Center channel speaker design pet peeve.

[bootman]

Don't forget four more for surround back and sides and four for atmos.

How do you ceiling mount these?

[DYohn]

The idea of matching loudspeakers all around is good, however impractical it might be. Matching is most critical for surround music. For movie soundtracks, the front three should be voice-matched at least for best results. However, users should do whatever works for their setup and suits their taste.

[Perpendicular]

I'm not afraid to say this. Personally, I would prefer all the same speaker brand/model of loudspeaker all around (the right thing to do) but that's just not possible in my current space and a lot of 'other' folk's spaces. Sometimes you need to do what you got to do. So, my side surround speakers are different than my front three. Of course, I use room correction and it really helps to match all five of my loudspeakers together and is doable with the particular speakers I've chosen. Is it perfect and the way I should have it? No. But works for the time being and is better than no surround sound at all. 

[ludi]

I tried a couple of center speakers, but it was never a success. So finally I solved it by not using a center speaker anymore: problem of matching solved.

[teaman]

Jan 3, 2016 16:21:01 GMT -5 ludi said:

I tried a couple of center speakers, but it was never a success. So finally I solved it by not using a center speaker anymore: problem of matching solved.

Hopefully not for HT. Cannot imagine HT without a center speaker unless you are running stereo...

[Deleted]

Jan 3, 2016 16:21:01 GMT -5 ludi said:

I tried a couple of center speakers, but it was never a success. So finally I solved it by not using a center speaker anymore: problem of matching solved.

What were/are your L&R speakers?  Post a photo of your front L to R area, maybe someone here can help.

[ludi]

Jan 3, 2016 16:58:10 GMT -5 teaman said:

Jan 3, 2016 16:21:01 GMT -5 ludi said:

I tried a couple of center speakers, but it was never a success. So finally I solved it by not using a center speaker anymore: problem of matching solved.

Hopefully not for HT. Cannot imagine HT without a center speaker unless you are running stereo...

No I'm not running stereo. I run a 4.2 setup with a phantom center. And to be honest, I don't miss the center speaker at all: the dialogue is in my setup exactly in the center in the middel of the TV screen, horizontal and vertical.

[ludi]

Jan 3, 2016 19:52:08 GMT -5 @chuckienut said:

Jan 3, 2016 16:21:01 GMT -5 ludi said:

I tried a couple of center speakers, but it was never a success. So finally I solved it by not using a center speaker anymore: problem of matching solved.

What were/are your L&R speakers?  Post a photo of your front L to R area, maybe someone here can help.

Here is a picture of my setup from about a year ago. I now have an XMC-1 and a 60" TV instead of the 40" in the picture.


As you can see I have the Magnepans 1.7. With this setup it is difficult to have a compatible center speaker. On the other hand with the Maggies the phantom center is not only horizontal but also vertical in the middle, while with a center speaker underneath the TV set the sound will be lower than the picture.

[teaman]

I cannot imagine trying to match the Maggies for a center. I see your point.

[DYohn]

Phantom center channel can work for small systems like that if you sit in the sweet spot. But for best reproduction of a movie soundtrack you really do need a center channel. Trying to voice match those Magnaplans would be a challenge, but you might try their center channel speaker: www.magnepan.com/model_MMGC

[ludi]

Jan 4, 2016 12:41:27 GMT -5 DYohn said:

Phantom center channel can work for small systems like that if you sit in the sweet spot. But for best reproduction of a movie soundtrack you really do need a center channel. Trying to voice match those Magnaplans would be a challenge, but you might try their center channel speaker: www.magnepan.com/model_MMGC

Actually I'm sitting mostly in the sweet spot. I've looked at that center speaker before, but so far I didn't felt the need with the current set-up. And I already stretched the WAF quite a bit with these speakers

I use my system mostly for watching concerts in surround sound, and only once in a while a real movies. I guess for movies the center channel is more important than for music. Although in my setup and sitting on my favorite spot watching a movie the dialogues seems to originate from the center of the TV. I doubt how much improvement I'll get by adding an extra speaker.

[teaman]

Jan 4, 2016 13:23:00 GMT -5 ludi said:

Jan 4, 2016 12:41:27 GMT -5 DYohn said:

Phantom center channel can work for small systems like that if you sit in the sweet spot. But for best reproduction of a movie soundtrack you really do need a center channel. Trying to voice match those Magnaplans would be a challenge, but you might try their center channel speaker: www.magnepan.com/model_MMGC

Actually I'm sitting mostly in the sweet spot. I've looked at that center speaker before, but so far I didn't felt the need with the current set-up. And I already stretched the WAF quite a bit with these speakers

I use my system mostly for watching concerts in surround sound, and only once in a while a real movies. I guess for movies the center channel is more important than for music. Although in my setup and sitting on my favorite spot watching a movie the dialogues seems to originate from the center of the TV. I doubt how much improvement I'll get by adding an extra speaker.

For $299 I would at least try that center to see how it balances things out for you ludi.

