Center Channel Advise

[Johnd]

Good speakers don't have timbre. Timbre by its nature is an aberration. Timbre matching is making sure all speakers have the same errors, and that means usually of frequency response.

I'm always amazed that often when visiting a dealer different speakers from the same manufacturer can be like chalk from cheese. However things are improving as I now note there are far more similarities than differences from good designers and stables.

What I'm saying is that there should be no more reason to timbre match speakers than amplifiers. I do think the better designs are moving closer.

Opinion? Yeah, I've got one.

Well, that's just not true. Timbre is an individual instrument's, or, in this case, speaker's sound quality:resonance.

Without timbre, a pipe organ would sound like a concert piano.

 

[Warpdrv]

I see what he is getting at here, but the only problem is that all speakers are so different, in sound characteristics that its hard combine different lines, and much harder to combine different brands but its not impossible, Its easier for us to help you by suggesting you stay within your lines to get close to the cleanest soundstage...

I had a mismatched soundstage before, and I could never figure out why It sounded like crap until I started researching... I will not go back to mixing and matching, they were all polk but the centers were far to small to match the fronts so they sounded lacking.

If nothing else, try to find something in your budget, and put it in there and see how it sounds to you... make sure your dealer is aware of what your doing, and will let you audition in your own home for a short period.



With beautiful looking speakers like those, and Im sure they sound great as well... I would have a hard time downgrading. Then only in the future kick yourself for losing them.

Have you looked on Audiogon.com for your speakers used.. you might find a good deal there..

http://buy.audiogon.com/cgia/cls.pl?spkrmoni&1202561259

 

[fmw]

Your front 3 speaker must be the same to have a seamless front sound stage. It's called Timbre Match.

And with HT that is what is so important with the center channel, the dialog.

Must is a pretty strong term. The reality is that what comes from the center vs. the LR are different content almost all the time. A purist would suggest that timbre matching is important but, to me, it is nice but not very important. To me it is more important to have a center that reproduces voice the way you like. I have on rare occasions heard the the effect of my timbre-mismatched center. I can probably count the number of times over the years on my fingers. I've never been bothered by it for more than a second.

 

[Warpdrv]

A purist would suggest that timbre matching is important but, to me, it is nice but not very important.

I would say here that NOT VERY IMPORTANT is also strongly worded here.
The center channel doesn't just produce voices, the sound from the mains blend from right to left more often then not, maybe you just don't notice as your fronts sound good together...

It is important, perfect match, maybe not so much but closely matched should be a goal here.... In this situation, it looks like the OP cannot attain a perfect match, and at trying to find something close would be good.

There are obviously a difference of opinion, but I would suggest to not just go buy a center with 3" drivers to match 6" drivers....

just try to find something that sounds close and your good to go... as with surround speakers, it is less imperative to use identical speakers to your front...

I think we are giving the OP a good idea here, that its possible to be flexible, but also for best results listen and let your ears tell you what works for you...

 

[2string]

I agree 100%! I would kick myself down the road. My thoughts are the center channel should be geared for voices full and rich you know like the guy on the FM station late at night. It should have about the same size drivers and tweeters as the L&R. Keeping the Auditors I would still have a wicked 2 channel too. I'm still unsure if the 2303ci 100W per channel will push the Auditors. Can robbing them of current hurt the drivers? My room is not that big so I won't be playing it that loud.

 

[Warpdrv]

I think you'll be ok on the power there, 3 speakers, not as big a difference as sharing the load on all 7 channels...

It will drive them, if its already driving the mains just fine, I doubt it will be a problem... Although I don't have the specs on the speakers...

 

[2string]

Any ideas on a close matched center from the people who may have heard the Auditors. I know ultimately it's my ears and decision but I could use some help. Theres not much around here to try..

 

[TLS Guy]

Hmmm.

