Pros and Cons of Transmission Line speakers

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planet10 said:


I'm pretty sure. That is where Morel USA gets their drivers (or am i getting this mixed up with Peerless India?)

here is what Bob Stout (LDSG) has to say:

Now one has to ask where Morel USA is getting their speakers

Yes Peerless India does exist. I have been trying for many years to get them to cooperate with th DIY world but they claim they dont have the time (however other soruces have told me that they are very suspicious of DIYers). BTW Peerless India also OEMs drivers for many EU and US brands. These OEM contracts keep chainging and the list of old and present contracts is awfull long to detail here.

I agree wholly with what Bob Stout says.

If Morel USA sourced it's parts in India I can find out. It is probably not from Peerless India but North India also has a few companies in this biz. (I live in Mumbai-Bombay on the West Coast).
 
Hi, I'd like to put up the question for Audio Nirvana drivers.
I have pair of super 15" and would like to try labirinth cabinet design.
There are two different approaches I have found in the Internet to seal walls and to damp the channel. Could you comment them?
 
I'm afraid that you'll need to outline what methods you found on the net, for anyone to comment on them...

Generally, 15" drivers are a bit awkward to use for a transmission line. You'll end up with an fairly huge box. Box speakers are jokingly called "monkey coffins", but this will be one fit for a gorilla ;p

If you want to do a transmission line, you can start with some info at Leonard Audio: TL Design Basics | Leonard Audio

Then you'll find more info at Martin Kings website Transmission Line Theory

Then get the Transmission line software from Leonard Audio: Leonard Audio | Audio Engineering Resources

When it comes to seal enclosures, I like using expanding polyurethane glue in every joint. If you stick to ordinary carpenters glue and screws, use silicone or acrylic to seal joints. If you're making a convoluted transmission line, this is really awkward to apply after you've assembled the enclosure.

To get good results, dampening needs to be applied with different densities in the tunnel. Foam doesn't work really well - you'll need to use something like acousta-stuff or polyfill and weigh out the proper amounts. In the old days, the preffered material was long haired wool. This needs some chicken wire or other stuff inside the tunnel to keep it in place.

Design the linee with the software, and fiddle with it until you need the least amount of filling to get a smooth frequency response. Then you build. In general, the driver needs to be placed offset from the end of the line to dampen ripples. This gives a much better result than stuffing the bejeebers out of it.

Have a look at Marting Kings Yahoo group for more info. (Group name is quarter-wave).

Johan-Kr
 
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