[copperpipe]

I'm with ludi on this one; though I really never tried a center channel, with the bookshelfs I'm using I don't feel the need for one either. VLC does the phantom channel mixing for me in this case.

Actually @chuckienut mentioned "leakage", and that has me wondering; you hear a small "bang" off to the left, but it is "leaking" into the center channel too; so now you have a left speaker and a center speaker playing the same effect. Even though it's stronger in the left, you still have 2 speakers playing the same source sound (messing up the stereo effect).

In theory, shouldn't 2 high quality L and R speakers be all you need? We all talk about imaging and soundstage etc., seems to me voices are not special in that regard, why even bother with a center? Spend the savings on better L and R ??

[monkumonku]

Jan 4, 2016 13:54:15 GMT -5 copperpipe said:

I'm with ludi on this one; though I really never tried a center channel, with the bookshelfs I'm using I don't feel the need for one either. VLC does the phantom channel mixing for me in this case.

Actually @chuckienut mentioned "leakage", and that has me wondering; you hear a small "bang" off to the left, but it is "leaking" into the center channel too; so now you have a left speaker and a center speaker playing the same effect. Even though it's stronger in the left, you still have 2 speakers playing the same source sound (messing up the stereo effect).

In theory, shouldn't 2 high quality L and R speakers be all you need? We all talk about imaging and soundstage etc., seems to me voices are not special in that regard, why even bother with a center? Spend the savings on better L and R ??

But let's say you are using two speakers, listening to dialog. If you are sitting off more to the left or the right than center, then the dialog will sound like it is coming from whatever speaker you are closer to. If you have a dedicated center channel, then even if there is some bleeding or leakage (if you aren't using SD's - Speaker Depends) the dialog will sound like it is coming from the center of the screen.

That said, I find that the mind acts to place the dialog anyway. Like if I am watching something with a mono soundtrack, if the person speaking is on the left of the screen, it seems to me that the voice is coming from the left side. The voice seems to come from wherever the person is on the screen. My mind isn't so persuasive that a car moving from left to right fools me into hearing the sound shift from left to right as it would in stereo but the mind does influence how I hear things.

[copperpipe]

Jan 4, 2016 14:14:32 GMT -5 monkumonku said:

But let's say you are using two speakers, listening to dialog. If you are sitting off more to the left or the right than center, then the dialog will sound like it is coming from whatever speaker you are closer to.

But the same argument holds true for music and (especially) sound effects too. If you have great L/R speakers with a wide sweetspot then this is less of a problem. I tend to watch movies in the sweet spot anyway though

Jan 4, 2016 14:14:32 GMT -5 monkumonku said:

That said, I find that the mind acts to place the dialog anyway. Like if I am watching something with a mono soundtrack, if the person speaking is on the left of the screen, it seems to me that the voice is coming from the left side. The voice seems to come from wherever the person is on the screen. My mind isn't so persuasive that a car moving from left to right fools me into hearing the sound shift from left to right as it would in stereo but the mind does influence how I hear things.

Agreed.

[gus4emo]

Ok people, so what's the big difference between these two scenarios, one center channel speaker has two big woofers, a midwoofer, and a tweeter, ported or not, and it goes down to 40, the other center channel speaker has one let's say 6 1/2 inch woofer and a tweeter, ported or not, goes down to 60, but you cut off both at 80, so frequencies from 80 down go to the sub...what's the sonic difference between the two?

[Lsc]

The difference in watching movies recorded in 5.1 or 7.1 etc., with a center channel is that you are actually sending your center channel information to your center channel. This is the same as a stereo setup with great imaging speakers where it is sending the 2 channels to the 2 speakers. Each channel of the source is being sent to the speaker.

Watching a 5.1 movie with a phantom center, it's splitting the center channel to the L&R speakers and hoping that the imaging will place the information at the center.

With some setups where a good matching center is hard to find, I agree that running it in phantom mode with no center will yield better results, especially if you usually watch alone and sit in the sweet spot.

[KeithL]

The easiest way to think about it is simply to think about what you hear when a sound source is REALLY in the center of the front of the room vs if it's coming from speakers.

In principle, if you're actually sitting in the center of the room (in terms of left-right), then, when you hear a sound located in the center, you would hear the same thing whether you had a real center channel speaker or just two speakers ("a phantom center"); the sound would be of equal loudness in both ears. However, if you're anywhere else in the room, that approximation breaks down. With a real center, if you move your body to the left, then you hear the sound coming more from your right, because the speaker really is more to your right. However, with a "phantom center", as you get closer to the left speaker, you hear the sound coming more from your left, which actually puts the apparent sound source in the wrong place, and in fact exaggerates the error between the apparent source point and where it should be.

