WE 755A

[xcortes]

Awesome exercise. I learned a lot. Clearly there's resonances in the big boxes that need to be tamed. I out the speakers back in them (again) and will continue moddin them to tame them without killin them.

[johnsonad]

I was reading an artice on the 755 today where people prefered the resonant 618C cab over the stock WE cab which was very solid. They felt the resonance of the cab added to the 755 sonic signature.

http://junkyardjukebox.blogspot.com/2012/10/wealtec-755a-thinking-inside-box.html?m=1

[xcortes]

Yep, those are the ones I have. My big boxes were made resonant on purpose and they're even more resonant. Like a big cello. But a tad too much. The good thing is resonance can be tamed little by little 'til one find the sweet spot. Right now they're colored.

Having said that, they suck you into the music. The music has soooooul.

All this reminds me of Mr Sakuma who has a lowther pm6 in a beer barrell. And legend says Sakuma brought tears to the unbreakable and alway very tough Doc B when he heard his "concert" at VSAC (no with the beer barrell though).

[xcortes]

Now I know why Joe Esmilla loves them so much. Of all the things they do and they don't they just shine with a violin. The Oistrakh TP album and the WE are a match made in heaven. The orchestra behind is a mess but Oistrakh....

Time to play my old 2 track tapes where the orchestra is a mess anyway!

[xcortes]

Violin concerti

[keto]

Loose the orchestra, and get some more string quartets :-)
Late 60's Guarneri Quartet playing Beethoven? Or, Szeryng playing Bach?

[xcortes]

Yes Tom,

Chamber music is "la neta".

Not as spectacular as big scale symphonic and not an audiophile genre per nature but, in my opinion, more sofisticated and profound.

[xcortes]

But we disgress. Allow me to go back to my big PJ style boxes. I reviewed the outside taken measurements at higher resolution and two things became obvious.

I'll focus first on the "valley" at around 3khz. When analyzed at higher resolution it is clear that there's a profound null at 2.7khz, with a 180 degree phase change and a lot of energy delayed 72msec.

[xcortes]

Phase

[xcortes]

Delayed energy

[xcortes]

72mSec is 25 cm.

The inside side to side is 28cm. So it looks like there's a large resonance at that frequency that creates cancellations.

Additional resonances at 3.0, 3.1, 3.4 and 3.8 khz.

Lots of resonances to tame.

[xcortes]

Now, if I analyze the other valley at around 200 hz. A detailed view shows that the situation here is different. Here we don't have a null but a slow decrease in response. Also no phase change.

[xcortes]

So my theory here: the boxes are poorly sealed and the response is more like an ob response. And a mess below.

[Doc B.]

Are you taking these measurements outside and away from walls? If not, it's very difficult to get accurate measurements down around 200Hz and lower.

[xcortes]

Outside and away from walls indeed.