How in the hell do you work this thing? (1 Viewer)

[LaMarcus]

Got the PE 250 (plate amp) yesterday. I see how you hook it up to the sub, read manual to see how you hook it up the the receiver. But I see this crossover only going down to 40hz. And I heard Phil say disable the crossover on the amp. But I don't see how you can do that.

Unless your supposed to modify the crossover like the book is saying.
"Locate R26 and R27 on the pre-amp board. Using a low watage soldering iron and desolding braid, remove the two resistors."

Is this what I have to do to get to 20Hz? frowning:

 

[Marcelo T]

I had this amp for a while. You may be confounding crossover with subsonic filter. To disable the crossover, set it to the highest position. This way you will use the receiver’s crossover. The subsonic filter is a high-pass crossover, used mainly to protect the speaker from ultra-low frequencies. To alter the subsonic filter you will need to do some soldering. If you want it to go to 20hz, make sure that the subsonic filter is below that. You can check this by looking at the value of the resistors. Hope this helps.

 

[Michael R Price]

LaMarcus, the "crossover" is a lowpass filter that limits the sub's output with increasing frequency so your other speakers can take over; 40Hz is a plenty low setting for this. It means the sub will produce frequencies mainly under 40Hz. There is a switch to defeat this function, I think.

Did you receive a model with bass boost or without? If it does not have bass boost(R26 is 56K and R27 is 120K), you don't need to modify it; its response extends to 20Hz. If it does, then you may have to modify it to get acceptable sound.

 

[LaMarcus]

Mine doesn't have the bass boost. So this means I'm cool right? And turn the crossover up all the way so it will play all bass freq. Okay, gotcha, thanks fellas.

 

[Michael R Price]

Yep, you're cool.