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Two amps - one set of speakers

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Teeza's picture
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Teeza's picture
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RE: Two amps - one set of speakers

[Third time lucky? - why does this site keep losing the body text?]

I have an AV amp and 5.1 speaker set-up used for all sources but I don’t like the sound with music.

I have another amp that I prefer for music listening but I only have room for one set of speakers.

What is the best way to enable both amps to output to the single set of speakers (not simultaneously)?

All suggestions gratefully received.

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RE: Two amps - one set of speakers

If your receiver has pre outs . . Then

 

http://www.whathifi.com/video/how-to-add-hi-fi-to-your-home-cinema

 

On the very site Smile

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RE: Two amps - one set of speakers

Thanks Ryan. [Couldn't see anything using IE - switched to Firefox and all OK.]

That's something I could try BUT is it the only option?

Presumably that could "unbalance" the sound with movies as the main fronts will be driven by the music amp.

Could the spare (bi-amping) terminals on the speakers be utilised (without removing the jumpers)?

Is there a such a thing as a speaker switch box or splitter?

 

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RE: Two amps - one set of speakers

Teeza wrote:
Presumably that could "unbalance" the sound with movies as the main fronts will be driven by the music amp.

Not really: either the AV receiver's automatic set-up will take care of this, or you can adjust levels manually in the receiver's set-up menus. And some stereo amps are desined with a 'unity gain' or 'AV bypass' input for just this purpose.

Teeza wrote:
Could the spare (bi-amping) terminals on the speakers be utilised (without removing the jumpers)?

No – that'll connect the receiver and the amp together, and runs a serious risk of blowing the output section on one or both of them.

Teeza wrote:
Is there a such a thing as a speaker switch box or splitter?

There's one made by US company Niles, but it seems hard to come by, and Beresford makes one, but I haven't tried it.

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RE: Two amps - one set of speakers

Not too difficult to throw together a basic two-way speaker switcher which only connects one amp at a time to your speakers,  You can even cobble one together from a two-gang two-way light switch from B&Q/ebay etc.  You only need to switch the +ves, the returns can stay connected.  Or if you feel you really must disconnect the -ves too, buy a four-gang two-way switch.

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RE:Two amps-one set of speakers

Andrew Everard wrote:

Not really: either the AV receiver's automatic set-up will take care of this, or you can adjust levels manually in the receiver's set-up menus. And some stereo amps are desined with a 'unity gain' or 'AV bypass' input for just this purpose.

Perhaps "unbalanced" was a poor choice of adjectives - I was thinking more in terms of tonal quality. Something to trial I think.

Andrew Everard wrote:

No – that'll connect the receiver and the amp together, and runs a serious risk of blowing the output section on one or both of them.

Good point Andrew - well received.

 

Andrew Everard wrote:

There's one made by US company Niles, but it seems hard to come by, and Beresford makes one, but I haven't tried it.

 

The Niles product wouldn't win any beauty contests! The Beresford has a couple of good reviews linked to the site, it seems well priced and is (a little) prettier. Worth considering.

 

 

 

Does anyone have one of these units?

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RE: Two amps - one set of speakers

MajorFubar wrote:

Not too difficult to throw together a basic two-way speaker switcher which only connects one amp at a time to your speakers,  You can even cobble one together from a two-gang two-way light switch from B&Q/ebay etc.  You only need to switch the +ves, the returns can stay connected.  Or if you feel you really must disconnect the -ves too, buy a four-gang two-way switch.

 

You are probably right but as I don't even seem able to post text to this forum without either losing it, duplicating it or failing to quote !- I'll leave that to people with more fingers than thumbs!

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RE: RE:Two amps-one set of speakers

Teeza wrote:
Perhaps "unbalanced" was a poor choice of adjectives - I was thinking more in terms of tonal quality. Something to trial I think.

Indeed, but provided you're using a receiver with automatic set-up and equalisation, that should take account of any difference in tonality between the amp and the receiver, and adjust the receiver's front-channel EQ accordingly

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RE: RE:Two amps-one set of speakers

Teeza wrote:

Andrew Everard wrote:

Not really: either the AV receiver's automatic set-up will take care of this, or you can adjust levels manually in the receiver's set-up menus. And some stereo amps are desined with a 'unity gain' or 'AV bypass' input for just this purpose.

