I have a 2009 Acura TL and it has a rather odd shaped trunk, the bottom is mostly flat with raised curves on the side, and I would like to run two Kicker 15" subs in it, according to my calculations each sub SHOULD have enough volume inside, however after some thought, I wondered, why haven't I ever seen any oddly shaped sub boxes before, is my build going to suffer issues of audio waves bouncing around incorrectly? I plan on adding braces and a divider straight down the middle to have them in their own separate enclosures, I've seen people say they've had issues with shared airspaces, but I'm wondering if the oddly shaped back (as it needs to match my trunk's shape) might have adverse effects on the waves as they come back.
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Thread moved to Car Audio.It's what you have to work with. There isn't much you can do.
Are you going with a sealed or a ported enclosure?
Are you going with a sealed or a ported enclosure?
No, on the contrary, the oddly shaped box will reduce (distribute) effects of resonances in the box. Also the box will be more rigid, which is good.
The only disadvantage is it's more complicated to build. That's probably the reason few people are doing it.
Make sure all joints are air tight!
I'm planning on sealing both sides to have a dual sealed enclosure in one box
That's a huge relief, I'm planning on lining every single part where the wood joins together with something out of a caulk gun, I haven't done enough research yet to find what would have the strongest bond with the most minimal effect on performance. This build will be finished in a couple weeks, wood is stupid expensive right now!
If you get complete air tightness, it can blow up like a balloon when the temperature inside is different to outside.
AllenB, that's indeed a good point.
however, when heating up the pressure from cabin will be released via air gaps (as the car cabin is usually not airtight). the box interior air will heat up as well, expand and may push the woofer diaphragm out (and vice-versa with cold temperatures). so maybe it's ok to have some very small gaps for air pressure balancing.
however, when heating up the pressure from cabin will be released via air gaps (as the car cabin is usually not airtight). the box interior air will heat up as well, expand and may push the woofer diaphragm out (and vice-versa with cold temperatures). so maybe it's ok to have some very small gaps for air pressure balancing.
All you need is wood glue to seal the gaps unless the cuts/joints are bad.
A sealed enclosure won't be sealed like a car tire. Is the enclosure going to be carpeted?
A sealed enclosure won't be sealed like a car tire. Is the enclosure going to be carpeted?
I'm planning on mixing some wood dust and wood glue to varying thicknesses based on the large and small gaps I'm going to have to deal with, but I've never thought about it exploding. My previous enclosure was a standard prebought rectangle with no gaps, but it was also significantly smaller. I do intend on adding carpet on the backsides, but once I finish the front, I plan on laying some nice, epoxy-covered slabs of wood to give it a very refined and nice look. Adding some holes in the rear to allow for air to exit to prevent expansion would be pretty easy, I'd just need to know the ratio of size so my sealed enclosure doesn't, as AllenB said, become a ported box. Once that's all said and done I plan to reinforce the everliving crap out of it, as I've already dropped $120 in wood, I'd rather not have to repair it.
It doesn't need to be large at all, the atmospheric variations happen very slowly compared to when the cone moves with a signal. Simply drilling the usual tiny hole to pass the wires through and not filling with silicone should be enough, for example.
Plenty of people have sealed enclosures in cars never heard of heat/cold expansion of air creating any audible effect.
There's a few reasons you dont see many boxes that are odd shaped, one is difficulty in fabrication, many use fiberglass for this reason which has its own difficulties for the uninitiated punter. Often the extra gain of space you think your getting is wasted in material thickness
Another is they are often built into spots that hide most of the enclosure, hell there's a highly experienced installer on youtube who goes all the way to building crazy shaped aperiodic enclosures for subs and to get awesome midbass up front in footwells! Pssound is a truly impressive installer
There's a few reasons you dont see many boxes that are odd shaped, one is difficulty in fabrication, many use fiberglass for this reason which has its own difficulties for the uninitiated punter. Often the extra gain of space you think your getting is wasted in material thickness
Another is they are often built into spots that hide most of the enclosure, hell there's a highly experienced installer on youtube who goes all the way to building crazy shaped aperiodic enclosures for subs and to get awesome midbass up front in footwells! Pssound is a truly impressive installer
Sealing the box will be fine, It will never be a air lock. Air will get out of the screwholes, through the sub gasket or terminals before it blows the box. My question is why do sealed when going with 2 15s? With that being your choice it seems you are not going for SQ and you want more bass, Trunk builds need to at least be ported if you want more bass but blow through is best, however not a easy feat. If the rear seat folds down you can do subs facing forward but need to seal the trunk off from the cabin or you lose a lot. I built a box for a Acura (Might have been a "newer" TL which seats did not drop) very similar but ported for 1 15 and sounded great and hit hard. I built the box and then made a faceplate that hid all the odd shapes of the box, also served as the third baffle.
