Amp goes into protection mode at high volume

[Hotbred]

Arghhhh. I had a person set up 4 ceiling speakers in my kitchen that are controlled through a volume control knob. Here’s my set up:

4 Polk Audio RC80i ceiling speakers

Sony STR K750P

1 Volume control knob

The receiver runs two pairs of speaker wire from front channels on the back of the receiver to the input channels of the volume control knob. From there, I run 4 pair of speaker wire from two output channels on the volume control knob to the 4 speakers. I have tried hooking the up wires parallel and as a two separate series from the volume control knob output to the 4 speakers. No matter what I do, it put the receiver into PROTECT mode once I turn the volume up to a level where it’s above talking level.
I can’t figure out what I am doing wrong. The speakers are compatible with an 8ohms receiver and 20-100watts. The receiver is capable of 8-16 ohms and powers 100watts per channel.
I blew one receiver already and bought this Sony used. Both receivers are doing the same thing.
Please help!!!!

 

[TLS Guy]

Arghhhh. I had a person set up 4 ceiling speakers in my kitchen that are controlled through a volume control knob. Here’s my set up:

4 Polk Audio RC80i ceiling speakers
View attachment 53736

Sony STR K750P
View attachment 53737

1 Volume control knob

The receiver runs two pairs of speaker wire from front channels on the back of the receiver to the input channels of the volume control knob. From there, I run 4 pair of speaker wire from two output channels on the volume control knob to the 4 speakers. I have tried hooking the up wires parallel and as a two separate series from the volume control knob output to the 4 speakers. No matter what I do, it put the receiver into PROTECT mode once I turn the volume up to a level where it’s above talking level.
I can’t figure out what I am doing wrong. The speakers are compatible with an 8ohms receiver and 20-100watts. The receiver is capable of 8-16 ohms and powers 100watts per channel.
I blew one receiver already and bought this Sony used. Both receivers are doing the same thing.
Please help!!!!

So, you are about to blow another receiver. What are your volume controls and speakers? I suspect that you did not use impedance matching volume controls. I guess this installation has exceeded your competence, so post graduate education is required.

 

[lovinthehd]

An avr isn't the best tool for the job, but more info about the volume control and use might help. Is the volume control for all four speakers simultaneously or each individually or what? I suspect you'd do better just using the avr's volume control, and play some sort of all channel mode in mono (if possible with that avr). Why four speakers in a kitchen?

 

[Hotbred]

An avr isn't the best tool for the job, but more info about the volume control and use might help. Is the volume control for all four speakers simultaneously or each individually or what? I suspect you'd do better just using the avr's volume control, and play some sort of all channel mode in mono (if possible with that avr). Why four speakers in a kitchen?

The kitchen is a wide open design. Quite long.

The volume control knob controls all 4 speakers.
The knob says it can handle up 8 speakers.

An avr isn't the best tool for the job, but more info about the volume control and use might help. Is the volume control for all four speakers simultaneously or each individually or what? I suspect you'd do better just using the avr's volume control, and play some sort of all channel mode in mono (if possible with that avr). Why four speakers in a kitchen?

The kitchen is a wide open space that is fairly large.
The volume control knob says it can handle multiple speakers and it is being used to control all 4 simultaneously. I changed the jumper settings to reflect the impedance but it still cut the receiver out.

I think the guy who put it in used 18g wire from the speakers to the volume control knob. I am also wondering if the connection in one of the speakers isn’t connected well as I heard this can cause the receiver to cut out too. I separated my shoulder a week ago so I can’t pull them out of the ceiling to check.

I may just hook up two speakers instead and see if that works and leave two dead. Waste of a couple good speakers.
I’d rather not have to use the volume control on the receiver cause it’s in my basement. I guess I could buy a bluetooth adaptor for it.

 

[lovinthehd]

What is the specific make/model of this volume knob? I doubt the gauge of speaker wire is the particular issue, but rather all the speakers on the one pair of amp terminals. Some avrs can be controlled by wifi apps or even a RF controller. Four speakers can be a waste, especially if you're trying for some sort of stereo image to be proper anywhere in the kitchen....it just won't be. Better to use mono, and two just may work fine.

 

[Hotbred]

I have no idea what kind of volume knob is. There’s no brand name or model number.
I’m guessing there are impedance issues by tying two speakers together and that is what is screwing it up.

 

[Hotbred]

What is the specific make/model of this volume knob? I doubt the gauge of speaker wire is the particular issue, but rather all the speakers on the one pair of amp terminals. Some avrs can be controlled by wifi apps or even a RF controller. Four speakers can be a waste, especially if you're trying for some sort of stereo image to be proper anywhere in the kitchen....it just won't be. Better to use mono, and two just may work fine.

Would something like a yamaha R S202 work better for what I am trying to do?
I sourced the problem. I bypassed the volume control knob and only ran two speakers into the receivers 2 front channels and it works great.
Either the switch is not the right one or it’s faulty. I tried only running 2 speakers through the volume control knob and it still cut out. Has to be a problem with the switch.
The yamaha I’m looking at looks like it can support 2 sets of speakers to be either ran on their own a&b or all four together.

 

[lovinthehd]

Better to use a multi-ch amp than a two-ch amp for four speakers. A receiver like the R202 still is just a 2ch amp....running four speakers presents possible impedance load problems, and should have a warning in the manual or on the connection panel about when you run 4 speakers instead of 2 accoringly, depending on impedance. Still, running two pair of 2ch stereo speakers has other acoustic issues, still better to run mono, or just use two speakers for stereo if you can really get the imaging.