I think TLS is saying that there are speakers whose character disappears, and that there is then no need to match the LCRs for a seamless soundstage. Now, I've not heard everything out there, but I've heard a fair amount of nice stuff. I've always felt that speakers have the biggest impact on your system's sound (exclude the room), and that one can get the biggest variation by changing them. Some speakers sound more similar than others, but they generally have their own character. None are perfect.

TLS Guy, your statement implies that there are speakers out there that coult be mixed and matched. Could you give us three examples of these speakers, regardless of cost or anything else?

Sorry for the late reply OttoMatic, but I have have been otherwise occupied
most of the day. Also I wanted to give our question some thought.

I'm gratified that most respondents including yourself have understood what I was getting at with my intentionally provocative post.

Before I get into speaker lines that might be matched, I want to make some observations about the particularly unique and difficult job the center speaker has to perform. I think the design of a center speaker presents the designer with some unusually difficult problems. So much so that if I had to point to one item that so often, in my view, prevents multichannel systems from providing a truly satisfying experience, then I would single out the center speaker.

So what are the problems.

It must have excellent speech clarity and also be a superb speaker for the reproduction of music.

It must blend seamlessly with the left front and right speakers, so that voices sung and spoken can move freely across the sound stage with no noticeable change.

For music, especially multichannel SACD, it must be able to handle the equivalent power of the left and rights.

Unless it is part of system that uses a projector and pull down acoustically transparent screen it must be relatively small

Its acoustic center must be in close proximity to the screen.

Its dispersion pattern and listening window must be at least in the ball park of the left and rights. From my observations it is better if it has a slightly narrower listening angle in most rooms. I think this is because for most rooms the distance from the center to the outside speakers is usually less than 8ft. So there is constant risk of interference between the center and the front speakers.

Now, I have long felt, and I'm becoming part of a larger crowd, that these criteria are potentially best filled by coaxial or full range drivers, as close to the center of the screen as possible, either top or bottom.

The commonest solution is an MTM array mounted on its side. I'm sorry but this falls far short of an ideal solution.

The problem is that the listening axis is then vertical instead of horizontal, so sound is preferentially radiated to the ceiling and floor. Not only does this invite problems with room interaction, but getting a satisfactory blend with the outer speakers becomes nigh on impossible. I'm yet to hear one of these situations that does not disturb me. I know I'm not alone as other have commented about this. Now if you turn the speaker vertical you solve the dispersion, but then you have the WAF and the acoustic center gets rather far from the screen.

Now lets return to OttoMatic's question. I think there are some neutral speakers out there that can be mixed without attention being drawn. Lets just make one more comment about timbre. Instruments should have it speakers should not. And I will not back away from that view.

Now I think one needs to look among the ranks of manufacturers that have produced families of speakers that have very similar and neutral midband response. I have selected for examples B &W, KEF, Thiel and Monitor audio. There are other Quad for instance, and I know there are more out there.

Now KEF and Thiel have coaxial center speakers that are good performers.

http://www.kef.com/qseries/products.htm

http://www.thielaudio.com/THIEL_Site05/Pages/models/Current_Models/SCS4/SCS4_main.html

Now I think those could be matched with any of the lines above and give superior results. However I have to give the caveat that I'm saying this based on aural impressions and above all aural memory and all that that entails. But it is useful for a basis of discussion.

Now what about the kit and DIY end of the spectrum.

Well SEAS have an excellent 7 inch coaxial driver and crossover. It is available as a kit with or without the enclosure. It is the SEAS Loki.

http://www.madisound.com/MD04.html

I have a lot of experience with this driver and is an excellent performer. Now the crossover is not diffraction compensated, but if any one wants to build a speaker twice the volume of the Loki, with two drivers, I can give the circuit. One driver does not have the tweeter used, and obviously the driver with the tweeter connected is placed closest to the screen. his is a very neutral speaker with excellent voice clarity and superior musical performance.

