Subsonic Filter?

Hey guys, i'm just lookin at the spec sheet on my sub, to make a box, and it says to use a subsonic filter for the box I was looking at. What is a subsonic filter, and why would I use it with a ported box?1990 Honda Civic HB:

Clarion DXZ545MP H.U.

2- 6.5" Power Acoustik interiors

Diamond Audio 600.1 amp

Diamond Audio 15" M6MKII

Pyramid PB881X 4 CH. Amp

this is wierd. the 15" sub (the one i have) has a lower xmax than the 12 and the 10 inch versions. the 10 inch version has the highest actually. 18.3mm for the 10" sub, only 16mm for the 15" is that wierd to anyone besides me?1990 Honda Civic HB:

Clarion DXZ545MP H.U.

2- 6.5" Power Acoustik interiors

Diamond Audio 600.1 amp

Diamond Audio 15" M6MKII

Pyramid PB881X 4 CH. Amp

A subsonic filter is used to filter out certin notes. Usually its used to block any Hz levels under 20. The human ear cannot hear anything under 20Hz, yet some songs have notes below that. The subsonic filter removes these notes so the amp and subs do not need top work at making notes we cannot hear. Quite a few amps have these, im not sure if you can get one to add on to a amp or not. Im also not sure why they would recommed this when dealing with a box. Maybe someone else can shed some light on that matter.

For ported enclosures, best power handling performance and maximum speaker protection is obtained by using a sub-sonic (basically a high-pass filter) just below the port tuning frequency.  For sealed enclosures, a subsonic is used simply to keep very low frequencies from eating up amplifier power since the woofer cone remains dampened.  They are also called rumble filters.  If your amp or crossover or line driver does not have one built in, there are a few stand-alone filters available (Harrison Labs makes a nice one.)Support the12volt.com

thapimpfromchi wrote: i have a knob for sub bass.. is that the same thing?

Probably not, but what's the amp?

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no.    the knob is a gain control...you should have a crossover on your amp settings....As far as the excursion goes.   alot of sub makers are like this.   hell my eclipse's are light that, I have seen most audiobahn subs are like that as well...2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR

2007 USACI World Champion

2007 World Record

2006 USACI Finals 2nd Place

no, not the gain control. its got a sub bass knob too. its a Diamond Audio D3 600.1 I would take a picture for u but i cant find my digital camera at the moment. 1990 Honda Civic HB:

Clarion DXZ545MP H.U.

2- 6.5" Power Acoustik interiors

Diamond Audio 600.1 amp

Diamond Audio 15" M6MKII

Pyramid PB881X 4 CH. Amp

No, that control is a bass boost with frequency control.  It's explained in your owner's manual.  The amp does not include a subsonic filter.Support the12volt.com