Single sheet TH challenge

what are the effects of shrinking S1 (ala Othorn) for extra bracing of the driving mounting panel?

Another option is to double up on the mounting panel and using that extra layer to countersink the driver to ensure that when it's installed it lines up perfectly with the cutout in the panel (see example below), as even a small leak here has a significant impact on the response at lower end of the TH's passband.
 

Attachments

  • 20131229-phantasmo-2.jpg
    20131229-phantasmo-2.jpg
    263.4 KB · Views: 803
what are the effects of shrinking S1 (ala Othorn) for extra bracing of the driving mounting panel?

If you do that, but remove the cone correction pyramid, the response is about the same.

If you use neither, you lose about 1dB of output at 40Hz, and also get a small dip at 120Hz.

So I would go for either the narrow S1 or the cone correction for maximum output - my gut feeling is the cone correction would have a more symmetrical load on the cone, and thus less likelihood of cone damage at the high compression rate and outputs here.
 
- the back panel of the SS15 is 29x21" and that one doesn't have any inbuilt bracing..

actually the ss15 has 2 braces, one from the top to back panel, the other from the back to the bottom panel.

The panel with the most vibration is the front panel. An additional brace from the top to front panel cures that -- but requires material to be salvaged from the driver cut out to keep it as a single sheet.
 
Hi evereybody. Before three years I built two tapped horns - something very similar to TH-18 Flat to 35hz! (Xoc1's design), but in previous summer i decided to try different enclosure. I rebuild my existing enclosures, because i didn't want to pay 80 euro for plywood, because this was like a test enclosure and i wasn't shure about final result. My first project was too big and heavy and i just wanted something more compact and lightweight. And when i made cutlist i found that it is doable from one sheet including braces. I know that this is not a real tapped horn, but when i compared it with the first enclosure - side by side outdoor comparision, i found that there was only a slight low bass loss (40 hz and lower), but in other frequencies it sounded better, this is why i wrote in this thread. There wasn't big dips or rises in frequency response. In the second picture is spl measurement of the first project- black line is from 2 meters, red is hornresp. I didn't take 1w-1m measurement side by side because with ears i didn't notice difference from 45hz + in term of loudness and i was completely satisfied.
Box outer dimensions are 710x680x566, if build without casters, there will be only 90 degree cuts and in the third picture is a cutlist without plate for casters. In hornresp black line is small box and grey is big box. Driver is RCF LF18G401.
 

Attachments

  • l9ua.jpg
    l9ua.jpg
    154 KB · Views: 647
  • img0718g.jpg
    img0718g.jpg
    182.8 KB · Views: 637
  • duq8.jpg
    duq8.jpg
    82.8 KB · Views: 623
  • 95b5.jpg
    95b5.jpg
    81.1 KB · Views: 624
  • 2le5.jpg
    2le5.jpg
    220 KB · Views: 284
  • 7mnb.jpg
    7mnb.jpg
    182.7 KB · Views: 933
  • 4dot.jpg
    4dot.jpg
    141.3 KB · Views: 307
  • vtta.jpg
    vtta.jpg
    125.7 KB · Views: 304
  • mff1.jpg
    mff1.jpg
    71 KB · Views: 314
Hi evereybody. Before three years I built two tapped horns - something very similar to TH-18 Flat to 35hz! (Xoc1's design), but in previous summer i decided to try different enclosure. I rebuild my existing enclosures, because i didn't want to pay 80 euro for plywood, because this was like a test enclosure and i wasn't shure about final result. My first project was too big and heavy and i just wanted something more compact and lightweight. And when i made cutlist i found that it is doable from one sheet including braces. I know that this is not a real tapped horn, but when i compared it with the first enclosure - side by side outdoor comparision, i found that there was only a slight low bass loss (40 hz and lower), but in other frequencies it sounded better, this is why i wrote in this thread. There wasn't big dips or rises in frequency response. In the second picture is spl measurement of the first project- black line is from 2 meters, red is hornresp. I didn't take 1w-1m measurement side by side because with ears i didn't notice difference from 45hz + in term of loudness and i was completely satisfied.
Box outer dimensions are 710x680x566, if build without casters, there will be only 90 degree cuts and in the third picture is a cutlist without plate for casters. In hornresp black line is small box and grey is big box. Driver is RCF LF18G401.

