No delay for the tops needed in TH land, like you have to do with FLH.
qsc 152i's on each side vertically stacked with horns together is a pretty good setup for tops. You'd need to go 4 'OT style' per side to get appreciably better sound quality.
Just a guess, you are probably reasonably happy with 4TH's and 4 152i's, and going DIY for the tops is not going to gain you much, unless you need a ground stacked 'line' for larger outdoor shows. (which you might be considering, since you stated you'd build 4 more TH.) If you do that, increase your cabinet depth to 23" for stability, but keep your port tuning around 95-100hz -- and go 6 drivers high per side. (My 2c)
Again, congrats on your setup -- looks like fun.
I know one thing.... I'm gonna need a BIGGER trailer. LOL
Thanks for all your help Jim. keep up the great designs.
Regards,
SHAWN
Thanks for the encouragement. Right now I'm going through several installs where things have to be up high... so guess what, the big box is being shrunk.
Here's a set of eight 24" cubes at 63v each in 2pi that is safe xmax wise to 35hz, that I'm starting a run of. Each cube can be made from a single 42lb sheet of 1/2" ply. (quite the contrast to 2 sheets of 72lb ply each.) Yea it takes more power/drivers to get there, but my back will like me better the next day.
Not sure I want anyone dancing on 24" cubes... so the big box is probably right at home for you.
If it tests out well enough to post plans, I will. (maybe don will be kind enough to draw up something pretty for me again....)
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Will do. The small cabinet is not very creative... it's just a squashed version of the big cabinet. (I included the s1,s4,L23 for anyone curious)
And no, it does not compete down low with the big cabinet... for that, the big cabinet, well, lets just say I smile when I hear it.
Here's my arm chair quarterback sims. Looks like in a block of 4 they are very respectable to 40hz. In singles, the small cabinet is lacking.... Only testing will show if it has anywhere near the directionality of the big cabinet, and what resonances/reflectors are needed (if any) to get a good 'sound.'
EDIT: oops, just realized I didn't check xmax on big cabinet, 50v is all you should put into that to stay within 9.6mm xmax, which is 2db lower overall than what my graphs show. (with an xlim of 17mm you are safe with more power, just distortion will be setting in.) The big cabinet is safe xmax wise down to 32hz.... woof.
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Having simmed tapped horns endlessly with hornresp (I currently don't have the funds available to build my own) I came to the conclusion that the majority of 15" drivers are limited to 50V or less to keep within X-max.
This relates roughly to using a 300W@8 ohm amplifier.
With an 18" driver the X-max is not reached in the passband at the rated power, until the cabinet is nearly 600 litres or bigger
For example
Void Acoustics V1000 18" 1000W 10.5 xmax
Precision Devices PD 1850 800W 11.5 xmax
Or even the new PD1851 1000W 12mm xmax
These drivers seem to be able to keep within xmax at 89v which equates to
1000W @ 8ohms
As Danley says about the TH 118 Lower & Louder!
I'm in no way a PA expert, but some of the texts that I've seen suggests that many drivers would be at least starting into power compression at that level. At that high power level, T/S parameters also shift and the output no longer matches what the model predicts.
Looks like the Void is very hard to find at the moment, but these 18" drivers have a 5 inch voice coil and low power compression.
Precision Devices PD 1850 1.6db compression at 800W
Precision Devices PD 1851 1.7db compression at 1000W
The Eminence 3015lf is a great 15" driver for a tapped horn, mostly due to its long excursion and price. But if the size of the rig is an issue these 18" drivers might give more headroom per cabinet....
The new lighter boxes
JBell,
which drivers will you use? Just wondering if they will be easily available this side of the pond.
A cut-down version sounds great, for small gigs I currently have no subs. The gigs needing the real big TH seem to be only every 2 months.
Am I correct in assuming that the large and small tapped horns should not be mixed, just like BFM horns?
Regards, Ben
JBell,
which drivers will you use? Just wondering if they will be easily available this side of the pond.
A cut-down version sounds great, for small gigs I currently have no subs. The gigs needing the real big TH seem to be only every 2 months.
Am I correct in assuming that the large and small tapped horns should not be mixed, just like BFM horns?
Regards, Ben
Having simmed tapped horns endlessly with hornresp (I currently don't have the funds available to build my own) I came to the conclusion that the majority of 15" drivers are limited to 50V or less to keep within X-max.
This relates roughly to using a 300W@8 ohm amplifier.
With an 18" driver the X-max is not reached in the passband at the rated power, until the cabinet is nearly 600 litres or bigger
For example
Void Acoustics V1000 18" 1000W 10.5 xmax
Precision Devices PD 1850 800W 11.5 xmax
Or even the new PD1851 1000W 12mm xmax
These drivers seem to be able to keep within xmax at 89v which equates to
1000W @ 8ohms
As Danley says about the TH 118 Lower & Louder!
The best 15" driver for a TH is probably the BMS15N850, this has 16mm Xmax (using the same formula as the other drivers) and is fine up to 1kW.
There are 18" drivers with even more Xmax if you want to go beyond 1kW to allow bigger peak power handling, not continuous rating:
(see spreadsheets here)
14mm :18sound 18NLW9600, B&C 18SW115, Turbomax 1800i
16mm : BMS 18N850V2
(the TH118 uses the 18NLW9600)
Does the Vas difference mean this is not suitable as a drop-in replacement for a blown 3015 LF?