If you are cutting by hand, any silicone sealant around the inside corners that works for wood will work just fine. I use window and door caulk. Another option is coating the inside with fiberglass resin, tedious and multi day task unless you spring for the UV cure type. Shape of the box doesn't have any ill effects, Placement, size, what driver and tuning(if ported) is much more important
If you are cutting by hand, any silicone sealant around the inside corners that works for wood will work just fine. I use window and door caulk. Another option is coating the inside with fiberglass resin, tedious and multi day task unless you spring for the UV cure type. Shape of the box doesn't have any ill effects, Placement, size, what driver and tuning(if ported) is much more important
I'm sure this got a little out of hand. The original point is that a sealed box doesn't need to be completely sealed, just relatively sealed 😉
I prefer sealed enclosures (personal preference). The cabin gain will help with the really low bass.
For people new to enclosures, they're much easier to get right.
Calculations for ports don't always result in the right tuning frequency. You need to test to confirm that the port is properly tuned, especially for enclosures like this.
How does the newbie know what tuned frequency will be right for the vehicle and the music they listen to?
If he wants to divide the enclosure, it will require significantly larger port volume which will take away from the internal volume and again, complicate the calculations.
There is no need for a subsonic filter with a sealed enclosure.
For people new to enclosures, they're much easier to get right.
Calculations for ports don't always result in the right tuning frequency. You need to test to confirm that the port is properly tuned, especially for enclosures like this.
How does the newbie know what tuned frequency will be right for the vehicle and the music they listen to?
If he wants to divide the enclosure, it will require significantly larger port volume which will take away from the internal volume and again, complicate the calculations.
There is no need for a subsonic filter with a sealed enclosure.
This is my first enclosure build and I've actually never had any experience with Ported boxes, so I think it'd just be safest as of right now to follow through with the design I've already put into place. It might not sound as high quality as a ported box but I'm mainly looking for deep bass that shakes the car. Changing things last minute can make all this way more complicated, but I also plan on making a faceplate to give it a more refined look. I've got a friend that helped me install the wiring into my car who also helps me with tuning so getting it right shouldn't be too hard, my main concern as of the moment is longevity.
And I've been reading everything all of you have been saying and I'd just like to say I really appreciate all the help and advice, I'll have to make sure to keep updating this as it progresses, the final product should be amazing, especially with all the refinements I'll make using the information I've been getting from this Forum.
Sound even though subjective will more than likely be better in a sealed enclosure. My kind of subwoofers can not be put into a sealed enclosure so no choice for me 😂
It is not free but UCAA (ultimate car audio app) is a fantastic app to help with figuring out volume, port area, port tuning and will also give you a idea where your sealed box will land. I've hit tuning frequency every time according to my spl meter.
I didn't see anything about what kicker subs you are using.
As I said above, I don't get the choice with my subwoofers but to port. 4"-5" of xmax is going to blow the box or blow the cone. That's a whole lot of air to displace.
However there's no need to split the box, doing so obviously hurts nothing. I just seen the size of the equipment and I've seen it all too many times where the person isn't after what sealed boxes produce. Do they work, absolutely, price of wood these days one can't afford to test boxes anymore 😂
Tuning frequency i haven't noticed change depending on cabin. Port area, port length and chamber volume seem to be really the deciding factors for ported, cabin will change how loud it will be though but peak remains pretty consistent. Port placement is typically always facing back in a trunk build unless you seal the trunk off like stated above as well.
And for a newbie to figure out what's best, just like the shape they didn't know about, they ask! First thing I always ask when building a box is "What kind of music do you listen to and do you want to feel the bass or hear the bass?". However drivers should be chosen after figuring out the aforementioned.