Single sheet TH challenge

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#1,201
weltersys said:
Xoc1’s TH18-2 has the same physical dimensions as the DSL TH-115 or TH-118, and similar frequency response as the TH-118, which uses the BC18SW115-4.

The DSL TH-118 is rated at about 105 dB one watt one meter (spec sheet uses 28.3 volt at 10 meters).

My slightly larger volume Keystone BC18SW115-4 loaded tapped horn actually measures about 98 dB sensitivity in the upper range (same as a JBL-SRX 728, a slightly larger 2x18"), about the same as Xoc1’s TH18-2 Hornresp sims.

I have communicated about the disparity with Tom Danley, although he agreed that the disparity sounds too large, he stands by the spec sheet figures. He did share the actual plans of the TH-115 with me, Xoc1’s TH18-2 are nearly identical other than one small detail that Tom does not believe would make much difference in sensitivity.

Josh Ricci has tested a DSL DTS-10, his test results show a much lesser sensitivity than Danley’s spec sheet, very much in line with the disparity between Xoc1’s TH18-2 or my Keystone compared to the DSL TH-118.

My tests showed the TH increased the sensitivity of the BC18SW115-4 by 6 dB over a slightly smaller BR cabinet with the same low corner.

Six dB is a big deal, another 6 or 7dB on top of that with the same FR and cabinet volume (and fold pattern) is IMHO, impossible.

Art Welter
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Looking closely at the Danley TH118 Spec Sheet
http://www.danleysoundlabs.com/pdf/TH 118 spec sheet.pdf
It does say 4 ohm 28.3V @ 10 metres.
Is this not equivalent to 40V @ 10 metres or 4V @ 1 metre for an 8 Ohm driver🙄
Regards
Martin (Xoc1)
 

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#1,205
Xoc1 said:
Looking closely at the Danley TH118 Spec Sheet
http://www.danleysoundlabs.com/pdf/TH%20118%20spec%20sheet.pdf
It does say 4 ohm 28.3V @ 10 metres. Is this not equivalent to 40V @ 10 metres or 4V @ 1 metre for an 8 Ohm driver. Regards Martin (Xoc1)
Click to expand...

tb46 said:
Hi Xoc1, That's correct, but it only accounts for 3dB. Regards,
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Hi Martin and Oliver,
In Danley's sheet, they seem to use the reference of 2,83V @ 1m in a ½ Space environment for 108dB avarege and 114dB at 138Hz peak. In that case Martin's Xoc1 TH18-2 does perform even 3dB higher in average.

Danley's SPL response shows that the hardware inside cannot be similar to Martin's Xoc1-TH18. Tom seems to trade 3dB (average) for extra extension down low. Also the peak at 138Hz of Danley’s TH118 is evidence of lower resonances. If you look to the impedance plot it becomes much clearer. While the Cox1-TH18 has his impedance peaks at 45Hz and 104Hz, Danley’s TH118 impedance peaks are at 43Hz and 95Hz.

Looks to me Danley’s TH118 has an 1/3WL of 33Hz and a 1/4WL of 23Hz. That is also a logical explanation for the 3dB less average sensitivity of Danley’s cab in favour for 5Hz extension. That sounds very realistic to me.
 
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#1,206
Djim said:
Hi Martin and Oliver,
In Danley's sheet, they seem to use the reference of 2,83V @ 1m in a ½ Space environment for 108dB avarege and 114dB at 138Hz peak. In that case Martin's Xoc1 TH18-2 does perform even 3dB higher in average and 1dB higher in peak.

Danley's SPL response shows that the hardware inside cannot be similar to Martin's Xoc1-TH18. Tom seems to trade 3dB (average) for extra extension down low. Also the peak at 138Hz of Danley’s TH118 is evidence of lower resonances. If you look to the impedance plot it becomes much clearer. While the Cox1-TH18 has his impedance peaks at 45Hz and 104Hz, Danley’s TH118 impedance peaks are at 43Hz and 95Hz.

