I don't know anything about isobaric setups, and don't claim to. Having said that, this is not an isobaric setup (lol). In the pics, the subs are facing each other, but when I get the project finished, they will be angled towards the rear of the car. I thought that same thing about facing each other, so I avoided that as best I could. The main reasons I went with this setup is 1)I have 2 subs, not 1; 2) not enough room around the gas tank to make something there (these are SPL subs and need lots of room); and 3) I HAVE to keep my spare tire in place and accessable.

The sound enters the cabin of the car through the stock sub location - I took it out so it acts as a giant port to the trunk. I will also port the boxes on the top or back to allow more sound to come through.

I havn't done any dynamatting (yet?). Before I started this project, I had a massive ported box in my trunk. It sounded great inside the car, and from the outside it wasn't all that noticeable until I cranked it up. There aren't any rattles that I can hear, with the exception of some plugs that I did my best to secure. I may dynamat this summer if it starts to bother me.

 

engin_ear is very correct.
also, If porting get a simple parameter guide to make proper ports for sub and box size. just poking a hole in the box for a port will not do.

Its always best to build sealed enclosure for first timers. They also sound best in SC trunk without going through too much trouble.

great start,very nice looking so far

 

Excellent work RSTSpeed, can't wait to see the finished project.

 

As far as building to specs, I'm going on memory - Audiobahn's website (audiobahninc.com) doesn't have specs for boxes and I don't really know where else to look for them. If I ever find my manual for the subs, then I will look in there. As of now, they're AWOL.
If memory serves me, the box should be between 1.5 and 2 cubic inches. Based on PerryInLA's calculations for his box, I estimate I am near the 1.8 ft^3 mark... but that is a VERY rough estimate. I also believe the port size is to be 3" to 4" in diameter. I plan on making it around 4", and adding some sort of "deflector" inside the box (does that make sense? I can't tell...). I'm still torn on where to put the port - on the top or on the back side. I'm leaning toward putting them in/on back because I think it will force more air into the cabin, and it obviously won't be "firing" into the trunk lid. Any thoughts on this?

Technics - thanks man! I'm gonna do my best to get it done and post pics Sat. night or Sunday... in time for Spring Break the following weekend! lol

 

I walked inside from the garage at exactly 5:48 AM... the project is finished with the exception of some minor tweaks. If this doesn't make sense, then ignore it cuz I'm really tired. Pics to come tomorrow...

 

Finished... I have a few little details to wrap up, but it's done for the most part.
Also, can anyone answer this:
When I have my stereo on (car running) everything works, but when I turn my volume up to a certain point, it SOUNDS like the speakers/music gets louder, but the subs/bass stays at the same level. It isn't very loud in the car at all. Any answers? Oh, and this was NOT the case before I carpeted it, so it's not due to the cancellations your guys were talking about earlier. There should be less of that now than before due to box positions.

 

OK, I just figured out what the problem was... When I finished off the boxes and amp rack, I also went and got two spring-type connectors to screw into the back of the box for the speaker connections. I was looking for the screw-down type, but I went to 3 places and nobody had them, so I got the spring-loaded kind. Anyways, I took one sub out and ran a direct wire from it to the amp, bypassing the connector all together. I turned the system on and compared the two subs. It was a WORLD of difference, I could see the right sub (directly wired) moving, whereas the left sub (still using the connector) I couldn't - and yes, it was on. I checked. So I bypassed the connector on the other sub, too. SOOOOO much better.
Moral of the story - those cheap spring-loaded connectors suck. They degrade sound quality and don't allow enough power through them, despite the fact that I was told they should be good up to 1000watts (I'm running no more than 640 through each).

 

Well, I dunno if anyone is reading this anymore, but...

for the skeptics our there, here are the specs/requirements for my woofers:

- dual 4-ohm voice coils
- non-pressed pulp cone with 2" foam surround
- 120-ounce double-stacked magnets
- frequency response 20-500 Hz
- power range 50-700 watts RMS (350 watts per coil)
- peak power handling 1,400 watts
- sensitivity 92.7 dB
- top-mount depth 5-13/16"
- sealed box volume: 0.7-1.63 cubic feet
- ported box volume: 2.06 cubic feet
- Recommended Sealed Box Volume: Audiobahn recommends a sealed enclosure with an internal volume of 0.718 cu/ft to 1.63 cu/ft.
- Recommended Ported Box Volume: Audiobahn recommends a ported enclosure with an internal volume of 2.064 cu/ft and one 4" diameter x 12.3" long port.


...so I was pretty close on my memory/estimates of box size and port.

 

so does your trunk rattle? See i was going to just do a trunk install, but i hate trunk rattles. The setup i have has absolutely no trunk rattle...and the bass is earshattering inisde...

heres my install

https://www.clublexus.com/forums/sho...hreadid=108793

 

I know your setup, I kept up with the progress in the thread you made -VERY nice, btw!!

No, the trunk doesn't rattle. I don't know how or why, but it doesn't. I have the plate secure very well, so it doesn't make any noise, either. The only rattle I notice is the plugs from the OEM CD changer and amp under the passenger side sub, but I have to have my head to the box (trunk open, of course! lol), and I only think I hear that b/c I know to listen for it. If I notice any rattles, I'll do some dynamatting this summer. But that's not in the plans right now.

 

I do not think I was being skeptic. I am a pro installer with many years. My advice was free since you posted this online, I commented. You DO have cancellation with this set-up. Maybe you do not have trained ear for car audio yet but in proper setup you will hear a clear difference in sound. woofers facing each other like that is never good. only good for 'flashy looks'.

Spring loaded connection is more than enough for the components you are using. ANABA Group not known for SQ

over-all nice installation for someone getting into their car for the first time.

 

I'm sure there is some cancellation, but not too much. The subs face the rear of the car more than the pics show. But with all of the constraints I had, it's the best I could do.
I had the spring clips connected to the subs, not components. I dunno if that's what you meant or not. Anyways, they definately affected the quality of sound and amout of power going to them. I ran a line directly from the amp to the sub (went through the port, lol.... hey, it worked) and volume and quality increased dramatically, without touching the gain or crossover. Maybe the brand of clips I had was cheap, I don't know. I just know what I heard.

 

Sorry so late on this thread........

RSTSpeed -- you did a great job man, looks like a professional quality install

 

LOL, no prob man! Thanks a ton!