Beyond the Ariel

[soongsc]

Originally posted by gedlee
...
Now if the enclosure was an oblate spheriod then at the edge the surface is flat and so there would be less diffraction here and the directivity would be the same as that of a piston in an infinite baffle.

...

I knew you were going to mention this part sooner or later.

[gedlee]

ITD and IID have nothing to do with polar response, sorry.

[gedlee]

Originally posted by john k...

I have to say that I like Earl's impulse response. I don't see a lot of high frequency noise on it. Not surprising considering the foam plug should act as a low pass filter.

Yes, in a certain respect the foam is a LPF, but it is very small for the main wave and much larger for the HOMs, which travel a longer path through the foam, as do the reflections. So the foam does LPF the main wave, but it LPFs the diffraction and reflections to a much greater extent, resulting in, once re_EQ to flat, a net benefit.

[soongsc]

Originally posted by gedlee
ITD and IID have nothing to do with polar response, sorry.

Well, I should call that TD and ID respectively.

[gedlee]

Meaning what? ITD and IID have a precise meaning. TD and ID don't - "Time Difference" and "Intensity Difference"!? Difference from what? What is it you are trying to say?

[ro9397]

Earl Geddes' posts describing the flattening of room modes in the bass, by employing multiple subs strategically sited throughout the listening room (w/ quasi-random phase relationships) transformed my room from one in which bass was virtually unlistenable into some of the best bass I've heard. The frosting on the cake is that it is the most efficient known method to achieve the sound of large room bass in a domestic listening room.

At age 54, having done this for many decades, as best I can surmise Dr. Geddes provided more audible benefits than everything else I've learned prior combined. The benefit can not possibly be overstated.

The benefits infinitely outweighed $8k equivalent value of ASC acoustic soffit & any prior benefits from EQ.

I am well familiar w/ the sound of live acoustic instruments, pretty good player of a choice Martin HD28LSV (adirondack top). Just ordered a Ryan Thorell custom (IMO one of the top luthier's in the world at the incredible age of 29). Also regularly hear great pianists play my wonderful Chang grand.

Earl also personally is responsible for about $5500 USD saved in components. Kudos to Earl. I owe Earl a nice dinner if I ever cross his path.

[gedlee]

Originally posted by ro9397

Earl also personally is responsible for about $5500 USD saved in components. Kudos to Earl. I owe Earl a nice dinner if I ever cross his path.

Thanks! Thats just enough savings to buy a pair of Abbeys! Good bass desrves good mains.

[dlr]

Thanks for the responses. End of the OT diversion.

Dave

[soongsc]

Originally posted by gedlee
Meaning what? ITD and IID have a precise meaning. TD and ID don't - "Time Difference" and "Intensity Difference"!? Difference from what? What is it you are trying to say?

I reviewed my notes and found I got some things mixed up. Sorry for the confusion. I will now put on my dunce cap and go to the corner for a while.

[g3dahl]

Originally posted by Truetone
A message to all those patiently waiting for 425 horns: I picked up the outstanding orders from the shop today . . . Will post photos from horn-shed if there is interest.
best rgds, martin

Yes, please!

Gary Dahl