"Home Theater" Speakers

[flyzipper]

Place the center above the screen, problem solved. Even if the speaker ends up quite close to the ceiling, it will be much better than a low mounted one with a table right in front.

And a GOOD center does not sound like the sound comes from the speaker, it sounds like it comes from the screen - the speaker "disappears".

I disagree with the assertion that the quality of the speaker will mask its location.

Listen to a system that employs ceiling speakers for LCR channels if you have any doubt.

Being able to to determine where a sound originates is a key survival faculty that allows animals to pinpoint the location of danger, prey, etc.

PS - if your table is the only problem... move the table

 

[echopraxia]

I disagree with the assertion that the quality of the speaker will mask its location.

Listen to a system that employs ceiling speakers for LCR channels if you have any doubt.

Being able to to determine where a sound originates is a key survival faculty that allows animals to pinpoint the location of danger, prey, etc.

Here’s a new idea (for this thread) I’m surprised nobody has mentioned yet: Why not two speakers (dual mono center), one above and one below the TV? This will create a phantom vertical center, but with a real horizontal center! Seems like the best possible option for anchoring voices as correctly as possible to a physical (not acoustically transparent) TV.

 

[flyzipper]

Here’s a new idea I’m surprised nobody has mentioned yet: Why not two speakers, one above and one below the TV? This will create a phantom vertical center but with a real horizontal center point! Seems like the best possible option for anchoring voices as correctly as possible to a physical (not acoustically transparent) TV.

Comb-filtering of the high frequencies when the delay between the two sources are (highly likely) different?

Also, I've read that that two horizontal sources are able to create the "stereo" effect, but two vertical sources... not so much.

I'm hoping somebody with more depth of knowledge on the matter can fill in the blanks or correct my lack of insight.

(I'd be curious to try it though, to experience the effect myself)

 

[jhaider]

I think it’s a matter of opinion whether a below-the-TV center channel adds more than it detracts. I think most of us will agree that two really great LR towers are definitely better than three terrible front channels (imagine e.g. Definitive Tech Mythos Gem’s — among the absolute worst “home theater” speakers I’ve ever heard). So to extend that logic, it’s not at all a stretch to argue that the vertical imaging shift (from an under-TV center channel.

There is no logic in a leap from “good speakers beat crappy speakers” to some imagined “vertical imaging shift,” sorry. To the extent that your alleged “vertical imaging shift” is actually a thing, it is driven by a visual cue of seeing the low loudspeaker as discussed earlier.

And for the record I called nobody dumb, but omitting the center channel is in my view a very stupid idea.

 

[Sancus]

Here’s a new idea (for this thread) I’m surprised nobody has mentioned yet: Why not two speakers (dual mono center), one above and one below the TV? This will create a phantom vertical center, but with a real horizontal center! Seems like the best possible option for anchoring voices as correctly as possible to a physical (not acoustically transparent) TV.

Mainly because I don't want to buy that many Genelec 8351Bs But yeah, it's viable, if certainly a pain to mount.

E: Also a pain to time-align since they are different distances from the listening position and I don't think it's is a supported configuration in most AVRs.

 

[jhaider]

Listen to a system that employs ceiling speakers for LCR channels if you have any doubt.

Have you ever heard such a system? I have, once: a demo of a theater room with those angled Revel 3-way ceiling speakers that have a forward angled MTM and a backwards angled flat woofer in front, and I think cheaper Revel ceiling speakers for surround. They didn’t play any program I knew, just action movies. However, the sound certainly sounded like it came from the screen, except when the woofers bottomed (likely due to religious fixation on an 80Hz subs-mains crossover when the speakers needed higher).

The late audio innovator David L. Clark also designed his home theater system with soffit mounted front, surround, and rear speakers. This was pre-Auro/Atmos.

Being able to to determine where a sound originates is a key survival faculty that allows animals to pinpoint the location of danger, prey, etc.

Unless there’s a visual stimulus to anchor spatial perception and override the audio spatial cues!

 

[flyzipper]

For what it's worth, here are the design guidelines for QSC certified theatres and placement of their SC-2150 screen channel speakers.

1. Prepare three platforms, left, center, and right, sturdy enough to safely support the SC-2150, and with the capability of vertical adjustments.
2. Place the loudspeakers platforms and adjust the height so that the Mid-Hi system is at approximately 5/8 of the screen height.
3. Position the SC-2150 so that the front of the loudspeaker is about 6” (15 cm) from the perforated cinema screen.
   
