All things being equal....

[BigDaddy13440 3]

Just a for instance:

Say you have an enclosure 40" wide x 32" long x 30" high, The port is 38.5" wide (facing forward), 6.5" in height, and 24.5" in length - tuned to approximately 34Hz (I'm assuming a driver XMax of 20mm.)

The Net enclosure volume is 14.40 cubes, less driver displacement.

You have the option of placing (4) 15" subs on the top baffle, or (9) 10" subs. Which do YOU choose, and why?

What subs would YOU do? Roughly 1.5 cubes each for the 10's, or 3.37 for the 15's.

Either way, it would be possible to run whatever amp at 1 ohm Mono - Strapped SAZ3500's, anyone?

I'd be VERY interested to see/hear/speculate what the XCONS would do......

Edited February 24, 2009 by BigDaddy13440

[KU40 173]

Why did you need to assume a driver xmax? That doesn't play into configuring a port. As for subs......interesting, they have like the exact same sd. ha. Well.....I'd choose 15s because most of them can play lower than their same-model 10s. But I don't know how you'd wire 9 subs for 1 ohm? I suppose you could do 4 ohm DVCs and wire each in series then all the subs in parallel for a .88 ohm load. May be close enough to 1. That's the only way you'd be able to have them all receive the same power.

[seanbw 1]

it's give and take like all aspects of audio.... the tens will give you more motor force and more coil surface area to dissipate heat, the 15's will get lower and louder (i'm assuming the 15's will have higher efficiency than the 10's given the same port and cone areas). my .02: go with the tens if you have gobs of overhead power, go with the 15's if you have adequate power but want more deebeez down low

[BigDaddy13440 3]

Why did you need to assume a driver xmax? That doesn't play into configuring a port. As for subs......interesting, they have like the exact same sd. ha. Well.....I'd choose 15s because most of them can play lower than their same-model 10s. But I don't know how you'd wire 9 subs for 1 ohm? I suppose you could do 4 ohm DVCs and wire each in series then all the subs in parallel for a .88 ohm load. May be close enough to 1. That's the only way you'd be able to have them all receive the same power.

(4) 15's, either single 4 ohm coils, or dual 1 ohm coils

Parallel or series/parallel config to equal one ohm.

(9) 10" subs - dual 2 ohm models, 18 coils total

Wire coils in series groups of three, gives you a 6 ohm load.

Then wire the 6 groups in parallel, gives you a 1 ohm load.

The only reason I'm assuming driver Xmax of 20mm is to give adequate port area for the subs to breathe, using Port Calculator. Still a shade smaller than what is recommended......

[KU40 173]

ah so you were doing it right and using xmax for port area. I'm so used to hearing people use the 12 sq. inches per cubic foot that I was thinking you were using xmax for length or something. me.

Wiring in threes, that's an interesting solution.

[BigDaddy13440 3]

OOPS - inadvertently posted while I was replying..... see the next post.....

Edited February 25, 2009 by BigDaddy13440

[BigDaddy13440 3]

ah so you were doing it right and using xmax for port area. I'm so used to hearing people use the 12 sq. inches per cubic foot that I was thinking you were using xmax for length or something. me.

Wiring in threes, that's an interesting solution.

Or, 6 coils in parallel, then the (3) groups of 6 in series.... either way gets you to 1 ohm.

But back to the original question...?

Suppose two 3500's strapped @ 1 ohm, or 7000 watts (give or take a few)....

1750 watts per each 15" woofer, or roughly 778 watts per each 10". I'd assume the lower power to each 10" sub would make them more efficient?? Doesn't efficiency exponentially lower as you add more power???

Would you go for the maximum low-end extension of the 15's (assuming the frequency response differs from a 10 to a 15)? Or would you go for max SPL, assuming the (9) 10's would be more efficient than the (4) 15's?

Which would be better for a daily driver, SQ-wise? Would the 10's have better transient response, and blend better with the rest of the system? What if you already have an excellent 8" (or 2) or 10" midbass driver?

You've got the box, what to put in it!?!

What's the chance anyone has (9) 10" subs and (4) 15" of the same make and model? Any of the -CON's, DP's, lvl4's, etc???? Simple matter to change a baffle......... :bigclap:

[bassahaulic 155]

I would do the 4 15"s...... move ALOT of air. I'm not sure how the 10"s would keep up with it.

I just don't see how 9 10"s could do this....... I could be wrong though.

[BigDaddy13440 3]

Anyone else?

For SQ, I'd probably do the 10's myself, as each sub would receive less power, and would in turn be less likely to fatigue and come close to a thermal meltdown.

If I wanted the maximum low-end response, probably the 15's?

But for sheer SPL, would it be best to find the resonant frequency of the vehicle, and probably go with the 10's?Again, back to the whole "efficiency vs power" debate?

At 40" x 32" for the baffle, it would almost be possible to do (20) 8" subs, but I don't think I've ever seen an 8" with an OD of under 8.25"..... but (16) of them would surely fit on the baffle.

So...... (16) 8" subs as another option? Approximately 0.8 cu ft each ported?

[BigDaddy13440 3]

Anyone else?

For SQ, I'd probably do the 10's myself, as each sub would receive less power, and would in turn be less likely to fatigue and come close to a thermal meltdown.

If I wanted the maximum low-end response, probably the 15's?

But for sheer SPL, would it be best to find the resonant frequency of the vehicle, and probably go with the 10's?Again, back to the whole "efficiency vs power" debate?

At 40" x 32" for the baffle, it would almost be possible to do (20) 8" subs, but I don't think I've ever seen an 8" with an OD of under 8.25"..... but (16) of them would surely fit on the baffle.

So...... (16) 8" subs as another option? Approximately 0.8 cu ft each ported?

Can ANYBODY run some projected numbers, see what kind of output and response each would have?

(4) 15's vs (9) 10's vs (16) 8's?

For curiosity's sake, say the enclosure is 42 x 34 x 27 - now there is PLENTY of space to put (20) 8's on the baffle. Approximately .65 cubes each..... numbers for (20) 8's?

[KU40 173]

download winISD alpha and put them on there. You'll have to decide on specific drivers, though. Response in the box depends entirely on drivers chosen. Simply going with generic cone size won't tell you much. By that notion, the four 15s have 707 sq. inches, nine 10s have 707 sq. inches, and twenty 8s have 1005 sq. inches. But the 8s won't play as low as the 10s, which won't play as low as the 15s. Each set has its tradeoffs.