• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

What SHOULD An HT Center Channel Speaker Sound Like?

Jim Shaw

Addicted to Fun and Learning
Forum Donor
Joined
Mar 16, 2021
Messages
557
Likes
1,006
Location
Northeastern Ohio, USA, in the woods
Why do we test home theatre dialog (center channel) speakers as if they are expected to be like mains?

Is it unreasonable to expect HTCC speakers to be optimized for human speech? Yet we persist in expecting them to have the same quality and character as the main front channel speakers. We know the range for intelligibility of the human voice, and it ISN'T 20 Hz to 20 kHz. It's more like 150 Hz to 5kHz. And it should be cardioid, not all beamy with 2 woofers and two tweeters.
.....
Further, why doesn't anybody make a powered center channel speaker for HT? In adding a center channel to a 2.1 system to accommodate HT, why can't we just take the high-level lines to the main channel speakers, feed them as signals into an amp in the center channel, and use bandwidth shaping to accommodate dialog, not all the music and car crash sounds? Is Atmos a law of nature?

As a crowd of one, but possibly more, I would like very much to buy a single box, place it dead center in front of the TV, plug it in, connect a couple of small signal leads to the main channel speakers, tune it up, and voila! have better dialog. And not have to step back to a sound bar, or up to a rack of hardware, MDF boxes, and more remote controls to do it.

Klipsch, Polk, Emotiva, and all the rest: why is there no such product?

-Just one guy's view, who's anti-wire clutter and 7.1.1 contraptions.
[stepping aside and awaiting all the it-can't-be-done testimonies.]
 

abdo123

Master Contributor
Forum Donor
Joined
Nov 15, 2020
Messages
6,867
Likes
7,051
Location
Brussels, Belgium
The producers of the show should optimize the audio track so you don’t need to play DJ or bob the builder to comprehend the conversation.

Most of the time even the worst offenders of center speakers are ‘okay’ but it is room accoustics that are hindering intelligibility.
 

LightninBoy

Addicted to Fun and Learning
Forum Donor
Joined
Jan 9, 2019
Messages
690
Likes
1,351
Location
St. Paul, MN
Is it unreasonable to expect HTCC speakers to be optimized for human speech?
Given that the center channel is expected to reproduce more than dialog, yes.
Yet we persist in expecting them to have the same quality and character as the main front channel speakers. We know the range for intelligibility of the human voice, and it ISN'T 20 Hz to 20 kHz. It's more like 150 Hz to 5kHz. And it should be cardioid, not all beamy with 2 woofers and two tweeters.
Most center channels are objectively worse than mains because of the beamy nature of the horizontal MTM design. Everyone would be better off if center channels actually had the same quality and character as the mains. But most do not because of compromises made to sit horizontal under a TV.

I can assure you that dialog is crystal clear with a center channel designed with the same principles as a main speaker and measures well against the parameters used to measure mains.

Are you having troubles with dialog in your system?
 
Last edited:

ta240

Addicted to Fun and Learning
Joined
Nov 7, 2019
Messages
876
Likes
1,423
Given that the center channel is expected to reproduce more than dialog, yes.
Exactly. The main dialog may tend to come from the center but so does much of the rest of what is going on; basically everything that is centered on the screen comes from that speaker.
 
OP
Jim Shaw

Jim Shaw

Addicted to Fun and Learning
Forum Donor
Joined
Mar 16, 2021
Messages
557
Likes
1,006
Location
Northeastern Ohio, USA, in the woods
My no 1 advice is to first determine whether it’s the speaker or the room.

If the closer you sit to the speaker the clearer the dialogue is then the speaker is not the problem.
The converse is true, thus (lack of) the speaker is the problem. If dialog intelligibility weren't a common problem, what use would we have for any center channel, ever??

I come from the avionics world where we worry a lot about speech intelligibility. A hifi speaker over a passenger's head makes intelligibility worse than one optimized for the human voice. The same for the captain's microphone and the air controller's headphones. Hifi can make a muddle of dialog.
 

HooStat

Addicted to Fun and Learning
Joined
May 11, 2020
Messages
800
Likes
831
Location
Calabasas, CA
Is it realistic to expect most people to address room issues for home theater? (Not the people on this site who are willing to put in the work, but the 99% of other people who expect things to work.) Plus, a center channel is often compromised in terms of design or placement. I suspect that a center channel optimized for a typical room and bad placement might sound pretty good and measure pretty poorly. It begs the question of what a center channel should really be/do.
 

abdo123

Master Contributor
Forum Donor
Joined
Nov 15, 2020
Messages
6,867
Likes
7,051
Location
Brussels, Belgium
The converse is true, thus (lack of) the speaker is the problem. If dialog intelligibility weren't a common problem, what use would we have for any center channel, ever??