   (editorial - all three screen channel speakers are identical, highly capable, on the same level, and neither above nor below the screen)

That looks like this...

... and I'd bet $100 that any sane person, who's able to pick any seat they want, isn't going to pick the front 1/2 of the house.

Source - https://www.qsc.com/resource-files/.../sc-2150/q_spk_dcs_sc2150_quickstartguide.pdf
Source - https://www.qsc.com/resource-files/corporate/q_cin_ctp_specifications.pdf

 

[Kvalsvoll]

Looks like we had similar idea at similar time

But regarding a good center channel sounding like voices are coming from the TV... how is that possible? Either speakers are precisely localize-able or not. If they are, then the lower vertical position will be audible. And if the speakers are not precisely localizable, then what’s the point of a real center channel at all?

I think we do benefit from the fact that human hearing is much more finely tuned to locate sounds in the horizontal plane than the vertical, but height differences are still audible to some degree.

We hear left-right, or horizontal. Height can to some degree be detected from changes in frequency response, but then you would need an object that moves in the height direction, because you need a reference.

Whether a speaker reveals itself as sound source is determined by properties of the speaker, and to some extent its acoustic surroundings, again depending on the speakers radiation pattern. Generally, a speaker that disappears well and image well for ordinary 2-ch stereo, will also disappear well used as a center.

It is true that a good 2-ch system can produce a soundstage where 3-d also extends into the height dimension, with instruments having different both location and apparent size in the height direction. But the speakers obviously have only one fixed height.

 

[flyzipper]

Have you ever heard such a system?

I have.

They prioritize aesthetics over fidelity, and I can understand why such layouts exist, but I wouldn't make that choice for my own system.

I doubt you would either.

Unless there’s a visual stimulus to anchor spatial perception and override the audio spatial cues!

VCA (ventriloquist center array)... patent that, you'll make a fortune.

Seriously though, whether watching a film, or playing a first person shooter (where I'm hyper focused on the action on the screen)... I perceive the centre audio to originate from below the screen (if that's where it's placed). Is it less distracting if I'm focused on visual cues? Yep. Would I rather avoid that setup? Absolutely.

 

[Kvalsvoll]

I disagree with the assertion that the quality of the speaker will mask its location.

Listen to a system that employs ceiling speakers for LCR channels if you have any doubt.

Being able to to determine where a sound originates is a key survival faculty that allows animals to pinpoint the location of danger, prey, etc.

PS - if your table is the only problem... move the table

There are technical properties of a speaker that makes it more likely to reveal itself as sound source. Distance to nearby reflective surfaces also matters, so you should avoid placing the center very close to the ceiling - or floor, if possible.

 

[Chromatischism]

Here’s a new idea (for this thread) I’m surprised nobody has mentioned yet: Why not two speakers (dual mono center), one above and one below the TV? This will create a phantom vertical center, but with a real horizontal center! Seems like the best possible option for anchoring voices as correctly as possible to a physical (not acoustically transparent) TV.

I've thought about this before, too. I think in the end it's probably not worth it versus just doing a phantom left and right.

 

[Putter]

I've thought about this before, too. I think in the end it's probably not worth it versus just doing a phantom left and right.

I seem to recall that was tried in the days of Dolby Surround and Pro Logic. No idea how successful it was.

 

[Chromatischism]

And for the record I called nobody dumb, but omitting the center channel is in my view a very stupid idea.

What if your speaker maker does not make a center channel speaker and only sells the bookshelves in pairs?

Or what if your speaker maker does not make a center channel speaker but you are able to buy a single standmount, but then you are left with a single speaker handling that channel, which is less capable than the two that it replaced? All the while the center channel in movie soundtracks tends to be mixed hotter than the rest?

These are the problems I have been or am currently faced with. Therefore, I would only purchase a center channel speaker if it had double the power and sensitivity as my left and right. You commonly see this with dual woofer center speakers used with single-woofer L and R speakers. Buchardt doesn't currently offer one, so I would have to find the closest match. I've looked at some options, but the trouble I run into is cost versus reward. Even if I managed to afford it and make it fit (both are questionable) the benefits in my narrow symmetrical room where I am always seated in the center would be minimal.

