On Wed, 27 Aug 2014 11:43:37 +0100, Bob Latham
wrote:

In article ,
RJH wrote:
On 27/08/2014 11:09, Bob Latham wrote:
In article ,
Don Pearce wrote:

Or that there are much better ways to load speakers than transmission
lines.

I would be interested to hear what these are and in what way they are
better other than box size.

I suppose there's many ways to skin a cat. My preference (shaped by
price and space too) over the years has come down to sealed box or
transmission line. Wonder what Don has in mind.

Yes, those are the two I've found best of all. The one tends to be
enormous and the other very inefficient. I've yet to hear bass from a
ported reflex enclosure that I actually like.


Ported can be very good. It all depends on how you set the Q. Most
speaker makers try to take advantage of the resonance curve to prop up
the bottom end. The result is peaky, one-note-type response with a
very poor phase response. If you de-Q the whole thing and sacrifice
some of the bass boost, you get a response very like that of a
transmission line, but without the huge size.

And of course transmission lines can be tuned exactly t The purist
method is to load the line sufficiently with Dr. Bailey's long fibre
wool that very little sound emerges from the port at resonance. The
line behaves something like an infinite baffle. But reduce the packing
density, and you can invoke a very similar boost curve to the reflex
speaker, and with a very similar sound.

d