Invisible Tiny Subwoofer
 

Hi,
I have constructed a little subwoofer for my SA/2. I'll fit behind the rear covering near the tail lights here:


https://cimg3.ibsrv.net/gimg/www.rx7...d056a1d6ea.jpg

If your are interested to build it too, you can use my drawings:

http://rx7.hendriknitsche.de/woofer.pdf

If you will build one, please let me know :)
The box is calculated for the omnes audio SW 6.01

Nice drawing. Can you convert it from metric to US inches??

I put a Subaru subwoofer in my car. Its real small, I want to say 3" deep x 8" x 7", but IDK. It doesn't make a whole lot of noise, but it helps.


I wanna say I pulled it from a late 90's Forester, but I don't remember. It took some thinking to figure out what all the wires mean. It has an internal amplifier so power it up and put some signal to it and it'll thump. If you can find one I'll post up how I have mine wired.


EDIT: when you go to pull it; you'll find it under the drivers seat. It might be in the high end model suby.

@KansasCityREPU: Please give me a break. You can easy convert it by yourself ;)

@Qingdao: Oh, interesting idea. Thank you for this hint, but I think I will keep up my Idea.

Today, I build a paper model of the subwoofer and it don't passes the test. The emergency wheel could not be at its place, when the subwoofer is build in. So I had to make a new drawing and a new model. The new one is perfect. At the picture, you can see the old one in the back and the new one in th front:

https://cimg4.ibsrv.net/gimg/www.rx7...bfe49edfa7.jpg

As you can see it fits perfectly and you can put the trunk covering back in.


https://cimg8.ibsrv.net/gimg/www.rx7...839d8521b5.jpg

The new drawing is located at the old address http://rx7.hendriknitsche.de/woofer.pdf.
The new version also is very much easyer to build.

Very nice. I love it when people are motivated and smart enough to tackle these type of jobs. Very smart to build a mock up from paper. After it fits you can use the pattern to make it from a strong material.

Good idea and good job!!

Good luck and enjoy!

Rich

Nice idea. What size driver are you planning to use?

In a previous vehicle, I removed the jack mount, and put a pair of JBL Control 1 speakers back there. The sound was very good.

Control One | Rugged 200-watt Wall-mount Bookshelf Speakers

Thank you for your motivating words :-)

@elwood:
I plan to use the Omnes Audio SW6.01:
Lautsprecher Shop | OmnesAudio SW 6.01 | Lautsprecher Selbstbau
It is very good for very small closed Boxes.


https://cimg9.ibsrv.net/gimg/www.rx7...5af91dc4d7.jpg

Looks like a good choice. I see you already have some insulation ready to put inside the enclosure. If you plan to go with a sealed enclosure; try to make the volume the same as the driver manufacturer's specs. It will make a big difference in the sound.

Also, check so see if the recommended volume includes the driver or not.

Great job! Love the stealth installation.

Here's something to consider though. Some of these engineered underseat subwoofer solutions do a pretty amazing job. I don't think any of them actually fit under the seat of an RX7 due to the fact they seat so close to the floor (and there are lumps in the floor to contend with as well), but they may well sit in an inverted position or on the floor behind the carpet in the very location with custom box was installed.

A Kicker Hideaway is only 352mm x 238mm x 79.4mm (13 7/8" x 9 3/8" x 3 1/8"). Enclosure is matched with subwoofer and integrated 150W RMS amplifier. Wouldn't be surprised if it fit.

@elwood:
I planed a sealed enclosure and I have simulated the enclosure. The perfect volume is about 6.5 litre. The maximum possible volume is 5.5 litre because there is no more place behind the carpet. I have talked to some people that are professional enclosure builders at a german hifi board. They say you can get "virtual volume" by using the insulation inside of the box. You can calculate this as well and it will be around 6 litre with the current geometry. The expected sound will be a very clear and dry bass, not very low frequences but you will come down to 55Hz at -3db and relativly low amplitudes but that will just matters, if you want to play music very loud and techno or something is the music of choice. I think that is very good and it will be a "stealth installation" for the price of a decreased audio level.

