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The Centre channel: what signal gets sent to it? How demanding compared to Left and Right?

sarumbear

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It's a great speaker, but it depends on the requirements in order to assess whether it's capable, or not.

If the design objective is reaching THX refence levels at 20Hz, the Salon2 would be incapable of that (on its own).

THX calls for speakers to be capable of 105dB peaks, and subwoofers be capable of 115dB peaks -- at the listening position.

Factors that were considered are the Salon2's published specs of 86.4dB@1m efficiency and -6dB@20Hz, plus factoring in a reasonable listening position that's likely 4m rather than 1m. Doubling the distance reduces SPL by 6dB according to the inverse square law, so factor a -12dB attenuation should be applied based on doubling the 1m distance twice, and then granting a 3dB bonus because there are 2 sources.

My math says that's about 8000 watts to coax 115dB of 20Hz energy at a 4m listening position, but as speakers they'd only need about 500watts to reach the 105dB objective for those frequencies.

wattsefficiency4m distance -12dBtwo sources +3dB
186.474.477.4
289.477.480.4
492.480.483.4
895.483.486.4
1698.486.489.4
32101.489.492.4
64104.492.495.4
128107.495.498.4
256110.498.4101.4
512113.4101.4104.4
1024116.4104.4107.4
2048119.4107.4110.4
4096122.4110.4113.4
8192125.4113.4116.4
16384128.4116.4115dB target

All that said, if one or both of them are positioned such a 20Hz null exists at the listening position, then this goes from incapable to impossible... and illustrates the point that was made earlier -- that optimal speaker position isn't always optimal for producing bass, and that subwoofers are useful tools to keep in our audio toolboxes.
You made your point. However, I disagree. Your calculations and expectations are exceedingly simplistic and hence misleading.

Have a good day.
 
OP
Newman

Newman

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So this turned from a center channel discussion to a multichanel layout normative one ?

Just follow whatever the international standar says (ITU BS.2159-8 [07/2019]) and you can always make little cm/angle degree changes based on preference or special cases (difficult rooms), there is no more to it.
...and those reports (incl BS.775) strongly prioritise compromise and downward compatibility over performance.

This is the issue with slavishly following standards. (Not that the reports mentioned are even standards...although BS.775 could be described as equivalent to a standard by way of being a Rec doc). They are not the route to maximal results. eg in BS.775 the angular range for surround speakers includes an angle that Toole describes as unsatisfactory for 5.1, based on research.

Ditto Dolby. Toole notes their 7.1 recommendation includes an angle between front speakers that is narrower than one would want for music. He combines BS.775 and Dolby with some further recommendations from research to come up with a layout that differs from both.

So, IMHO, there is indeed "more to it".

P.S. if someone wants to describe the opinions of others as "exceedingly simplistic", they should be making that comment on posts that recommend slavish adherence to standards, instead of giving them 'likes'!
 
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flyzipper

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Your calculations and expectations are exceedingly simplistic and hence misleading.
I showed my inputs and reasoning because I'm happy to know where my logic is flawed.

It's not my intention to mislead, so I'd very much like to know how I'm wrong (exceedingly simplistic) so I can update my reasoning.

Or do you simply disagree that anyone would want reference at 20Hz?
 

Sancus

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I showed my inputs and reasoning because I'm happy to know where my logic is flawed.
I actually think your numbers are probably too generous :) At least for <80hz. However, there are some effects that would help the speakers. There is also boundary reinforcement and the fact that 6dB/distance doubling is for an open field/anechoic chamber, not a normal room. That said, unlike subs, most people aren't putting their speakers in corners where they'll get the most reinforcement. With typical "some ways into a room" placement I doubt you'll get more than 3-6dB that way, if you're lucky.

I would guess 1-4K watts is probably enough based purely on sensitivity. However, that doesn't consider distortion. A Salon 2 has 3x8" woofers, which is about the same as a sub with a 14" woofer, except that its woofers and port are not designed for sub-bass output. So, it is quite likely that a typical 12" ported sub will have more distortion-free output at 20hz than a Salon 2. Is 2 10-12" subs enough bass for home theatre? IMO almost certainly not, unless your room is pretty small, but not many people are going to have speakers like that in a small room.

