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Discussion Starter · #1 ·
Ok, so I wanted to try an ABC box because I had heard some great things about them and I had just enough room to fit it in the space I was willing to sacrifice in the trunk. I know it looks like a mess but it sounds amazing. Gets super low and accurate. Loud but clean. I'm impressed.

1.3 net tuned to 33/66hz using 3" PVC with some old flared ends I had laying around. Fi BL 10" powered by a Cadence A7HC.

Starting to come together.


Side view. 14" total height, 10.75 deep. The lip on the bottom is 4" total. 2" inside and 1.25" under. Just tall enough to clear the gas tank hump. Fits like a glove and netted me another ~ .4cf over just resting it on the hump. The back seats aren't a 45* angle so I got another 3" on the top side, which was another .5cf.


Test fit pics.



Inside view of the mess of plumbing. I couldn't have gotten the tuning I wanted without porting externally.


All buttoned up and ready for a listen. Pre-carpet (obviously). I may still make a false wall which is why I didn't carpet yet.



Ok, well that's it. Like I said, it sounds great. Version 2.0 is going to be a down/forward firing set-up through the ski pass.
 

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VERY cool Sniper!

I've not read too much into ABC enclosures but the idea is very interesting to say the least! Can you go into more detail about your design and how you landed on your particular tuning frequencies and the steps involved? I know lots of members who'd like to learn about this including myself!

Here is what I found on the alignment theory... Dual Chamber Ported Enclosures
 

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Discussion Starter · #3 · (Edited)
Thanks. It's actually really simple. Just find the optimal volume of a normally ported box for your sub and the tuning frequency that you want. For me it was 1.25 and I chose 33hz because it's a great tune for a daily box. Then just take your internal volume and make two chambers- one 1/3rd of your target net and the other will be 2/3rds. Now find your port length of the entire internal volume using any of the baziillion online calculators. 1.3cf @ 33hz was like 28" with a 3" flare. Now make 3 identical ports. Port each chamber with one and port the two chambers together with one. What this does is make the smaller chamber exactly one octave higher than the larger chamber, hence the 33/66hz tuning.

Geez. that sounded complicated but it was actually really simple with the PVC. It can get really hairy with slot ports like most people use. And the box is only bigger than a normal box by the volume of the 2 extra ports which for me was ~ .228cf. Just make sure that when calculating net volumes you take into account port and driver displacement. My driver is .16cf and more of the port in that chamber is external so it just takes a little math.
 

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Discussion Starter · #5 ·
Well, if I keep that set-up, I will make "in-lays" to make the box look flush all the way across and maybe make a full false wall and seal it off from the rest of the trunk. You actually can't hear any port noise at all in the cabin. From the trunk though there is a lot because of the situation of the ports and the fact that I didn't install the flared ends on the externals yet. The passenger one is actually firing directly against my highs amp so that doesn't help either. Today was really just a test run. Tomorrow I am going to miter the ports and direct them into the corner and install the aeros. That should all but eliminate any port noise.

I went driving tonight just to listen to it. Man, it is murdering the lows.
 

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Here is what I found on the alignment theory... Dual Chamber Ported Enclosures


Old school box. I haven't seen one in years. After playing with ABC's and snailshells, car audio died out for me. Right when I read "ABC", it made me smile. :)


ABC=Aperiodic Bi-Chamber


You'll probably find some very good old threads on the TermPro forums.
 

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Ok, well that's it. Like I said, it sounds great. Version 2.0 is going to be a down/forward firing set-up through the ski pass.


First, nice choice for the sub. I remember when the RE's first came out, I still have a few XXX's laying around.

If it were me, I would attempt to build the box so the sub fires through the ski-pass and the ports go through the rear deck. It will almost have the "hatchback" effect, but not quite. Going wider on the box should allow you to build slot ports also to minimize any port noise(if you have any now).

:)
 

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That's looking good!

Can I ask what the purpose of the plumbing pipes are? Is it there just to hide the wiring?
 

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Those are the ports.
 

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A port is an enclosure vent that tunes the resonant frequency of the box to a certain frequency. Most of the time you choose a frequency where the sub needs some help, or a little boost. Response on a lot of subs starts to run out mid 30's which is why you see most people tuning to about 32hz. Basically, the sub gets help from the enclosure to produce sound around this note and it keeps the speaker from moving TOO far and blowing itself up.
 

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Thanks for the explanation ItalynStylion. Although I still don't get it. I'm just a tad slow when it comes to sound installation. That's why I have a sub and amp in my car that is disconnected! lol
 

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Discussion Starter · #14 ·
If it were me, I would attempt to build the box so the sub fires through the ski-pass and the ports go through the rear deck. It will almost have the "hatchback" effect, but not quite. Going wider on the box should allow you to build slot ports also to minimize any port noise(if you have any now).

:)
Sub through the pass and port through the rear deck is the plan, but I coulnd't find any positive (or negative for that matter) reviews on porting this way. Every rear deck "port" that I have seen is just holes to let more sound into the cabin. Not actual ports. I figure it can't sound worse, so I am going to do it. Worst case scenario is that I have a couple of vents in the deck. I thought about taking the 6x9's out and using their spot to vent through, but I just love my rear fill too much.

I'm not worried about port noise. Like I said, it's just because it's porting right up against my highs amp and the fact that I didnt' install the flares on the externals yet. I couldn't go any wider if I wanted to anyway.
 
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