Speaker sharing - automatic switch

  • 2 July 2007
  • 8 replies
  • 3608 views

Userlevel 2
Hi all,

I'm thinking of getting a Sonos system, but have a dilemma before I commit.

I hate lots of remote controls.

I currently have a DVD connected to a TV, and a universal remote control. I would like to add a pair of speakers, that is shared by the TV and the Sonos. The Sonos would ideally override the TV sound when it is switched on, therefore leaving me with only 2 remotes, and the Sonos would work as normal. This would require some sort of automatic switching device - I found a load of posts by Buzz, but unfortunately I got a bit lost. (It was quite technical, and used American phrases of which I was unsure)

The way I see it is I have two options:

1. A ZP80 and the TV connect to a line-level switch. It defaults to the TV, and when the ZP80 is called it picks that. This then passes to an always-on power amp that drives the speakers. Will this be able to detect the Z80 coming on, and will the Sonos and TV volume controls work?

2. A ZP100, and an amp for the TV. The speakers from the ZP100 and the amp connect to a speaker-level switch, which again defaults to the TV, and switches to the ZP100 when it is switched on. Will this be able to detect the Z100 coming on, and will I need a special switching amp?

Does this make sense?

Anyone's thoughts would be greatly appreciated.

Thanks!

8 replies

(It was quite technical, and used American phrases of which I was unsure)



Sorry, I try to reply in a way that will be useful to the person asking the question. All of the posts give similar information, but with some added details that I think will be useful to the latest poster.

There are different products available in different regions. I am familiar with the US products. What country do you shop in? Users from your area can help you find local products.

Either of your schemes can work, however, I recommend connecting the automatic switch to allow the TV to capture the speakers, not the SONOS. The sound detection schemes are not perfect. Detecting the TV is more reliable than detecting the SONOS.

I have some questions for you:

How many video sources do you have? You mentioned DVD, do you have Cable TV or Satellite?

Does your TV have speaker outputs?

Does your TV have a video output? (Usually labeled "monitor" or "video out".)

Are you using HDMI video connections?

---

Yes, there are "special" amplifiers that are often used in this sort of situation. Some of these units will automatically turn ON when a signal is present and turn OFF a few seconds or minutes after the signal ends. Another special feature is turning ON in response to a "12Volt trigger". The trigger is simply a voltage that some sources provide when they need the amplifier. While SONOS does not provide a 12V trigger, many home theater receivers or processors provide the trigger. A few of the automatic speaker selectors provide a 12V trigger. I'm not aware of any TV's that provide a 12V trigger, but it is common on video projectors. The main advantage of the 12V trigger or signal activation is power savings. By the way, SONOS will manage its power very efficiently.
Userlevel 2
Sorry, I try to reply in a way that will be useful to the person asking the question. All of the posts give similar information, but with some added details that I think will be useful to the latest poster.

No need to apologise - I appreciate that you tailor your answers to the specific user. The user in question seemed to fully understand - it was just me who didn't!

I'm in England, by the way.

In answer to your questions:

How many video sources do you have? You mentioned DVD, do you have Cable TV or Satellite?

I currently just have a DVD player connected by Scart to the TV. The sound plays out of the TV speakers. I may possibly add a Freview (free extra digital channels) box at some point in the future, and connect it to another Scart on the TV. This would still leave one Scart spare on the TV.

Does your TV have speaker outputs?

The TV does not have traditional speaker cable outputs (i.e. it doesn’t have the cables that go directly to the left/right speakes). It does have a headphone jack, and the third Scart can output sound via a Scart to ‘red-and-white plugs’ adaptor cable, I believe. (By ‘red-and-white plugs’, I mean the ones that go in the back of an amp.)

Does your TV have a video output? (Usually labeled "monitor" or "video out".)

I believe so, although I’d have to check. The third Scart also outputs video too, I believe.

Are you using HDMI video connections?

Nope.

Can I ask what you mean by “SONOS will manage its power very efficiently”? Does you mean that as Sonos is ‘always-on’, when it itsn’t outputting sound it uses very little electricity, so is cheap to run? Because that would be good.

Thanks for all your help – I greatly appreciate it. Sonos is going to be a big investment for me, so I want to get it right.

All the best,

Dazed & Confused
Dazed & Confused,

SONOS will switch OFF its power amplifier a second or two after the music is paused or muted or the list of tracks to be played is exhausted.

There is a version of the automated speaker switch that looks for a video signal. SCART connectors are very rare in the US. I don't know what signals are available on an average SCART connector. If your 3rd SCART connector sends out video only when the TV is ON, you could connect this video output to the automated switch and have foolproof operation.

