMC speakers, I used a mission 77c (i think) they can be bought new for about £100. It did a very creditable job.

Rod

You have the new CB6? Nice!

 

[MikeD]

have you tried watching movies in stereo (shock horror! ) to see if they suffer the same effects?

 

[Matt F]

A while ago, I did a few experiments with "phantom" centre vs real centre and this was with an identical centre to the front pair (and identical amplification) so it was a pretty balanced test.

I was surprised how good it sounded running in phantom mode - pretty acceptable in fact as long as you sit in the sweet spot. However, when I switched the centre back in everything came forward and seemed more focussed, in front of the screen. In short, it was notably better running with a matched centre speaker.

If using the dedicated centre that is matched to your mains isn't an option then you could try some quality alternatives such as the Pro-ac Lowrider mentioned or perhaps the likes of the KEF 200C or Monitor Audio Gold Reference centre. It might take you a while to find one that matches closely with your mains though and it should be noted that most, if not all, of these quality centre speakers need decent amplification (i.e. not bodget AV amps) to sound their best.

Matt.

 

[7_V]

I'm really glad that it seems to be so important that the centre speaker matches the main speakers for HT (an area where I have had no experience so far) as my forthcoming centre and rear speakers are sonically identical to the main speakers. Could this be my big market?

There's one thing that I find interesting about front centre speakers and I posed this question on the AudioAsylum forum some time ago...

Why are so many front centre speakers designed to be laid out 'the wrong way' (in other words, with the speakers horizontal rather than vertical)?

I can't think of a single reason for this. In fact, in terms of dispersion, I can think of reasons why it's a bad idea. When I posted on AA, they didn't come up with any reason either, except it may make physical placement easier (on top of the TV). In other words, it's generally a cock-up and most of the manufacturers of HT equipment just followed like sheep (no surprise there).

Can anyone on ZG pour any more light onto this issue?

 

[lowrider]

7_V

You must be teasing us...

Of course the shape of center speakers follow the placement constraints...

 

[Ian J]

Originally posted by 7_V
Why are so many front centre speakers designed to be laid out 'the wrong way' (in other words, with the speakers horizontal rather than vertical)?

It was agreed by a committee comprising the designer, accountant and marketing director and the designer was outvoted.

The marketing director thought that it would be easier to sell the concept of a centre speaker if it was less noticeable and the accountant rather liked the idea that a "dedicated" centre speaker could be sold at a higher price than a common or garden ordinary one so the die was cast.

 

[rodrat]

My centre speaker would be a metre tall if placed on its end on suitable stand. My TV is only 90cm from floor to top. I might get a better sound, but I could see bugger all. Apart from the fact my TV weighs 75kg precluding it being wall mounted, even a plasma screen would be to high up to view it in comfort. I would suggest that for most living room situations, the centre speaker can only be laid on its side.

However, I accept that centre speakers may be part of a black operation from area 51.

Rod

 

[7_V]

Originally posted by Ian J
... and the accountant rather liked the idea that a "dedicated" centre speaker could be sold at a higher price than a common or garden ordinary one so the die was cast.

In fairness to the accountant, to magnetically screen a speaker (properly), you have to put another magnet on the back and a can around the two. It is more expensive.

Originally posted by rodrat
My centre speaker would be a metre tall if placed on its end on suitable stand. My TV is only 90cm from floor to top. I might get a better sound, but I could see bugger all.

You guys are so damn fussy.

 

[Johns Naim]

Greetings all

Thank you all for the most kind and helpful comments so far.

I am in between a bit of a rock and a hard place, in that I have only one room at my disposal currently, to do duties for both 2 channel and HT use.

I currently run a Naim 2 channel setup, (ducks and runs for cover ) with SBL's. My current thoughts are that they are not the most suitable speakers for HT, due to their back to the wall placement and the limitations that imposes upon sound staging etc.

For music, that is not an issue, however, for HT where a large and immersive sound field seems to be of primary importance re that vital being there factor, their relatively limited sound-staging abilities are.

I have thoughts of saving for the Naim matching center, but it is very expensive, and whilst it may improve the dialogue intelligibility issue, I'm less sure that it would improve my system overall in the sound-staging stakes, which is another performance area of HT that I'd like to be able to address.

