THANK YOU. This is exactly what my goal is. We invested over $2500 in 18TBX100 drivers back in 2009. Were they the best drivers on the market? Probably not. But they were an excellent value proposition that we knew would work well for future projects, like this enclosure upgrade. We never wanted to keep the Yamaha boxes, but like anything, you make the best of what you can afford at that time.
I see BR designs everywhere I go from Red Rocks to indoor arenas. There must be a reason for this.
I am hoping I can build 4 new enclosures with covers for around $2000. Combine this with the investment made in the B&C drivers, and hopefully I'll have something that mimics (meaning comes close) to touring quality BR subs at a fraction of the cost. To offer perspective, there is an ad on SoundBroker for 6 L-Acoustic SB218s. For $17000. Got cash?
I just want the absolute best I can get with what we've got. The BR design really works best for our needs.
OK, 24" is your desired width, but what is your max acceptable depth, height as the best overall performing reflex alignments are high aspect ratio ones [aka MLTL, ML-TQWT]?
GM
GM
Sounds like you're on the right track. It would be helpful to go back to your first post and update it with some design criteria - external dimensions, freq response -3db point, weight, material cost per unit, amplification and EQ used, etc. Then post your design so far.
Saying you've "never heard them sound good" is just ridiculous. Because A. What are the details of EVERY setup YOU have heard that never sounded "good"
And B. what were you A/B'ing against that the tapped horn was the poorer performer? Or you've never done an A/B with proper setup for BR vs. tapped horn?
Box size is larger that's known. But driver price is much lower. Extension is directly proportional to box size so that's known up front before you build as well. Gotta have a realistic idea of what size cabinet you can live with for target SPL.
DSP is a must, so phase is no problem with proper setup and system integration.
Bandwidth, we are talking about subwoofers here. Not low mid tapped horns so a full two octaves with a peak at upper response is fine, it will actually sound "punchier" to most people with stronger upper response as opposed to a BR with flat upper response. Again this is with proper integration to match the top speakers, using DSP this is not a problem.
I'm not pushing one design over another, but just don't make statements like that for no good reason.
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Yes TB46, I am at work, so it will take me a little time to read the thread and check out your PDFs.
GM - 24' is correct. I was originally at 24x52x30 but revised to 24x48x32 because whether we set the subs vertical or horizontal, the height to lift our 215lb TX8s off the ground will be the same. In doing so, the internal volume came down a little- from around 16 c/ft to 15.5 c/ft. We can go back however.
Generally speaking, as long as the internal volume stays the same as well enclosure tuning, the rectangle shape of the box doesn't matter, right..??
Here is a pic of our speaker stacks. We actually have 3 pairs of SW218s, 2 loaded with the B&Cs.
This is the musical group: www.6milliondollarband.com
GM - 24' is correct. I was originally at 24x52x30 but revised to 24x48x32 because whether we set the subs vertical or horizontal, the height to lift our 215lb TX8s off the ground will be the same. In doing so, the internal volume came down a little- from around 16 c/ft to 15.5 c/ft. We can go back however.
Generally speaking, as long as the internal volume stays the same as well enclosure tuning, the rectangle shape of the box doesn't matter, right..??
Here is a pic of our speaker stacks. We actually have 3 pairs of SW218s, 2 loaded with the B&Cs.
This is the musical group: www.6milliondollarband.com
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OK, just wanted to make sure.
A T/S max flat alignment for dual drivers can take up to ~11 ft^3 net using published specs, so a ~15.5 ft^3 cab gives some tuning flexibility, but will wait till you answer turbodawg’s Qs before ‘running the numbers’.
GM
^agreed. Height should be 45" so one can lay the boxes on their sides and fit two across on a large truck (90"). Unless you had specific packing figured out already. But then that limits you to only using that one trailer or that one truck.
Sorry, I've just never heard them sound good. One time was with a Danley TH-118 in a large room supporting a band, the other was a pair of TH-118 in a local night club. Neither sounded impressive to me, they sounded wooly and bloated. They also sounded poorly integrated, which was clearly a setup issue. IMHO.
