I have a Kenwood Excelon x802-5 5 channel amplifier running 4 JL audio coaxials at 50 RMS. There is two gain controls, one for channel A and another for channel B. Each gain controls two channels. To set the gain, I used a multimeter and a 1000hz test tone at 0db. Target voltage was about 14.1. Issue is I can get close to that voltage (about 13) but if I go past a certain point on the gain, the amp starts to buzz, and the next channel jumps to about double the voltage. Is this normal? Is the amp clipping, or should I call Kenwood?
1. Does the amp play flawlessly with normal music?
2. Are you using the same signal source for normal music and the test tone?
3. Do both pairs of channels react the same?
4. Are you doing this with speakers connected?
5. Is the buzz coming from the amplifier (internally) or is it being driven into the speakers?
6. Do you have an oscilloscope?
2. Are you using the same signal source for normal music and the test tone?
3. Do both pairs of channels react the same?
4. Are you doing this with speakers connected?
5. Is the buzz coming from the amplifier (internally) or is it being driven into the speakers?
6. Do you have an oscilloscope?
1. Amp plays good with music.
2. Music is from Spotify, I believe the test tone was on mp3
3.Both channels and gain knobs react the exact same with the buzzing sound and the jump in voltage.
4. Speakers are not connected
5. Buzz is definitely from the amp, as the speakers are not connected.
6. I just ordered an oscilloscope on Amazon and I’m gonna try resetting all the gains with multiple test tones when it comes.
2. Music is from Spotify, I believe the test tone was on mp3
3.Both channels and gain knobs react the exact same with the buzzing sound and the jump in voltage.
4. Speakers are not connected
5. Buzz is definitely from the amp, as the speakers are not connected.
6. I just ordered an oscilloscope on Amazon and I’m gonna try resetting all the gains with multiple test tones when it comes.
Just a little more insight that I forgot to add. When the buzzing occurs, it only jumps voltage on one channel. The other channel stays around 13 or 14. For example, when the buzz occurs, front left channel will be at 13.1 and right front channel will be around 22.9
If you only feed the two channels that remain at the lower voltage, does the amp do anything strange?
This is a class D amplifier so it may do strange things without a load. Can you load the two channels being tested with a speaker that can handle the power, does one channel still behave oddly?
When is the scope going to arrive?
Why are you setting the gains by voltage? It's rarely usable.
This is a class D amplifier so it may do strange things without a load. Can you load the two channels being tested with a speaker that can handle the power, does one channel still behave oddly?
When is the scope going to arrive?
Why are you setting the gains by voltage? It's rarely usable.
I can try loading the two channels when the scope arrives. It should be here in like 2 days. I originally set it by voltage because it is my first install and I did not want to spend the money on a scope, and it seemed easier than doing it by ear.
What you generally do (when setting it by voltage) is to set the gains so that the head unit will never be able to drive the amp to clipping and that may be desirable for those who have far more power available than they need, it's typically not practical for most listeners. Add to that that many audio sources are not recorded to reach 0dBfs and you have some music that would never be able to get full power from an amplifier.
Even using a scope (although very good) isn't going to be perfect. Using common sense and listening for stress from any component is generally best.
One more suggestion for you and others... You can buy cheap junker scopes(DSO138 is an example, OK for audio, useless for repair) from eBay for about $25 (maybe about $50 after you buy a few more things to make it practical) and use them to monitor the output of your amplifiers in the vehicle. You could wire it and the amplifier output channels to a rotary switch (break before make) and be able to monitor any amplifier for distortion any time you change the music source or push your system to the limits. People who NEVER drive their amps to clipping would be surprised how often they actually drive their amps to hard clipping.
Even using a scope (although very good) isn't going to be perfect. Using common sense and listening for stress from any component is generally best.
One more suggestion for you and others... You can buy cheap junker scopes(DSO138 is an example, OK for audio, useless for repair) from eBay for about $25 (maybe about $50 after you buy a few more things to make it practical) and use them to monitor the output of your amplifiers in the vehicle. You could wire it and the amplifier output channels to a rotary switch (break before make) and be able to monitor any amplifier for distortion any time you change the music source or push your system to the limits. People who NEVER drive their amps to clipping would be surprised how often they actually drive their amps to hard clipping.
I would never even try to run a D-amp without a load. They don't work that way. The speaker is neccesary resistor in the circuit.
No scope will change anything about this. If you really need to do this adjustment, get some realistic load resistors, preferable 8 Ohms.
No scope will change anything about this. If you really need to do this adjustment, get some realistic load resistors, preferable 8 Ohms.