Whats A Subsonic Filther?

[Denis22]

what's a subsonic filther and what's phase 0/180

i have a rockford punch 1000/1 amp its a older one i think like 2000-2003 model and i'm just trying understand its functians

[iceman88]

if im not wrong i had one of these on my Vibe Monobox 4 amp and it cancels out frequencies below 30 hz

[LSN2meBoom916]

A subsonic filter limits the frequencies the sub amp will play/allow through, and it varies based on what amp you have. Some go as low as 15-10hz most have a low side of 15hz or so. It's so you're smaller subs or subs that have limitations based on the box you've built can play louder than if they were "fighting to reproduce" a freq. that is technically out of it's limitations/abilities to make.

If you have 10's that can only get down to 30hz based on their freq response or the tuning of box, or other factors/etc, you can actually play them louder if you lessen the the strain on them by not asking them to play the freq's that cause them to bottom out. This is done by setting the LOWER limit of your subsonic filter accordingly.

Phase has to do with the subs being wired together or oppsing each other in terms of Pos/neg. I posted a Lengthy response on phase Q's a while back:

http://www.stevemeadedesigns.com/board/ind...p;p=entry

Lemme know if that doesnt clear it up.

[Denis22]

yeah that's helps but how do i find out what the box is doing like hz stuff i'm so lost on that part... sorry

[LSN2meBoom916]

Unless you have access to some Test/Audio equipment: (TL mic/sensor/laptop/RTA (real time analyzer))...

The cheapest easiest way is to do this:

Find a TEST TONE CD w/ KNOWN frequencies on it, in as SMALL of increment changes as possible from track (i.e. track one=a tone or sweep 0hz-10hz, track 2= tone or sweep from 11hz-20hz, etc on up through about 200hz or so is all you'd need for your bass/midbass/midrange.

If you can't "mic it" while you're going through the tracks...

Just listen as best you can and try to dtermine where the "good bass" and "bad bass" freq's are for your system and note what tracks/HZ's are beyond the abilities of your setup...

On a mic/TL/laptop/RTA it would all be on the screen-you just gotta do it by ear in this case-

(this would show you your peak freq, and what freq's don't play so well on your setup so you know where to filter the low end amplification/x-overs)

So once you know what tracks, and thus what freq's are not ok on your setup, set ur subsonic filter AT or JUST ABOVE the HIGHEST freq that stresses your system TOO much and it will thus be prevented from playing ALL those dangerous/stressful freq's BELOW that freq. Wherever you set it, will be It's LOWER LIMIT, and it will only play bass of that freq and ABOVE.

Once that's done, assuming you're powering it all properly and not in danger of roasting anything, CRANK THAT BEEZY and enjoy!