DSP causes low power output from amplifier?

[ThxOne Premium Member]

For a little while I have been thinking my US Acoustics Barbara Ann has been messing up at low to medium volume levels. I use my DSP's twin knob remote to control overall system volume and sub level from the other knob. I kept my Kenwood HU at max undistorted volume no matter what. Channel 1 would output sound at like half the output of channel 2. Not until I turn the volume of the DSP up to 3/4 and up would channel 1 finally open up to the correct volume. It has been so frustrating that I was going to replace the amp. But....

Today it was acting up like normal but I decided out of the blue to turn the head unit down and crank the DSP volume. BAM!! Instantly from the lowest of audible volume to max volume the amplifier plays normal with no issues with channel 1 cutting power. I don't know why or what was causing the issue but for 5+ hours straight there have been no further issues. Can anyone explain what may have caused this? RF 3Sixty.3 DSP - Kenwood eXcelon 706S head unit. So now I am using the head unit to control overall system volume. Still using the remote for the sub level.

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[Jimg]

I know almost nothing on car audio so
I am not 100% correct on your issue

but
I have a dayton dsp 408
On the Dayton DSP the max input voltage of 3.2 volts
I have a JVC 750bt that will put out 4V clean at max volume,, so at max volume it is sending more voltage to the DSP than is recommended.

I measured the output on the head unit to be able to only turn up the volume to 32
this will give 3.2 volts at 80hz, So I set everything with 32 being max volume on the JVC

I wonder if the the dsp you are using has a max voltage input going into the DSP through the RCA's and the Kenwood at max volume is sending more voltage than the dsp can handle and causing issues.

I would check if the rockford DSP has a max voltage input.


I hope someone with more knowledge than I will respond

 

[ThxOne Premium Member]

I know almost nothing on car audio so
I am not 100% correct on your issue

but
I have a dayton dsp 408
On the Dayton DSP the max input voltage of 3.2 volts
I have a JVC 750bt that will put out 4V clean at max volume,, so at max volume it is sending more voltage to the DSP than is recommended.

I measured the output on the head unit to be able to only turn up the volume to 32
this will give 3.2 volts at 80hz, So I set everything with 32 being max volume on the JVC

I wonder if the the dsp you are using has a max voltage input going into the DSP through the RCA's and the Kenwood at max volume is sending more voltage than the dsp can handle and causing issues.

I would check if the rockford DSP has a max voltage input.


I hope someone with more knowledge than I will respond

When setting up the RF DSP it does an auto thing where it finds the max clean 2v input from the head unit. So it brings in 2v and outputs 8v. 2v on the Kenwood is volume 35 of 40. Volume 40 is 4v clean.

 

[Jimg]

I don’t know if this matters
it shows in the input sensitivity on the Barbara Ann to be 6.0 volts

so The 8v output on the dsp may be to much?

hopefull someone will confirm if this could be the issue

 

[ThxOne Premium Member]

2. Based on the input circuit of your amplifier, select either a balanced or unbalanced output for the 3Sixty.3 to match your amplifiers input. The 3Sixty.3 utilizes a special compensation network to ensure in either position the maximum output voltage is 8VRMS. For most RF amplifiers you are going to want the switch positioned in the unbalanced position.

(From the 3Sixty.3 Manual)

I don't know if it is going to affect the amp negatively. Should just make it so you have to use slightly less gain when setting the gain. I did set them with an O-scope and there was to clipping.