I have not check on the Tangerine's glue, but I have changed the 'phragms out several times and didn't notice anything amiss.
I took some quick measurements with my iPhone RTA app this morning...I did these from right on top of the horns - I realized afterward I probably should have done them from 1-3 feet out. Still, it's pretty much what I thought I was hearing. The question is, how much of this is due to the phase plugs vs. other stuff?
If it's all due to the phase plugs, it looks like a pretty compelling case for the superiority of the radial/Tangerine types...these measurements were taken on pink noise with the Markwart L-pads set to the middle (12 o'clock)....
- - - Updated - - -
I just spoke to Bill at GPA. He said he could replace the circumferential phase plug with a Tangerine. I'm going to do take more measurements - and swap the diaphragms out - before I go to the trouble of sending the speaker to GPA.
As already noted, there's a major difference beyond phase plugs that explains the HF performance difference, so what needs to be tested is a comparison of an 808-8A, 802-8G in M19s or any speaker using the M19's 811, XO and pretty sure there will be little, if any, difference since with such a high XO point the 802-8A's phase plug won't be so resistive nor will the horn's inertance be so high, hence less HF roll off up high.
GM
- - - Updated - - -
The 802-8G was a whole new design, not just a different phase plug, i.e. gave up a little LF for more extended HF. I've no experience with any Altec large format driver other than the early 288, but again it in theory would only do if the new 288s are redesigned to do similar. Is there any measurements posted somewhere? I couldn't find any.
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
Opinion is only as valid as its verifiable supporting evidence.
Bookmarks