I'm looking to build a PA top cabinet with 2-12" and a horn and need help with designing the cabinet. thinking four cabinets total and have them trapezoidal to work together with minimal phase issues. similar cabinets would be the JBL SRX722.
my first thought was to go with B&C speakers and horns. possibly speaker model 12NDL76? And for horns maybe the DE95TN? any suggestions on cabinet design?
my first thought was to go with B&C speakers and horns. possibly speaker model 12NDL76? And for horns maybe the DE95TN? any suggestions on cabinet design?
You would get more expert eyes over in multiway forum.
You're in luck. I already downloaded the B&C catalog. You should have provided Qt, vas, Fs in your original post.
Qt = .2, Vas 73 L Fs 50 Hz Watts 400 sensitivity 100 db flat response 400 hz to 2 khz, rolls off 18 db @ 100 hz & 40 db @ 50 hz. Recommended enclosure 42 L recommended tuning 65 hz.
You planning to cross over to the sub @ 200 hz? not much use below that.
Qt .2 means a vented enclosure. David B Weems recommends a port size 1/7 the area of the woofer. 2 woofers of 522 cm^2 is 1044 cm^2. So you need a port of about 36 cm diameter.
Doubling the # of drivers doesn't fit my training. Suppose VAS would double but I have no experience with that.
Suggest you try the simulator vituixcad . Or Read the David B Weems book Designing building & testing your own speaker system.
I would prefer an eminence deltaline-2512 which doesn't dive in response so precipitously at 200 hz. 100 hz is only about 5 db lower than 1000 hz. https://www.eminence.com/speakers/speaker-detail/?model=DeltaliteII_2512
You're in luck. I already downloaded the B&C catalog. You should have provided Qt, vas, Fs in your original post.
Qt = .2, Vas 73 L Fs 50 Hz Watts 400 sensitivity 100 db flat response 400 hz to 2 khz, rolls off 18 db @ 100 hz & 40 db @ 50 hz. Recommended enclosure 42 L recommended tuning 65 hz.
You planning to cross over to the sub @ 200 hz? not much use below that.
Qt .2 means a vented enclosure. David B Weems recommends a port size 1/7 the area of the woofer. 2 woofers of 522 cm^2 is 1044 cm^2. So you need a port of about 36 cm diameter.
Doubling the # of drivers doesn't fit my training. Suppose VAS would double but I have no experience with that.
Suggest you try the simulator vituixcad . Or Read the David B Weems book Designing building & testing your own speaker system.
I would prefer an eminence deltaline-2512 which doesn't dive in response so precipitously at 200 hz. 100 hz is only about 5 db lower than 1000 hz. https://www.eminence.com/speakers/speaker-detail/?model=DeltaliteII_2512
I'm up for anything really. Just looking to match or beat JBL cabinet if possible. The B&C 12" speaker I was looking at was rated for 800 watts continuous and I thought lower frequency than that. I must have posted the wrong model number.
The idea is to have 2-12" plus horn that is very efficient without a ton of wattage... And without breaking the bank. I entertained building the PM90 cabinets but cost was a little high.
I don't know your location, but here in the US the B&C 12NDL76 is $227 and the Eminence deltalite-2512 is $169. Both are neodynium magnets which are rare earth magnets. If you could stand 3 lb more per driver for alnico magnet, the eminence Deltapro-12A is $139. Still an aluminum basket for flatter high frequency impedance rise (due to flux heating up a steel basket).
Watch those watts. 12NDL76 was *800 W continuous" but they don't tell you that is music power, and low crest music at that. That driver also has a "400 w" spec, which would be AES and more likely to prevent burnups if you're driving hard & compressed on stage.
I meant double Vbox instead of VAS in previous for 2 12" drivers, I don't know really how that works on box size. Mr. Weems didn't cover it. Whatever, don't make any two dimensions of the box the same. That doubles size of the internal reflections at one frequency.