Perhaps "unbalanced" was a poor choice of adjectives - I was thinking more in terms of tonal quality. Something to trial I think.

There are a number of people running this kind of setup on here, none of them have an issues around tonal matching.

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RE: RE:Two amps-one set of speakers

The_Lhc wrote:
There are a number of people running this kind of setup on here, none of them have an issues around tonal matching.

Including me: Onkyo TX-SR875 (at the moment) into the Naim SuperNait's unity gain AV input, and it works splendidly for movies, while taking the elderly Onkyo out of the equation when streaming music.

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RE: Two amps - one set of speakers

Andrew Everard wrote:

Indeed, but provided you're using a receiver with automatic set-up and equalisation, that should take account of any difference in tonality between the amp and the receiver, and adjust the receiver's front-channel EQ accordingly.

The_Lhc wrote:

There are a number of people running this kind of setup on here, none of them have an issues around tonal matching.

Andrew Everard wrote:

Including me: Onkyo TX-SR875 (at the moment) into the Naim SuperNait's unity gain AV input, and it works splendidly for movies, while taking the elderly Onkyo out of the equation when streaming music.

It’s not that I don’t believe you (I do!) but I find this somewhat counter-intuitive. Amps can have such different and distinct voices that I find it hard to accept that auto-equalisation can turn a humble device into an electronic mynah bird. Is mimicry just careful equalisation?

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RE: Two amps - one set of speakers

Teeza wrote:
It’s not that I don’t believe you (I do!) but I find this somewhat counter-intuitive. Amps can have such different and distinct voices that I find it hard to accept that auto-equalisation can turn a humble device into an electronic mynah bird. Is mimicry just careful equalisation?

The equalisation will endeavour to achieve a flat frequency response, so if the stereo amp in use has a distinctive character, the EQ will adjust the frequency response of the affected channels to flatten things out again as well as it can.

It does this just as it will boost the gain of the front channel outputs should the stereo amp not deliver as much gain as the amps inside the receiver used for all the other channels, and compensate should the amp introduce some delay into the chain (which the receiver will 'see' as the front speakers being further away, invert phase, and so on.

Of course this will only affect the operation of the system when in home cinema mode, and will have no effect on how the stereo amp sounds when playing music.

And before anyone else asks – what's your receiver, stereo amp and speakers?

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RE: RE:Two amps-one set of speakers

Teeza wrote:

The Beresford has a couple of good reviews linked to the site, it seems well priced and is (a little) prettier. Worth considering.


Does anyone have one of these units?

Hi Teeza, I have one and have been very pleased with it from day one. I personally felt it made a noticeable difference with the front stage, but then again I never made any effort to do any kind of ABX testing etc. In hindsight I do also wonder if I'd put enough effort into the Audessey set up previously, which benefited greatly from spending time gettin right. 

What did make me uncomfortable using the AVR/stereo combo was the amount of time it meant my stereo amp was on, which is Class AB and produces more heat than the Onkyo! As my stereo amp has no remote, other members of the family would invariably leave it on overnight which would get my goat up also!

 

 

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RE: RE:Two amps-one set of speakers

margetti wrote:

Hi Teeza, I have one and have been very pleased with it from day one. 

 

Thanks Margetti. Can you confirm one thing it said in the review that is absent from the manufacturers site:

 

Although only one amp can be switched through at any one time (this is OK) the reviewer said that amp could then feed both sets of conected speakers - is that right? Can buttons A & B be in the "on" position at the same time?

 

I think we all have issues with training our families how to operate our kit. Roll on the invention of the remote that can read minds!

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RE: Two amps - one set of speakers

Andrew Everard wrote:

The equalisation will endeavour to achieve a flat frequency response, so if the stereo amp in use has a distinctive character, the EQ will adjust the frequency response of the affected channels to flatten things out again as well as it can.

 

I've just re-watched the video and it does suggest there could be issues with tonal matching. Glad it does not affect your set-up. I think I just need to try it out. The next problem is access to the back of my kit - don't know any anorexic contortionists by any chance?