15N850
Fs Hz 37
Re Ohm 5.6
Qms 7.38
Qes 0.34
Qts 0.33
Vas L 110.96
Mms kg 0.167
Cms mm/N 0.17
BL 25.2
Sd m2 0.0845
Xmax mm 13
Le1k mH 1.43
Le10k mH 0.58
3015LF
(fs) 42Hz
(Re) 5.31
(Le) 0.92mH
(Qms) 6.82
(Qes) 0.41
(Qts) 0.39
(Vas) 158.8 ltr/5.6 cu. ft.
(Vd) 846cc
(Cms) 0.14mm/N
(BL) 18.6 T-M
(Mms)101 grams
(EBP) 102
(Xmax) 9.6mm
(Sd) 881.1cm2
(Xlim) 17.0mm
Regards, Ben
15N850
Fs Hz 37
Re Ohm 5.6
Qms 7.38
Qes 0.34
Qts 0.33
Vas L 110.96
Mms kg 0.167
Cms mm/N 0.17
BL 25.2
Sd m2 0.0845
Xmax mm 13
Le1k mH 1.43
Le10k mH 0.58
3015LF
(fs) 42Hz
(Re) 5.31
(Le) 0.92mH
(Qms) 6.82
(Qes) 0.41
(Qts) 0.39
(Vas) 158.8 ltr/5.6 cu. ft.
(Vd) 846cc
(Cms) 0.14mm/N
(BL) 18.6 T-M
(Mms)101 grams
(EBP) 102
(Xmax) 9.6mm
(Sd) 881.1cm2
(Xlim) 17.0mm
Regards, Ben
It's not the Vas difference as such that matters, it's the fact that all the T-S parameters (BL, Mms, Cms) are different.
Depending on the box design it might or might not work as a drop-in replacement in the same cabinet, try simulating in Hornresp to find out.
Note that the BMS Xmax spec (13mm) is the conservative "linear Xmax" number (voice-coil overhang), most manufacturers now add Hg/4 or Hg/3 to get a bigger number which is supposedly closer to the 10% THD point (which I believe is what Eminence now use for the 3015LF 9.6mm figure) -- the BMS would be 16-17mm using this method, which means about 5dB more output or 3x the Xmax-limited power handling.
But the BMS driver is also about twice the price...
Depending on the box design it might or might not work as a drop-in replacement in the same cabinet, try simulating in Hornresp to find out.
Note that the BMS Xmax spec (13mm) is the conservative "linear Xmax" number (voice-coil overhang), most manufacturers now add Hg/4 or Hg/3 to get a bigger number which is supposedly closer to the 10% THD point (which I believe is what Eminence now use for the 3015LF 9.6mm figure) -- the BMS would be 16-17mm using this method, which means about 5dB more output or 3x the Xmax-limited power handling.
But the BMS driver is also about twice the price...
You read my mind... mini clone was my target, using a 3015lf and having nothing but sawdust left over from a single sheet of ply. The cube shape won't look as nice as the mini, and it's not as small... but it should be a super quick build. (which is very important to me.)
TH fanboy ready to build some more!
Speed and economy are two very important factors. Especially in combination with weight reduction. If this gets off the ground, I will build some.
Will the response be unchanged by adding more, like the big TH, or will stacking more make them play lower, like the BFM horns?
Regards, Ben
Speed and economy are two very important factors. Especially in combination with weight reduction. If this gets off the ground, I will build some.
Will the response be unchanged by adding more, like the big TH, or will stacking more make them play lower, like the BFM horns?
Regards, Ben
Ben & Flip:
Ben: check my 1 cab and 4 cab sims. Yes it plays lower in a pack, look specifically at the 40hz mark on each.
Flip:Yea more 3015lf excursion would be nice in the big cabinet, but in the small cabinet I'm good above 40hz up to 63v. Not sure the Vc really wants much more than that, so more excursion would be a waste. I think this cube is about as good a fit for a 3015lf as I've been able to come up with.
As far as easy... Rip 4x8 sheet 24" wide on table saw, turn and cross cut 2 panels 24x24 for side/side. Then move fence to 23.5" and crosscut 24x23.5 top/bottom. Take the other half and rip to 23. Crosscut a 23x23.5 for the back, move fence to 15, cut 2 at 23x15 for front and baffle, move fence to 11, crosscut 1, move fence to 10, crosscut 2. Use circle jig to cut baffle opening -- All done, and the about 10" long left over is there to make braces out of.
Nothing left over but dust...
Ben: check my 1 cab and 4 cab sims. Yes it plays lower in a pack, look specifically at the 40hz mark on each.
Flip:Yea more 3015lf excursion would be nice in the big cabinet, but in the small cabinet I'm good above 40hz up to 63v. Not sure the Vc really wants much more than that, so more excursion would be a waste. I think this cube is about as good a fit for a 3015lf as I've been able to come up with.
As far as easy... Rip 4x8 sheet 24" wide on table saw, turn and cross cut 2 panels 24x24 for side/side. Then move fence to 23.5" and crosscut 24x23.5 top/bottom. Take the other half and rip to 23. Crosscut a 23x23.5 for the back, move fence to 15, cut 2 at 23x15 for front and baffle, move fence to 11, crosscut 1, move fence to 10, crosscut 2. Use circle jig to cut baffle opening -- All done, and the about 10" long left over is there to make braces out of.
Nothing left over but dust...
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you caught me editing my post (doing this from memory, as I'm not in the shop...) back is 23x23.5
Here is a cartoon of what I remember. (dimensions are approximate, could be up to 1/2" off)
I really didn't want to post anything until I had a couple built/tested. oh well... anyone wanting to jump in early -- go ahead.
Here is a cartoon of what I remember. (dimensions are approximate, could be up to 1/2" off)
I really didn't want to post anything until I had a couple built/tested. oh well... anyone wanting to jump in early -- go ahead.
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