The problem with (most) Center Channel speakers

[ErinH]

I have been wanting to address this topic for a while. I've got a LOT of hours into this, from measurements to sound recordings to building the presentation. My hope is that it will provide insight into problematic designs and help people understand how to use objective data to get a better idea of what speakers' compromises make most sense for their particular needs.

I provide objective anechoic data, in-room measurements and some simulations using ripple tank. I also use sound demos of various center channel speakers - recorded using binaural mics in my home theater - to illustrate the difference in sound as you listen on-axis (0 degrees) and off-axis at 25 degrees. So, make sure you have some headphones nearby for that.

It's a LOT to get through so I purposely left some aspects out (which I explain in the video). If you have any questions please ask there as I plan to create a follow-up live Q&A at some point (if necessary).

 

[Hetfield]

I have been wanting to address this topic for a while. I've got a LOT of hours into this, from measurements to sound recordings to building the presentation. My hope is that it will provide insight into problematic designs and help people understand how to use objective data to get a better idea of what speakers' compromises make most sense for their particular needs.

I provide objective anechoic data, in-room measurements and some simulations using ripple tank. I also use sound demos of various center channel speakers - recorded using binaural mics in my home theater - to illustrate the difference in sound as you listen on-axis (0 degrees) and off-axis at 25 degrees. So, make sure you have some headphones nearby for that.

It's a LOT to get through so I purposely left some aspects out (which I explain in the video). If you have any questions please ask there as I plan to create a follow-up live Q&A at some point (if necessary).

Dude that was one of the best home theater videos I have ever watched and I'm not joking. It literally answered 99% of my questions on why I myself thought most center channels suck. Really awesome because it's a question I have had for a really long time.
The best sounding center channel I ever had was not a center channel, it was a bookshelf, Def Tech SM65 LCR. Has absolutely no issues with dialog anywhere in the room. My speakers now are better overall except the center which is ok, but still lacking.
I'm gonna look to try something different at some point. The SVS Prime center is first up even though though a different brand from my other speakers.

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[ErinH]

I'm gonna look to try something different at some point. The SVS Prime center is first up even though though a different brand from my other speakers.

Also make sure you look at the other data I provide in my reviews (as well as the data James provides here on AH). As I said in the video, I left out some aspects, such as linearity, to focus on horizontal dispersion. The SVS, IIRC, has decent linearity and should take well to EQ so it's a reasonable choice. But it may not have the best linearity in its size/price class. Therefore, while it does have very wide horizontal radiation, there may be other aspects about other speakers - speakers that may not have quite the width of the SVS - that you prefer. It's all a juggling act.

Again, not saying the SVS isn't a good option. It is. I have all the data on my site to show it. I just want to stress that the video was focused on one key aspect and I assumed - for the sake of the video's length - that linearity in response was not an issue.

 

[Hetfield]

Also make sure you look at the other data I provide in my reviews (as well as the data James provides here on AH). As I said in the video, I left out some aspects, such as linearity, to focus on horizontal dispersion. The SVS, IIRC, has decent linearity and should take well to EQ so it's a reasonable choice. But it may not have the best linearity in its size/price class. Therefore, while it does have very wide horizontal radiation, there may be other aspects about other speakers - speakers that may not have quite the width of the SVS - that you prefer. It's all a juggling act.

Again, not saying the SVS isn't a good option. It is. I have all the data on my site to show it. I just want to stress that the video was focused on one key aspect and I assumed - for the sake of the video's length - that linearity in response was not an issue.

Thank you, and appreciate the input very much. I look at it like a try out. I had the JBL A125C and it was ok. I have the JBL 520C that I like but it's lacking in ways. Here is what I am looking for, and this is the one that stays. I'm looking for Audyssey to set the level of the center channel because Audyssey is actually really good with that part and I feel absolutely no need to up the level on that center channel. That's all I want really.
There is something wrong with a center channel of you get to bump the level 2-3 dB. But maybe that's too simplistic.

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[SithZedi]

Thank you for making a very informative video and clearly delivered. Echoing (no Pun) Het's comments, I have some thinking to do too. I run a Vienna Acoustic Theatro as my Center, to match to a pair of VA Mozart L & R. The dialogue is beautiful and faithful at 0 but does drift off to the side. Don't want to replace the Theatro but will experiment to see if I can mount it straight up and see the difference.

 

[ErinH]

I have the JBL 520C

I have data for this one on my site as well.

 

[kini]

Makes me glad I went with Kef. My Q650 is great. Especially its ability to "lift" voices just where they need to be. Even if I sit 3' from it, the voices still seem to be coming from the screen.

 

[ryanosaur]

Absolutely excellent topic and very well covered!
Thank you, Erin!!!

 

[shadyJ]

This is good stuff Erin! Something I have been harping on for years. I wish I thought to make a video this well organized and accessible!

 

[Danzilla31]

Yeah great job Erin I'm subscribed to your YouTube Channel and I really love your content. It's been cool watching you grow with this the last couple years

Also love the Daily HiFi podcast you do with Joe N Tell and Youthman and the other guys

Great stuff!

