Drivers for 2x10 +1

[Ludo]

Looking for feedback on whether these drivers would be reasonable for a small, 2x10+1 PA system that will be used primarily for outdoor events and parties for music playback and announcements? The coverage needs to extend up to ~150x150 feet and these would be used with one or more subs.

2 x B&C-10CL51, 10" driver http://www.bcspeakers.com/product.php?id=0000000186

Radian 475PB-8, 1" compression driver http://www.parts-express.com/pe/showdetl.cfm?Partnumber=294-702

Selenium HM25-25, 1" throat horn http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-312

Louis

[Randy L]

Since you say it will be used outdoors, you should seriously consider using at least two 18" subs (or some great folded horn designs using smaller subs) for decent bass. With that said, the frequency response curve of the 10's show it rolling off pretty high for a sub, which typically crosses over at ~80hz.

I'd recommend getting at least two 12" drivers per side, with 15" woofers in a full range PA being the best choice. OR...you could do what I did for outdoor events (large corporate picnics, and block parties).

I ran (dual 18" but you should be OK with a single 18") subs per side topped off with a bi-amped speaker consisting of a 15" woofer, two 8" mids and an compression horn. Instead of that expensive Radian driver, take a look at the Selenium compression drivers, namely the DH220.

What will you be using as a crossover?

[Paul O]

the frequency response curve of the 10's show it rolling off pretty high for a sub, which typically crosses over at ~80hz.

Agreed, you'll have to find another driver that provides some more low end extension, though I don't think you will have to go to a larger driver to get that, a Deltalite 2510 should do it. But you will have a problem covering an area that wide unless you have at least 2 cabinets side by side and splyed around 60degrees. If this was just going to be used as a single point system in this application then you're good with 2 cabinets but if you want speakers each side of a stage then you need 4 tops.

[Ludo]

I am wondering why you guys are saying that the 10" B&C drivers would not have adequate low end extension? They have 5.5mm of x-max and when I model 2 in a 40L ported enclosure tuned to 65Hz, I get an F3 of 70Hz and an output of 120dB at 1m with 200W; so at 50m that should still be a decent 86dB.

Also, I was thinking of a 1.2KHz x-over with the horn.

The 18" subs sound good. Would you expect any degradation in the sound quality with the 18s vs a larger number of 15s?

Louis

[Music is life]

I am wondering why you guys are saying that the 10" B&C drivers would not have adequate low end extension? They have 5.5mm of x-max and when I model 2 in a 40L ported enclosure tuned to 65Hz, I get an F3 of 70Hz and an output of 120dB at 1m with 200W; so at 50m that should still be a decent 86dB.

Also, I was thinking of a 1.2KHz x-over with the horn.

The 18" subs sound good. Would you expect any degradation in the sound quality with the 18s vs a larger number of 15s?

Louis

Because they are being raised up off the ground (or floor) so the crowd can here them better. This is the first place where you are losing a lot of bass. 2 10's are a good idea, but with subs.

JMO

[Ludo]

Because they are being raised up off the ground (or floor) so the crowd can here them better. This is the first place where you are losing a lot of bass. 2 10's are a good idea, but with subs.

JMO

I am not questioning the need for subs, as I stated in my original post, but I'm not clear why the B&C10CL51 lacks adequate low frequency extension to reach down to 80Hz? I suppose there will be a 6dB loss from 4-pi radiation when mounted on poles, but I was figuring that could be eq-d out?

Louis

[Paul O]

Well.. I based my comments off the response curve, with the falling response below 150hz I didn't think the driver would handle much power at the low end of the spectrum, but after modeling it that doesn't seem to be the case.:o Using the same tuning you described the box will handle 500w at xmax and produce 125db above 100hz which is quite good. It looks like that comp driver will handle a 1.2khz crosover as well, but assuming a stacked driver arrangement you will have to either employ a semi 3-way crossover so only the driver next to the horn covers all the way to the crossover frequency or use an MTM driver arrangement to minimize comb filtering between the 10's at the crossover.