Looks to me Danley’s TH118 has an 1/3WL of 33Hz and a 1/4WL of 23Hz. That is also a logical explanation for the 3dB less average sensitivity of Danley’s cab in favour for 5Hz extension. That sounds very realistic to me.
Click to expand...
In post 1188 your graph says 1w 1m sensitivity for the Xoc1 TH18-2 with the B&C18SW115 is 98.7 dB.

The adjusted average sensitivity for the DSL TH-118 is 105 dB.(108 -3 dB ).

Why do you say that Xoc1 TH18-2 is 3dB higher in average and 1dB higher in peak?

Art
 
#1,207
weltersys said:
In post 1188 your graph says 1w 1m sensitivity for the Xoc1 TH18-2 with the B&C18SW115 is 98.7 dB.
The adjusted average sensitivity for the DSL TH-118 is 105 dB.(108 -3 dB ).
Why do you say that Xoc1 TH18-2 is 3dB higher in average and 1dB higher in peak?
Art
Click to expand...
I use 1w/1m in 2 Pi spaces as a reference for comparing all cabs in my table, which is the original AES standard to prevent confusing from different impedances. Danley measures with 2,83V with a 4 Ohm driver in 1/2 Space as his sheets explains. But if you want to be more precise it will probably end in a difference of 2,6 to 2,8dB, have to do some accurate recalculating before putting Danley's cab in the table.
 
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#1,210
Problem is we don't have an impedance plot of the Xoc1-TH18 (other then a HornResp model) to compare with the Danley's TH118 measurements for exact conclusions, but I do agree my 1/4WL assumption is a little too low.

However, I did use Danley's SPL chart and recalculate the plot from SG3225 from the Cox1-TH18 loaded with a 8Ohm B&C 18NW100. I think we can assume SG3225's equipment isn't as precise but it does give a general idea. The less roll off in the end in favour of the Cox1 is because SG3225's measurements were done at 2 meters if I remember correct (or filter settings?). To me it looks like Danley has made a mistake in his conversion calculation.

Danley's TH118 is in red and Xoc1-TH18-2 is in blue.
Danley-TH118_vs_Xoc1-TH18-2.jpg
 
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#1,212
Quick question guys. I just built my first ss15 and have a 3015LF arriving on Friday. Glue is curing as i type (on my hands too). I plan to try it out this weekend with a Bash plate amp from OAudio. Here is my concern. It only has a subsonic filter that goes up to 25Hz and I worry it may even give a little EQ around this cut. It puts out 325 watts into 8 ohms. I'd hate to kill my brand new 3015lf on the first go.

I'm struggling with hornresp to find out what the max power would be assuming no high pass filter whatsoever. I assume all is ok at 1 watt but when would I run into excursion issues?
 
#1,215
This is my amp for my indoor HT sub so this weekend is only temporary until I find a dedicated amp. Don't really want to modify it just for a couple days.
Do you happen to know when I would run into excursion issues (wattage) without any high pass filter? 100 watts?
 
#1,217
screamersusa said:
Furysubs go low enough for dubstep etc with 3015 in them.
Click to expand...

Really? Is the HR input screen on your website accurate? Cause I don't get good response (let alone down to 30Hz) w/the 3015LF using the numbers there or in the file "furysub_2009_try_dwg.pdf". Maybe there's another update..?

Djim said:
TH_overzicht_02.jpg
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And maybe throw jbell's Stadiumhorn in there!

Though big, those may be my best bet for my dubstep/dnb shows. I won't have enough $ for more amps for a few months, so I gotta wait on the 18" THs and work w/what I've got for now (six 3015LFs and just enough to power for them).
 
#1,219
I don't currently have any stadiumhorns. I have the 6 drivers, however. 2 are currently in SS15 enclosures, 2 are in BFM T48 enclosures and 2 are still new in the box. Right now I'm looking to put all 6 in same enclosures (instead of mismatched) in a system that can reach down to 30-35Hz.
 
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