Best bargain here in US is used speakers. I picked up some low use SP2(2004) last year for $200 each, Took me 9 months to find them, and a 300 mile drive RT, but the cost of one bass & horn driver is $340. The crossover & box are free. Bands leave the road all the time, have to liquidate to pay the rent. Need cash now! Craigslist for used equipment here in US, Gumtree in UK. Ebay has speakers but shipping is not economic for things that big. Have to be local pickup. I had to scan 8 craigslist locations musical instruments to find the SP2. Were in a city 150 miles away. I listened to the SP2 with a CD player & an amp to check the drivers were original. Boxes with trashy replacement drivers are no bargain unless hugely discounted.
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The B&C 12NDL76 is 400w AES, 800 "continuous" (3" voice coil), compared to the Eminence Deltalite-2512's 2.5" voice coil with a bit more than half the power rating at 250w AES, 500w music program (also double the AES rating). The B&C 12NDL76 has a higher Fs and a smaller Vas, better for smaller boxes. More Xmax too, cleaner at higher excursion.
In the suggested 42L 65Hz Fb box, it's 3dB down point is 68Hz, plenty low considering you are using subs.
Indianajo evidently is reading the B&C charts wrong (they can be hard to read..). Due to having nearly double the Bl (magnetic strength) the 12NDL76 is near the same sensitivity (slightly less below 250Hz slightly more up to 900Hz) as the DL-2512, and the higher power rating will result in less thermal compression- you get what you pay for. The charts below compare the infinite baffle in wall response of the two drivers.
As far as HF drivers, going with 3" diaphragms to keep up with a pair of high power 12" crossed in the 1kHz/1.25kHz region is a good idea, though better (more uniform dispersion past 10KHz) horn options are available in a 1.4" exit diameter than 2".
If you are planning to use a pair of trap cabinets per side, the HF horn dispersion -6dB point should be no more than 60 degrees to avoid comb filtering- unfortunately the only 60x40 horn B&C offers in 1.4" is the huge ME64.
Art
18Sound XT1464 gives pretty decent pattern control and loads low enough to be a good candidate for this kind of project.
B&C responded to my inquiry about the cabinet design. Here's what they said:
we don’t have at present a design consisting in two 12” and HF driver.
The only one available uses a single 12” + 1.4” HF driver.
This is the F122AN, you can find this design under the “Suggested Design “section on our website (https://www.bcspeakers.com/en/resources/suggested-designs/)
This design uses the 12NW76 woofer that is a better match with the HF driver (DE820).
You can modify this design to use two 12NW76 as follows:
- double the internal height of the cabinet (to double the internal volume)
- use two reflex ducts instead of one (same diameter and length of the one indicated on the drawing)
- the 12” should be wired in series connection, to avoid level unbalance with the HF driver. Hence the low pass section of the crossover filter have to be modified, doubling the inductor value ( 2.5 à 5 mH) and halving the capacitor value ( 30 à 15 uF).
we don’t have at present a design consisting in two 12” and HF driver.
The only one available uses a single 12” + 1.4” HF driver.
This is the F122AN, you can find this design under the “Suggested Design “section on our website (https://www.bcspeakers.com/en/resources/suggested-designs/)
This design uses the 12NW76 woofer that is a better match with the HF driver (DE820).
You can modify this design to use two 12NW76 as follows:
- double the internal height of the cabinet (to double the internal volume)
- use two reflex ducts instead of one (same diameter and length of the one indicated on the drawing)
- the 12” should be wired in series connection, to avoid level unbalance with the HF driver. Hence the low pass section of the crossover filter have to be modified, doubling the inductor value ( 2.5 à 5 mH) and halving the capacitor value ( 30 à 15 uF).
The B&C ME60 horn with a 1.4 to 2" adapter could be another option. I have boxes here loaded with the Deltalite 2512, they are a single 12 design but I did test out a dual driver config just for fun and they can produce quite a lot of output. I wouldn't agrue against using a more powerful driver though, if these will be used outdoors the deltalite would likely be run for all its worth which isn't ideal, it's always better to have more driver than needed for reliability purposes. Maybe consider the Kappalite 3012HO as a candidate instead.