Reply With QuoteNot sure if that PPI has a subsonic filter. Is it a mono class D amp?
You really do need SSF to eliminate those frequencies below the tuning frequency of the ported box.
Does having a ported enclosure necessitate having a subsonic filter? i had a problem blowing subs (Cerwin Vega Accurate Image 12") in my ported box last summer and found out that my sub might have been trying to play sounds lower than the port frequency.
I had a PPI A600 art series driving one sub, and a PPI crossover dividing the signals.
The new setup is dual Kicker Comp VR 12"s in a large ported enclosure. The PPI crossover remains but I added a Hifonics BXD1500 with subsonic filter and remote bass adjustment.
Question;
Does the PPI have a subsonic filter?
Is a filter necessary or just a good idea?
I know that I am running more power than I should but that is the way of life
Not sure if that PPI has a subsonic filter. Is it a mono class D amp?
You really do need SSF to eliminate those frequencies below the tuning frequency of the ported box.
No the PPI amp is a stereo amp, and I am 99%sure the PPI crossover has no SSF.
I hope the new setup lasts longer than the last. I only got 5 1/2 hours of loud listening time out of it last weekend with all three amps hot as hell.
That is with 2 Trojan t-105's 6-v, and I am adding 2 more.
the less powerful amp setup with 3 Interstate 27's lasted only 2 hrs
Plus I'm adding an onboard charger.
I think I have a problem
What's your problem?
What did they tune the port to?
Too much stereo junk = Problem
Do they have a stereos Anonymous ? (sp)
Roz, what is your take on having a SSF? In how I understand they work it is a neccesity for ported but does it need/help in sealed boxes?
Chime in INTERNET STEREO PROFESSIONALS
Originally posted by BOBALOO
Roz, what is your take on having a SSF? In how I understand they work it is a neccesity for ported but does it need/help in sealed boxes?
I'm not Roz...but I'll take a shot.
A subsonic filter is not needed in a sealed box, because the sealed airspace creates a stiffer suspension. As the sub tries to reproduce the low frequencies (that humans can't hear), it attempts to travel beyond it's excursion design limits...
...but the sealed air suspension holds it back.
In a ported box, there is nothing to hold it back because the air moves freely through the port (and you can't hear the overexcursion until it's too late).
Originally posted by Havasu Hangin'
I'm not Roz...but I'll take a shot.
A subsonic filter is not needed in a sealed box, because the sealed airspace creates a stiffer suspension. As the sub tries to reproduce the low frequencies (that humans can't hear), it attempts to travel beyond it's excursion design limits...
...but the sealed air suspension holds it back.
In a ported box, there is nothing to hold it back because the air moves freely through the port (and you can't hear the overexcursion until it's too late).
Adding to HH's post...
The parameters of the speaker will determine if a speaker is suited for large, small, sealed, ported, infinite baffle, or bandpass enclosures.
The calculations for your ported enclosure are not only to find the measurements for the correct tuning of the port for a specific frequence, but are to calculate enough airspace inside the enclosure to help provide some suspension for the driver. This is why you need to know the size of your box and port in order to recommend a subwoofer. Unless you decide to replace the box....
Originally posted by rivercrazy
You really do need SSF to eliminate those frequencies below the tuning frequency of the ported box. Especially at high volume...
Thanks guys, for the very good explanation. I used the design volumes from kicker for the new sub box and have a SSF on the hifonics.
How far under the tuning freq should I cut off the low frequencies.
Or how should I go about setting it?
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