hey cplkittle, or anyone else that has recently been talking about the use of ss filters in their box design......i am wondering exactly how you guys accomplish this and why you are such sticklers for using ss filters in your ported enclosure designs. i have made a decent number of ported enclosures, but i have always made them to the exact manufacturer recommendations or close to it.....do you only incorporate these filters when going out of the manufacturers range of recommended power to the subs or trying to get more spl......please elaborate on this subject as box building is a whole world in itself...
Replies (6)
Relax_The_Mind on 01/21/2004 19:27:02
SS Filters are used to block frequencies below the tuning frequency of the box. Going below that frequency can/will cause damage to the subwoofer from overexcursion. Not to mention being that the box is tuned/designed to a desired frequency the frequncies below that bar would hardly be audible. It doesnt really relate to gaining SPL.
We are such sticklers for using filters because many of us spend a couple hundred dollars on a subwoofer and a simple $25 on Passive SS filters is a lot cheaper than a new woofer or woofer repair.
I would say a majority of people are ok with many of the pre-fab ported enclosures and building them to specs as standard amp presets are fine.
For the more serious audio enthusiast SS filters are quite hand as to not blow your speakers from overexcursion because we like to play subs at the limits of their specs. Ported enclosures need a lot less power to reach is xmax than sealed boxes.
Its like if a car was tested to blow up if it went any faster than 100mph...rather than just be careful of not going over 100mph i would rather be safe and put a speed limiter on it.. Especially people who like to put 500hp engines in a pinto.
RTM
cplkittle on 01/21/2004 20:46:52
agreed
The excursion goes off the charts once you go below the tuned frequency. Say you have a sub in a ported box tuned at 35Hz. The Xmax of the sub is 15mm. At 35 Hz, your excursion will be its lowest (around 5 or 6mm) at 30 it will probably peak at the sub max of 15mm, at 25Hz, you might be looking at 30mm
20Hz = 45mm
10Hz = 110mm
it rises at an accelerated rate (theoretically) and the reason I use that term is that obviously your speaker will not exceed its maximum excursion level.
ttocs on 01/22/2004 02:55:33
subsonic filters are almost never a bad idea...
A great way to get one and make your bass a little more tunable is with the pg bass cube. It is a one band parametric eq,with a subsonic filter. I have never had a customer complain about the price or performance once it was installed.
fitz1465 on 01/23/2004 00:20:18
good info, thanks
swez on 01/24/2004 21:07:25
Agreed... SS filters are almost a must in ported enclosure to protect your woofers from over-excursion. This is especially true in high excursion subs.Don't mess this one up, or a recone is imminent!
Basically, if you tune your port to 35 Hz., and allow high power signals to reach the sub at below port tuning... the subs power handling before we reach X-max is much lower than RMS power rating... hense over-excurusion and a blown sub at even low power.
Subs go spastic below port tuned frequency! (no back pressure as in sealed enclosures) If you have high wattage going into the sub at these frequencies, the sub will self destruct.
Swez
erikcooper on 01/26/2004 00:27:14
I think my sub amp that I got for my 15 has a built in SS filter. Can anyone chek for sure? And if so should I use it?
It is the Audiobahn A1500HCQ
Replies (6)
Relax_The_Mind on 01/21/2004 19:27:02
SS Filters are used to block frequencies below the tuning frequency of the box. Going below that frequency can/will cause damage to the subwoofer from overexcursion. Not to mention being that the box is tuned/designed to a desired frequency the frequncies below that bar would hardly be audible. It doesnt really relate to gaining SPL.
We are such sticklers for using filters because many of us spend a couple hundred dollars on a subwoofer and a simple $25 on Passive SS filters is a lot cheaper than a new woofer or woofer repair.
I would say a majority of people are ok with many of the pre-fab ported enclosures and building them to specs as standard amp presets are fine.
For the more serious audio enthusiast SS filters are quite hand as to not blow your speakers from overexcursion because we like to play subs at the limits of their specs. Ported enclosures need a lot less power to reach is xmax than sealed boxes.
Its like if a car was tested to blow up if it went any faster than 100mph...rather than just be careful of not going over 100mph i would rather be safe and put a speed limiter on it.. Especially people who like to put 500hp engines in a pinto.
RTM
cplkittle on 01/21/2004 20:46:52
agreed
The excursion goes off the charts once you go below the tuned frequency. Say you have a sub in a ported box tuned at 35Hz. The Xmax of the sub is 15mm. At 35 Hz, your excursion will be its lowest (around 5 or 6mm) at 30 it will probably peak at the sub max of 15mm, at 25Hz, you might be looking at 30mm
20Hz = 45mm
10Hz = 110mm
it rises at an accelerated rate (theoretically) and the reason I use that term is that obviously your speaker will not exceed its maximum excursion level.
ttocs on 01/22/2004 02:55:33
subsonic filters are almost never a bad idea...
A great way to get one and make your bass a little more tunable is with the pg bass cube. It is a one band parametric eq,with a subsonic filter. I have never had a customer complain about the price or performance once it was installed.
fitz1465 on 01/23/2004 00:20:18
good info, thanks
swez on 01/24/2004 21:07:25
Agreed... SS filters are almost a must in ported enclosure to protect your woofers from over-excursion. This is especially true in high excursion subs.Don't mess this one up, or a recone is imminent!
Basically, if you tune your port to 35 Hz., and allow high power signals to reach the sub at below port tuning... the subs power handling before we reach X-max is much lower than RMS power rating... hense over-excurusion and a blown sub at even low power.
Subs go spastic below port tuned frequency! (no back pressure as in sealed enclosures) If you have high wattage going into the sub at these frequencies, the sub will self destruct.
Swez
erikcooper on 01/26/2004 00:27:14
I think my sub amp that I got for my 15 has a built in SS filter. Can anyone chek for sure? And if so should I use it?
It is the Audiobahn A1500HCQ
Copyright ClubKnowledge 2009 * All Rights Reserved