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Here is my very crude prelim design (looks a lot like a GSub, eh?? Or a Peavey SP218, or a QSC GP218..whichever you prefer). I've revised the external dimensions now to be 48"x24"x32" and this has been updated in my BassBox Pro box calculations. In answer to Turbodawg's questions and to provide some additional specs;
1. This is a dual chamber design
2. With a 1.5" front baffle recessed 2 inches, less the width of the center baffle, I am calculating the internal dimensions @ 22.5 x 45.75 x 28.75 approx 15.5 ft^3 but I still need to subtract for bracing and the wheel cutaway which I have not done yet
3. Fb = 34hz currently; F3 = 33.53hz
4. 3/4" Baltic Birch plywood (Home Depot)
Crossover: 100hz as preset in Yorkville TX8P, DBX-312 EQ for high pass filtering
Subwoofer amp: Crown XLS-5000 2500wpc @ 2ohms
Desk: Midas Venice F32
Packing our 15' truck will not be an issue. We can rearrange as needed, I don't know what the material costs are yet. I am guessing each box will be 180-200lbs. Anything else?
1. This is a dual chamber design
2. With a 1.5" front baffle recessed 2 inches, less the width of the center baffle, I am calculating the internal dimensions @ 22.5 x 45.75 x 28.75 approx 15.5 ft^3 but I still need to subtract for bracing and the wheel cutaway which I have not done yet
3. Fb = 34hz currently; F3 = 33.53hz
4. 3/4" Baltic Birch plywood (Home Depot)
Crossover: 100hz as preset in Yorkville TX8P, DBX-312 EQ for high pass filtering
Subwoofer amp: Crown XLS-5000 2500wpc @ 2ohms
Desk: Midas Venice F32
Packing our 15' truck will not be an issue. We can rearrange as needed, I don't know what the material costs are yet. I am guessing each box will be 180-200lbs. Anything else?
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Note that home depot does not sell baltic birch AFAIK. They sell 5-ply "birch" which is actually poplar faced with birch. They do sell some fairly nice cost effective poplar ply:
PureBond 23/32 in. x 4 ft. x 8 ft. Poplar Plywood-770579 at The Home Depot
Baltic birch will run you about twice as much.
PureBond 23/32 in. x 4 ft. x 8 ft. Poplar Plywood-770579 at The Home Depot
Baltic birch will run you about twice as much.
On the bracing, I prefer to see the unsupported panel span to kept to around 8". So that means 2, maybe 3 braces on the 30" side and 2 per chamber on the 52" side. If that makes any sense. I would also rather see a 3"x1/2" brace vs. a 2"x3/4".
I see. Is the Baltic Birch worth the extra cost? If Poplar Ply give us 98% of BB at half the cost, we'll look in that direction. Ok on the braces, can do.
Both Lowe's and HD locally sell it, though you must order it at the service desk and pay in advance. According to both, if it can be had through a local distributor they have an account with, they will order it and the pricing I've gotten is at the going rate or a little less, so at worst they save me the long haul to get it since both are almost only walking distance away.
GM
GM
I was thinking about the necessary delay for timing correction with big lengthy horn paths when the driver is not front loaded, and internal diffractions or reverberations.
How to Calculate a Delay Tower
Understanding Cabinet Diffraction ? Audioblog
http://www.synaudcon.com/site/wp-content/uploads/2011/12/Notes-Pages.pdf
You can make it from cement coated cardboard if you brace it enough, so material choice boils down to how durable they must be and how much effort/space you're willing to devote to bracing, reinforcing corners, etc..
GM
I've built with home depot 1/2" (3-ply) and 3/4" (5-ply) with good results, but many people on here think it's a bad idea due to the possiblity of voids causing an issue. I would cost out both options. All high end pro cabs I'm aware of use real baltic birch.
HIFI/HT apps need no-void plus rigidity to ensure no little aggravating resonances, but prosound is at such a high SPL that this is moot. Sufficient bracing is required though to keep it from 'drumming'/maximize acoustic efficiency.
GM
GM
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