 

[Tom C]

Here’s a new idea (for this thread) I’m surprised nobody has mentioned yet: Why not two speakers (dual mono center), one above and one below the TV? This will create a phantom vertical center, but with a real horizontal center! Seems like the best possible option for anchoring voices as correctly as possible to a physical (not acoustically transparent) TV.

I asked that very question in post #203. Crickets...

 

[yourmando]

I asked that very question in post #203. Crickets...

@flyzipper answered this: it’s because it would cause comb filtering, if the distances from the speakers to LP are even slightly off. Very easy to hear—have someone move one of the speakers.

Generally, pointing a copy of the same channel from 2 different speakers to the same location is avoided, unless a decorrelation algorithm is applied. This, plus other processing are what upmixers like Auro 3D Auromatic does to extract ”height” channels from existing channels. These aren’t just copies of the source.

When copy arrays are used, they are typically to fill sound over a larger area and the dispersion overlap is minimized (to avoid comb filtering), such as targeting a lower deck vs upper deck.

 

[Chromatischism]

We hear it all the time when a singer is mixed to both left and right speakers so they appear in the center. How is that any different?

 

[Hifisound]

Measurements of the 815, 828 and 835 active speakers. Non-german speaking readers use deepl for translation.

Anybody seen/found measurements for JBL PRX835 ?

 

[echopraxia]

Anybody seen/found measurements for JBL PRX835 ?

Yes: https://www.audiosciencereview.com/...me-theater-speakers.15795/page-10#post-515056

 

[echopraxia]

There is no logic in a leap from “good speakers beat crappy speakers” to some imagined “vertical imaging shift,” sorry. To the extent that your alleged “vertical imaging shift” is actually a thing, it is driven by a visual cue of seeing the low loudspeaker as discussed earlier.

And for the record I called nobody dumb, but omitting the center channel is in my view a very stupid idea.

Maybe I need to explain in crystal clear detail, in case the analogy wasn't obvious enough: If Preference(2x really good speakers) > Preference(3x really bad speakers), then it's not at all far-fetched to suppose that in some cases we will find Preference(2x really good speakers) > Preference(2x really good speakers & 1 really bad center channel speaker).

(It should be obvious that preference of a multi-speaker system is not any simple linear combination of the speakers contained within, in the sense that adding a speaker of positive nonzero standalone preference certainly can reduce the overall score of a system.)

If we admit that adding a bad speaker to a good system can make the overall system sound worse, then we must admit that the same is true of adding a really good speaker, integrated poorly. Some argue this is the case for a vertically mal-positioned center channel. It's fine to disagree with that. But it's by no means a "very stupid idea" to suspect an extremely good two channel system might sound better than that same system with a below-the-TV center channel speaker added to it.

 

[echopraxia]

We hear left-right, or horizontal. Height can to some degree be detected from changes in frequency response, but then you would need an object that moves in the height direction, because you need a reference.

Whether a speaker reveals itself as sound source is determined by properties of the speaker, and to some extent its acoustic surroundings, again depending on the speakers radiation pattern. Generally, a speaker that disappears well and image well for ordinary 2-ch stereo, will also disappear well used as a center.

It is true that a good 2-ch system can produce a soundstage where 3-d also extends into the height dimension, with instruments having different both location and apparent size in the height direction. But the speakers obviously have only one fixed height.

Like the horizontal plane, our ability to pinpoint a sound in 3D is aided not just our processing of the sound from a fixed head position, but processing of how what we hear varies as our head moves. Once we add head rotation to the HRTF picture, perhaps you can see how we can locate a sound source vertically, even if it's frequency response is modified to 'emulate' a sound coming from lower/higher than it actually it: our ability to locate a sound by subconsciously correlating the HRTF's relative changes in frequency response as our head's pitch angle changes is an algorithm that works for any sound (of sufficient audible bandwidth), independent of that sound's frequency response. As to how obvious or subtle this is, I can't say (other than give personal anecdotes), but this clearly can't be ruled out entirely.

It's also possible that different people are attuned to horizontal and/or vertical imaging differently than others. For example, I've heard a good number of speakers over time, and not once have I ever heard a convincing ability to separate sounds in space vertically -- only horizontally, and even then, barely more than one dimension. I'm not saying speakers can't project an overall soundstage that is wide and tall; rather, I am saying that this spaciousness is usually achieved uniformly, not in a way that allows one instrument to be placed really 'high altitude' while another is simultaneously really 'low altitude'.