Two 12's ported or one 15 PR

[gckless 5,000+ posts]

So, I recently dropped in my two ported tens, and while they are decent both in output and SQ, I'm already looking forward. I've got about 3.75cu.ft. gross to work with, and I will be upgrading to a 3.5k, I'm thinkin a Crescendo BC3500D right now. So here are my 2 options:

1. Two DC Level 4 12's

Ported to around 31~33Hz

2. One DC Level 5 15"

Two 12" Passive Radiators, tuned to around 31Hz

The DC subs were just an example, I'm open to any brand, was just giving examples of caliber of sub. I think mounting inverted will be the way to go to maximize space, so sexy back ends are a must, and I do like neo.

I went with the PR's on the 15" in order to save space, and was also wondering if I would gain output with more cone area versus a port. In my mind, Vd is the same either way, so it shouldn't matter, right? And I know you're supposed to go larger with the PR, but Vd is actually what you are concerned about, and the little bit of extra surface area combined with the little bit of extra Xmax adds up to about double Vd of a Level 15.

I'm just looking to gather ideas now, won't be building for some time.

Click to read more...

 

[T3mpest 10+ year member]

So, I recently dropped in my two ported tens, and while they are decent both in output and SQ, I'm already looking forward. I've got about 3.75cu.ft. gross to work with, and I will be upgrading to a 3.5k, I'm thinkin a Crescendo BC3500D right now. So here are my 2 options:
1. Two DC Level 4 12's

Ported to around 31~33Hz

2. One DC Level 5 15"

Two 12" Passive Radiators, tuned to around 31Hz

The DC subs were just an example, I'm open to any brand, was just giving examples of caliber of sub. I think mounting inverted will be the way to go to maximize space, so sexy back ends are a must, and I do like neo.

I went with the PR's on the 15" in order to save space, and was also wondering if I would gain output with more cone area versus a port. In my mind, Vd is the same either way, so it shouldn't matter, right? And I know you're supposed to go larger with the PR, but Vd is actually what you are concerned about, and the little bit of extra surface area combined with the little bit of extra Xmax adds up to about double Vd of a Level 15.

I'm just looking to gather ideas now, won't be building for some time.

Not quite sure what your question about PR's is? A PR takes the place of a port. It moves air just a like a port would do. You need more vd than the sub in either cone area or xmax. Generally you want 2x the vd of the subwoofer to make sure the passive won't bottom out when driven hard. A sub and passive radiator has about the same output profile as a single sub with a adequately large port. The PR setup will have more versatility because you can change tuning on alot of PR's. Any chance you could fit 2 12's with 2 15 PR's? That'd be probably be the best if you could make it work

 

[NASTY08IMPALA 5,000+ posts]

What kind of vehicle you running? i personally like 2 12 s over a single 15. ..i run the bc3500 on 2dd3512.s and love it ..stupid loud...and the level 4 you chose would ve a great fit ..they like smaller enclosures.

 

[gckless 5,000+ posts]

Not quite sure what your question about PR's is? A PR takes the place of a port. It moves air just a like a port would do. You need more vd than the sub in either cone area or xmax. Generally you want 2x the vd of the subwoofer to make sure the passive won't bottom out when driven hard. A sub and passive radiator has about the same output profile as a single sub with a adequately large port. The PR setup will have more versatility because you can change tuning on alot of PR's. Any chance you could fit 2 12's with 2 15 PR's? That'd be probably be the best if you could make it work

Yeah, the PR's I would go with are TC Sound's VMP models. I would have to take a look at the two 12 with 2 15's option. I have room in my trunk, problem is the damn opening of the trunk is small, and my seats don't fold down. I think my only option would be woofers side or up firing, PR's rear firing. Going ported would be much cheaper and smaller, so easier to fit in there. But PR's intrigue me, you don't see them all that often. From everything I have read they are the best of both worlds, with only cost as a hinderance.

What kind of vehicle you running? i personally like 2 12 s over a single 15. ..i run the bc3500 on 2dd3512.s and love it ..stupid loud...and the level 4 you chose would ve a great fit ..they like smaller enclosures.

I've got a Subaru Legacy. Have you heard a 15" in your vehicle? What are your 12's tuned to?

 

[NASTY08IMPALA 5,000+ posts]

Yeah, the PR's I would go with are TC Sound's VMP models. I would have to take a look at the two 12 with 2 15's option. I have room in my trunk, problem is the damn opening of the trunk is small, and my seats don't fold down. I think my only option would be woofers side or up firing, PR's rear firing. Going ported would be much cheaper and smaller, so easier to fit in there. But PR's intrigue me, you don't see them all that often. But from everything I have read they are the best of both worlds, with only cost as a hinderance.


I've got a Subaru Legacy. Have you heard a 15" in your vehicle? What are your 12's tuned to?

yes ive ran single 15 before i like the 12.s better..im tuned to 33

 

[T3mpest 10+ year member]

Have you ever done woofers upfiring in your vehicle. If you know that works well in your trunk (not all trunks do well woofers uo) your best bet is woofers upfiring and PR's facing the trunk lid since you can't vent into the car. Another good option is woofer facing the front and passives side firing. My last setup was woofers facing the trunk lid and 4 passives, one one each side and 2 on the back.