PMC TL or QWT? - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 8th April 2008, 02:13 PM   #11
diyAudio Member
Scottmoose's Avatar
Join Date: Mar 2005
Location: UK
I can imagine how you feel Martin. However, in fairness to PMC, they are a relatively big & well-known company as far as specialist hifi speaker manufacturers go, & have been around a while. IIRC, they were started by ex BBC employees in the early 1990s & they've tended to stick with TL type cabinets throughout. Think a sort of TL version of Harbeth & you'd be about there -their speakers have generally been well recieved by the hifi press & studios alike, & they should have sufficient funding / profits to do a decent amount of their own research. I've certainly no evidence that they are directly using your sheets for commercial designs, but I have heard that they know of your (& George Augspurger's) work on the subject. It'd be surprising if they hadn't, so I suspect at the least, it'll have had some influence on them in recent years. Whether it's direct or indirect though is something I suspect we'll never know. FWIW, I reckon the latter is the more likely option in this case.
"'That'll do", comes the cry of the perfectionist down the ages.' James May -The Reassembler Community sites
  Reply With Quote
Old 8th April 2008, 03:41 PM   #12
Colin is offline Colin  United Kingdom
diyAudio Member
Join Date: Aug 2003
Location: UK
PMC also make great play of consistency between units (they don't pair match they 'all' match) so I would imagine they trial and error a new design by building it to get the balance right. As they sell into the broadcast and professional market, they can probably afford to do that. As Scott says, they have been around a while.
  Reply With Quote
Old 8th April 2008, 07:56 PM   #13
diyAudio Moderator
planet10's Avatar
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Originally posted by Scottmoose
Olney's 'Electronics' article appeared in April 1937

Karma was on my side... i have run across only 1 early copy of Electronics and it was this one...

community sites,, ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 8th April 2008, 09:13 PM   #14
diyAudio Member
Scottmoose's Avatar
Join Date: Mar 2005
Location: UK
How lucky was that?

It makes an interesting read. Something that gives me a wry smile every time I see Olney's old AL write-up: whole lot more measurements in that than in Bailey's TL article some 28 years later.
"'That'll do", comes the cry of the perfectionist down the ages.' James May -The Reassembler Community sites
  Reply With Quote
Old 9th April 2008, 03:49 AM   #15
diyAudio Member
Join Date: Jan 2007
Originally posted by MJK

That is now three commercial ventures that have come to light in the past couple of weeks using the worksheets under questionable circumstances. This is getting harder and harder to take. I must be a complete idiot to continue trusting people to do the right thing.
May I make a suggestion, as a software person? There is no shortcut -- you have to appoint someone to act as your representative, who will contact the intellectual property people at various speaker companies and offer them licensing.

This is a normal, everyday thing. It's just compliance vs. non-compliance. It's almost certainly not outright dishonesty so much as laziness and sloppiness. Legal departments (or lawyers on retainer) love to clean up those things -- that's how they justify their existence.

If they reject licensing, leave your options open without stating them. Just one programmer's opinion -- IANAL.

Edit -- by the way, I'm not saying you shouldn't be steamed! An organization stole my software while lying right to my face, and I literally could not sleep until I had shut them down. So I relate.
  Reply With Quote
Old 9th April 2008, 11:23 PM   #16
diyAudio Moderator Emeritus
pinkmouse's Avatar
Join Date: Apr 2002
Location: Rotherham, England
PMC use a combination of Akabak and their own proprietary software for design. There was a tech background article on them in one of the UK trade comics a year or so ago.
Rick: Oh Cliff / Sometimes it must be difficult not to feel as if / You really are a cliff / when fascists keep trying to push you over it! / Are they the lemmings / Or are you, Cliff? / Or are you Cliff?
  Reply With Quote
Old 10th April 2008, 12:05 AM   #17
diyAudio Member
Join Date: Jan 2008
Nice thread to read guys.
Had a look at the link about the ATL system but they did not show a picture of the ALM1's incorporation...

We had it on loan and it truly is a great sounding monitor. Some people didn't like it because of the group delay on the bass but I thought it was really nice and full compared to some other units.
Any thoughts?
  Reply With Quote
Old 10th April 2008, 12:11 AM   #18
diyAudio Member
Join Date: Jul 2004
Location: Groningen

And special thanks for posting the original Olney article! I really like the way it's written. Considering it's age and being a scientific publication.

Regards Roland
  Reply With Quote
Old 10th April 2008, 10:23 AM   #19
Graham Maynard's Avatar
Join Date: Dec 2003
Location: UK

Just looked up Arthur Bailey's acoustic transmission line Wireless World text.

No reference to B Olney, nor to Mr D Barlow's prior measurements given in a lecture at the then Brit.I.R.E on 24-01-62.

Appararently H J Leak and J Bolinbroke also examined 'line' characteristics but not known if published

Cheers .......... Graham.
  Reply With Quote
Old 2nd November 2014, 04:02 PM   #20
diyAudio Member
darkmatter's Avatar
Join Date: Sep 2007
Location: East Anglia, UK
Excellent thread and info saved me from starting a new one the search engine is indeed one's friend!!
  Reply With Quote


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

New To Site? Need Help?

All times are GMT. The time now is 08:27 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2