 

[mono-bloc]

Your problem is in the way the speakers are connected series or parallel. The chances are your running with a 4 ohm or lower load. Which your AVR simply can't handle
As for your stated output load of the AVR at 100 watts, That's with ONE channel driven. In reality your AVR is probably producing something like 25 watts per channel. with all channels driven. You say everything works with only two speakers connected, That's simple because it's not working hard and probably only has a 8 ohm load to contend with.

 

[TLS Guy]

I have no idea what kind of volume knob is. There’s no brand name or model number.
I’m guessing there are impedance issues by tying two speakers together and that is what is screwing it up.

I would bet that volume control is your problem. My bet is that it is not an impedance matching control, or if it is, it is not wired correctly.

If you don't understand then you need to hire a competent pro. That will be cheaper than blowing receivers.

 

[highfigh]

The kitchen is a wide open design. Quite long.

The volume control knob controls all 4 speakers.
The knob says it can handle up 8 speakers.


The kitchen is a wide open space that is fairly large.
The volume control knob says it can handle multiple speakers and it is being used to control all 4 simultaneously. I changed the jumper settings to reflect the impedance but it still cut the receiver out.

I think the guy who put it in used 18g wire from the speakers to the volume control knob. I am also wondering if the connection in one of the speakers isn’t connected well as I heard this can cause the receiver to cut out too. I separated my shoulder a week ago so I can’t pull them out of the ceiling to check.

I may just hook up two speakers instead and see if that works and leave two dead. Waste of a couple good speakers.
I’d rather not have to use the volume control on the receiver cause it’s in my basement. I guess I could buy a bluetooth adaptor for it.

Some volume controls use resistors, some use a part for each speaker that's a transformer with the usual primary winding on the front end and multiple 'taps', or discrete windings for the output level. You need to find out which type was used and make sure the amp isn't connected to the wrong side of the control. It happens.

If you're cranking the Sony's volume control and keeping the wall-mounted control at a very low setting, you're doing it wrong and you're wasting power. When you do that, the control will become hot and if it's operating that way for a long time, it overheats, the resistance changes and it can fail. I had to take a stereo receiver in for service because the volume control in the homeowner's kitchen shorted and killed the amplifier.

These volume controls are made for background audio, not balls out, high SPL operation. Best way to achieve that involves multi-channel amplification and some way to control the level for each speaker or pair of speakers. Unfortunately, the control for this is usually near the amplifier because sending line level audio to a control and back to the amp is far more likely to pick up noise, so equipment like the dbx ZOne Pro exists, which uses a control voltage from the keypad to adjust the level at the source end.

 

[slipperybidness]

I guess this installation has exceeded your competence, so post graduate education is required.

I'm gonna have to remember that and use it! LOL, that is classic, thanks for a chuckle.

 

[slipperybidness]

Arghhhh. I had a person set up 4 ceiling speakers in my kitchen that are controlled through a volume control knob. Here’s my set up:

4 Polk Audio RC80i ceiling speakers
View attachment 53736

Sony STR K750P
View attachment 53737

1 Volume control knob

The receiver runs two pairs of speaker wire from front channels on the back of the receiver to the input channels of the volume control knob. From there, I run 4 pair of speaker wire from two output channels on the volume control knob to the 4 speakers. I have tried hooking the up wires parallel and as a two separate series from the volume control knob output to the 4 speakers. No matter what I do, it put the receiver into PROTECT mode once I turn the volume up to a level where it’s above talking level.
I can’t figure out what I am doing wrong. The speakers are compatible with an 8ohms receiver and 20-100watts. The receiver is capable of 8-16 ohms and powers 100watts per channel.
I blew one receiver already and bought this Sony used. Both receivers are doing the same thing.
Please help!!!!

So, this person that set it up for you, what did they say when you told them about the problem?

I certainly hope you didn't PAY somebody for installing your problems.

 

[Pogre]

Check for damage to your speaker cables or for stray strands of wire at your connection points.

*Edit: okay yeah. Might not have the right unit for the job in a stereo receiver too...

 

[highfigh]

Check for damage to your speaker cables or for stray strands of wire at your connection points.

*Edit: okay yeah. Might not have the right unit for the job in a stereo receiver too...

Between the receiver and VC, that would cause the protection to trigger immediately, between the VC and speakers, maybe.

 

[Pogre]

Between the receiver and VC, that would cause the protection to trigger immediately, between the VC and speakers, maybe.

Yeah, after I read some more I realized this isn't a typical ht setup and above my paygrade, lol.

 

[highfigh]

Yeah, after I read some more I realized this isn't a typical ht setup and above my paygrade, lol.

It's actually pretty simple, but the installer doesn't seem to know that the DC resistance should be checked from the amplifier end BEFORE any connections are made. That's mandatory if someone doesn't want to puke an amplifier and it was the first thing I did before reinstalling the receiver after it was repaired. I saw a dead short on one channel, then checked it at the VC end, finding that the speakers were fine, it just had a dead VC.

Also, the fact that the VC has impedance jumpers doesn't mean the amplifier will be happy.

 

[BMXTRIX]

I'm blown away that you had an installer put in a standard AV receiver instead of a proper distribution amplifier rated to handle a 4 ohm load and that you have no idea what volume control is being used. That should have been on your Bill of Materials when you purchased things. Since the volume control is one of the most critical pieces of a multi-speaker setup and the amplifier is as well. The speakers are almost secondary. At the price you likely paid for them, you deserve to have a name brand volume control that can handle the power going through them along for the ride.

Not knowing the speaker gauge is not great either. I would expect at least 16 gauge as a minimum. That should have been specified up front.

At this point, the basics you can do are to pull the speakers out of the ceiling and to pull the volume control out of the wall. Speaker gauge will be written on the speaker wire housing. If it doesn't have a jacket on the speaker wire, then you potentially hired someone without the proper experience for this type of work.