I think it's very unlikely any floorstander, short of monsters like the JTRs with 15" woofers, would be satisfying in a HT scenario. But in any case, it isn't possible to precisely calculate output without making assumptions about room volume and speaker placement.
 

sarumbear

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I showed my inputs and reasoning because I'm happy to know where my logic is flawed.

It's not my intention to mislead, so I'd very much like to know how I'm wrong (exceedingly simplistic) so I can update my reasoning.

Or do you simply disagree that anyone would want reference at 20Hz?
For starters that 115dB level is for the LFE channel. LCR is not required to achieve that. There is no LFE in music, it is an element of a film soundtrack. You should have a subwoofer in a theatre, home or cinema. Nobody can argue that. It is the same as having to have the centre speaker.

The 115dB level is not the reference either. Reference level is 85dBSPL. 115dB is the peak level expected for the subwoofer to produce. LCR is expected to produce 105dBSPL peaks and in real world at most 100dBSPL.

Little understanding of physics and self-belief of the contrary create these confusions.
 
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sarumbear

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P.S. if someone wants to describe the opinions of others as "exceedingly simplistic", they should be making that comment on posts that recommend slavish adherence to standards, instead of giving them 'likes'!
Sorry teacher, shall I go to a corner and stand facing the wall? Or do you think "there is more to it"?
 

abdo123

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It's a great speaker, but it depends on the requirements in order to assess whether it's capable, or not.

If the design objective is reaching THX refence levels at 20Hz, the Salon2 would be incapable of that (on its own).

THX calls for speakers to be capable of 105dB peaks, and subwoofers be capable of 115dB peaks -- at the listening position.

Factors that were considered are the Salon2's published specs of 86.4dB@1m efficiency and -6dB@20Hz, plus factoring in a reasonable listening position that's likely 4m rather than 1m. Doubling the distance reduces SPL by 6dB according to the inverse square law, so factor a -12dB attenuation should be applied based on doubling the 1m distance twice, and then granting a 3dB bonus because there are 2 sources.

My math says that's about 8000 watts to coax 115dB of 20Hz energy at a 4m listening position, but as speakers they'd only need about 500watts to reach the 105dB objective for those frequencies.

wattsefficiency4m distance -12dBtwo sources +3dB
186.474.477.4
289.477.480.4
492.480.483.4
895.483.486.4
1698.486.489.4
32101.489.492.4
64104.492.495.4
128107.495.498.4
256110.498.4101.4
512113.4101.4104.4
1024116.4104.4107.4
2048119.4107.4110.4
4096122.4110.4113.4
8192125.4113.4116.4
16384128.4116.4115dB target

All that said, if one or both of them are positioned such a 20Hz null exists at the listening position, then this goes from incapable to impossible... and illustrates the point that was made earlier -- that optimal speaker position isn't always optimal for producing bass, and that subwoofers are useful tools to keep in our audio toolboxes.

The Salon 2 will measure flat in-room (if not peaking honestly, -10 dB 20Hz is flat in-room) due to room gain at 20Hz, feel free to read more about that here:


Also the -6dB by doubling of distance is in anechoic conditions, consider that 'worse scenario' calculations.
 

sarumbear

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The Salon 2 will measure flat in-room (if not peaking honestly, -10 dB 20Hz is flat in-room) due to room gain at 20Hz...
Repeating here to make it clear that 115dB is not the required level of the LCR. THX requires LCR to generate 105dB at 0dBFS. That is the peak level, which is 20dB above the reference level. Such a high level never exists on a soundtrack as it is dangerous to reach the 0dBFS. Hence there is always 2-3dB headroom allowed, which means LCR speakers are required to peak at around 102dBSPL, which is well within the capability of a large floor-stander like the Salon2, each having the equivalent of a 14" woofer.
 

abdo123

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@flyzipper I found the Spin for the Salon 2, it looks like the -10dB point is @20Hz so it will measure in-room flat 20Hz to 20KHz.

