Advice for tuning US Amps

[Myster 10+ year member]

I have my trusty ol' US Amps 4085 installed and need some help tuning, since I lost my manual awhile ago. The front channels are running CDT CL-61 and rear channels are running Focal Access.

I used my DMM and set the voltage to 18.4 volts front/rear.

Should I select the LPF/HPF setting? If lowpass filter is used how should I determine the frequency for front/rear ?

Sorry for the noob Q's, first time tuning myself.

thanks

-sean

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[FoxPro5 5,000+ posts]

I have my trusty ol' US Amps 4085 installed and need some help tuning, since I lost my manual awhile ago. The front channels are running CDT CL-61 and rear channels are running Focal Access.
I used my DMM and set the voltage to 18.4 volts front/rear.

Should I select the LPF/HPF setting? If lowpass filter is used how should I determine the frequency for front/rear ?

Sorry for the noob Q's, first time tuning myself.

thanks

-sean

I think you'd want to HP both of them...which just filters out the lower frequencies and allows the higher frequencies to pass...get it?? You just need to find the frequency point to start the filter. Most amps have a fixed slope of like 12-24db/oct and will go down to ~50hz so maybe start there and see if you hear the mids break up or bottom out at that point. If they do, work your way up a little...to 80hz maybe??

 

[Myster 10+ year member]

So I rechecked everything this morning and I think the front right channel is toast!

The 3 remaing channels the volts were fine but on the front right channels it was reading ~1.0v ; while the front left was @ 18.4

Is the channel toast?

Edit: Voltage was checked with my DMM while playing a 1khz sine wave / no speakers were hooked up to the amp ( speakers not wired yet)