Speaker switches/distribution

scola77

scola77

Out on the Tiles
I want to distribute a vintage 2 channel pre-amp (125 watts per channel) to 2-3 sets of speakers + powered sub. The speakers are your typical 2-way coaxial in-wall speakers, and are rated at max 150 watts and 8 ohm. I am looking at adding a speaker switch/selector. Most of the time I will be using 1-2 pairs of speakers. Occasionally I would use the 3rd pair (outdoor).

Will I notice a degradation of sound quality by using a switch/selector? Is there a switch the community can recommend that is both cost effective and quality built?

Just trying to find a way to use this old receiver in a modern "home theater" setup.
 
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I really cant hear a degradation in sound quality when using a decent speaker selector, but I admit that through measurements its probably there. Note: I've only used one pair at a time.
 
Adcom GFS-3 speaker selector, or one of it's GFS-* mates... the number is the number of speaker sets it can handle. Contains a protection circuit if you energize more than 2 pair at a time.
 
What you need to be aware of is the total load presented to the amp's output.

A single pair of 8Ohm speakers present 8Ohms load. A pair of such speakers in parallel, present 4Ohms. Three pairs of such speakers present a reduced load of 2.6Ohm.

All these values are nominal and many speakers have an irregular impedance plot with even less load at certain frequencies.

Most amps are rated for a minimum of 4Ohms load and the less the impedance the higher the current the amp must feed to the speakers. The amp may not be able to deliver that.

Now, if even one of the speaker pairs is rated at 4Ohm nominal, then it's a whole different story and most amps will fail to driver the three pairs at higher volume levels.
 
scola77 said:
I want to distribute a vintage 2 channel pre-amp (125 watts per channel) to 2-3 sets of speakers + powered sub. The speakers are your typical 2-way coaxial in-wall speakers, and are rated at max 150 watts and 8 ohm. I am looking at adding a speaker switch/selector. Most of the time I will be using 1-2 pairs of speakers. Occasionally I would use the 3rd pair (outdoor).

Will I notice a degradation of sound quality by using a switch/selector? Is there a switch the community can recommend that is both cost effective and quality built?

Just trying to find a way to use this old receiver in a modern "home theater" setup.
Click to expand...

A couple notes to add:

1 - If it's putting out 125 watts per channel, it's not a preamp, it's probably a receiver or an integrated amp.

2 - We'd need more info on the powered sub to tell you how you should/could hook that up. Make/model/inputs/outputs/controls/etc.

3 - I've always heard a degradation in sound quality using speaker selectors, but with coaxial in-walls I'm not sure it will matter much. Generally I hear a loss of high frequencies and stereo seperation.

4 - Multiple speakers in stereo doesn't really make for a "home theater" setup. Multiple speakers in the same room running the same signals actually cancel out different frequencies depending on where you are in the room.

5 - I currently have Radio Shack, Niles and Adcom selectors. This particular Radio Shack model is cheap and flimsy, with light-gauge connectors and no load resistors. The Niles has load resistors, dual amp inputs and individual volume controls; but the removable I/O connectors can be annoying. The Adcom has large resistors and decent twist-lock connectors.

6 - When these load resistors are in line to protect your amp, they're also wasting a percentage of your amp's power. If the 125W rating you mention is a realistic spec, you'll probably be fine for what you're describing. If 125W is the amp's draw from the wall, your actual WPC rating is substantially less, and you might not get the sound level you desire once it's trying to push 6 speakers through load resistors.

7 - When installing the outdoor speaker, be careful to think about water accumulation. My general practice has always been to run outdoor speakers from a dedicated amp that I didn't care about, since most of the hundreds of outdoor installations I've done have had some kind of issue during their lifetimes (critter damage, landscaper damage, corrosion, water, etc.). Unless you can do a good job at controlling their environment (under an overhang in a screened-in porch is "outdoor", but pretty controlled), carefully check the load on the speaker wire before firing them up with any valuable amp.

Have fun...

je
 
Fred Sanford said:
A couple notes to add:

1 - If it's putting out 125 watts per channel, it's not a preamp, it's probably a receiver or an integrated amp.

2 - We'd need more info on the powered sub to tell you how you should/could hook that up. Make/model/inputs/outputs/controls/etc.

3 - I've always heard a degradation in sound quality using speaker selectors, but with coaxial in-walls I'm not sure it will matter much. Generally I hear a loss of high frequencies and stereo seperation.

4 - Multiple speakers in stereo doesn't really make for a "home theater" setup. Multiple speakers in the same room running the same signals actually cancel out different frequencies depending on where you are in the room.

5 - I currently have Radio Shack, Niles and Adcom selectors. This particular Radio Shack model is cheap and flimsy, with light-gauge connectors and no load resistors. The Niles has load resistors, dual amp inputs and individual volume controls; but the removable I/O connectors can be annoying. The Adcom has large resistors and decent twist-lock connectors.

