BillFitzmaurice.info

Bill,
Can you tell me expected/calculated output increase from changing from BP102's to KL3010LF's in T39's please.

From what I've been reading, and since there are no BP102 T39 charts, the S2010 at 27V is +20dB over baseline, the 3012LF is +26dB with 56V.
You don't advise 56V in the T39 plans any longer, 50V is max, and the BP102's are limited to 35V.

My older plans don't have the KL3010LF listed, but I understand that their voltage limit is in the order of 50V also in the T39, whereas in other designs the 3010LF can be taken to 55V, so is 50V correct?

I'm anticipating a significant enough increase with the greater Vd, increased Xmax and higher voltage limit compared to the BP102, but thought I'd check.

The other added bonus is I can just set all sub outputs to amp channels to 50V to simplify setup...

With the same Sd it takes doubling of xmax to give 6dB of increased maximum output. If the BP102 isn't enough I'd switch to a twelve, as doubling Vd also gives 6dB.

Bill Fitzmaurice wrote: ↑Wed Aug 09, 2023 9:42 pm With the same Sd it takes doubling of xmax to give 6dB of increased maximum output. If the BP102 isn't enough I'd switch to a twelve, as doubling Vd also gives 6dB.

Thanks.

Sd and Xmax is increased comparing the 3010LF to the BP102, and while the Vd of the 3012LF is greater than the 3010LF, it's not a doubling and Xmax is less than 1mm greater in the 3012LF.
My 20" T39's are built to max width for 10's already and I'm hoping for a drop in substitute, rather than a rebuild or changing a baffle in the boxes.

There has to be something.
The 3010LF has greater Vd (+33%), Sd (+40 sq. cm), and Xmax(+2.3mm)than the BP102
Given that, what would I gain going from BP102 to KL3010LF?

You're considering too many variables where only one matters, Vd, as that's the product of Sd and xmax. A 33% increase in Vd will get you about 2dB.

Bill Fitzmaurice wrote: ↑Thu Aug 10, 2023 6:30 am A 33% increase in Vd will get you about 2dB.

Thanks!

Ok, that's the increase, but...

Does that mean with 1 cab I can expect around 126dB max at 100Hz with the 3010lf?
Is that the right number?

According to the plans, that I have, the limit for the BP102 is 35v and for the 3010LF it is 50v.
Also, the 3010LF has a 4db increase over the BP102.

Tom Smit wrote: ↑Thu Aug 10, 2023 9:19 pm According to the plans, that I have, the limit for the BP102 is 35v and for the 3010LF it is 50v.
Also, the 3010LF has a 4db increase over the BP102.

Cool, thanks Tom!

Are you using the V-plate mate?

Keryn O'Shea wrote: ↑Fri Aug 11, 2023 4:43 am Are you using the V-plate mate?

When I can!
I'm a little leary outdoors with a single 12mm ply layer V plate anywhere were punters can decide it's an instant dance platform.
Maybe if I doubled it up I'd use it more...

Grant Bunter wrote: ↑Sat Aug 12, 2023 3:25 am ...were punters can decide it's an instant dance platform.

Rough crowd out there man? I have a cattle prod you can use..

Grant Bunter wrote: ↑Sat Aug 12, 2023 3:25 am

Keryn O'Shea wrote: ↑Fri Aug 11, 2023 4:43 am Are you using the V-plate mate?

When I can!
I'm a little leary outdoors with a single 12mm ply layer V plate anywhere were punters can decide it's an instant dance platform.
Maybe if I doubled it up I'd use it more...

If you weren't so danged far away, I'd give you mine! I have two of 'em. Double thickness and sturdy as hell. Just don't v-plate anymore since we went to stacking for the big shows.

Keryn O'Shea wrote: ↑Sat Aug 12, 2023 5:16 am Rough crowd out there man? I have a cattle prod you can use..

Pfft wouldn't do a thing. I reckon just after breakfast they go "Is this working? (Apply to self, press button) Yeah not to bad, will need new batteries next week".

Bruce Weldy wrote: ↑Sat Aug 12, 2023 8:34 am If you weren't so danged far away, I'd give you mine! I have two of 'em. Double thickness and sturdy as hell. Just don't v-plate anymore since we went to stacking for the big shows.

Thanks Bruce
Are Texans like Aussies? Is a big drive "just down the road a bit"?

Bruce Weldy wrote: ↑Sat Aug 12, 2023 8:34 am Just don't v-plate anymore since we went to stacking for the big shows.

How big is big for you Bruce? Which sub model and configuration are you stacking?

Keryn O'Shea wrote: ↑Sat Aug 12, 2023 4:42 pm

Bruce Weldy wrote: ↑Sat Aug 12, 2023 8:34 am Just don't v-plate anymore since we went to stacking for the big shows.

How big is big for you Bruce? Which sub model and configuration are you stacking?

Bruce has 6 x T39 3012lf at 23 15/16" IIRC with Otops 12's and a T24 for drum fill if required, and places them based on coverage requirements...