TH-18 Flat to 35hz! (Xoc1's design) - Page 61 - diyAudio
Go Back   Home > Forums > Loudspeakers > Subwoofers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 18th May 2012, 05:50 PM   #601
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by Djim View Post
Okay, Phase shifting is probably not the correct term but if Danley doesn't use a similar approach how is it possible to expect linear cone movement of both edges of the driver at high excursion when their position is separated by the diameter of the cone?
I don't understand your question.

I have not heard a DSL TH-118.
Langston Holland owns a number of DSL TH-118 with 18 Sound drivers and TH-115.
Langston is very meticulous and rigorous in his testing. He reports that the TH-18 sound good even with as much as 6000 watts, IIRC.

The TH-115, with B&C15TBX100 can't handle anywhere near that level without sounding bad.

I have only hit the Keystone with around 3000 watts, but I think they could take another 3 dB no sweat.

The addition of the "V" type throat should make the Xoc1 TH-18 loaded with a good driver capable of high output without the cone stress reported by PASC in his comparison to the Keystone.

Art
  Reply With Quote
Old 18th May 2012, 07:40 PM   #602
Djim is offline Djim  Netherlands
diyAudio Member
 
Join Date: Dec 2009
Location: 'Ollanda
Quote:
Originally Posted by weltersys View Post
The TH-115, with B&C15TBX100 can't handle anywhere near that level without sounding bad.
Have you any idea about the power that the 15TBX100 can handle in the TH-115 before it gets sounding bad?
  Reply With Quote
Old 18th May 2012, 11:32 PM   #603
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by Djim View Post
Have you any idea about the power that the 15TBX100 can handle in the TH-115 before it gets sounding bad?
In this thread Langson said it takes 3) TH115's to equal the output of (2) TH118's:

Danley TH118 Review and Measurements

I canít find a later reference where Langston tried one of his QSC PL380 amplifiers in bridged mono mode (8000 watts)in to a four ohm TH-118, (more than the Camco amps he now normally uses) but IIRC he said something to the effect that it took the output to a new level he had not heard before.

Trying that with a TH-115 loaded with a 15TBX100 would probably result in short term massive distortion followed by long term silence .

I think in light of the extra power handling with clean output the TH-118 has over the TH-115 Langston later discovered, it may be closer to 2/1 than 3/2.

My observation is that a single Keystone with the BC18SW115 can outperform between two and four dual 18Ē BR cabinets of similar size with drivers in the 6-8mm Xmax range.
A slightly larger dual 18 BR using BC18SW115 and twice the power would probably be capable of slightly more, and cleaner output than the Keystone.

Art
  Reply With Quote
Old 19th May 2012, 11:01 PM   #604
Zero D is offline Zero D  United Kingdom
diyAudio Member
 
Join Date: Aug 2009
Thumbs up R.G.Pruden

@ PASC

Re US 3,047,090

WoW what a great catch, thanks for posting

Actually is was patented by R.G.Pruden in 1962, but applied for in May 1957. Just over 55 years ago ! As we can see from the image, it wouldn't look out of place if posted as a design in here, for eg.

Yet another almost forgotten tech, from way back when, along with so many others that seem to have been overlooked etc ? Even if there "might" have been not much call for lots of bass, low or otherwise in the Fifties or Sixties, by some in certain quarters, there is NO doubt that plenty of records, emerging and continuing on from back then and afterwards, contained decent bass, and would have benefitted imenseley from such a design.

The rock n roll era had been in full swing for a number of years already, and the sixties explosion had already started to happen. PA/Band systems at the time were in there infancy, and with more and more groups/acts touring etc requiring more db's to fill larger and larger venues to cater to more people, several of these designs would have made a Big difference.

Quite why he wasn't able to capitalise on his invention, is a mystery ? and a great pity ! Even if sound companies in the sixties hadn't taken it up, his patent would still have been in force up until 1982. So in the seventies and onwards when sound got a lot more serious, i'm amazed nobody "appears" to have snapped it up !

Maybe he got rejected for years and gave up trying ? Another one that got away, at the time anyway. Thank goodness Tom Danley independently discovered this gem, all these years later. Because otherwise it might have been a long time before we were able to enjoy this brilliant invention.

R.G.Pruden, if you're still alive, you've made a Lot of people very happy, so THANKS for your genius
Attached Images
File Type: gif rgp.gif (87.9 KB, 843 views)
  Reply With Quote
Old 20th May 2012, 12:50 AM   #605
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
US 3,047,090

"i'm amazed nobody "appears" to have snapped it up !"

It might have to do with the series of those saxophone holes in the box.

On the other hand US 2604182 from 1948 is a 200hz tapped-horn for a table-top radio.

Loud-speaker with a tapered horn coupled to the speaker diaphragm
__________________
Candidates for the Darwin Award should not read this author.
  Reply With Quote
Old 8th June 2012, 05:58 AM   #606
diyAudio Member
 
Join Date: May 2012
Quote:
Originally Posted by Xoc1 View Post
Hi Everyone
I made a start on measuring the cross sectional areas across various sections through the speaker driver. It immediately becomes apparent that the area is virtually constant over a distance roughly related to the diameter of the dust cap.
This means that the shape of the cone correction should have a flatttened area not just a V point as DJims last suggestion here
C/E/X PA Flat to 30 (FT30) PA TH Awesomeness

When we add this to Arts comment in post 528
TH-18 Flat to 35hz! (Xoc1's design)
it makes more sense.
If we put all these observations together what we end up with with the TH18 / SS15 folding is something like the attached sketch.

Regards Xoc 1
What a great thread! I've been following from a far and thinking about building the TH. Xoc 1, were you able to model your design for the cone correction and did it change the response at all? As the horn length/volume is increased, I am excited to see how that affected the response.

Regards,
CharlieK
  Reply With Quote
Old 15th June 2012, 05:53 AM   #607
rpowell is offline rpowell  United States
diyAudio Member
 
Join Date: Dec 2008
FYI, the new Danley site has ISO and side views of the TH118 so the mystery of the guts is revealed. The TH18 plan, even with the centered flat "V" is similar to it, but far from an exact replica.
  Reply With Quote
Old 15th June 2012, 01:47 PM   #608
diyAudio Member
 
Join Date: Jan 2011
NeoDan pointed that out to me. Cool to see he put the drawings up!!
  Reply With Quote
Old 15th June 2012, 05:36 PM   #609
diyAudio Member
 
Join Date: Jan 2008
Quote:
Originally Posted by rpowell View Post
FYI, the new Danley site has ISO and side views of the TH118 so the mystery of the guts is revealed. The TH18 plan, even with the centered flat "V" is similar to it, but far from an exact replica.
Where on the Danleysite is a view of the TH-118 "guts"?
  Reply With Quote
Old 15th June 2012, 05:38 PM   #610
diyAudio Member
 
Join Date: Jan 2011
Folding is very similar but slight differences. Bracing is different (doesn't look to be hollowed out)
Art it's under the images...
TH 118 | Danley Sounds Labs | Danley Sound Labs, Inc.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
18 inch labhorn design. mulletdude Subwoofers 23 27th November 2013 09:43 PM
Ciare 18 bass horn design soundhead Subwoofers 5 22nd September 2013 09:33 AM
2 18 bass design simpleacoustic Subwoofers 101 15th May 2011 10:22 AM
I want my Avalanche 18 to go flat to 15hz thadman Subwoofers 10 11th November 2006 03:54 AM
Looking for suggestions on a 1300W Dual 18 sub design. mjcohen Subwoofers 5 21st December 2004 08:38 AM


New To Site? Need Help?

All times are GMT. The time now is 03:48 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2