Spin%2B-%2BRevel%2BUltima2%2BSalon2.png
 

flyzipper

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I have just two speakers. They go sufficiently low enough for music.
I think our disagreement stems from how we use our systems. Let's go our separate ways to allow this thread to get back to the OP's centre channel discussion -- you enjoy your excellent pair of speakers with music, and I'll enjoy my system with music, movies, video games, and anything else I choose to throw at it. Have a nice day.

To everyone who added to the discussion by pointing out that room gain will help the low end, thank you.

Even though I neglected that, it was inadvertently accounted for when I didn't use -6dB@20Hz in the start of my exceedingly simple model.

Apologies for to all for distracting from the OP.

In my defence, my answer to all questions in audio is add more subwoofers -- I clearly need to curb my enthusiasm for low end (publicly, at least). :)
 

Justdafactsmaam

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No artist ever ‘intended’ 2-ch stereo. They made music, and translation to a recording was in the hands of the producer.

Also, the information I get from recording engineers is that musicians ask them only to make the recording that will sell the most volume. The artists listen to the mix and ask themselves, “Are people going to want to buy this, or does it need to sound different?” If the answer is yes and no need to change it, the master is approved.

Even in the case where the musician(s) are deeply involved in the production, it is usually at the mixing of the tracks stage, hence, still part of ‘making music’ such as where to cut in an instrumental or vocal or sound effect, at what level, etc. Not so much about how many tracks to end up with.

As for multichannel, music producer and engineer Mark Waldrep used to say, “Show me an artist that’s heard great high-resolution multichannel and I’ll show you a surround sound convert.”

A good example is King Crimson. Clearly they worked together with the sound engineers to craft all their special effects, fades, etc. And decades later, when Steven Wilson approached Robert Fripp about accessing the recording tapes and making fresh multichannel mixes, Fripp was very negative about the project, but agreed to let Wilson do just one song as a demo. When he heard it he completely flipped his opinion and said something like “that’s the way we would have wanted it to be at the time, if we only had the technology”. And a major project was born to remix their albums into surround.

So I reckon there is about a 1% chance that 2-channel productions are all the artists ever wanted their work to be, in terms of sonic production values.
Artists’ intent without specific direct testimonial is speculation and hearsay. Also their intentions are not sacred.

There’s no reason to take any stance here. Lots of old stereo recordings are getting remixed in multichannel. If someone is into it great. If not then no problem. Options are not a bad thing. If some people are loving upmixed remixes I am happy for them getting what they want. And for those who dislike revisionism the original mixes don’t magically self destruct when they do remixes.
 

dasdoing

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No artist ever ‘intended’ 2-ch stereo. They made music, and translation to a recording was in the hands of the producer.

Also, the information I get from recording engineers is that musicians ask them only to make the recording that will sell the most volume. The artists listen to the mix and ask themselves, “Are people going to want to buy this, or does it need to sound different?” If the answer is yes and no need to change it, the master is approved.

Even in the case where the musician(s) are deeply involved in the production, it is usually at the mixing of the tracks stage, hence, still part of ‘making music’ such as where to cut in an instrumental or vocal or sound effect, at what level, etc. Not so much about how many tracks to end up with.

As for multichannel, music producer and engineer Mark Waldrep used to say, “Show me an artist that’s heard great high-resolution multichannel and I’ll show you a surround sound convert.”

A good example is King Crimson. Clearly they worked together with the sound engineers to craft all their special effects, fades, etc. And decades later, when Steven Wilson approached Robert Fripp about accessing the recording tapes and making fresh multichannel mixes, Fripp was very negative about the project, but agreed to let Wilson do just one song as a demo. When he heard it he completely flipped his opinion and said something like “that’s the way we would have wanted it to be at the time, if we only had the technology”. And a major project was born to remix their albums into surround.

So I reckon there is about a 1% chance that 2-channel productions are all the artists ever wanted their work to be, in terms of sonic production values.

most artist main request is: make it loud lol
 
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