Transmission Line

[Dr C]

Hi all - I recently had the opportunity to hear a pair of transmission line speakers - PMC's OB1. The sound ? Awesome. Powering them were the preferred brand - Bryston's.

1. Wanted to check with you guys if anyone has paired PMCs or other types of TL speakers with Rotel amps.

2. I heard that the TL speakers are quite inefficient - would a RB1070 be enough or would I have to get a 1090 ?

3. Any one else heard the OB1s or the FB1s or TB1s or the active PMC sub ?

Rgds - Dr C

[David Meek]

Hi Doc, I recommend you post this next door in the Mission Possible DIY forum, too. Our speaker poobahs over there have a really good chance of answering these - especially #2.

Sorry, I can't help much, my minimal transmission line knowledge comes from reading Listener and The Audiophile Voice.




David - HTGuide flunky
Our "Theater"
Our DVDs on DVD Tracker

[ThomasW]

Jon and I experimented extensively with TL's some 30 yrs ago. We probably made a dozen+ incarnations. Please note that nothing has changed in the basics of TL design since that time.

Inefficient? You bet, we made one with a single DVC 10" driver that could take the full output from a Phase Linear 700 amp!!!!

In reality TL's are a different form of ported box, and in our opinion they don't offer the benefits of a standard ported design. For further discussion of TL's vs ported see one of the more recent back copies of AudioXpress magazine (sorry but I can't remember the specific issue).

Now using efficient drivers TL's can of course be made more efficient.

TL's like all things slightly 'different' have developed a cult like following. These guys are some of the more ardent TL fans.

The pairing of the amp with the speaker will of course be dependent on how efficient the particular speakers are, how big your room is, and how loud you like to listen....

IMO there's no such thing as too much power..

Hope this helps

Regards
Thomas




theAudioWorx
Klone-Audio

[Dr C]

Thks for the advice guys - I was looking more at "finished" TL designs rather than making my own as I don't have the time to go around looking for drivers to match desins, getting material and am a real goofball-who-thinks-he-can-DIY-but ends-up-with-crap !

Nevertheless i will try to post in the other forums and am real envious of folks like Thomas who has the skill to do the things he does

I listened to the PMCs about 2 months ago and am in 2 minds to get them - deep (24Hz) sound from a relatively small enclosure, detailed midrange, good 3 dimensionality, wondrous cabinet finish ...

Just wanted to gauge the impressions of others who have heard them.

Actually, after reading all the DIY projects - I'm tempted to try and do something for rear speakers. :LOL:

Dr C

[jethro]

Dr C,

I haven't heard the OB1's but I own the IB1's. They are fantastic speakers (in my opionion). I'm using a Bryston 4B-ST to drive them so I can't comment on the suitability of a Rotel amp. However, I am the moderator of a Bryston/PMC discussion forum on another site. Membership is free, and the site is not sponsored by Bryston nor PMC, however their employees take part. You may find the discussion group useful. I believe it is against rules to post links so if you want more info please e-mail me.