@KYPREO:
I don't think that the underseat subwoofer would fit there, if you mean the location I choose for my installation at the back of the car behind the carpet (I hope I understood that right, I'm note a native english speaker). As you can see in my drawings, there is much less place than it would need to fit it there. These underseat subwoofers has been my first choice but in the moment I explored the hidden space behind the trunk, the idea was born to build my own subwoofer :)

I see you've done your homework. I'm sure it will sound very nice. What do the the hifi board people say about the amplification of low frequencies by placing it in the corner of the vehicle? I just put some bookshelf speakers on top of the cabinets in my kitchen, and the bass was boosted significantly by the interaction with the wall, ceiling, and cabinets.

Nicely done. It's been done a few times on here. Below are a couple other examples. I know another member did solo baric square subs back there.

~T.J.

https://cimg0.ibsrv.net/gimg/www.rx7...86c607d727.jpg

https://cimg1.ibsrv.net/gimg/www.rx7...1356aa5a41.jpg

Well that's pretty awesome.. Gonna have to look into that after the street port, repaint and blow through set up.lol

Subscribed!

Did you have a chance to mirror the design on the other side and see how it all fit together?

What internal volume did you find this to be?

Personally, I'm using a pair of CDT Audio ES-06+ subwoofers run at 8 ohm off of a 5th channel on my amplifier and planned to use a vented box designed in WinISD/WinISD Pro.

Here's the response I was going for:


https://cimg1.ibsrv.net/gimg/www.rx7...7e5fe572f5.png

I was going to do something very similar to you frox, but then there was the added problem of hiding the amplifier. I ended up using a small powered subwoofer like this Pioneer Carrozzeria Subwoofer System TS WX120A 150W MAX Powerful Amplified | eBay in the same location. It does the job, but there are probably better ones.

yup, that looks like the one I pulled from the Subaru in the junk yard. Like this one...

2003 2006 Subaru Outback Legacy Baja Subwoofer Amplifier Speaker Upgrade New | eBay

I stashed it behind my seat. Works great.

Definitely NOT the same level of fidelity out of an underseat subwoofer though, unless it's in a bass reflex port configuration like this Alpine Type R 8": Alpine Type R 8" Ported Box

Another alternative would be top firing to gain +3dB off of the rear window glass, like this Gen 3/4 Camaro box: Camaro Top Firing Enclosure


Overall, it's still best to port given the space here... Sealed enclosures are FAR too peaky for my tastes and I'd rather have more lower end and flat response to be truly SQ.

The spec sheets I've seen show a larger recommended enclosure and peakier response for ported applications (see the attached Infinity sheet). The only downside to a sealed enclosure seems to be lower efficiency.

My friend's GC 2.5RS had one of those. (Well, has. The car still exists, a different friend owns it now. I'm angling to buy it next when he gets bored with it. It looks like Bunta's WRX ;) )

It's weird, it's not that you hear the bass from the subwoofer, it's more of a seat shaker device. What is weird that it works great, you mentally get the sound quality of a good subwoofer but without the headache on long drives because it's not actually pounding your eardrums deep into your skull. I like it.

I don't think there'd be enough room under the seat of an FB (SA/2) for it to fit, sadly.

^ no problem hearing mine. Its mounted alongside the tailight behind the carpet pointin at the front seat. (because rear seats). Can actually even get that percussive feeling through your chest cavity.
Still wouldnt be as good as a proper box with a proper driver and amp like Frox is doing though.

Yup, its my butt rumbler :lol:
I wanna get another for the passenger seat, but I haven't been to the junkyard it a while.

Na, it doen't fit under the seat; I have it in the small gap between the seat and the storage bins.

And no its not a heart stopper and it probably doesn't produce the most clear perfect audio out there, but I've got a 2.5" exhaust that plays a cool turbo sound. \m/

I'm in the process of talking with Mark at CarAudioFabrication to see about designing a ported enclosure for me using your dimensions, Frox.

If this ends up working out for me, I'll sell these boxes to the community. WinWin. Only cost me $50 for designs. ;)

I was leaning towards an 8" driver in a sealed enclosure, mounted in the driver's side storage bin (battery's in the passenger side bin). But this rear mount option is interesting.

If you haven't considered it, look at how much volume you can get by removing the jack and mounting bracket. I'm sure I can find another place to store those parts.

Winfield, that's a REALLY good point. Almost enough space to build a properly ported enclosure! Hmm, I wonder...