Bass boost vs BFD question (1 Viewer)

[Wes Nance]

Hi,

I'm settling in with my Stryke 1204 PR sub, and am trying to get a handle on the sub's response in my room. It definitely drops below 25hz, and I'm sure it's a result of the 20hz f3 of the stock boost setting on my PE 250w plate amp combined with my room response.

I think eventually I'll get a Behringer Feedback Destroyer and EQ for the room, but I'm wondering if in the meantime it would be worth it to change the amp's default boost level, to a 1 or 2 db boost around 21hz or so (fb for this sub) which would net me around 4 or 5 db at 20hz.

This would bring the response level a bit more uniform throughout the range to crossover at 80hz, although I've got a big (6db or so) peak around 28hz and a big (6db or so) dip around 56hz.

Should I just wait till I have the BFD and eq everything from there?

Thanks for the help. . .

Wes Nance

 

[Wayne A. Pflughaupt]

Wes,

No need to wait for the BFD to experiment. Do whatever you think sounds best.

Regards,

Wayne A. Pflughaupt

 

[Jack Gilvey]

The 3db of attenuation at 20Hz will certainly have a noticeable/measureable effect on response. If it's not that much of a hassle, I'd certainly experiment with different amounts of boost at Fb (not below) to extend response.

 

[Wes Nance]

Jack,

Remind me how your amp is setup from Adire? I remember you saying it's 1db boost at 20hz. What is the corner frequency? I've been modeling a bunch of different values in Excel to try to come up with something that still rolls off below fb, but doesn't hurt response down to 20hz, or even has a small boost there.

Thanks-

Wes

 

[Jack Gilvey]

The stock boost/filter in the AVA250 has a Q of .96 and an Fc of 18Hz. There's a shallow, wide boost from 20Hz up to about 35Hz or so with a peak of ~1dB @ 25Hz, and an F3 of ~13Hz.

Could I trouble you for the link to that Excel program?

 

[Wes Nance]

Jack,
Thanks for the info- I figured it might be good to see what Dan came up with for the default on his version of the amp.
The link to the Excel stuff is here:Excel sheets It's the plate amp filter link. Pretty helpful.
I looked at Rudy's mod from the PE board, but I think I'm more concerned about the rolloff of the HP filter with a PR sub than the LP filter. . .
Wes

 

[Jack Gilvey]

Thanks, Wes.

 

[Wes Nance]

Jack,

I'm trying to decide whether to go for flat response from the amp, with a gentle roll off below fb, or some sort of boost.

For a "flat" response, try these values for the two resistors:

80 and 190.

For 2 db boost, what about 33 and 190?

I'm a bit leary of the PE supplied values for 2db boost, 47 and 220- I think there's too much boost below fb (21.5hz) for my sub.

I may just go for the "flat" response, and then fix everything else eventually with a BFD.

Wes

 

[Jack Gilvey]

I may just go for the "flat" response, and then fix everything else eventually with a BFD.

That's probably your best bet since it's much easier to experiment with eq with the BFD than it is soldering resistors. I think your focus with the amp should be to get the infrasonic filter where it'll do the most good , and use the BFD for eq functions.