Here is my diffraction compensated TLS using this driver. This uses active compensation, but I have worked up a passive circuit.

http://mdcarter.smugmug.com/gallery/2424008#127077096

Now there is one other interesting possibility using this driver. It is E.J. Jordan's JX92S full range driver. In personal correspondence he assures me this is the modern version of his famous Jordan Watts module, that caused such a stir when it was first introduced in the early sixties. I was the Canadian agent for Jordan watts back in the seventies. I still have a stash of around 100 drivers. Now these drivers are extremely neutral and accurate. They are a significantly limited in power handling below 100 Hz

http://www.ejjordan.co.uk/drivers/jx92.html

http://www.ejjordan.co.uk/drivers/

Here is a vented alignment in a 0.5 cu ft box. It is power limited to 20 watts below 100 Hz because of cone displacement issues.

File: Jordan JX92S.bb6
-----------------------------------------
Driver Properties
Name: JX92s
Type: Standard one-way driver
Company: E.J. Jordan Designs
No. of Drivers = 1
Fs = 45 Hz
Qms = 1.35
Vas = 15.28 liters
Cms = 1.77 mm/N
Mms = 7 g
Rms = 1.48 kg/s
Xmax = 4.5 mm
Xmech = 6.75 mm
P-Dia = 99.63 mm
Sd = 78.54 sq.cm
P-Vd = 0.0351 liters
Qes = 0.58
Re = 4.5 ohms
Le = 0.142 mH
Z = 8 ohms
BL = 4 Tm
Pe = 50 watts
Qts = 0.4
no = 0.231 %
1-W SPL = 88 dB
2.83-V SPL = 88.29 dB
-----------------------------------------
Box Properties
Name:
Type: Vented Box
Shape: Prism, square (optimum)
Vb = 0.428 cu.ft
Fb = 42.69 Hz
QL = 7
F3 = 50.16 Hz
Fill = minimal
No. of Vents = 1
Vent shape = round
Vent ends = two flared
Dv = 1.63 in
Lv = 6.86 in

Here is the closed box alignment in a box.

Now here is the closed box alignment in a box of only 0.125 cu.ft! Because of the size of the box, the driver does not exceed its xmax within its power range. Any how I would recommend crossing over at 100 Hz

F3 is 98 Hz, and it will produce 103 db!

File: Jordan JX92S.closed.bb6
-----------------------------------------
Driver Properties
Name: JX92s
Type: Standard one-way driver
Company: E.J. Jordan Designs
No. of Drivers = 1
Fs = 45 Hz
Qms = 1.35
Vas = 15.28 liters
Cms = 1.77 mm/N
Mms = 7 g
Rms = 1.48 kg/s
Xmax = 4.5 mm
Sd = 78.54 sq.cm
Qes = 0.58
Re = 4.5 ohms
Le = 0.142 mH
Z = 8 ohms
BL = 4 Tm
Pe = 50 watts
Qts = 0.4
1-W SPL = 88 dB
-----------------------------------------
Box Properties
Name:
Type: Closed Box
Shape: Prism, square
Vb = 0.125 cu.ft
Qtc = 0.707
QL = 20
F3 = 98.16 Hz
Fill = heavy

Now if someone wanted to build a 5.1 or 7.1 system round those with a really good sub crossing over at 100 Hz, you would achieve what the good Dr Amar Bose has failed to do. You would need only one driver in each satellite. I'm pretty certain the system would have awesome performance, and have great WAF. Food for thought indeed.

 

[TLS Guy]

Opinion? Yeah, I've got one.

Well, that's just not true. Timbre is an individual instrument's, or, in this case, speaker's sound quality:resonance.

Without timbre, a pipe organ would sound like a concert piano.

Instruments should have timbre, speakers should not.

 

[mazersteven]

The reality is that what comes from the center vs. the LR are different content almost all the time. A purist would suggest that timbre matching is important but, to me, it is nice but not very important.

