T39 In a 4Runner

[MissileCrisis]

So I got a car to replace my waterlocked Focus Wagon. Toyota 4runner 96 (lifted). After returning the annoying wheels/exhaust to stock it is lots of fun to drive and has enough storage space to fit a T39 between the wheel wells (as well as a T60 without removing the seats, 2 if <=39 inches wide total).

I decided to put my T39 in it as a car subwoofer since the car was wired for it and all I had to do was troubleshoot an electrical issue, solder a wire/route the turn on wire and good to go. I'm running it off of an Alpine MRP-M850 I bought locally for 70 bucks. The amp should be able to put out 55 volts if I push it, it's really beefy, and the provided power ratings are given in rms. Quite the steal for that calibre of an amp. I can attest that the amp can exceed 30 V (measured with dmm) with no issues into my 8 ohm T39, any louder and I would lose my head. I've actually taken it louder with my friend in the car for 2-3 seconds.

What it's like:
Imagine taking a stack of 4 T39 wall loaded in a room standing 6 feet away, That's what it feels like to have one 15 inch wide T39 in the car with you (at high power). For demo purposes I used the car receiver highpass of 40 Hz, it's running off of the RCA aux out of the amp that is powering all of the door speakers (which have outboard crossovers, go figure). 4 volts is groovin' highway loud, 10 volts is approaching club (guessing 110+) 30 volts is clearly exceeding 120, not measured though. This is just based off of how it felt, very physical.
What's scary is the prospect of putting a T60 in the car, just to see.
You don't really need a limiter because you cannot drive the vehicle (like at all) above 30ish volts.

Can you say perfect fit?

[CoronaOperator]

That's what I'm talking about! Awesome!

I wouldn't bet on that amp going a hair over 39volts. Car amps are ment for low impedance high current applications. Higher voltage just isn't their style.

[sine143]

considering cabin gain, the only benefit you'll get from a t60 is *boominess* below 40hz. the t39 should be well suited to a vehicle for both output and SQ, providing decently flat response into the mid 20s.

[osse]

as I highly doubt my AT are going anywhere under 120 db in my small nissan micra, this must be really brutal. Very big car tho so it might be similar response to my AT in my micra. It is as brutal if not more than my four t30's corner loaded in the >40-50 hz register.

[Ryan A]

T39 is the mega-autotuba. I've also tried it before with stunning results.

If you have the room it's the best sub for for car use because the cabin gain gets you extra extension and output so it plays everything an AT will play, only louder.

[MissileCrisis]

The t39 doesn't seem to go below 35 much in car, t60 would be able to handle the low content at loud levels. I'll see how high voltage the amp can handle. Without load.

[MissileCrisis]

I'll remove the high pass for the t60. The door speakers have their own independent high pass.

[Ryan A]

The t39 doesn't seem to go below 35 much in car

Because you have a high pass on it. If you remove the high pass for T39 you'd get better results. I'd probably only do that with car drivers installed though as they're better suited physically to the low freq's than say the 3012lf.

[MissileCrisis]

This is a lab 12 loaded, resonant frequency =22. I also tested with 32 hz hp.

It sounds great for what I listen to in the car. But boy would the t60 give a good massage.

[sine143]

it might give a good massage, but wouldnt be musical... as 20 to 50 would completely dominate response.

the autotuba is tuned high (like any good SQ car sub should be) so that post cabin gain, it produces a pleasing result to the ears.

take the hipass off the t39 and you will see lol. its just like jamming with a sealed lab 12 under 45hz (which should still be pleasing to the ears).

[Disco-inferno]

Rolloff for the T39 below fc is 24dB/oct so output below 45Hz will dropp down very fast. So fast, that the cabin gain won't compensate enough, to extend the frequency response much below 35/40Hz.

But still, i think it must have been very impressive

[sine143]

aye, but cabin gain starts piling on at 12 db an octave around 55 hz, putting 25hz around 24 db up

[osse]

aye, but cabin gain starts piling on at 12 db an octave around 55 hz, putting 25hz around 24 db up

Isn't that more like 12-15 dB up?