The ATL™ (Advance Transmission Line Speakers) from PMC®

The world's leading professionals rely on the accuracy of PMC's ATL™ designs everyday to create much of the music and sound you hear in Hollywood films and studio mastered albums. PMC's ATL™ (Advance Transmission Line) enclosures have taken loudspeaker design to the highest level. A PMC transmission line design utilizes sophisticated cabinet construction, proprietary drive units and patented absorption materials and techniques. The main driver is placed at the end of a long tunnel (the transmission line), which is heavily damped with acoustic absorbent material which absorbs upper bass and higher frequencies that radiate from the rear of the main driver. The lowest frequencies remain in phase and emerge from the large vent at the end of the line, which essentially acts as a second driver. The air pressure loading the main driver is maintained, controlling the driver over a wide frequency range, significantly reducing distortion. As the loading on the main driver is maintained at all volumes, the frequency response also remains consistent regardless of listening level.
Please visit: www.engineering...

[@aussie_philosopher8079]

PMC. Everyone's knows they are quality to the T that why we love them.

[@johnpartridge7052]

Seems to be a lot of different schools of thought with tl design. I’ve built one and the driver is placed 1/3 of the way down the length of the line and the line has a gradual decreasing taper. Stuffed with long fibre wool in the first half of the line...it sounds very good to me.

[@porkchopspapi5757]

John Partridge What driver did you use?

[@antoleyo3857]

I built TL system and it heights four feet four inches to satisfy me. Cheers from Indonesia

[@bunchlead]

PMC make the best speakers imo.

[@johnpartridge7052]

The foam has been placed instead of wool to aid manufacturing not the performance IMO.

[@Bassotronics]

Lovley technology.

[@mrbo23]

I have designed, calculated and build a TM myself und must say this is just a sales gimmick. In order to get a 40Hz Bass you need a 2 meter long channel. This here seams to be ca. 0,9 meter. So the lowest bass would be about 100 Hz at best. Where is the "advance" ? You get better result whithout Tm in such size box.

[@poolwizard3856]

Bramburg showed in his experiments that wool and other fibers slows the speed of sound significantly. If I recall around 430ft/sec

[@porkchopspapi5757]

That was just a demo unit.

[@myfagan]

Obviously a counter top display for demo

[@tonys4396]

Sales gimmick my ass. Go listen to a set of Acoustic Zen Adagio's with two 6 1/2 inch woofers and one ribbon tweeter that do down to 30 dB. THEN say they are a gimmick.

[@angeloinferno6553]

Wool and hair have surface textures that often help BECAUSE it works better on some frequencies than others, and filling an enclosure with wool controls more of the air than lining with foam, that and only some of the low notes from the opening are in phase with the speaker, that's why wool lining is needed, not just to reduce reflections and tune the length of the t-line, but to mute magnitude of those peaks and dips in the freq response. Misinformation like this is why it can be so hard to find info about building your own t-line.

[@Mortison77577]

What kind of hair do they use? Not human hair!

[@porkchopspapi5757]

I think I recall the problem with wool is it breaks down at high spl.

[@lio1234234]

@@Mortison77577 long haired sheep wool typically

[@svtcontour]

I heard a few of their models. I heard the DB1, TB2, OB1 and EB1. I had mixed feelings. I thought the DB1 and EB1 were fantastic. I thought the TB2 adn OB1 were quite unimpressive. Maybe it was other factors at play but that was my feeling on it at the time.

[@helgihelgi5444]

TDL

[@BogdanSerban]

He says that it absorbs the mid and high frequencies, but the highs are reproduced by the tweeter which has a closed back... Also, the TL should be waaay longer to even work.

[@erroljansen5980]

T-line length depends on what the speakers Fs is, so this speaker has a high Fs.

[@porkchopspapi5757]

How large & knowledgeable is your speaker research and development department?

[@bdc211]

You explained a transmission line enclosure in theory... What you havnt told us is why you think you've nailed the calculations to make yours worth buying......

[@porkchopspapi5757]

B. C. Did you not see the client list? Have you never heard PMC? Excellent reproducers.

[@doverlabs]

This is still rudimentary design. The best way to fix a lot of the issues in a transmission line is to drive another unit in-phase placed 1/3 down the length of the line.

[@k20aa]

IMF & TDL Would take the pepsi challange any day of the week with PMC Imf speakers & TDL The best transmission line speakers ever......

[@myfagan]

I have IMF 50s.... they are 40 years old and are better than most "high end" models today

[@donk1822]

I have a mint pair of TDL Studio Ones, the better version with the rebated drivers. In their price range at the time only the Tannoy DC3000 could eviscerate you in a similar fashion.

[@robertt6430]

Take a look at ipl acoustics.

[@jimrourke2554]

PMC is lying to its customers and is incapable of designing a proper loudspeaker. The i series is a particularly massive failure with WAY TOO MUCH bass reponse. Speaker is totally imbalanced. I suppose PMC does not have a drug testing program in place for its employees.

[@amgineacoustic]

all about the SM75 in a nutshell just buy ATC

[@spel2024]

Dutch for sure... XD

[@johnnystoka6625]

A ridiculous price because they use fancy foam lol

[@pacosoundaruba]

Blablabla...

[@GhostMotivation591]

LOL i can just hear by the way he talks english he's dutch

[@porkchopspapi5757]

PyroTimeBitch I can see by his hair that he has a short haircut....?