Music/home cinema setup

lucid · 29 Oct 2019 at 12:44

jpaul said:
yes I don't understand ..
listening to a movie using avr, sub will receive the two signals, one from avr and another via the hi-fi amp, even if the hi-fi amp has been set to a pre-configured volume, as soon as you change the (master) volume on the avr, to turn it up or down, the sub's overall volume may not remain in the correct balance with respect to the rest of the music, if the gain on the two amplifiers is different. ... so moreover , you need to switch off the sub's input from the hi-fi amp when using the avr.

(Indeed, even for the L+R front speakers driven by the hi-fi amp ... how do you ensure they maintain the correct volume in the balance as the avr's volume is changed.)

Simple, meter it.

The AVR has a test tone generator and dB-marked volume scale. Get a smartphone with a mic and download a free audio meter app. Test and measure each main channel at various volume points within the normal listening range for movies. If the sound level shows a consistent progression across the measured channels - within +/-1dB - then that's close enough that no one would pick up any difference.

Incidentally, have you done a similar test on your own AVR? You know, checking the absolute accuracy of the volume tracking of each channel's amplification relative to the others? I bet you haven't. You just took it on faith that they're matched.

Also, no need to turn the sub's high level input off for movie use. Doing that will do more harm to the sound since you'd be disabling tge bass reproduction of the front channels.

hornetstinger · 29 Oct 2019 at 13:09

Also, no need to turn the sub's high level input off for movie use. Doing that will do more harm to the sound since you'd be disabling tge bass reproduction of the front channels.

Umm no it won't as your speakers are receiving filtered audio 80hz and up and life is 80hz and down PLUS you are sending it filtered 80hz and up from speaker outputs.

Bad idea. Bass frequencies will be summed so it'll be a mess.

I tried it a while ago but settled on sub for movies only, RCA from avr to sub only. If I had two subs I'd switch the other one off

lucid · 29 Oct 2019 at 13:17

hornetstinger said:
But that's not bass management, the system you are describing is combining and summing signals.

Better to run sub in av mode only, run a it controlled a/b switch box or buy two subs,or have two different systems

I understand it's not the way that you would like to see it done, but until you start funding other people's music and surround systems then you can't really expect someone to abandon their budget and buy two(!) subs - and of sufficient driver-size that you deem acceptable - just to keep you happy.

In the real world people have families and have to fit AV and music around the space they have and within the budget they've set. Doubling or tripling the budget and throwing out bits of furniture just to fit in what you think they should have just isn't realistic.

hornetstinger · 29 Oct 2019 at 13:26

Simples buy one powersound s-7201 for music and another one for movies.

Or better yet so it right and not have combined and summed life plus mains otherwise it's the same as lfe + mains setting you get on bass management which messed it up (double bass)

hornetstinger · 29 Oct 2019 at 13:29

Hehehe

lucid · 29 Oct 2019 at 13:39

hornetstinger said:
Umm no it won't as your speakers are receiving filtered audio 80hz and up and life is 80hz and down PLUS you are sending it filtered 80hz and up from speaker outputs.

Bad idea. Bass frequencies will be summed so it'll be a mess.

Nope. You haven't grasped what's going on.

hornetstinger said:
I tried it a while ago but settled on sub for movies only, RCA from avr to sub only. If I had two subs I'd switch the other one off

Umm no, you didn't. The SVS SB-12-plus and the SB-13-Ultra both use the STA plate amp and it doesn't have the same feature.

hornetstinger · 29 Oct 2019 at 13:43

lucid said:
Nope. You haven't grasped what's going on.

Umm no, you didn't. The SVS SB-12-plus and the SB-13-Ultra both use the STA plate amp and it doesn't have the same feature.

I own three subs currently.
Svs SB 12 plus, in the hifi system
Svs SB ultra 13 in the av system
Wharfedale diamond sw-150 in the pc system

The SB 12 plus has 525w bash amp, the pc ultra had 750w bash amp, the SB ultra 1kw sledge amp.

The new versions of the pc ultra have a new sledge amp

The pc ultra had the bash amp, the SB ultra has the new sledge amp. As close as gonna get between sealed and ported models unless you diy.

hornetstinger · 29 Oct 2019 at 13:52

I've grasped what you're saying, when I had av and stereo system joined I ran into the same problems, so I know what you're talking about. Had av pre amp plus stereo pre amp, and wanted sub for music and movies. So RCA for lfe plus bass managed bass on RCA from av pre amp plus RCA out from stereo amp for hifi, but either way it is just bad, as combining and summing bass frequencies. The only way would be a 12v trigger and switch inputs on the sub, if such a sub existed. Or just don't bother because more hassle than its worth. Use sub for movies only with hifi floorstanders only. Eventually when I split the systems up completely that sorted it.

Also I like having two crossovers on the sub, 80hz for movies, 60hz for music, as either

A) want my sub to reproduce higher up for movies to lessen burden on the amps (not a problem now as have 300w X 7)

B) sounds better with mains reproducing higher as speakers too big for the room (not a problem now)

C) sub handles bass better than speakers and able to play louder and cleanrr

D) prefer higher crossover for movies, lower crossover for music

For music 60hz sub works for me but for movies I have it a bit higher. In the hifi it's set a lot lower as mains go low so too much overlap is bad

It could be one or more reasons on the above, all depending on room, speaker type, amplifier power, sub woofer quality, and personal bass preference.

