Built an enclosure, which of my subs is better suited?

[CorNut]

I built an enclosure for a mustang and miscalculated the airspace a bit. I have ~1.9 cu ft after port displacement if I tune it to 32hz, ~1.85 if I tune it to 31hz. It was supposed to be 1.75 at 32hz after port & sub displacement but I didn't realize the port wall was too long. I can change it to do a second 90 which will make it tuned a little lower or since I made the enclosure too big, I can cut it down a bit and still maintain a 32hz.

 

It was originally designed for a CT Tropo-12 D2 but I have a CT OZONE-12 D2 or Sundown SA-12 classic/rev3 I can throw in it too. The amp is a Jensen xda91rb which dynos ~610w certified, ~740w before clipping. Which sub will work best with that amp, and do I leave it with more airspace at 32 or less airspace at 31? I suck at WinISD, the car has some 8" Kicker RT's & kappa 5x7 coax's in the doors. It's for an 08 mustang. Here's a pic of the enclosure as it sits now.

[Joe X]

Not sure about your box calculations but the difference between 1.75 and 1.85 cf are minimal, you know since you have both subs you could finish the box and then try both subs in it and see which one you like better.  Just do check your calculations to be correct.

[CorNut]

3 minutes ago, Joe X said:

Not sure about your box calculations but the difference between 1.75 and 1.85 cf are minimal, you know since you have both subs you could finish the box and then try both subs in it and see which one you like better.  Just do check your calculations to be correct.

I was going to router for a flush fit, I guess I can just install the second baffle after I listen to it. Do you think maintaining a 32hz is the better option? The port area is 32in. I tried to match the specs to the Tropo-12 recommended enclosure. The OZONE-12 calls for 1.65 at 32, and the Sundown SA-12 rev3 I'm afraid I'll underpower with that amp. Maybe it'll work though, unfortunately it's not my car so I'll just have to swap subs around in my house if it comes to that. Assuming my calculations are correct, on paper which sub would you think will respond best? I'll finish it Sunday and update pics. The port wall isn't glued in yet because I'm still unsure what to do with it. 

[Joe X]

1 Hz tuning difference is inaudible, I wouldn't work some more to change it,  as for the subs the CT OZONE-12 seems better fit for your power and box size, but being these such small differences I wouldn't be thinking a lot about it. I'd be more concerned about a significantly miscalculated box.

 

 

[CorNut]

I don't know how I managed it, when I drew it out it all seemed fine. When I actually measured internal dimensions with a tape measure (after already cutting everything) is where I realized my mistake. 

 

I think my workmanship is fine, my actual designing isn't the best. I've designed some I'm proud of and others which made me feel dumb (like forgetting about wood thickness), I haven't made that mistake again lol. I'm getting better, what I need to do is learn how to use software, I don't know why but that's where I struggle. I appreciate your responses here, and also the help you've given others in the past because I've learned from that too.

[Joe X]

I agree your work looks very nicely done,  when in doubt post your designs for review before cutting, one way to verify calculations is sketchup, pretty effective at that but it does have a learning curve.

[CorNut]

I decided to DuraTex it instead of carpeting, it's drying now. Unfortunately I ran into 2 issues, 1 was my fault and the other is possibly CT Sounds'. While cutting the opening for the port with a flush trim bit, I lost my grip on the right side as I'm sure you can see in the pic. I'm bummed about it but it'll be in the guy's trunk and it isn't like it's made for show, it's just a single mid-level 12" that'll be powered by a $70 Jensen amp (pawn shop). The second issue is my circle jig or CT Sounds' specs, they said the cutout was 10.94" for the OZONE-12 so I did 11" with my circle jig. It's (jig) always been accurate so I'm not sure what happened there, but I guess I'll find out on my next enclosure if it cuts small on that one too. I ended up having to enlarge it with a jigsaw but it's a good fit despite being ugly.

 

The enclosure itself, I ended up changing it a bit, I went with a slightly larger port area (33") and I recessed the second baffle. After all's said and done, the enclosure is down to 1.58 cu ft with 33" port area @ 32hz. That's pretty close to the 1.65 cu ft with 32" port area @ 32hz CT recommends. I probably won't get a chance to put the sub in until next Sunday but I'll listen to it & throw the DATS V3 on it to test my tuning. The motor was too big to use a roundover bit, I had to position the sub a bit higher than the Tropo I was originally designing the enclosure for. It would've been nice to do but I think the flush trim cleaned it up enough. He's getting the enclosure w/sub for a steal, he won't complain that's for sure.

[Joe X]

Looks like a box for a 12 DC audio level 4 judging by baffle strength, port area and net volume, in case the guy wanted to upgrade equipment later on.

[CorNut]

Thanks for the suggestion, I actually told him it'll be more box than he needs if he wants to upgrade later. The motor on the ozone is just over 7", the DC looks to be 7.75" which will still fit above the shelf behind the driver. This is the guy's first system, if he's anything like his dad he'll be wanting to upgrade soon.

[CorNut]

After testing, its actual tune ended up being 29hz, for this car it's not a big deal. He has 4 Kappa 5x7's and 8" Kicker RT's in the factory speakers locations. There'll be plenty of bass, just nothing down low which this will still do a good job. I have a CXA400.1 I run on a converted PC power supply as a 12v source. It had my house rumbling even with that small amp. I could very easily reach in and cut/alter the port while giving additional airspace to the sub to get it closer to the 1.65 it asks for. It sounds fine as is and it has an Fs of 30hz so I don't think it's necessary.