Adventures In Transmission Line Loudspeakers

Background to all this was me trying anything, with what I had available, to get close to the sound I want (and some of you know how pedantic I can get regarding that...).

All I had at hand was some carpet offcuts, bits of crafting felt, glue and rubber bands. Not much to go at.

At which time I had no idea about transmission lines at all. I rolled the carpet offcuts up which made a tube (well damped) and shoved them in the back of the half open cabinets (see pics).

After a good listen I concluded this was akin to a church organ pipe tuning a particular frequency. Wanting to make sense of this I did what we always seem to do these days - I googled until I started to see similarities, which led me to the transmission line.



Please feel free to roll about laughing.



Excuse my appearance. Picture taken using my phone.

And the design I came up with which is what I think Stefan will be building (dreading the cost of all this ... )

Today I had a listen to Chris Firth's FH3's fitted with Alpair 7M's (thanks for bringing them Chris, it was good to see you again).

These have to be heard to be believed. Chris brought some of his digital files on his Squeezebox, and we spun some vinyl via the Accession MC. The vinyl included Porcupine Tree's Incident album, and Chris had another Porcupine Tree album on Squeezebox, and so we both know the FH3 can handle rock rather well, which as we're both partial to the stuff that's a good job.

I'm not blessed with reviewers tongue so I won't wax lyrical and leave the story there (Chris might like to chip in though).

Well I rather enjoyed myself, and that's despite my deflicted left ear.

I had a list of questions, top of which was "will Graham like what these do?".
I didn't need an answer, as the broad grin spoke volumes, so we have another victim to the charms of the FH3s.
The sound was magnificent, harmonically rich, rhythmically adept and fleet of foot, and above all truly engaging and entertaining, a testament to Graham's electronics, and to the FH3s sporting Alpair7s.

I'm particularly partial to a bit of Brand X, and their album "Unorthodox Behaviour", and the first two tunes, "Nuclear Burn", and "Euthanasia Waltz" were rendered in all of their strange, melodious beauty - this is "no mates" music of the highest calibre, and Phil Collins has never sounded so good on drums.

On the vinyl front we had Foxtrot from Genesis, and The Incident by Porcupine Tree, and both were truly engaging with their complex instrumental arrangement and occasional bombast.

Other material from the usual suspects (Dire Straits, Steely Dan, Daft Punk and Jeff Buckley) sounded phenomenal.

My questions were how does the Accession/Majestic/Proprius sound - I know now, and I'm left wondering how much I could get if I sold my son for medical experimentation .....

I enjoyed my visit - thanks Graham



Edited by Chris Firth - 30 Dec 2016 at 7:08pm

Graham I wish the very best with your TL design I have been a huge fan for over 40 years. They are sadly not very fashionable with commercial manufacturers there are an odd manufacturer in Germany and USA but other than pmc very thin on the ground. Back pressure/loading is important so once you arrive at a working model sure you will find difffering materials and density will impact on the sound quite a lot. Will watch with interest as small TL designs have been virtually non existent (until now).

Did you prefer the FH3 to your carpet tube? If so do you think they took up to much floor space for your needs? I could make you a pair of those as well You'll have more speakers than me soon

I love that photo of the carpet sticking out of the back of that speaker, I've got it as my screen saver at the moment!

Stefan

Edited by KJFAudio - 30 Dec 2016 at 11:12pm