Transmission line speakers

PCMs have gotten some very good reviews in the English press.

Mcgarick- The term you're looking for is, "PACE"(a quality of live music that T/Ls and TQWPs retain better than most designs): (http://www.hificritic.com/downloads/Archive_A7.pdf)

Rodman99999, for a very long time, I've struggled for the right term to describe the low frequency performance of a true TL loudspeaker. So far, I've yet to find it. Many folks seem to prefer "pitch", but that doesn't satisfy me, either.

What I'm talking about is that sense of being able to clearly discern the notes, and actually hear the music present in the low frequencies, just as we can through the mids and treble, as opposed to the "one note bass" of most competing products. The loudspeakers I use in my main system are ported or horns, and they do not come close in this regard.

What speakers are you using in your system? Were they produced by IMF or KEF, or more of a homegrown variety?

As I said, a purist would not consider the alignment VR employs to be a true TL. This fueled an extremely long and contentious debate here many years ago.

Finally, to reiterate another point in my first post, which Duke also spelled out, true TL is prone to a dip in the mid/upper bass response that leaves the speakers actually coming off as bass shy and cold.

When I owned my speaker company in Florida, a customer(very affluent) came in(1980) that wanted a pair of subs to go with his Acoustat Model IIIs. We experimented for some time with a number of designs and drivers(his $$). The best combo turned out to be the 10" woofer that Milo Nestorovic was using in his passive/active bass system, in an 8', tapered, folded, progressively damped(we settled on bonded dacron) transmission line. These were actively bi-amped with a Dahlquist DQ-LP1 and a Hafler DH-500(both modded). Proper damping(it took some doing) in the line effectively cancelled any frequencies but the very lowest(desired reinforcement) and eliminated them from the vent's output(no mid-bass dip). These were positioned upright(48" tall) between the planars, to eliminate time/phase problems. They integrated beautifully(no lag/great imaging and sound stage). The bi-amped KEF LS3-5A/B139 (in acoustic suspension) system I built/owned got sold, and his system duplicated, after I heard the dynamics. The only problems I've ever had with thinness have been room related(only lately). An expensive divorce forced me into a pitifully small listening room(nulls at 60/120/240hz). A modded TacT RCS 2.2X has solved that, enabling me to position the TLs, on their sides with the drivers in the room corners, to more evenly load the room(bi-amped with Maggies). No problems ever with "one note bass"(can't tell the kick from the double bass, etc/no definition or pitch). Part of that does come from having an amp that will control the driver in a basically undamped(no air suspension) enclosure too. I'm now using a modded TransNova 9505, that keeps an iron grip on the 10's. Things have progressed nicely since 1980. The only bass system I've encountered that makes me want is the Lyngdorf W-210, but I couldn't use them in my room anyway. No one sells the drivers separately now, or I'd have a pair in my TLs.

Quote:
"Rodman99999, for a very long time, I've struggled for the right term to describe the low frequency performance of a true TL loudspeaker. So far, I've yet to find it. Many folks seem to prefer "pitch", but that doesn't satisfy me, either."

I'm listening to Bob Dylan's Modern Times CD,and was reading comment Trelja's comments,and it dawned on me that one quality that comes through,that's unique, is bass depth.The bass is so clear that you actually get bass depth,and this recording has that.
This may add to the timing affect. Very cool.

Those PMC's are pricey,maybe eBay, used sometime...