6 - When these load resistors are in line to protect your amp, they're also wasting a percentage of your amp's power. If the 125W rating you mention is a realistic spec, you'll probably be fine for what you're describing. If 125W is the amp's draw from the wall, your actual WPC rating is substantially less, and you might not get the sound level you desire once it's trying to push 6 speakers through load resistors.

7 - When installing the outdoor speaker, be careful to think about water accumulation. My general practice has always been to run outdoor speakers from a dedicated amp that I didn't care about, since most of the hundreds of outdoor installations I've done have had some kind of issue during their lifetimes (critter damage, landscaper damage, corrosion, water, etc.). Unless you can do a good job at controlling their environment (under an overhang in a screened-in porch is "outdoor", but pretty controlled), carefully check the load on the speaker wire before firing them up with any valuable amp.

Have fun...

je
Click to expand...

It is an integrated amp - my bad. Great advice though, thanks.
 
Fred Sanford said:
You're welcome. Now give us the answers to #2! :banana:

je
Click to expand...

It is a Yamaha model YST-SW315, 80 watts (it says 80 watts on the back, but all the documentation suggests 250). It has multiple inputs and outputs.

2 pairs of left/right main inputs (from amp) and 2 pairs of left/right main outputs (to speakers). It also has an RCA style input for the subs for both left and right channels.

yamaha_yst_sw315-400-400.jpg


yamaha-yst-sw315.1122104.jpg
 
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scola77 said:
It is a Yamaha model YST-SW315, 80 watts (it says 80 watts on the back, but all the documentation suggests 250). It has multiple inputs and outputs.

2 pairs of left/right main inputs (from amp) and 2 pairs of left/right main outputs (to speakers). It also has an RCA style input for the subs for both left and right channels.

yamaha-yst-sw315.1122104.jpg
Click to expand...

Gotcha. Ok, then...

Keep in mind that whatever you do to balance this sub in with one pair of speakers will have to be adjusted again when you run two pair of speakers...and then again when you add the third pair of speakers & the load resistor. Your amp's load will change each time, and the level balance between sub & room speakers will therefore also change.

Most subs like this (but not all) will have a high-pass crossover in between the speaker-level inputs and the speaker-level outputs. This would take some of the low-frequency information out of the signal gong to your full-range speakers. This is usually a good thing, so your full-range speakers work less & let the sub do its thing. I would probably try wiring my main (most-often used) speakers this way. An exception to that might be if you wanted the speaker selector to be able to defeat/silence the sub entirely.

The Adcom suggestion should work for you, if you're not looking for volume controls to balance the levels between speakers. Niles and Russound and others make alternatives.

Another option (depending on your Integrated Amp) would be to take a preamp-out signal to the sub...don't know if your Integrated Amp has those jacks, though. Tape output won't work well, as it's a constant level output...you want something that varies with the main volume control's setting.

je
 
The Adcom GFS-3 also has a dedicated headphone outlet.
My system did not have one previously.
I run KLH 17's & Dynaco A-10's.
I got mine on flea-bay with a BIN for $19.


Steve
 
I used to own that same Yamaha sub, and ran it from both the speaker level and line level inputs with different set-ups. I had it adjusted to only produce the frequencies below where my main speakers rolled off. If your amp has pre-outs, that's where I would connect the sub. I can vouch for the Adcom switches too, I have one of their 6 speaker switches. I've also owned switches from Niles and Russound, and the Adcom is the one you want.:yes: I use mine to power satellite speakers in different rooms of the house. It definitely cuts the high frequencies when the protection switch is engaged, but since I'm only running multiple pairs when having a party, etc., it isn't an issue for critical listening.
 
P. Shivers said:
I used to own that same Yamaha sub, and ran it from both the speaker level and line level inputs with different set-ups. I had it adjusted to only produce the frequencies below where my main speakers rolled off. If your amp has pre-outs, that's where I would connect the sub. I can vouch for the Adcom switches too, I have one of their 6 speaker switches. I've also owned switches from Niles and Russound, and the Adcom is the one you want.:yes: I use mine to power satellite speakers in different rooms of the house. It definitely cuts the high frequencies when the protection switch is engaged, but since I'm only running multiple pairs when having a party, etc., it isn't an issue for critical listening.
Click to expand...

To really complicate matters (and hijack my own thread), how would you address a quad integrated amp (4 main speaker outs and 4 remote speaker outs)? In this scenario I would technically not need a switch, but I would still have to hook it up to the subwoofer. The quad amp I am considering now is a Marantz 4400, and it does have pre-outs. Going the pre-out route would kill the speaker outputs on the 4400 and then require a switch coming off the sub, correct? Or I could hook the sub up only to the main fronts outputs on the marantz and then connect the main front speakers directly to the sub (other speakers would connect directly to the 4400).

At the risk of sounding simplistic, which way is more gooder? :D

By the way guys, thanks to everyone who is helping out. I am extremely grateful to the advice given here!

marantz4400w6.jpg
 
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