SWR Mod Idea

[father of fires]

I have an SWR SM 400S. I have been experimenting with high pass filters (or low cut filters) to clean/tighten up the low end.

I'd like to be able to use the built in crossover. I would just set the crossover point really low and run the "high" output back into the power amp.

The problem is, is that it only goes down to 100hz. I would need it to go to at least 40hz. Maybe even 30hz.

Is a mod like this possible.

Just want to throw this out there to people smarter than me.

Thoughts?

[Alex1984]

I believe what many people did was turn down the bass then use the lowest parametric to boost it up.

[Derk_Falsco]

Originally Posted by Alex1984

I believe what many people did was turn down the bass then use the lowest parametric to boost it up.

I've tried it this way and there was still enough low end to fart out my speaker cab. I tried the opposite and had great results. I used the lowest semi-parametric mid control and set it to about 35hz then killed it. Usually between -10 and -12db. Then I balanced out the low end using the bass shelf. Makes it a little awkward for the rest of the eq but luckily that eq section has overlapping frequency bands, so with a little tweaking I was able to get a nice sound without needing that 4th mid eq point. Gave me a nice tight low end without the inaudible speaker killers. Give it a try and see if it works out for you.

[Alex1984]

+1, my bad, I remembered wrong.

[BassmanPaul]

I'm not really in favour of modifying commercial designs. One day the amp will be passed to someone new who will not know how to deal with your modification. The simplest way to do what you ask is to run a high pass filter in your effects loop. Ten bucks in parts is all it needs to implement such a filter.

Paul

[father of fires]

Originally Posted by BassmanPaul

I'm not really in favour of modifying commercial designs. One day the amp will be passed to someone new who will not know how to deal with your modification. The simplest way to do what you ask is to run a high pass filter in your effects loop. Ten bucks in parts is all it needs to implement such a filter.

Paul

What? Are you saying TB members are fickle with gear?

I just figure those $10 in parts could be put inside the the amp.

I was hoping it was as easy as swapping a few caps and resistors.

[father of fires]

Originally Posted by Derk_Falsco

I've tried it this way and there was still enough low end to fart out my speaker cab. I tried the opposite and had great results. I used the lowest semi-parametric mid control and set it to about 35hz then killed it. Usually between -10 and -12db. Then I balanced out the low end using the bass shelf. Makes it a little awkward for the rest of the eq but luckily that eq section has overlapping frequency bands, so with a little tweaking I was able to get a nice sound without needing that 4th mid eq point. Gave me a nice tight low end without the inaudible speaker killers. Give it a try and see if it works out for you.

I've messed around with this before but not recently. I'll definitely give it another go.

Thanks.