There is also another, and more subtle, difference that you may or may not notice depending on your room and your speakers. With a real center, and a symmetrical room, the center speaker is relatively far from the side walls, and relatively closer to you, so most of the sound you're hearing from it is direct sound, and the reflections from both sides of a symmetrical room will be delayed somewhat longer - and equally. With a "phantom center", both speakers where the sound originates are closer to the side walls, so you'll probably be getting a higher proportion of reflected sound. And, beyond even that, you have more sound paths, and of different lengths. (Draw a picture in your head. With one real center speaker, and a symmetrical room, you get reflections from the left and right walls, both of equal delay lengths; with two stereo speakers, from each speaker, you get reflections from two different walls, each at different distances from the speaker. So you have more reflections, arriving over a wider rage of times, which tends to make the sound less distinct and more reverberent. And, because a significant proportion of the sound you hear is the sound reflected from the side walls, the sound source will seem to be even wider.)

Of course, the downside is that, the more physical speakers you have, the more opportunity there is for them to interact with each other, and your room, when a sound appears in two or more of them. 

In general, the phantom center works pretty well, especially if your speakers aren't too widely separated. But, if you have two speakers that are widely separated, especially if they're pushed all the way over against the side walls, and especially if your side walls are relatively reflective, then a center speaker will do a better job, and will help fill in the perceived "hole in the middle". This also suggests that, if you are going to use only two speakers, you should avoid spacing them too widely apart, you should keep them as far as possible from the side walls, and you should even consider treating the side walls so as to minimize early reflections from the speakers.

Jan 4, 2016 13:54:15 GMT -5 copperpipe said:

I'm with ludi on this one; though I really never tried a center channel, with the bookshelfs I'm using I don't feel the need for one either. VLC does the phantom channel mixing for me in this case.

Actually @chuckienut mentioned "leakage", and that has me wondering; you hear a small "bang" off to the left, but it is "leaking" into the center channel too; so now you have a left speaker and a center speaker playing the same effect. Even though it's stronger in the left, you still have 2 speakers playing the same source sound (messing up the stereo effect).

In theory, shouldn't 2 high quality L and R speakers be all you need? We all talk about imaging and soundstage etc., seems to me voices are not special in that regard, why even bother with a center? Spend the savings on better L and R ??

[KeithL]

A bit about ported speakers......

Under normal circumstances, the purpose of a port is mostly to "tune the enclosure"; the length of the port and the mass of the air inside it creates a resonant circuit with the air in the box and the mass and spring constant of the cone. This resonant circuit both controls the movement of the speaker cone near its resonant frequency and allows the sound produced by the rear of the speaker cone to contribute to its overall output. With most speakers, all of the calculations assume that the port itself will be operating "free air" (opening out into the room, with nothing restricting the flow of air into the room). With downward firing ports, and slot loaded drivers, the distance between the port and the floor is included in the calculations. (In other words, if you have a port firing downwards, two inches from the floor, then the "actual port" is the 2" high slot around the edge, between the cabinet and the floor, where the air escapes. The air flowing through the port carries part of the sound energy, which is added to that coming from the front of the cone.

If the port opens on the rear of the speaker then, by putting the speaker inside a cabinet, you are in fact altering all the calculations. The cabinet probably restricts the air flow, and delays the air from the rear port on its path back into the room. And, if the cabinet is too tight a fit, it may even end up acting as if the port opens into a second, more or less sealed, enclosure rather than being open to the room. This second enclosure is itself tuned. This may affect the sound in various ways.... none of which is as the designers intended. Usually, when you have a rear-firing port, you will be told the minimum distance you should leave between the rear of the speaker and the rear wall, and maintaining this recommended distance will avoid major interactions.

If you were to mount a speaker with a rear port in a wall, where the rear port was open to a different area (like the room behind the wall containing your equipment rack), then various effects might result. Because the port is unobstructed, it will still serve its function of tuning the enclosure to control the movement of the woofer cone near the tuned frequency. However, instead of being added to the output of the front of the cone, the output of the rear of the cone will be lost, which may result in lower efficiency. Also, because with many speakers the output of the port contributes different amounts at different frequencies, the frequency response of the speaker might change significantly.

And, if you're curious, there are several reasons why many speakers avoid a front-mounted port. First, with some subs, the cabinet is so small that there's no room on the front plate to mount the appropriately sized port. Second, there may be interior size considerations - like a port of the appropriate length needing to be mounted in a certain spot so it clears the magnet on the driver, or just plain fits inside the cabinet. And, third, sound from the rear of the speaker cone may escape through the port, or you may hear distracting noises caused by the air blowing through the port at high volume levels. (This is especially a problem with a sub, where the only intended output is low frequencies, which are difficult to localize. If you hear noises caused by air blowing through the port, or sound that escapes from inside the cabinet, they may not only be distracting, but may lead to your being able to localize the sub as a sound source. This is a common problem with poorly designed subs. All else being equal, facing the port downwards, or out the back, tends to minimize this.) 

  

[gus4emo]

Jan 4, 2016 22:57:54 GMT -5 gus4emo said:

Ok people, so what's the big difference between these two scenarios, one center channel speaker has two big woofers, a midwoofer, and a tweeter, ported or not, and it goes down to 40, the other center channel speaker has one let's say 6 1/2 inch woofer and a tweeter, ported or not, goes down to 60, but you cut off both at 80, so frequencies from 80 down go to the sub...what's the sonic difference between the two?