The ideal thing in HT is to have all the speakers the same all the way around. If this is ideal, then how can you state, "but not very important" to have a center channel timbre match the mains?

 

[jostenmeat]

My opinion is that "timbre-matching" is over-rated for HT purposes. Multi-ch music would be a different story. I know that many, many knowledgable and experienced folks feel otherwise. I am sure certain setups, rooms, and particular combinations allow for a great discrepancy of opinions.

If the CC sucks for dialogue, it doesn't matter to me one iota how well it matches with the mains, or the rest for that matter. Nothing bothers me more in HT audio than sibilance and/or distortion of the voice. Sometimes, this might be due to placement, source, electronics, etc, but you guys get my point. I'll take a mismatched center that provides superb dialog with zero audible sibilance than any other less-performing "matching" speaker, regardless of brand, cost, size, whatever... that's me.

I might feel that similar size is more important than brand. I have been told by a local dealer that Dolby and DTS recommened that similar cabinet size is more important than matching brands for HT. I think the Harley Davidson becoming a moped in the center might have a lot to do with the change in cabinet size/power-handling/"large"-vs-"small" speaker. Wouldn't that be more mismatched? ... Anyways, sounds such as Harley's, alien spaceships, bullets whizzing by, sword barely missing my head, tank shells, crazy dragon shrieks, etc, etc, are not "realistic" the way music is or the voice is. They are special effects, often artifcially created in studios, and the really small and fleeting differences in "timbre" (assuming I myself could detect it) of a wall exploding from a tank shell quickly panned from left to right is not going to be a serious issue for me, especially given all of the visual distractions, floor rumblings provided by the LFE, girl squeezing my arm, yada yada.

Do I agree that identical speakers would be a superior setup for HT? Of course, I often recommend to noobies to use the EXACT same speaker at all positions. However, I also tend to do this for reasons of having an upright bookshelf for the CC, hopefully to provide better performance and for less money. The setup would be matched in cabinet size, phase, x-over points, power handling, sensitivity, etc, yada yada.

OK, in light of my opinion, I at least don't think its SOOO important to have to give up the best 2-channel playback quality the OP can afford. I dumped a great portion of my money into the stereo portion of my rig, and simply went from there. I was really close to other certain brands of the conventional-dynamic type, and I even had "bookmarked" a couple of different center speaker stands with the intention of having a vertically arrayed, "matching" center channel.

Yikes, I am typing too much, sorry, ok, Mr. OP, one far fetched idea. Find someone in your same predicament (hit up all the SF sites, owner threads, etc), split the cost on a pair of a new or used set of auditors. Buy a speaker stand for it. My guess is $1500 apiece, and you will be perfectly matched.

 

[Tomorrow]

ALL loudspeakers flavor sound to some extent. Different brands/models incorporate differing trade-offs in speaker design and this is detectable to some degree, though sometimes it is neglible. I completely disagree with the statement that quality loudspeakers sound similar. One must be very careful to find similar voicing amongst brands. I'm sure it is possible with your speakers, but you'll need to do some auditioning. As far as mixing brands as different sounding as B&W with coaxial speakers like Thiel...you will be throwing away money.

2string, before selling off your lovely speakers, you may want to try using a 'phantom' center channel. Some people do so with good result and actually prefer the results over a 3-channel presentation. EDIT: Looking at your nice setup, I can see that is exactly what you're doing. Adding surrounds would be much less an issue than the CC.

Experiment!

 

[TLS Guy]

ALL loudspeakers flavor sound to some extent. Different brands/models incorporate differing trade-offs in speaker design and this is detectable to some degree, though sometimes it is neglible. I completely disagree with the statement that quality loudspeakers sound similar. One must be very careful to find similar voicing amongst brands. As far as mixing brands as different sounding as B&W with coaxial speakers like Thiel...you will be throwing away money.