 

[gene]

Eric;

Nice video and great analysis. Oddly, I posted a response in the comments last night but I don’t see it so here it goes again:

• You forgot about the worse horizontal offending topology, the infamous TWWWT design. Absolutely dreadful listening experience for anyone that isn’t directly on center.
• Pink noise aberrations are much easier to hear than actual program material and worth noting.
• It’s hard to believe we covered this topic over 15 years ago but here is our original article: https://www.audioholics.com/loudspeaker-design/vertical-vs-horizontal-speaker-designs
• But then I revisited realizing most people don’t sit more than 20 deg off axis and if they do, it’s usually by a side wall and not a good listening or viewing seat anyway: https://www.audioholics.com/loudspeaker-design/center-channel-speaker
• It’s important to note that AT screens are NOT without their issues, especially vinyl ones. I measured significant on/off axis comb filtering on a very expensive screen I’m currently using from Screen Innovations. To overcome some of these issues, you must build the screen OFF the wall to get it away from the speakers and also use heavy absorption material between the speakers. I plan on doing a YT video on this, hopefully soon.

IF you ever want to collaborate and come on our channel to discuss these topics, I’m game.

 

[ErinH]

Eric;

Nice video and great analysis. Oddly, I posted a response in the comments last night but I don’t see it so here it goes again:

• You forgot about the worse horizontal offending topology, the infamous TWWWT design. Absolutely dreadful listening experience for anyone that isn’t directly on center.
• Pink noise aberrations are much easier to hear than actual program material and worth noting.
• It’s hard to believe we covered this topic over 15 years ago but here is our original article: https://www.audioholics.com/loudspeaker-design/vertical-vs-horizontal-speaker-designs
• But then I revisited realizing most people don’t sit more than 20 deg off axis and if they do, it’s usually by a side wall and not a good listening or viewing seat anyway: https://www.audioholics.com/loudspeaker-design/center-channel-speaker
• It’s important to note that AT screens are NOT without their issues, especially vinyl ones. I measured significant on/off axis comb filtering on a very expensive screen I’m currently using from Screen Innovations. To overcome some of these issues, you must build the screen OFF the wall to get it away from the speakers and also use heavy absorption material between the speakers. I plan on doing a YT video on this, hopefully soon.

IF you ever want to collaborate and come on our channel to discuss these topics, I’m game.

Gene, you keep calling me "Eric" and I know you know better! lol

Noted. I looked at my blocked comments and don't see them there. Feel free to try again.

 

[Hetfield]

Eric;

Nice video and great analysis. Oddly, I posted a response in the comments last night but I don’t see it so here it goes again:

• You forgot about the worse horizontal offending topology, the infamous TWWWT design. Absolutely dreadful listening experience for anyone that isn’t directly on center.
• Pink noise aberrations are much easier to hear than actual program material and worth noting.
• It’s hard to believe we covered this topic over 15 years ago but here is our original article: https://www.audioholics.com/loudspeaker-design/vertical-vs-horizontal-speaker-designs
• But then I revisited realizing most people don’t sit more than 20 deg off axis and if they do, it’s usually by a side wall and not a good listening or viewing seat anyway: https://www.audioholics.com/loudspeaker-design/center-channel-speaker
• It’s important to note that AT screens are NOT without their issues, especially vinyl ones. I measured significant on/off axis comb filtering on a very expensive screen I’m currently using from Screen Innovations. To overcome some of these issues, you must build the screen OFF the wall to get it away from the speakers and also use heavy absorption material between the speakers. I plan on doing a YT video on this, hopefully soon.

IF you ever want to collaborate and come on our channel to discuss these topics, I’m game.

Erin on Audioholics! Now that's must see!

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[ErinH]

This is good stuff Erin! Something I have been harping on for years. I wish I thought to make a video this well organized and accessible!

Thanks, James. This one is obviously a known issue with many but I knew there were a LOT of people who not only weren't aware but don't really understand what we mean when we say "comb filtering" and "off-axis"... Those are the folks I wanted to make this video for. I'm happy to hear that it's helpful.

 

[gene]

Gene, you keep calling me "Eric" and I know you know better! lol

Noted. I looked at my blocked comments and don't see them there. Feel free to try again.

OK I posted it 3 times. Damn I did a Freudian slip with the spelling of your name I guess.

 

[TLS Guy]

Thanks, James. This one is obviously a known issue with many but I knew there were a LOT of people who not only weren't aware but don't really understand what we mean when we say "comb filtering" and "off-axis"... Those are the folks I wanted to make this video for. I'm happy to hear that it's helpful.

Very good presentation Erin.

I have railed against horizontal MTMs for years. They are unacceptable. The best audio and cosmetic solution is coaxial designs. Although in the small condo we had that was a secondary home, I used a full ranger and that worked well.

There is a problem with three ways though, which concerns the polarity of the mid in a three way. Because of lobing issues, you really want an even order crossover in a center. So usually you will have second order crossover, as fourth order has too many, and too large components to fit in easily as well as significant added cost.

The issue comes, when the left and right are two ways and the center a three way. In order to avoid a null at crossover the polarity of the mid is often reversed. This then puts the mid out of phase with the the woofers of the left and right speakers.

I ran into this problem with my in wall design for out great room. Luckily the null was very narrow. Accepting the null was audibly far superior to the out of phase condition between the center mid and the left and right speakers.

I suspect people have selected three way centers, and wondered why results are not what they expected when the mains are two way, or 2.5 way.

I should have anticipated this problem, but I admit I overlooked it, but the problem hit me four square as soon as I listened to the set up.

 

[Kvn_Walker]

Without even watching the video, I can safely assume the issue is the horizontal layout of center speakers.

If the audio industry can ever convince the furniture industry to build TV stands with vertical slots for vertical center speakers, you'll see this issue slowly resolve. Of course I doubt anyone is even trying. WAF is also always going to be a concern, except for those who can afford more esoteric solutions than just laying a speaker beneath the television.

Or, of course, coax center speakers. My last center speaker was a KEF iq2c. It was easy on the eyes and made to disperse.