Small 2 channel audio amplifier connection

[OilStained]

Asking assistance for myself. This is to power an unknown number of speakers on the ceiling inside a shop I’m currently running it like this. It was running good for the first 3 years, starting the this year, the audio became distorted and cuts out.

Some suggestions please, budget minded. This one was from Walmart. I don’t know the specs, but I suspect it to be 20watts per channel. I can look for an upgrade, say 40 watts per channel.

Did I connect correctly or not? Should it be like my sketch drawing or something else?

 

[rstsco]

Based on your diagram, you have not connected it correctly. R +/- should go to one speaker and L +/- another. R and L are separate circuits in an amplifier.

As for how many speakers can be driven by one amp? This depends on the design of the amplifier, the impedance of the speakers, and whether they are hooked up in series or parallel.

 

[Rand]

Looks like he tried to bridge the amp into 1 channel to run multiple speakers.

The owners manual does not suggest this is possible.

you want to go
LEFT + red
left - black

and if you have more speakers
right + red
right - black

the amp is 2-8 ohm stable per channel

 

[Cujet]

With inexpensive Class D amps like that, it is best to simply have a stereo input and hook a speaker per channel. Bridging the amp is not ideal.

When you bridge this kind of amp, you prob have a stereo input with each channel having different information and you are hooking the two outputs in such a way as to use both amplifiers (each channel is an amp) in series, mono output. Not ideal, and can result in missing musical information.

There are some really superb Class D amps available now. Fosi Audio V3 or similar. And there are some good cheap ones too. Many use a 12V power supply like yours. And that brings up the point, your power supply may be bad and not the amp. Try a car battery?

 

[The_Jeff]

Unknown speakers in the ceiling? Put an ohm meter on the wires. You might have an old PA system or something with wildly non-musical impedance.

 

[OilStained]

Unknown speakers in the ceiling? Put an ohm meter on the wires. You might have an old PA system or something with wildly non-musical impedance.

An unknown number of ceiling speakers, and unknown how they are wired. It was installed in 2009, these speakers were installed to provide music.

I will take a look at the type of speakers at my next visit to the shop.

 

[OilStained]

Looks like he tried to bridge the amp into 1 channel to run multiple speakers.

The owners manual does not suggest this is possible.

you want to go
LEFT + red
left - black

and if you have more speakers
right + red
right - black

the amp is 2-8 ohm stable per channel

Yes, can I make 2 channels into one?

 

[Lubener]

Yes, can I make 2 channels into one?

You can "Y" the input side but not the output side. That would give you basically one channel. However, it worked for three years and now it's distorted. I believe the amp now has an issue because of mis-wiring it.

You say unknown amount of speakers. Your amp wants to see an impedance of 4-16 ohms. You can only parallel connect two 8 ohm speakers per channel giving an impedance of 4 ohms or series connect two 8 ohm speakers per channel giving an impedance of 16 ohms. I am assuming they are 8 ohm speakers.

 

[Rand]

His amp will work for 2 to 8 ohms
But the instructions don't mention bridging
He really needs separate wires from both speakers in the ceiling to the amp

For the best solution. Or needs to buy a new amp that supports bridging.

Also needs basic information such as how the speakers are wired and what ohms.

 

[Rand]

For a quick and easy test check the ohms of the speaker wires. not foolproof but more than we know now.

Car speakers are typically 3-4 ohms and home speakers around 8 ohms.
then of course parallel(half resistance) vs series( doubled resistance)wiring

that assumes the speakers have the same resistance.

but ideally they should at least be wired in stereo.. 2 separate sound channels.

 

[Lubener]

Best solution but most expensive is to go with a 70 v system.

 

[Arc]

Yes, can I make 2 channels into one?

I bridged an old amp like you did into one channel for a subwoofer and it worked for a while. Eventually it started sounding bad and then it died. I looked up the manual online after it stopped working and it said it wasn't bridgeable.

 

[mk378]

This is almost certainly a 70 volt system now. Unless there are a lot of speakers, you can use a small 8 ohm amp (the impedance of the system overall is more than 8 ohms) but it will not be very loud since the maximum output of the amp is only 20 volts or so.

That type of amp uses class D chips where each channel is internally a bridge. You cannot combine the channels externally either in series (bridge) or parallel. A parallel connection wouldn't gain anything anyway as you need more voltage not more current.

Since 70 volt systems are a parallel bus, a short in the wiring will result in overloading the amp and distorted sound.

 

[Rand]

This is almost certainly a 70 volt system now.

not sure how that can be concluded with the limited info given.
it could be 2 or 4 home theater in ceiling speakers..
or even old car speakers

 

[mk378]

That is plenum rated 18 ga wire, which would be typical of that type of system.

 

[Lubener]

That is plenum rated 18 ga wire, which would be typical of that type of system.

That means nothing. To be certain he has to look at the speakers for the presence of a transformer.

 

[SOUNDMAN5000]

OP, most but not all pro ceiling speakers you find in a restaurant, Doctors office, the mall etc are 70 or 100 volt speakers and may or may not be compatible or at a minimum require some over thinking and a few extra steps. Inspect the speakers and IF its 70V you will see a transformer or a dial on the front or back that should say 70V 100V.
However IF the celing speakers are designed for home use its just like a normal stereo speaker with a black and red ( -/+ )

 

[97prizm]

Asking assistance for myself. This is to power an unknown number of speakers on the ceiling inside a shop I’m currently running it like this. It was running good for the first 3 years, starting the this year, the audio became distorted and cuts out.

Some suggestions please, budget minded. This one was from Walmart. I don’t know the specs, but I suspect it to be 20watts per channel. I can look for an upgrade, say 40 watts per channel.

Did I connect correctly or not? Should it be like my sketch drawing or something else?
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The pyle looks like a car amplifier. Those typically don't work well with home audio.