In this arrangement the SONOS ZonePlayer would be the default system connected to the speakers and the SONOS controllers would be in full control. When the TV is turned ON, video output will be present at the SCART connector and the speakers will be transfered to an amplifier provided for the TV and the TV's remote would be in control.

All of the automated speaker switches that I've seen have a 12V trigger output. If the amplifier provided for the TV's sound accepts a 12V trigger, the amplifier will remain OFF until needed for the TV. When the TV is turned ON, the automated switch's 12V trigger will turn on the amplifier.

---

A number of us are grumpy because SONOS does not provide a 12V trigger output.
Userlevel 2
Thanks for your very comprehensive and useful reply. I think I'm getting there!

I don't know what signals are available on an average SCART connector. If your 3rd SCART connector sends out video only when the TV is ON, you could connect this video output to the automated switch and have foolproof operation.

My TV definitely has a connection that sends out video only when the TV is on. 'Foolproof' sounds good to me.

In this arrangement the SONOS ZonePlayer would be the default system connected to the speakers and the SONOS controllers would be in full control.

I guess this means I need a ZP100. How does the quality of a ZP100 and speaker switch compare to that of a ZP80, a relatively inexpensive amp, and a line switch?

I guess the advantage of the ZP100 is that it's more electrically efficient than having a shared amp for the ZP80 and the TV, which would be on all the time.

All of the automated speaker switches that I've seen have a 12V trigger output. If the amplifier provided for the TV's sound accepts a 12V trigger, the amplifier will remain OFF until needed for the TV. When the TV is turned ON, the automated switch's 12V trigger will turn on the amplifier.

That's great.

So let me get this straight:

The speaker output of the ZP100 and the amp go to the switch. The video out of the TV goes to the switch. When the TV comes on, the video out triggers the switch. The switch changes to the TV speaker cables, and it also sends a 12v signal to switch on the amp.

Is that the idea?

If it is, then:

Where do I get an 12v switchable amplifier of decent stereo quality, and how much do they cost?

Where do I get one of these switches? I'd like it to be 'plug-and-play' and of good quality, so it's not a weak link sonically.

Thanks for all your help! I would have been completely stuck otherwise.

I guess this means I need a ZP100. How does the quality of a ZP100 and speaker switch compare to that of a ZP80, a relatively inexpensive amp, and a line switch?


Not sure about the switches, but the Amp and DAC built into the ZP100 are extremely good for the price. In fact you would probably have to spend as much as the ZP100 or more on a separate amp which matched it.

The chances are if you plugged a typical £200 separates amp from Richer Sounds in you would be disappointed with the results, especially if you used the digital connection from a ZP80. This is because the ZP100 DAC is far better than the DAC in a typical £200 amp.

Of course if you need more power than the ZP 100 can give you, then an external amp is required, but I would suggest that, unless you go to expensive and carefully selected "audiophile" grade components, you would normally be better using the analogue outputs to connect the external amp.

Cheers,

Keith
Userlevel 2
Cool. Thanks for that reply. A ZP100 would be 'neater' too.

Of course if you need more power than the ZP 100 can give you, then an external amp is required, but I would suggest that, unless you go to expensive and carefully selected "audiophile" grade components, you would normally be better using the analogue outputs to connect the external amp.

Is the output of a ZP100 enough to drive some Monitor Audio BR2 comfortably? Apparantly they are 90 db/w/m sensitivity, 6 ohm, max 100 watts.

Thanks.

So let me get this straight:

The speaker output of the ZP100 and the amp go to the switch. The video out of the TV goes to the switch. When the TV comes on, the video out triggers the switch. The switch changes to the TV speaker cables, and it also sends a 12v signal to switch on the amp.

Is that the idea?


You've got it. With this scheme no user intervention is required.


Where do I get one of these switches? I'd like it to be 'plug-and-play' and of good quality, so it's not a weak link sonically.


This is where I'm going to let you down because the products that I'm familiar with are not usually available in the UK.

Niles has a very flexible switchbox.

Is the output of a ZP100 enough to drive some Monitor Audio BR2 comfortably? Apparantly they are 90 db/w/m sensitivity, 6 ohm, max 100 watts.


It's really difficult to tell from the manufacturers spec as there are no proper industry benchmarks.

These are quite sensitive speakers, which means they should produce a reasonable amount of sound from a lower powered amp.

I would have thought they would be fine, but a lot depends on other factors such as the size of the room, positioning, absorbency of your furniture, and how loud you like your music.

Cheers,

Keith

Reply