mad_machine (Forum Supporter)
mad_machine (Forum Supporter) GRM+ Memberand MegaDork
6/27/20 2:36 p.m.

I am in the slow process of updating the audio in my Disco.  The CD changer is dying and the head unit is still a cassette style.  I am going to be putting a bed in the back for camping with a storage tray/shelf on the back door, so I have to do something about the rear door's (remember it's not a hatch) subwoofer unit.  I was looking at a self contained unit from JBL and while I understand enough about audio (I do theatre lighting) to know that low frequency sounds are omni directional,  I am wondering if a small unit under the passenger seat where the CD changer currently lives,  would be enough to give the sound in my Landy enough oomph to fill it out.  

 

I tend towards High Fidelity with a large part of my musical collection comprising of Classical and rock/classical crossovers (I do recommend the East Village Opera Company)  so I am not looking for lots of heavy bass,  just enough to fill the music out and bring it to life.  If anybody has any experience with under seat self contained subwoofers, I would like to see your responses.

Dusterbd13-michael (Forum Supporter)
Dusterbd13-michael (Forum Supporter) MegaDork
6/27/20 2:53 p.m.

Ive run a polk db8 sub in a .5 cu ft box (12x12x6 inch inside dimensions roughly) with 150 watts rms in about every car for the last decade. Its a sub that nails every musical style ive thown at it except for electronic stuff with sustanid super low bass. Its only an 8 aftwr all. 

Curtis73 (Forum Supporter)
Curtis73 (Forum Supporter) GRM+ Memberand MegaDork
6/27/20 3:07 p.m.

I just typed a huge response and when I went to post it, the forum said "get out the map we're lost."  Grrr.

Long story short.  You need volume/displacement for bass.  You can get that either with a large enclosure, or a lot of power and a high excursion driver.  The former is more efficient, the latter is more expensive.  Pick two: cost, size, dB.

Getting the drivers as far from your ears as possible is one way to help.  I know that isn't possible with underseat subs, but consider this:  A 60hz sound wave is about 21' long.  In order for it to actually successfully make an audible pressure wave, it has to reach trap (the first reverse in the oscillation) which happens at the quarter wave length... about 5'.  If you put a sub nearer to your ear, most of what you'll hear is the wave bouncing around the interior and coming back to you.

If you build an underseat sub, you can fire it fore/aft, but then you're limited on driver surface area given the small height.  You can fire it up/down, but a very large percentage of the amplitude will be squelched when the wave hits the seat or floor before trap length.

I would see if you could fit a forward-firing 6x9 sub under there.  Oval speakers are not as stable in the bass frequencies (harmonics vary across the different radii) but it is a good way to get more surface area in a given space.

Have you experienced tactile drivers?  (bass shakers)

bigdaddylee82
bigdaddylee82 UltraDork
6/27/20 7:01 p.m.

I don't have any experience with aftermarket pre loaded units, but my VW Golf has the Fender Audio System, and that comes with an 8" sub and enclosure that fits within the spare tire's wheel, under the rear hatch floor.  I don't know how much power the amp is feeding it, but it provides tight, punchy, bass, and is impressively compact and light, you've got to remove it to get the spare tire out.

Kicker has a shallow mount 6-3/4" CompRT sub, I've been eyeing for the center console in my Wrangler.

pointofdeparture
pointofdeparture UltimaDork
6/27/20 7:41 p.m.

I'm a big fan of the NVX QBUS8 underseat unit. I've put one in three different vehicles now (currently have one in my E28 under the back seat) and was extremely happy with the results. For what you're looking for I think it would do the job very well.

Let me know if you have any specific questions.

https://www.sonicelectronix.com/item_96824_NVX-QBUS8v2-Under-Seat-Powered-Subwoofer-Enclosure-with-Integrated-Amplifier.html

mad_machine (Forum Supporter)
mad_machine (Forum Supporter) GRM+ Memberand MegaDork
6/27/20 10:51 p.m.

this is what I am looking at: The JBL BassPro SL2

 

https://www.crutchfield.com/p_109BASPRO2/JBL-BassPro-SL-2.html?cc=07

aircooled
aircooled MegaDork
6/27/20 11:58 p.m.

From the page of the product listed above:

With cars getting smaller every year, JBL understands that the need for compact powered subs is greater than ever.

uhm..... what?  What, was this written in 1977?

Doesn't exactly inspire confidence in JBL's understanding of current trends in the automotive industry.

mad_machine (Forum Supporter)
mad_machine (Forum Supporter) GRM+ Memberand MegaDork
6/28/20 12:46 a.m.

smaller on the inside.  They are getting bigger on the outside.  

m4ff3w
m4ff3w GRM+ Memberand UberDork
7/2/20 1:46 p.m.
Curtis73 (Forum Supporter) said:

I just typed a huge response and when I went to post it, the forum said "get out the map we're lost."  Grrr.

Long story short.  You need volume/displacement for bass.  You can get that either with a large enclosure, or a lot of power and a high excursion driver.  The former is more efficient, the latter is more expensive.  Pick two: cost, size, dB.

Getting the drivers as far from your ears as possible is one way to help.  I know that isn't possible with underseat subs, but consider this:  A 60hz sound wave is about 21' long.  In order for it to actually successfully make an audible pressure wave, it has to reach trap (the first reverse in the oscillation) which happens at the quarter wave length... about 5'.  If you put a sub nearer to your ear, most of what you'll hear is the wave bouncing around the interior and coming back to you.

If you build an underseat sub, you can fire it fore/aft, but then you're limited on driver surface area given the small height.  You can fire it up/down, but a very large percentage of the amplitude will be squelched when the wave hits the seat or floor before trap length.

I would see if you could fit a forward-firing 6x9 sub under there.  Oval speakers are not as stable in the bass frequencies (harmonics vary across the different radii) but it is a good way to get more surface area in a given space.

Have you experienced tactile drivers?  (bass shakers)

I just learned more about audio in 2 minutes than in anything else I've ever read.

 

Thanks!

dropstep
dropstep UltraDork
7/2/20 2:16 p.m.

I have a single jl10 built into my center console in an extended cab pickup. Running it at 400w rms with a 500w peak and it's loud enough to make my head hurt. The console box is a ported box. It's 14x12x 4- 6 1/2 because of the floor taper

Subscriber-unavailabile
Subscriber-unavailabile HalfDork
7/2/20 6:46 p.m.

All I know is the ladies like it!!

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