I come from the avionics world where we worry a lot about speech intelligibility. A hifi speaker over a passenger's head makes intelligibility worse than one optimized for the human voice. The same for the captain's microphone and the air controller's headphones. Hifi can make a muddle of dialog.

The converse is true, thus (lack of) the speaker is the problem. If dialog intelligibility weren't a common problem, what use would we have for any center channel, ever??

I come from the avionics world where we worry a lot about speech intelligibility. A hifi speaker over a passenger's head makes intelligibility worse than one optimized for the human voice. The same for the captain's microphone and the air controller's headphones. Hifi can make a muddle of dialog.
Is your speaker flat on-axis with a smooth directivity?

I feel that is essential for the point you’re trying to make.
 

ta240

Addicted to Fun and Learning
Joined
Nov 7, 2019
Messages
876
Likes
1,423
Unless they are going to reformat the surround sound mixing to have one channel just for dialog then there is no way of having a center speaker just for that. Besides the voices need to blend with the other sounds happening in the center to sound natural. For me it would be more distracting to have the voices jump out way too much.

I think a good center channel speaker can solve both well enough for most people and a bad center channel can really make it hard to hear the dialog.
Unfortunately, testing is showing that most center channels suck. That can leave someone thinking a big change in the way surround sound works needs to happen.

I've had a bad one and a center channel that sounds okay straight on. With the bad one I was continually turning the volume up and down to try to hear the dialog and not get driven out of the room with the louder parts. With the okay one I only have to do that when sitting at an angle; when straight out from it I never have an issue understanding the dialog. My next purchase will be one that works like that off to the side too.

Sure, it could probably be better with sound treatments but I'm not going to add them to our living room because it is plenty good enough without it and the issue my system has is the speaker.

I come from the avionics world where we worry a lot about speech intelligibility. A hifi speaker over a passenger's head makes intelligibility worse than one optimized for the human voice. The same for the captain's microphone and the air controller's headphones. Hifi can make a muddle of dialog.

But in avionics you are typically trying to overcome low resolution audio to hear the best you can. With movies (most at least) they are high quality sound and you just have to keep it that way. And with avionics, all you want to hear is the voice; whereas with movies you still need to hear other things. Because nobody does surround sound mixing for movies with a separate dialog channel.

Decent speakers with a decent AVR should solve the problem. And as has been mentioned a 2 speaker setup is fine if you are sitting in the center by yourself. The super fancy stuff with room treatments is just for the people looking for that extra step towards realism.
 
OP
Jim Shaw

Jim Shaw

Addicted to Fun and Learning
Forum Donor
Joined
Mar 16, 2021
Messages
557
Likes
1,006
Location
Northeastern Ohio, USA, in the woods
Is your speaker flat on-axis with a smooth directivity?

I feel that is essential for the point you’re trying to make.
I wish only to improve dialog with a practical center channel. Lots of folks do that. I would prefer to not rearrange all the furniture in my room to accomplish it. In fact, I won't. But my chief issue is whether we really want or need center speaker sound quality of the mains to simply improve dialog. I think you are saying yes. But for what reasons?
 

Timcognito

Major Contributor
Forum Donor
Joined
Jun 28, 2021
Messages
1,360
Likes
5,833
Location
NorCal
 

Jon AA

Senior Member
Forum Donor
Joined
Feb 5, 2020
Messages
387
Likes
794
Location
Seattle Area
I wish only to improve dialog with a practical center channel. Lots of folks do that. I would prefer to not rearrange all the furniture in my room to accomplish it. In fact, I won't. But my chief issue is whether we really want or need center speaker sound quality of the mains to simply improve dialog. I think you are saying yes. But for what reasons?
Because it plays the bulk of everything happening on the screen--not just dialog.

MultiChannelDistribution.jpg


If you have a center channel and it's of low quality, the entire soundtrack of the movie will be lousy--not just the dialog.

The converse is true, thus (lack of) the speaker is the problem. If dialog intelligibility weren't a common problem, what use would we have for any center channel, ever??

So that everything happening on the screen actually sounds like it's happening on the screen for all the viewers who don't happen to be in the sweet spot. Without a center channel, to anybody sitting to the left or the right of the sweet spot, the center image moves with them to that side. This can be reduced a little bit with quality narrow dispersion speakers set up with "extreme toe," and that helps a bit, but it's a poor substitute for a proper center channel.

This is less of an issue for music listening as one can close his eyes, imagine the entire soundstage moved over with him and possibly get a "good enough" experience. But when you see things happening over there but the sound is coming from over here, it makes for a very poor experience.
 

