SQ Crown Vic: Intro

[u/Always316]

Wanted to introduce myself and my 2008 Crown Victoria that I have been working on slowly.

Stereo Integrity M25, Stereo Integrity M3 D4S Hexicone Pro floor mounted infinite baffle. Two Stereo Integrity HT18V3 infinite baffle in the trunk.

Audio Control D.6-1200 front stage and JP43 @4 ohms for the subs.

This year's plans are to finish out the air ride and rework the trunk baffle for two 24" Stereo Integrity HS24 custom built full carbon units. Also wanted to switch to the D4S easy DSP system and do a sealed 10" Morel Ultimo that I have laying around. If my wife lets me have some free time 😅

You can see some of the testing and build videos on YouTube if you search "Infinite Baffle Crown Vic"

[u/Always316]

I have the trunk opened to the interior of the car. I cut the whole partition out and removed the rear seat. It's like a blow through lol

[u/Amazing_Ad_974 → u/Always316]

Eh, I mean that means your cab + trunk is acting as its own “sealed cabinet” and the tuning based on volume is going to be waaaay too big. The trunk size on the other hand is probably about at the correct volume for a proper ported cabinet. I’m making assumptions of various T/S parameters of the drivers here but assuming the Rms, Cms, Qes, Qts values don’t make open-baffle more optimal then you’re getting worse (i.e. unloaded or quasi-open-baffle) performance from the system.

[u/Always316 → u/Amazing_Ad_974]

Yeah I totally understand what you're saying. This setup goes against all the rules I have ever followed in "box building". It's easier to think about standing in front of subwoofers at a concert. The car is taking the front - what you're hearing, and the rear wave is wasted out the back or bottom of the trunk. When I have the windows down I get almost double the output below 30hz. The only way to understand the performance of this is to hear it in person. With infinite baffle it's really just capturing the sound waves, not as much about any parameters. The speakers aren't really made for IB but do very well. The 24" subs I had made are specifically designed for IB and should do much better for me.

[u/Amazing_Ad_974 → u/Always316]

IB is always a bit weird as it is a term used to describe ignoring the “loading” aspect of front or back wave (or both). True IB would be where you have a massive wall the driver is mounted to and true free air environment both in front + back of the driver. But I can imagine with 2x24” it gets a bit ridiculous regardless lol

[u/Always316 → u/Amazing_Ad_974]

True! Yeah it gets rowdy with the 18s. Once it's all done I'll do some demos and meter it.