[Ludo]

Well.. I based my comments off the response curve, with the falling response below 150hz I didn't think the driver would handle much power at the low end of the spectrum, but after modeling it that doesn't seem to be the case.:o Using the same tuning you described the box will handle 500w at xmax and produce 125db above 100hz which is quite good. It looks like that comp driver will handle a 1.2khz crosover as well, but assuming a stacked driver arrangement you will have to either employ a semi 3-way crossover so only the driver next to the horn covers all the way to the crossover frequency or use an MTM driver arrangement to minimize comb filtering between the 10's at the crossover.

Thanks for taking a look at that driver Paul. I looked at the 2510 and it models better in a larger enclosure, will play lower, and it also appears to have a beefier magnet structure with heat sinking, but I'm not sure all of that is necessary for my application. Its also a bit more expensive.

One other thing I am wondering about is that the 1" driver/horn combination appears to roll of in the top octave. Is the best way to handle that by applying eq or by using a slotted type of super tweeter? I would think the super tweeter would maintain more uniform horizontal dispersion.

Louis

[Paul O]

I wouldn't worry about some high end rolloff it sounds more natural to my ear anyway and if it is something you feel you want/need to correct for it's not hard to do with an EQ.

[Music is life]

I am not questioning the need for subs, as I stated in my original post, but I'm not clear why the B&C10CL51 lacks adequate low frequency extension to reach down to 80Hz? I suppose there will be a 6dB loss from 4-pi radiation when mounted on poles, but I was figuring that could be eq-d out?

Louis

Hey Louis
Yes, my misunderstanding. Read too fast.
IMO 80hz is possible with that driver but I would not do it. Personally, I would build smaller and cross over at 100Hz or pick another driver.
JMO

[Ludo]

I wouldn't worry about some high end rolloff it sounds more natural to my ear anyway and if it is something you feel you want/need to correct for it's not hard to do with an EQ.

Ok, I'm inclined to buy a couple of these drivers and start experimenting with the MMT and MTM configuration.

Louis

[Ludo]

Hey Louis
Yes, my misunderstanding. Read too fast.
IMO 80hz is possible with that driver but I would not do it. Personally, I would build smaller and cross over at 100Hz or pick another driver.
JMO

Any specific suggestions for building "smaller" and which driver I should look at? I looked at some of the 8" drivers and they'd have a hard time keeping up with a pair of 10" drivers. I was thinking that the 2x10 configuration per side was already pretty small, with decent output, and as Paul suggested, I could double up on the number of cabinets per side when needing higher output.

Thanks,
Louis

[Music is life]

Any specific suggestions for building "smaller" and which driver I should look at? I looked at some of the 8" drivers and they'd have a hard time keeping up with a pair of 10" drivers. I was thinking that the 2x10 configuration per side was already pretty small, with decent output, and as Paul suggested, I could double up on the number of cabinets per side when needing higher output.

Thanks,
Louis

What I meant was build with this driver but smaller cu ft:
http://www.bcspeakers.com/product.php?id=0000000186
So make the cab small enough to have a bit of a bass hump and cross it over at 100Hz. Say 1.3 cu ft for 2 tens. You might not get that small depending on the depth of the tweeter horn and driver. So be careful there.

The 2510 I think will model better for what you are trying to do.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-591

That might get you your 80Hz. Depending how much volume you need.
Just some thoughts.
Perhaps others might have better advice.

[Ludo]

What I meant was build with this driver but smaller cu ft:
http://www.bcspeakers.com/product.php?id=0000000186
So make the cab small enough to have a bit of a bass hump and cross it over at 100Hz. Say 1.3 cu ft for 2 tens. You might not get that small depending on the depth of the tweeter horn and driver. So be careful there.

The 2510 I think will model better for what you are trying to do.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-591

That might get you your 80Hz. Depending how much volume you need.
Just some thoughts.
Perhaps others might have better advice.

I'll try some different cabinet size and tuning options with these two 10" drivers over the course of the next week before placing an order. It looks like they can both work down to 80-100Hz reasonably well.

Thanks,
Louis