Assuming all have the same sealed/ported volume and same port size. I know the pics aren't to scale so don't take that into consideration. I have seen pretty much all of these types used, so I know any would technically work but I wonder about cancellation with all but # 2. The box would be for 8 10's, tuned to 45hz with about 35 cubes total if you're curious. I would have never considered facing subs at each other in the past but I've seen some of the loudest 4th orders with subs facing right at each other like design 1 and 3 so it might not be as much of an issue as I was always told.

 

All are 4th order walls in case that wasn't obvious and the crap drawing is an overhead shot. I only angled the baffles so you could see how many subs were in each spot in the pics. They would all be straight up and down in the actual build. The port would be centered in all designs except # 2, that would be drivers side.

 

Here are my personal thoughts on all 4.

 

# 1. I see this design used all the time so it must work at least ok. I just don't like the idea of a non common chamber as I feel it would be pretty hard to get the cu/ft of both to be identical. I would have thought in the past cancellation would be an issue but as I said above some of the loudest 4th orders I've seen use this layout.

 

# 2. Common Chamber and no Cancellation issues, so I would think it would do well. However with some subs being much closer to the port I don't know if it would affect output or have issues in that regard.

 

# 3. Common Chamber but possible cancellation - I don't see many people go this route but I sort of like the design. It keeps the subs in the same chamber and farther from the port.

 

# 4. Common Chamber with an angled wall. Some say you MUST do angles to avoid cancellation so I figured I'd throw a design in like this. I don't like it because it would be fairly hard to get the cu/ft measurement to be exact. A square is much easier to calculate and build correctly for me personally.

 

I could also turn the sealed section in design # 2 sideways so all the subs face the port which is how my current setup with 4 10's is, but it isn't a wall. It's just a 16 cu/ft box with the port facing the hatch. Some say they will unload this way, but I currently don't seem to have any issue with that as far as I know. Music played will be a wide variety but the end goal is basically the same as most, stupid low and stupid loud when I play stuff such as Decaf. It has a decent amount of windshield flex now with the 4 but I want more. My amp (MB Quart ONX1600) is 1 ohm stable so I can add 4 more subs and still be fine since I am currently only running it at 2 ohms. It won't double the power but will gain some. It is rated 1,100 @ 2ohms and 1,600 @ 1ohm but in reality it is probably more like 500-700 @ 2 and 800-1,000 @ 1. Subs are my cheapo Lanzars but I ain't got the budget for baller subs.

 

Thanks for any input you care to provide.

Honestly I wouldnt exceed around 1.5 cubes on most 10s unless you like unloading the shit out of your 10s im at aboit 2 cubes ea and they are hating life

In the sealed or ported portion? In this new design they are at about 1.35 each sealed and 3.5 each ported. In the current box they are at 1 each sealed and  2.6 each ported. I don't have a ton of power so I am building it as efficient as possible. I am also trying to get as much low end as possible. I can currently get mid 20's pretty well, I did a bit more volume in the new design to try and squeeze a bit more out of the low end. My current box and the new design are 2.6:1 sealed to ported ratio. 

Talking about potential cancellation is meaningless unless you also include frequency and distance/dimensions. 

 

Also, angling the baffle will affect standing waves/reflections within the enclosure but isn't going to do too much about cancellation from the drivers (if any even exists).  But  as above, standing waves is a wavelength vs distance/dimension issue so you can't discuss standing waves without knowing those two items. 

The distances would be about 20-22" from wall to wall if that helps. The frequencies played will be the usual subwoofer frequencies of 20-60hz. 

Edited April 7, 201312 yr by Polish

Then you have absolutely zero to worry about regarding either cancellation or standing waves.  Wavelengths are way too long compared to the dimensions you are dealing with.  Angled baffling, subwoofer placement, etc....none of this matters for you.

Thanks very much for the input. I appreciate it. 

Has anyone ever tested similar designs to see which yields the greatest SPL? I know with all the variables it probably isn't comparable but I am just curious if any are truly better in terms of pure output. Mainly comparing design # 2 with the rest, a side firing wall vs walls firing at each other. Also the variant of # 2 I mentioned which is how my current box is, where all the woofers fire directly at the ported portion of the enclosure. Thanks in advance. 

Has anyone ever tested similar designs to see which yields the greatest SPL? I know with all the variables it probably isn't comparable but I am just curious if any are truly better in terms of pure output. Mainly comparing design # 2 with the rest, a side firing wall vs walls firing at each other. Also the variant of # 2 I mentioned which is how my current box is, where all the woofers fire directly at the ported portion of the enclosure. Thanks in advance.

Again, you don't reference a frequency. If it is broadband, then none of the above and a standard ported design will win. Of course even if you were clear with a frequency it will only hold true in that vehicle with the constraints you've included.

The tuning frequency of all boxes is 45hz, as specified in my very first post so one can assume it will peak there but that could vary by a bit once in the car obviously. So I cannot just name a single frequency and say "this one", just not possible. I was just asking in general terms if any of the designs are known to be more efficient or better for pure spl. I am not at all concerned with "Sq" or "flat response". I am concerned with maximum pressure, nothing more. I have modeled numerous ported setups for these subs, they are many Db's down across the board compared to a 4th order so they are out of the question. Sure it is a flatter graph, but that is not my end goal. If I were I wouldn't be walling it or putting so many subs in.  I'd be running a single sub of much better quality. 

Edited April 8, 201312 yr by Polish

Be carefull with the gain. If you plan on playing music I would keep it under 4db.

I would prefer option 2.