You don't send two signals, or should I say you don't want two signals.

lucid · 29 Oct 2019 at 14:24

hornetstinger said:
I own three subs currently.
Svs SB 12 plus, in the hifi system
Svs SB ultra 13 in the av system
Wharfedale diamond sw-150 in the pc system

The SB 12 plus has 525w bash amp, the pc ultra had 750w bash amp, the SB ultra 1kw sledge amp.

The new versions of the pc ultra have a new sledge amp

The pc ultra had the bash amp, the SB ultra has the new sledge amp. As close as gonna get between sealed and ported models unless you diy.

All very interesting, but unless any of those plate amps had the ability to combine high- and low-level inputs in the way the MJ and BK subs do, then utterly irrelevant.

hornetstinger · 29 Oct 2019 at 15:04

You don't want it to combine inputs that's the point. You want one or the other not both.

lucid · 29 Oct 2019 at 15:54

hornetstinger said:
You don't want it to combine inputs that's the point. You want one or the other not both.

That's only the point with conventional subs.

The MJ and BK subs are different. That's the whole point!

hornetstinger · 29 Oct 2019 at 15:59

Even if the inputs had separate crossover and gain levels that's still not good enough.

lucid · 29 Oct 2019 at 19:45

hornetstinger said:
Even if the inputs had separate crossover and gain levels that's still not good enough.

"Good enough" By whose standards... Yours? The standards where only minimum-12" £800+ subs will do.... and the OP needs a pair?

I get the impression that nothing anyone else can suggest will be good enough according to you.

You've been participating in this thread for as long as I have. So far I don't recall seeing your suggestion of speaker switch, or come to that, any costed solutions that are going to be suitable for a person clearly working on a fairly tight budget. But hey, if you want to put forward some serious suggestions, then be my guest.

[God knows what @One More Solo is making of all this]

hornetstinger · 29 Oct 2019 at 20:16

Better than giving advice about sending two signals and summing up bass frequencies.

My solution is for have sub use with avr movies only

lucid · 29 Oct 2019 at 21:50

hornetstinger said:
Better than giving advice about sending two signals and summing up bass frequencies.

My solution is for have sub use with avr movies only

BIB: You said you understood it, and that bit in bold just proves that you don't.

jpaul · 29 Oct 2019 at 22:17

OK: but

hornetstinger said:
summing up bass frequencies

in so much that it expresses why isn't the volume of the bass elements going to be doubled up, from the sub being fed by the avr and the hifi, and is it easy to keep the levels of the bass and the rest of the spectrum in proportion - still seems a legtimate concern sorry .. really what I said earlier.

Sub connection from hifi, aside (is a lot of music genuinely produced with the equivalent of movies lfe, and if you have full range speakers down to 60hz anyway ..I've never invested)
- looks like you pick up one of these ebay for <£30 to switch speakers between amps, without losses
https://www.qed.co.uk/switching-units/ss-20-2-way-parallel-speaker-switch.html#tab1
*with* the discipline of making sure you switch on the amps exclusively.

lucid · 30 Oct 2019 at 02:00

jpaul said:
OK: but

in so much that it expresses why isn't the volume of the bass elements going to be doubled up, from the sub being fed by the avr and the hifi, and is it easy to keep the levels of the bass and the rest of the spectrum in proportion - still seems a legtimate concern sorry .. really what I said earlier.

Sub connection from hifi, aside (is a lot of music genuinely produced with the equivalent of movies lfe, and if you have full range speakers down to 60hz anyway ..I've never invested)
- looks like you pick up one of these ebay for <£30 to switch speakers between amps, without losses
https://www.qed.co.uk/switching-units/ss-20-2-way-parallel-speaker-switch.html#tab1
*with* the discipline of making sure you switch on the amps exclusively.

For a person living alone, and who has the discipline to double-declutch, then maybe. Put the same bit of gear in a house with other people, and my guess is it's only a question of when the magic smoke from one or both amps escapes.

Besides, @One More Solo has already lined up a s/h AVR with front channel pre-outs, at what seems to be a £70-cost-to-change, so why throw 50% of that budget at something that moves him further away from his final goal? Also, if we stick for a moment with @hornetstinger's idea of having to switch line level input sources to the sub, how would the QED cope with that?

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lucid · 30 Oct 2019 at 02:04

continued...

https://i.vgy.me/gHuxfw.jpg

hornetstinger · 30 Oct 2019 at 07:47

Another option is to

lucid said:
For a person living alone, and who has the discipline to double-declutch, then maybe. Put the same bit of gear in a house with other people, and my guess is it's only a question of when the magic smoke from one or both amps escapes.

Besides, @One More Solo has already lined up a s/h AVR with front channel pre-outs, at what seems to be a £70-cost-to-change, so why throw 50% of that budget at something that moves him further away from his final goal? Also, if we stick for a moment with @hornetstinger's idea of having to switch line level input sources to the sub, how would the QED cope with that?

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That means full range to the speaker in hifi mode.

Hahaha. The only other way is use high pass like a Bose system that is fine for hifi but won't work in av mode as going through two multiple sets bass management the high pass

hornetstinger · 30 Oct 2019 at 07:49

You're method is the outdated rel recommadation, this has been superceded with avr bass management.

What you are talking about will result in screwed up bass management.