Nice! Looks like hybrid TH or modified Cubo!
 
Here it is. When I compared my first tapped horn and this hybrid, I noticed that tapped horn sounded slower it wasn't so precise, but hybrid have a little less low end. I will try to find a frequency response, what I measured in summer without multimeter, but it will anyway show how it play. In fact I was very impressed, because it was smooth up to 165hz. When I listened to them outside, I couldn't notice who sounded louder, I thing that sensitivity should be in range of 103-104 db, meybe higher.
I am very happy with this box :) because it is one sheet project, I really like how it sound, it is easy to build, it is not so big and heavy like my first tapped horn, frequency responce is very smooth, there is almost no compression on driver at s2 - safer for cone, smaller diaphragm displacement comparing with tapped horn, small delay and finally that people just can't belive that so small boxes can create so much bass.
 

Attachments

  • hornresp.jpg
    hornresp.jpg
    88.4 KB · Views: 679
Prints of his 12 ss15?

Hello mr. FlipC, likewise have available 12 speakers Eminence Kappa Lite 3015LF, had made ​​six T48, but I'm not satisfied, because in Mexico DF I have to compete with clones of Yorkville LS1208 and Cerwin Vega L36 and 2x18 bass reflex, my question is.

1 -. The SS15 is competitive with models baffles I mentioned earlier?

. 2 - O for this purpose, it is preferable to make the ES15BL MicroHOG Staiper?

3.-How do I occupy the flat for their SS15?

4 -. SS15 Its 12 compared with 12 Cervin Vega L36, regarding SPL and sound sensation?

I hope you can guide me a bit since you already did that model, my idea is to make 24 or even 32 SS15 SS15, because here in Mexico DF use 32 to 40 Yorkville LS1208, as shown in the photos acontinuacion leave.


Here is the final result before the start of the night.
An externally hosted image should be here but it was not working when we last tested it.

Did a quick check at opposite end of room which read just over 115 DB. Room width is 112 feet. Setup is 15 feet off rear wall. Wasn't a sine wave. Was using Moby's GO 2006 remix.

It definitely fed my addiction for a bit.
 

Attachments

  • Yorkville-1jpg.jpg
    Yorkville-1jpg.jpg
    97 KB · Views: 587
  • Yorkville2.jpg
    Yorkville2.jpg
    159.4 KB · Views: 586
  • Yorkville3.jpg
    Yorkville3.jpg
    59.5 KB · Views: 308
I copied the LS1208 vs other subs (measurements not done by me) for reference.

I would say the ss15 and the ls1208 have similar fall off below 60hz, and would compare favorably in terms of overall sensitivity. The ss15 does not have the 80hz dip seen in this measurement of the ls1208.

The big difference is that the 3015lf is a 500watt driver, not a 2000watt driver.

I max out on the ss15 at about 128-129db per box. You can do your calculations from there.
 

Attachments

  • FreqRes1.jpg
    FreqRes1.jpg
    104.9 KB · Views: 310
129dB ?

JBell first of all thank you very much for taking the time and respond almost immediately, actually the graphics are not read, but reading your response, I assume, and correct me if I'm wrong, if I get 129dB SS15 each and every box I LS1208 gives 136dB, I imagine that will give me 6 SS15 sensation 4 LS1208, with the advantage that one is cheaper SS15 and saves me time amplification.

Plus I think the design SS15 goes below the LS1208, no?


Yorkville

I copied the LS1208 vs other subs (measurements not done by me) for reference.

I would say the ss15 and the ls1208 have similar fall off below 60hz, and would compare favorably in terms of overall sensitivity. The ss15 does not have the 80hz dip seen in this measurement of the ls1208.

The big difference is that the 3015lf is a 500watt driver, not a 2000watt driver.

I max out on the ss15 at about 128-129db per box. You can do your calculations from there.
 
I would have thought 6 wide V-Plated Titan 48s would be pretty good (the Tubas, far less impressive), though the driver choice in BFM stuff would limit the maximum power. According to my plans, 18Sound 15LW9300 are good to 80V each, though buying 6 new drivers is money! What width did you build? Small enclosures are predicted to stifle a 3015LF.
LS1208 good too, Cerwin Vega not so much, although in the size of stacks there probably hit fairly hard :D
Have you tried JBell's 'Stadium Horns?' They use the same driver.

