My OB using Eminence drivers and a Vifa dome.

[ashok]

I've got stuck with my Eminence OB design. The Eminence ( alpha8A) driver sensitivity is 98db ( 8 ohms ) and the tweeter ( Vifa D27TG , which I had ) is only 91db . I guess adding an L pad to the mid /woofer is meaningless as it would require very high power resistors to drop it by about 7 db . The sub would have it's own large inductor which would get it down to the required sensitivity and have the required response slope.

My measurements with the mic however shows the smoothed out curve to have just about 4 db difference.
I can get away with an active setup , which is what I'm currently working on , but it would have been preferable to make it with a passive crossover and use just one power amp.
I've been down the active drive mode long ago and it's messy when one wants to meddle with the setup.

 

[pedroskova]

The least expensive fix would be swapping out the tweeters for one of the Eminence Apt tweeters/horns, followed by swapping them for some neo3's. Both would be cheaper than going active, unless you already have the active unit in hand.

 

[ashok]

I could get the APT80 or 150. I have a spare Neo3PDR but that is again not sensitive enough . The APT's are.
Any other domes that do 98db or more (spl @ 1watt/1m ) ?

Thanks for the suggestion. I might try out the APT's if nothing else is useable. How do the APT's sound ?

Cheers.

 

[pedroskova]

Thanks for the suggestion. I might try out the APT's if nothing else is useable. How do the APT's sound ?

Cheers.

...don't know personally. I think Yunick used them with Alpha 15's and 6's and liked them.

Another possibility that has been mentioned by Magnatar and others is the B&C DE10 in a cheap Parts Express wave guide. That combo would come in at around $50 USD a side.

 

[ashok]

I made a mistake earlier. The sensitivity of the Alpha-8A is 94db.

The waveguides I've seen with measurements , seem to increase efficiency but more at the LF end than at the extreme hf end. But I guess the crossover can fix that .
I see a lot of work ahead ! But I'm impatient !