Subs - 21" vs 18"

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steve149 said:
The downside to most horn loaded designs is the open horn (aesthetics). And the downside to many home built setups I've seen is that they look home built .. or maybe 70's vintage.

For parties, proms, dances, it doesn't mean squat, but I've found, at least around here, that the open designs have lost aesthetic favor from the more formal event goers .. and scoops, earthquakes, and even open horned tops just aren't looked at favorably .. a reason I sold off my older pieces (Yamaha Club 15s, JBL MP215s, and Mackie SRM150s).
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Agreed but I think sound has the right gameplan here. At 20" width, lay them on their side and either hide them under the table or off to the side somewhere, maybe with a drape over them. I agree it needs to look good but it just tickles me when I get those comments about how great it sounds and they don't realize I'm using subs.
 
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soundinmotiondj said:
Duratex coating is EASY to roll on or spray on. This is the "modern" looking cabinet coating that most touring gear is using. Carpet (aka "rat fur") is so last century.

Here is a stack of four T39's with a V-plate. These are "hidden" behind a backdrop at the event.

View attachment 26213

Here are two T-39's and my DJ facade at an outdoor event. You can see a DR200 on a stand peeking out from behind the stone column.

View attachment 26214

Here is a pile of T39's and DR200's during the load in at a large event. There are ten of each cabinet in that pile. This is a cell phone pic...so it's a little blury.

View attachment 26215
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You have done them justice.

As I said, it's not a performance thing, as I'm sure those can out run what most put out, around here, it's aesthetics. Once they see the more current designs (duratex coated, rounded corners, full face grill, etc.), things like open horns and corner reinforcements then look last century.

For non-formal events, it really doesn't matter (and again, only from the prospective of some of the clients I have worked with up here).

I think it's the reason that some vendors (like Danley and JTR) have been moving to grills over their horns.
 
rickryan.com said:
Okay, now you're really twisting me up. When you say "BP102" are you talking Eminence BP102 (cheap) bass guitar drivers? I've been bracing for some ultra-expensive, long-excursion drivers. So, you're suggesting using an 8-ohm driver instead of a 4? Admittedly, I'm behind where you guys are but lets say I use that Carvin 3800lx amp. With a 4-ohm driver, 1 cab per amp side, I'm hitting each cab with 1150 watts vs 700 watts if I'm using an 8-ohm driver. Obviously, 8-ohm cabs would let me stack 4 cabs off that one amp (2 per side) but for the gigs I typically do I have a hard time seeing the day I'll want more than 2 cabs on a gig. Educate me some more, please.
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Yes. I use the Eminence BP102 "cheap" bass guitar drivers in my subs. The BP102 was/is the recommended driver for the narrowest version of the T39...14" wide external. These are 8ohm drivers.

Watts are really not the way to think about amps. Amps produce voltage and current.

Each doubling of watts will produce AT MOST +3dB of additional SPL. But, starting about 200w, power compression will start reducing that theoretical +3dB gain into something less, as the driver heats up it becomes less efficient. Above 400w, the net SPL gain is under +2dB per doubling of watts for most drivers (there are exceptions...the neo magnet drivers do especially well).

100w->200w = +3dB. 200w->400w = +3dB. 400w->800w = +3dB. 800w->1600w = +3dB.

Adding power above about 400 W takes a LOT of additional power, for not a lot of additional SPL.

Horns work best in BIG piles. A single horn is still good...but horns really benefit from having lots of friends along. In the V-plate arrangement shown above, the additional horn path covered by the plate causes the corner frequency actually drops by about 5Hz. That does not happen with a direct radiator.
 
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soundinmotiondj said:
Duratex coating is EASY to roll on or spray on. This is the "modern" looking cabinet coating that most touring gear is using. Carpet (aka "rat fur") is so last century.

Here is a stack of four T39's with a V-plate. These are "hidden" behind a backdrop at the event.

View attachment 26213

Here are two T-39's and my DJ facade at an outdoor event. You can see a DR200 on a stand peeking out from behind the stone column.

