what exactly does transmission line mean?

infrared

Hi guys, I've had my TF350s for some years now and they are know as transmission line speakers. What I get out of a 61/2 woofer and a tweeter is simply amazing w/ this tall slender line w/ only a minor kick out leg to hepl stabilize the the. YThey go very low I pushed very hard , not comparing to the bass slam of my 2Bs but ipressive just the same. So in the simpliest terms how does DMC do this. Now another issue I told you guys I got for free a pair of ALL LABS 81/2'' w/ tweeter 2 ways from my maintance guy. Now I dd get some negative or just warm response to these speakers. Even through some reviews calling them possible the original white van speakers. I have to diagree. I2st sound they easily keep up w/ my ADC 303ax 10'' 2 ways and the cnstruction is well looks like they did not skimp on anything. For instance the woofer retaining ring is a full 1/4'' billet aluminum which seems quite thick for a sh$t speaker. The beauty ring of the tweeter is exactly like my old and gone KLH #311 as is the black metal protection tweeter grill. Also on the is fuse protection and formally hanging warrenty car ala AR 3As.There is a saying that imitation is a form of flattery but I tink these deservea serious listen.

westmassguy

Google is your friend: http://en.wikipedia.org/wiki/Acoustic_transmission_line

[Deleted User]

The idea behind the transmission line speaker is that the woofer's rear wave passes through a long path (usually folded one or more times) so that only the lowest frequencies emerge from an opening. The first speaker I ever heard that used this design was the IMF TL series from England. They still stick in my memory as a great sounding speaker. Then Bud Fried used the transmission design on his speakers and the best sounding bass I've ever heard came from his "coffin" woofer, also a transmission line design.
I believe it's still being used in DIY speaker builders circles.

Jim Shearer

If you want to know more about TL theory & design, check out Martin King's site:
http://www.quarter-wave.com/
Cheers, Jim

Mr. Bubbles

The transmission line in its most basic sense is a Pipe with its length tuned to a certain frequency. The vintage DCM's (prior to Steve Eberbach leaving the company after it was sold to Mitek) were great I have collected a good may of those models and currently have just over 20 pairs of various models. However they are not true transmission lines, but a modified version. Eberbach was a great (maybe still is, i'm not sure) speaker designer. If you like the 350's, try to get your ears on some of the TF600's (considered by most, the sweet spot in the line) or some of the Time windows.

mhardy6647

If you (the OP, in particular) are interested in the various flavors of resonant enclosures (lines, pipes, and suchlike), here are two fine resources:

http://www.t-linespeakers.org/

and (for quarter-wave pipe enclosures):

http://www.quarter-wave.com/

I have one pair of mass-loaded, folded, tapered quarter-wave tube (pipe) enclosures loaded with the venerable (and really quite fine) Radio Shack 40-1354 twincone 5-1/4" inch twincone "fullrange" drivers. These were designed by Bob Brines and wring a rather surprising level of performance out of the very modest R/S drivers.

http://brinesacoustics.com/Pages/Proposals.html#RS 40-1354a

[DSC_6399 by mhardy6647, on Flickr

infrared

Thanks guys, Rereading my own post I must proof read better.Terrible. There is a pair of TF 600s still on sale @ Central Jersey C/L for $75. The guy won't budge but they have been listed for some time now and since I got my TF350s resocked and refoamed for $120, $75 doesn't sound all that bad. I have zero room left even though many over at AK consider the TF600s top notch even better than the 750s or 1000s. The Time Windows series is another animal from what I hear and the rare and vaunted 7s I only saw once for sale for $1600 @ U.S. Audio Mart.... NO affiliation.

mhardy6647

They're good speakers --- if you really don't need 'em, though... hold out for a pair of timewindows.

Mr. Bubbles

infrared wrote: »

Thanks guys, Rereading my own post I must proof read better.Terrible. There is a pair of TF 600s still on sale @ Central Jersey C/L for $75. The guy won't budge but they have been listed for some time now and since I got my TF350s resocked and refoamed for $120, $75 doesn't sound all that bad. I have zero room left even though many over at AK consider the TF600s top notch even better than the 750s or 1000s. The Time Windows series is another animal from what I hear and the rare and vaunted 7s I only saw once for sale for $1600 @ U.S. Audio Mart.... NO affiliation.

Though i have not heard the 700's I do prefer the TF600 over the 1000's and I do indeed own both. The 1000's have a little more bass and are definately a very good sounding speaker, but the 600's are just smoother, more balanced, and sound more accurate. probably due to the use of concentric mounting of the tweeter and the anti diffraction lens on the MW. I also do prefer my TW's over the TF series but cant say that the TW1's are truly that much better than the TF600's. They are different but the 600's are pretty sweet speakers. All incarnations of the QED I have or have heard sound pretty darn good too, but not quite to the point the 600's and TW's do.

$75 is a good price for the TF600's, especially if they are in good condition with ALL tweeters working. They have a single front and two rear firing tweets on each cabinet. Listen to be sure and if they do not all work that could be a talking point since they would need fixed. I have personally only run into one pair that had all 6 tweets working as they should. not super hard to fix but dealing with the grille socks can be a pain.

Mr. Bubbles

attached is an edited picture taken from a post at AVS forums. From the thread "Whatever happened to Steve Eberbach?". It shows the sweet spot for the TF600. Essentially the same for all Tf series speakers. It is not exactly as most would expect it to be.

GlennDog

Salk does QWT quite well . . . I picked these up this past spring

http://www.audiocircle.com/index.php?topic=125655.0

Sweet sound from a 2-way, especially if your space isn't Ginormous

GlennDog

I don't think the New & Improved CP has Edit ability??

So, I just wanted to add that besides being sexy as hell, they sound great & I would recommend an audition.

FYI, Jim Salk has no official store front (factory only, but is open to the public and very accomadating). Salk Owners appear to be a very open and sharing group, as many, many are willing to audition their speakers (to you, the newbie) to most who are genuinely interested in checking out the Salk House Sound . . . . fwiw, enjoy!

G

halo71

$75 for TF600's? If all drivers are working I would be all over that deal!