The SS15 interests me actually, because it's about the size of my 'DJ's Dream' vented box design which isn't quite out yet. That also uses a single sheet, almost. I need a offcut for one of the ports!
With a 3015lf is PREDICTED to run between 98 and 99 dB sensitivity with a 3015LF, from 40+ Hz and runs out of steam at 123-124dB where it reaches the 9.6mm Xmax at 55Hz.

The optimum 18 (I haven't found but something like a 140g version of a B&C 18TBX100, or a Kilomax Pro 18 with a BL of 25) would get me to 127dB PREDICTED with 99.5dB sensitivity. Corner loaded I've predicted 136-7dB to 37 Hz, but that's cheating :D

I've found vented boxes seem to hit a wall of ~125dB/1000cc 1m for about a 40Hz tuning. You can get more at the tuning frequency in a larger box. A lighter weight driver in a bigger box gets there with less power, but it's still the same limit. Tapped horns I presume give the enclosure a displacement gain. I haven't seen Hornresp sims of an SS15 but at 128-129dB it gets more out of the 15 than I do out of an 18, though I have not exceeded Xmax in any of my sims.
On another note, comparing 8 cubic feet boxes, what the hell is up with this Yamaha? Cone made of Lead or what?
 

Attachments

  • DJ Dream Yamaha T24.jpg
    DJ Dream Yamaha T24.jpg
    26.8 KB · Views: 199
Last edited:
Aargh! Why won't my other attachment show up!? Please note in the interest of fairness, I have not constructed and measured this box yet. I have built a half size with a Kappalite 3012lf (95-96dB to 40Hz and it is working rather well as a small subwoofer that fits in my tiny car.) I do have dimensions for all the parts if anyone's interested in trying one out. If it all goes well I'd love to be able to sell detailed construction plans elsewhere, doing as John Inlow does with his free dimensions for his 'Lab Sub' (man that thing is a complicated build by the looks of it!) but selling detailed construction notes. This would help novice woodworkers out.

Reducing the mass of the B&C to 140g brings the upper bass up to the 99/100dB line on the simulation. So far I have a rather complicated formula regarding recommended drivers:
Bl^2/(Sd^2*Re) should be around 8 x 10^-5 (units, gram, Tesla metre, Ohm, cm^2)
Mmd/Sd^2 less than 1.5 x 10^-4
 

Attachments

  • DJ Dream Hornresp B&C.jpg
    DJ Dream Hornresp B&C.jpg
    95.2 KB · Views: 220
Last edited:
Tim. This is "Single Sheet Tapped Horn" THread.

And if you are hitting a wall at 125db per driver with a 40hz tuning, select better drivers.

BC 18sw115. 15mm xmax. 130 db, single driver. 113liters net.

the yamaha? probably a qts in the .4 to .58 range.
 

Attachments

  • 40hz bc 18sw115.jpg
    40hz bc 18sw115.jpg
    245.1 KB · Views: 226
Well if you want to spend £600 (only $549 in US? Jealous!) on a driver for a small box and CONSUME POWER LIKE IT GROWS ON TREES, then that'll work well. I rejected the PD1850 (only £350) for similar reasons, However: I'll think you'll find that it follows the rule above. That driver looks to have a Vd of about 1800cc.
130 - 20*log(1800/1000) is indeed around the 125dB mark.

I have been able to play with motor strength and also series inductance such that the box has a 'smiling' response. Series inductors can 'EQ' the box by changing the impedance in certain places.

With a sealed box, there is one Spl 1m/displacement curve that ALL sealed boxes follow, no matter what driver you use or how you size the box. I believe that at the place of maximum displacement in the pass band of a vented enclosure, you are limited to around +6dB on the sealed curve.

I am however excited by the prospect of 146dB 1m to the upper 30s from two cabs coupled and corner loaded, which would get you the efficiency back. That's bass you can FEEL in your ears 'popping' from 10 metres away from the corner! Possibly the 'baddest' portable mobile DJ rig ever!

I am also interested in how well these would do in a reduced width version of JBell's stadium horns, or maybe 2 in series of a 20% wider version. This is only a rough guess based on comparing box volumes for a 3015LF and that B&C woofer (190L vs 113L) and using the same ratio for horn widths.