Zstring, before selling off your lovely speakers, you may want to try using a 'phantom' center channel. Some people do so with good result and actually prefer the results over a 3-channel presentation.

Experiment!

I agree with using a phantom center rather than downgrading to inferior speakers. However the better speakers are starting to sound more and more alike. We are going in the right direction.

 

[Sheep]

Instruments should have timbre, speakers should not.

Unless they were designed to have a certain Characteristic. Then, they will have timber. And there is more at play then JUST frequency response. MUCH more.

SheepStar

 

[fmw]

The ideal thing in HT is to have all the speakers the same all the way around. If this is ideal, then how can you state, "but not very important" to have a center channel timbre match the mains?

Because I don't think it is very important. Why is that confusing? I'm not against timbre matching. I wouldn't argue against the statement that having identical speakers all the way around would be ideal. But the ideal isn't very important to me. I've had them matched and mismatched. Doesn't matter to me.

Common sense should prevail. Using a computer speaker as a center channel along with full range mains wouldn't make much sense. In my case, I have small towers with 6" bass drivers in the mains and 2 6" bass drivers in the center. I let the sub handle the bass by designating all the speakers as "small" in the setup. close enough. They are different brands made in different countries. The HT listening experience is just fine, thank you.

 

[Johnd]

Instruments should have timbre, speakers should not.

I will repeat what Tomorrow and Sheep have written in a different way:

Without timbre in speakers you would have studio monitors whose aspiration is to be totally flat (this does not yet exist in the real world...all speakers have some sort of coloration). I have yet to experience any studio monitors that would befit my home theater.

Imho, timbre in speakers, or, put another way, coloration and character, whilst subjective in nature as to degrees of like and dislike, is what gives speakers their specific characteristics, their individual sound. Without timbre all speakers would be truly flat, and they would all sound identical (to the same ear). How could this possibly be construed as a good thing...a lack of choice in speaker selections? One of the most highly coveted things to the ht/music enthusiast...speakers that befit our own ears in our own environment.

 

[Johnd]

Because I don't think it is very important. Why is that confusing? I'm not against timbre matching. I wouldn't argue against the statement that having identical speakers all the way around would be ideal. But the ideal isn't very important to me. I've had them matched and mismatched. Doesn't matter to me.

Common sense should prevail. Using a computer speaker as a center channel along with full range mains wouldn't make much sense. In my case, I have small towers with 6" bass drivers in the mains and 2 6" bass drivers in the center. I let the sub handle the bass by designating all the speakers as "small" in the setup. close enough. They are different brands made in different countries. The HT listening experience is just fine, thank you.

Understood. For you that is fine. It is also quite possible that the mismatched speakers you've selected are close in timbre. Or if there is a problem, your ears just don't detect it. Either way, the general consensus for the rest of us is to match timbre for the front three, and possibly all 5 (or 7) if possible, especially for sacd. It would be disturbing to me to have entirely different coloration on the center than the mains. I would be troubled by it throughout all movies, and doubly so on sacd. Disturbing, and upsetting.

 

[2string]

Phantom center,I tried reading up on this but it's confusing to me. Can someone simplify what is actually is ?

 

[Johnd]

Phantom center,I tried reading up on this but it's confusing to me. Can someone simplify what is actually is ?

I think you're ill-advised to do that. You will generally only want a phantom center in ht if you don't have the processing, the room or the money.

You can set your processor to ignore the center, which basically sends the signals to the mains, but undesirable cancellations will occur, and you will never have a discreet center channel, which is a very important channel in movies (and surround music).

 

[fmw]

It would be disturbing to me to have entirely different coloration on the center than the mains. I would be troubled by it throughout all movies, and doubly so on sacd. Disturbing, and upsetting.

It might be for me too. Like I said, using a computer speaker for a center channel along with full range mains wouldn't make any sense and I'm pretty certain it would trouble me as well. I'm not fighting the "general consensus." I'm just saying that it hasn't proven to be very important to me.