T-Line protype Finished

[supa-roo]

Huh oh you, wrong martin, i know who the other one is, but alas, always seem to get the 2 names mixed up, especialy when typing, dont know where my mind wanders then.

Thanks for all the replies it seems, there is quite a large following, just a bit of a sillent one at times.

 

[EC8010]

Library search denied: Insufficient data.

Speaking of articles on TLs from Brit mags, does anyone have the Hi-fi World ? article from the early 1980's with 3 designs in a series mini-line / midi-line / maxi?

It can't be Hi-Fi World because that only started in 1993, but it might be Hi-Fi News as they still did quite a few constructional articles at that time. Another possibility was Practical Hi-Fi (now defunct). Any more clues? As library references go, your description is on the nebulous side of extremely vague.

 

[planet10]

Re: Library search denied: Insufficient data.

It can't be Hi-Fi World because that only started in 1993, but it might be Hi-Fi News as they still did quite a few constructional articles at that time. Another possibility was Practical Hi-Fi (now defunct). Any more clues? As library references go, your description is on the nebulous side of extremely vague.

I got the request in an email -- and now that i know it exists i am curious too

Used Dalesford drivers with a KEF DN12 XO (must be a 3-way then). I'll see if i can get more info (and maybe the original quester posting here).

dave

 

[EC8010]

I think it may be called the "Daline" and if so, it was in Hi-Fi News in the late 1970s. I don't have a copy.

 

[planet10]

I think it may be called the "Daline" and if so, it was in Hi-Fi News in the late 1970s. I don't have a copy.

I'm pretty sure i have a copy of that (can't bring it to hand), but it used a B110 in a 2-way, so that's not it.

dave

 

[kneadle]

Re: Re: This Week's System Setup.....

[I'm sure Martin will be flattered, but it is Martin J King not Martin Luther King (he was another famous American, but in a different field)

dave [/B]

I thought he was referring to MLK's namesake, the revolutionary monk who broke the Holy Roman Empire with the stroke of a pen.

Dave

 

[mrfeedback]

Dave, thanks for the rendered picture, and yes that looks real like the ones I have - picked them up at a swap meet for $30.00 years ago.
I believe that these were supplied as a kit by L.E. Chapman & Co and featured as an article in Electronics Australia mag in the early to mid seventies - my drivers are date stamped 1975.

I'm surprised you haven't pulled leads out from the B110 -- it is much better than the B200, particularily from about 2k up to the XO point. I have details of KEFs aB XO for the T27 if you want to tweak the XO (i wouldn't be surprised if the XO in the TL is a DN12.

The TL cabinet is running the B-139 only - DN12 crossover board is removed and mid and tweeter are disconnected.
A DOD 835 series II electronic crossover is doing the split - anybody have a circuit for this ?.
The B-110's have a short circuit across them to stop them pulsing in unison with the B-139.
The upper KEF cabinets are running 100Hz up and do the job quite well except for the T-27 tweeters that are not real flash in my books - not real extended highs and resonance down lower.
I have experimented with CR and LCR networks across the tweeter on one channel but need to get more bits to complete the job.
This does markedly improve the performance of the T-27 but still I think I prefer to fit some better tweeters to get more extended highs.
Overall this combination works very well, gives plenty of level and is clear and clean, and the bass impresses everybody that has heard this system.

Dave, can you give me details of the Kef aB crossover - thanks.

Eric.

 

[jackinnj]

Re: Bailey

Those B139 transmission lines look very like the A R Bailey design from Wireless World May 1972. I thought I had a copy, but I've just looked, and can't find it.

Is this what you were looking for?


http://www.tech-diy.com/pro9.htm

 

[EC8010]

As it happens, I now have the Bailey design, but I didn't have the Chris Rogers design, so thanks for that, Jackinnj!

 

[Dave Jones]

If people are looking for some TL design help, and maybe the MathCad worksheets are a little bit overwhelming, I have recently added a set of alignment tables for classic TLs to my site.

20 Hz > fs > 70 Hz
0.3 > Qts > 0.5
0.1 > SL/S0 > 10

I've been looking at designs where the "fs" used for tuning the TL is higher than the "fs" of the driver. Do you think it would work to extrapolate those tables a little, say up to 80 or 85 Hz? Higher?

Is it way too complicated to compute the tables "by hand" or with a simple computer program? I skimmed the article, but I am afraid I don't have enough time right now to study it.

By the way, I bought a MathCad 2001. (Haven't sent the check yet though.)

 

[planet10]

Chris Rogers design

There is at least one other version of that design (with another fold) and it is one of the few kits of the day that (in a 7th revision) is still available today.

http://www.remo.nl/rogersm.htm

An externally hosted image should be here but it was not working when we last tested it.

dave

 

[EC8010]

Good grief! Thanks for that.

 

[jackinnj]

or perhaps you were looking for this:

here's another one with cobwebs on it:
http://www.tech-diy.com/SOTATL.htm

 

[planet10]

Re: or perhaps you were looking for this:

here's another one with cobwebs on it:

That is the Atkinson line....

An externally hosted image should be here but it was not working when we last tested it.

dave

 

[KEFMAN]

I'm most interested in the development of your TL design

 

[mitaylor]

maxi midi & mini TLs from hifi News & record review

Hi I built a set of the "midi lines" in early 80'2 when I was about 18 yo using drivers and plans from WILMSLOW AUDIO in the uk - based on the now defunct DALESFORD Co. drivers (10" D100/250 & 5" D30/110 (B110 knock off) & 1" ferro-fluid tweeter D10R - I think it may have even used a KEF xover??)

the maxi & midi line plans are long gone (lent to a mate who "lost" them) but I still have the midi line article by PAtkinson and even have the DALESFORD driver specs from the Wilmslow Audio catalogue (contrary to my wife's opinion I don't hoard useless junk)

I can try and scan them - if anyone is interested?

I put the TLs away as my house is tiny plus I didn't want my kids to damage the irreplaceable bass drivers - I'll have to bring them out of retirement as they're grown up now...