Thoughts - JL Audio MicroSub in rear speaker spots
 

I have been thinking about how hard/easy it would be to incorporate one of JL Audio's MicroSub's into the rear speaker areas and having the sub speaker meet up to the existing speaker grill in the car panel.

If it would fit and I could fab a way of attaching it to existing points, it could be great for getting bass and keeping ALL the trunk space.


Thoughts on viability or is it more headache than it's worth and should just give up some trunk space?

http://www.jlaudio.com/car-audio-sale-subwoofer-systems

P.S. I'm at the planning phase and will be replacing the head unit, stand alone multichannel amp, component speaker system upfront. Just wondering if I should be deleting the back channels for microsubs, or go bigger sub in trunk and keep back two channels...

You can fit some 8" back there.. The enclosure will be a challenge for certain

This car really makes me wish I had fiberglassing skills.

After looking at the giant cavity around the rear speakers when I did my car stereo, I wondered why a vendor didn't design a box to go there. There is a lot of room, it's just an oddly shaped space.

Delete the two rear speakers no matter what, they are pretty much useless.

If you want the most output, you'll likely get it from a wheel well mounted box in the trunk, not inside the cabin. This seems counter intuitive, but I've seen it happen over and over in all kinds of different cars.

That said, the rear side panel would like have a smoother response curve.

My biggest goal is to retain all the trunk space. I use it on a weekly basis and almost every inch, for stuff when washing the car, going to the store, etc.

This is why I would like to utilize the back seat area for bass.

It could be done with a fiberglass enclosure, and have pretty good response. Unlikely the microsub enclosure would fit behind the panel.

So find a custom faber and ask them for a quote.

Any idea on how much things like that cost?

Honestly, not cheap. If it's hidden behind the panel, it might not be as bad as it doesn't have to be finished. But for example, a pair of sealed mid enclosures for a door generally cost over $2000 a pair for a nice looking finished product.

:confused0068: 2-3 square feet of saved trunk space isn't worth that much to me.

Maybe I can look into getting the cavity 3D scanned and 3D printed. :D

There's actually a car audio guy that's been building small bandpass boxes using a 3d printer, but his printers not big enough for that area. I had him 3d print the fluid tonearm damper for my turntable.

I've got a couple of JL Audio 6" subs new in box that I bought years ago for a project and never used. I wish to hell I could fiberglass worth a damn because they would be perfect back there.
I currently have a 10" in a box that just takes up way too much space. Sounds great, but I really miss my trunk.

A couple/three owners pulled this off in this thread with subs up to 10" IIRC.

http://www.ft86club.com/forums/showthread.php?t=66561

It was a lot of work.

http://i935.photobucket.com/albums/a...5.jpg~original

That is my pic, and yeah, it was a lot of work. In the end it sounded fine, nice even, but then I made the mistake of putting my fiberglass enclosure for the spare tire well from my STI in there. Just SO much more when placed in the trunk. Some of it is the proximity to the driver and the frequencies involved - you just aren't far enough away and that location doesn't couple to the interior very well.

If you insist on doing it I will give you my enclosure for the price of shipping. It would be good if someone got something out of it.

Nice offer.

I've been thinking of building a FG enclosure back there since I bought my car in 2012... never got around to it though, as it will be a ridiculous amount of work for an amateur like me.

Now the $2000 estimate I saw several posts back seems extremely excessive. I'd guess somewhere around $1k for a nice one-off custom enclosure for that space. If someone were to plan a GB for them, they'd probably come down to around $600 ea - but shipping would be really high, pushing the overall cost well above what the vast majority would likely be willing pay. On top of that, the enclosures for the trunk area already offered will almost certainly produce noticeably better sound.


I still might build one (after I finish a few other big projects). If/when I do, I will post it up here, and if there is enough demand, I might consider making a mold so that it could be duplicated. I have to admit, I'm not a pro at this sort of thing, so if I made a few, I couldn't promise high-end, show quality results.


Here's a simple FG enclosure I built to squeeze a 10" sub behind the passenger seat my MR2 without losing any passenger seat legroom or adjustability:
http://i70.photobucket.com/albums/i9...22_160610.jpeg

The $2000+ price was for sealed door enclosures for midbass speakers. The rear side panels would be similar in complexity and cost. Trunk enclosures are far easier, and therefore cheaper. Keep in mind a corner loaded trunk enclosure will pretty much always have a huge and sharp peak in response. Some people like this (makes it louder, generally in the frequency range most pop and rap music has their bass), but it's less musically accurate and won't be as clean as other mounting locations. I can post a few measurements to show this tomorrow.

Here are the measurements I promised. This is in a 2014 Kia Optima, but I've noticed similar results in every car I've tried it on, and knowing that a 12" sub can be fit under the glove box in the 86, its very relevant.

This is the measured response of the sub in the trunk corner, and under the glove box in the foot well. As you can see, despite the seat being completely up, the trunk is actually louder. But there is a huge peak of about 8db, at about 28hz. The peak amplitude and frequency will be different in each car, but it will be there. Also notice how ragged the response is, and that it starts to roll off faster than the up front sub. Green is trunk, blue is up front.

http://i254.photobucket.com/albums/h...psef8f0131.jpg

But much more telling, is this next set of graphs, the waterfall plots, which show how long it takes for an impulse to decay. Long decay times are THE cause of muddy or "slow" bass. Notice how the up front sub decays much faster than the trunk sub.

Trunk Sub
http://i254.photobucket.com/albums/h...ps8d56dae6.jpg

Front Sub
http://i254.photobucket.com/albums/h...psed27a3b1.jpg

Listening impressions followed suit. The trunk sub rattled everything, sounded muddy and un-clear. It was louder, but not in a good way. The up front sub by comparison had very few rattles, and was smooth, even with no eq. Individual bass notes were easy to hear.

@TOOSTUBBORN2FAIL

Do you have any info (build thread or pics, etc) of that 12" sub under the glovebox / footwell install you spoke of. There is room down and under there, would love to see it executed.

I'm at the hospital for my mom right now, but the diyma thread recently linked in the on axis speaker thread is the one. He had two subs ran ib, and dropped them for a single stereo integrity mkiv up front.