View attachment 26214

Here is a pile of T39's and DR200's during the load in at a large event. There are ten of each cabinet in that pile. This is a cell phone pic...so it's a little blury.

View attachment 26215
Click to expand...
That is what I use on my JBL Scoops, Duratex. As long as the speakers are not beatup I think they look just fine. Again the key to ready acceptance is to not have a clump of speakers around the DJ Booth to make things conspicuous. Big tall speakers such as The EV Quakes, JBL Scoops, Danley's etc may be taller than the conventional subs but take up just about the same footprint/space.
 
Aesthetics are subjective. This is one of the reasons that I prefer to hide the sound system.

Here is an example. The sound system is behind the backdrop. The subs are centered on the "circle logo". The tops are behind the drapes, about 10ft from either end of the stage, and are about 10ft off the floor. The room is just over 10k sqft. The camera position is about 60ft from the tops (the floor was 50ft deep, with a 8ft wide stage). I have no idea about the camera specs...this is just a random video I found from the event. At the camera position the SPL was in the 96-98dB (C-weighted, fast response).

[video=youtube;uWkZUjHXkVg]http://www.youtube.com/watch?v=uWkZUjHXkVg[/video]
 
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Haven't you always wanted your very own race car Wes? Driving it down residential streets is a bonus - I'm thinkin' more like Beale St, which is not residential!
 
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DJ Wes said:
If these T39's are as good as stated, wouldn't that be like driving a race car only on residential streets?
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To be clear, there is nothing magical about any particular piece of hardware. The physics of sounds applies equally to all gear. What is different, is that the DIY community (at least Bill's forum) takes the time to help educate builders about proper speaker placement, setting gain structure, setting limiters, and so on. That knowledge is at least as important (if not more so) than the specific hardware. I can use what I have learned to help make any PA system sound better.

Even so, because I followed the DIY path, and built a large modular system, I always have enough rig for the gig. So, I am able to "coast" my gear on "5" or "6" instead of having to run things on "11."
 
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soundinmotiondj said:
To be clear, there is nothing magical about any particular piece of hardware. The physics of sounds applies equally to all gear. What is different, is that the DIY community (at least Bill's forum) takes the time to help educate builders about proper speaker placement, setting gain structure, setting limiters, and so on. That knowledge is at least as important (if not more so) than the specific hardware. I can use what I have learned to help make any PA system sound better.

Even so, because I followed the DIY path, and built a large modular system, I always have enough rig for the gig. So, I am able to "coast" my gear on "5" or "6" instead of having to run things on "11."
Click to expand...

How would you rate those T39s, LAB drivers, 4-ohm, amp at 880watts against cube 18 radiators (like the JBL m-pros that I have)? Just thinking through this some more, I'm wondering if a good typical setup would be to couple these on the floor, at the front of the DJ table and put a drape over them. I'm thinking it would also act somewhat as a facade and keep drunks (and their drinks) from being hung over my PC/mixer. Also, didn't catch your thoughts on the $1150 price (pair).

@Wes - As long as I'm the guy driving the race car (and not my competitor), I'm cool with that. ;)
 
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rickryan.com said:
How would you rate those T39s, LAB drivers, 4-ohm, amp at 880watts against cube 18 radiators (like the JBL m-pros that I have)? Just thinking through this some more, I'm wondering if a good typical setup would be to couple these on the floor, at the front of the DJ table and put a drape over them. I'm thinking it would also act somewhat as a facade and keep drunks (and their drinks) from being hung over my PC/mixer. Also, didn't catch your thoughts on the $1150 price (pair).
Click to expand...

I have not heard either cabinet configuration you mention. There are detailed SPL charts on Bill's site, all in half space unless labeled differently. I don't recall the specific JBL model you have...but the MP418P spec sheet includes a SPL chart.

http://billfitzmaurice.info/forum/viewtopic.php?f=12&t=487

http://www.jblpro.com/mpro/PDF/MP418S.pdf

Bill's site also has a post on appropriate sub placement. In front of a table will not meet those guidelines.

http://billfitzmaurice.info/forum/viewtopic.php?f=10&t=398

The price seems reasonable.
 
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