I'm currently using Tannoy MX2's for rears, and am thinking of adding the center for the intelligibility reasons I've outlined.

IF I was sure that stereo 2 channel was to give way to multi-channel music surround via SACD or DVD-Audio, then it would make more sense perhaps to wait and add the matching Naim center channel, and eventually replace the Tannoys at the rear with other Naim spkrs as well.

However, I don't sense that this is about to happen anytime soon, and making large financial outlays when things still seem in so much flux, doesn't appeal to my pocket very much at the present time. Hence my thoughts re the Tannoy center, and wondering if it would improve things, or stuff it up completely re HT.

By keeping costs down, it also allows me the flexibility of upgrading to full-blown Naim multichannel music surround later, if indeed it ever eventuates into the mainstream, or if I find myself in different circmustances in the future, to be able to separate the two, and run the HT in a separate room, merely adding Tannoy fronts to complete the HT setup.

Hope this clarifies my thoughts a bit.

Cheers

John...

 

[jay]

Hi John

I would have a chat with your "dealer" about a suitable match to your SBL's - a cheaper alternative that is than the Naim centre. I think you'll be very surprised in the difference it will make.

The centre is incredibly important in home theatre. It carries a huge amount of information, not just dialogue. It's as if the front L/R channels support the centre. The centre does not "fill the gap" between them. When you have a speaker like the SBL it's doublely important because, as you say, they are hard against the front wall.

Here's where I'm coming from, experience wise.....I built my front left/right and surrounds around a centre speaker upgrade. I purchased a second hand Royd AV77 that gave such a full and attractive sound I had to match the rest of the front sound field with Royd Minstels. I was lucky enough to find a full set of 4 and have prob found another 2!

The benefit of having all speakers tonally matched is enormous but the fronts even more so. So I really do strongly suqqest that a centre is probably THE most important speaker in an HT system. If you can't tonally match get a second hand cheapie. You never know you could end up building a system around it!

Enjoy!

Jay

 

[7_V]

Originally posted by jay
The benefit of having all speakers tonally matched is enormous but the fronts even more so. So I really do strongly suqqest that a centre is probably THE most important speaker in an HT system.

Excuse my ignorance as a newbie to HT but in a typical HT system, what is the relative output by the front, centre and rear speakers? In an ideal world would all five speakers be identical or would they just be perfectly matched with the front pair larger?

 

[lowrider]

The center channel can play up to 80% of the sound, or so they say...

Actually my center has twice the drivers and box size as the front, the surrounds nearly half of the fronts... :MILD:

 

[jay]

Originally posted by 7_V
Excuse my ignorance as a newbie to HT but in a typical HT system, what is the relative output by the front, centre and rear speakers? In an ideal world would all five speakers be identical or would they just be perfectly matched with the front pair larger?

Hi Steve

That's right - all identical output.

You go through a full level set up process first up. Usually involves setting speaker size, distance to listening position and then level.

Levelling is done with white noise and SPL meter first - then adjust by ear.

Jay

 

[7_V]

Originally posted by jay
Basically you go through a full levelset up process first up. Usually involves setting speaker size, distance to listening position and then level. Levelling is done with white noise and SPL meter first - then adjust by ear.

I appreciate that jay but my question relates to what sized speakers are required for HT, relative to the front speakers.

Let's say that the front speakers equal 1 unit each. Then, according to lowrider, the front centre would equal 2 units and the rear speakers under 1/2 a unit each.

Any other views?

 

[wadia-miester]

Steve,

Tonal balance & Matching is critical for a quality a/v set up, the front speaker is responsible for all dialogue transactions so to speak, and the front stereo pair, giving the depth, abience and oepniness to the front stage area.
Quality centre speakers usually consist of 2 seperated bass/mid range units and a centre mounted tweeter, sort of D'appollata' array configuration only rotated through 90 degree's to the horizontal.
Rear speaker arrays (again Quality ones) usually run either a single/twin bass driver (downward firing ports or sealed box) with at least 2 tweeters (firing opposed corners) that can be cnfigurated for either Di-pole or straight in phase settings. T.