Apogee Acoustics

Can someone tell me what the Bass panels and Tweeter/Mid panel DC Resistance is without XO components (ie bass panel red to black wire dc resistance, and tweeter/mid panel Blue to Brown wire DC resistance) on a Duetta SIgnature is......

Doing some investigating. One speaker indicates 3 / 3 ohms, other says 3 / 8 ohms Tweeter & Bass panel...what is correct for a bass panel - 3 ohms or 8 ohms? I think I read somewhere that the bass panels are 3.8 ohms?

Just curious....

Depending on your meter and clean connections the bass should be 3.2 ohms, tweeter 2.6 ohms.

Is there an audible problem when playing the one measuring 8 ohms?

Jon

Yes, a slight change in audio - kind of like a cancellation null/void when you incorrectly connect the pos/neg of a speaker...noticable by me...

I think there is a disconnect of a paralleled (or series) ribbon loop on bass panel...

Could be that or a partial fracture where the ribbon exits the slant clamp side top or bottom onto the raised blocks. Sometimes the fitters at Apogee didn't leave an adequate strain relief and the ribbon gets fractured, normally so small you can't even see it.

Hello John

If I understand 3.3 and 3.8 for the pair - not 3 and 8? I have seen ribbons measuring as low as 3.1 and high as 3.6, readings slightly outside that indicate meter/contact resistance. The design of the Duetta panel is one that a fracture on a single loop will lead to a complete open circuit more often than a subtle rise in resistance so what you describe is more likely an issue of tolerance. What Jon mentioned with a partial fracture of a strain relief would also do it.

Perfect readings on a good meter are 3.25 -3.3 ohms for the Duetta Signature bass panel.

Curious - Graz

Well this is strange, it now reads 4.2 ohms on the bad bass panel...the tweeter is still 3 ohm. The other is 3 ohm on tweeter and 3 on the bass...

Quite a bit better than 8 ohm. I also note if I toe them in a bit more toward my listening position, the null is gone...strange.

I guess it better than before, still not perfect, but better.......

I took the covers off and noticed the top and bottom wooden clamp was very very loose. I tightened them, and now the DR resistance of the woofer panel reads 3 ohms like the other. I guess all is good again. Whoopee!

URGENT. These upper horizontal (top and bottom) clamps need to be;-

LOOSE enough to allow for damped (by the foam) movement of about 1-1.5mm,

TIGHT enough that they do not rock against the sides of the screws, or the screws wiggle.

Full tight will eventually make the bass "bag" near the clamp, especially at the bottom, and this will be a permanent problem once it has happened.


Take care - Graz

OK, noticed that along with the upper and bottom clamp tightening, I also tightened the metal clip on the lower side by the side clamp too (don't know what this metal clamp does). It appears that this side clamp returned the resistance back to 3.2 ohms, and not the upper and lower clamp. I will loosen the upper and lower clamp as Graz recommends.