Salida

Member
Joined
Nov 30, 2020
Messages
15
Likes
15
There are a lot of reasons dialog can be problematic.

Horizontal OoO (MTM) speakers are an abomination and have major issues off-axis.

Use center channel loudspeakers with the tweeter and midrange on the same vertical plane to get a decent power response.

Close in reflections from cabinetry, the TV itself, the floor, etc. should be reduced to improve dialog clarity.

Dialog seldomly comes completely from the center channel. L & R are usually active as well. Having timber-matched speakers with similar response characteristics will allow you to accurately place dialog and also increase intelligibility.

Also carefully setup gains time delays on your AVR to avoid comb filtering effects.

As a last resort, you can bump the gain of the center channel 3 dB.
 

LightninBoy

Addicted to Fun and Learning
Forum Donor
Joined
Jan 9, 2019
Messages
690
Likes
1,351
Location
St. Paul, MN
I wish only to improve dialog with a practical center channel. Lots of folks do that. I would prefer to not rearrange all the furniture in my room to accomplish it. In fact, I won't. But my chief issue is whether we really want or need center speaker sound quality of the mains to simply improve dialog. I think you are saying yes. But for what reasons?

If your *only* goal is to improve dialog and don't care about compromising anything else, then sure, the sound signature does not need to be similar to the mains. But you seem to be implying that dialog is the only purpose of a center channel, and that is false.
 

mj30250

Active Member
Joined
Dec 5, 2021
Messages
231
Likes
375
Why wouldn't you want the center speaker to sound like your mains, provided your mains are of good quality?

I watch a lot of YouTube content, which streams in stereo only (no center channel involvment). Provided the audio is well recorded and mixed, dialogue is completely crystal clear from the center seat.

Poor dialogue clarity from a center speaker is almost always caused by one or a combination of these:

A poor and / or unbalanced mix (reference aforementioned Nolan films)
A configuration issue
A room / positioning issue
A poor center speaker
 

Chromatischism

Major Contributor
Forum Donor
Joined
Jun 5, 2020
Messages
4,361
Likes
3,324
The center channel plays:

Voices
Car crashes
Explosions
Dogs barking
Footsteps
Gunshots
Doors knocking
Ocean waves
Multi-channel music

And the list goes on and on. It should be a speaker just like all the others in the system.
 

escape2

Addicted to Fun and Learning
Joined
Mar 8, 2019
Messages
821
Likes
853
Location
USA
We know the range for intelligibility of the human voice, and it ISN'T 20 Hz to 20 kHz. It's more like 150 Hz to 5kHz.
So what are you suggesting? Have a speaker that is neutered below 150 Hz and above 5 kHz? Why would you want such an atrocity when most speakers can easily deliver a fairly flat response across a much wider frequency spectrum?

BTW, male voice can easily drop to 80 Hz.
 

nerdoldnerdith

Senior Member
Joined
Sep 10, 2020
Messages
450
Likes
616
Location
Chicago
Why do we test home theatre dialog (center channel) speakers as if they are expected to be like mains?

Is it unreasonable to expect HTCC speakers to be optimized for human speech? Yet we persist in expecting them to have the same quality and character as the main front channel speakers. We know the range for intelligibility of the human voice, and it ISN'T 20 Hz to 20 kHz. It's more like 150 Hz to 5kHz. And it should be cardioid, not all beamy with 2 woofers and two tweeters.
.....
Further, why doesn't anybody make a powered center channel speaker for HT? In adding a center channel to a 2.1 system to accommodate HT, why can't we just take the high-level lines to the main channel speakers, feed them as signals into an amp in the center channel, and use bandwidth shaping to accommodate dialog, not all the music and car crash sounds? Is Atmos a law of nature?

As a crowd of one, but possibly more, I would like very much to buy a single box, place it dead center in front of the TV, plug it in, connect a couple of small signal leads to the main channel speakers, tune it up, and voila! have better dialog. And not have to step back to a sound bar, or up to a rack of hardware, MDF boxes, and more remote controls to do it.

Klipsch, Polk, Emotiva, and all the rest: why is there no such product?

-Just one guy's view, who's anti-wire clutter and 7.1.1 contraptions.
[stepping aside and awaiting all the it-can't-be-done testimonies.]
A proper mix won't just put dialogue on the center channel though. The center is just there to anchor the center image so that people sitting off center can still get decent imaging for what's happening on screen and sounds still mostly come from the right place on screen. In a proper mix the center will be used for everything that you see on screen, which accounts for the majority of content. You want it to match at least the left and right and ideally every speaker in the system. All of the bed channels should be identical.
 
Top Bottom