3way PA speakers

[Mihai Cimpoeru]

I have started building two 3way speakers using B&C 15NDL76, 8PE21, DE250 and Eminence H290B.

The enclosures are made from 15mm birch plywood, have a volume of 85L and are tuned to 50 hz.

 

[scholl]

Nice, the 15NDL76 with it's tight suspension like more power to sound it's best. For PA that's no problem.

 

[Mihai Cimpoeru]

I have a Tamp TSA 4-1300 that was measured at 1300w per channel at 8 ohm, so there is enough juice for it (to bad it does not sound that great)

 

[Mihai Cimpoeru]

Did some measurements of the drivers, the crossover points will be somwere in the 600hz and 1600hz area.

Nearfield measurements show tunning at 45hz although impedance measurement shows it at 50 hz.

I also did some tests outside but the Tamp does not sound nice at all fullrange.

YouTube

 

[chris661]

Does the 8" have it's own back chamber?
It's unclear from the pictures.

Chris

 

[Mihai Cimpoeru]

Yes the mid has it's own enclosure made from a 20 cm diameter water pipe. The net volume is at 4.8 liters, enough to get it down to the frequency that i need.

 

[kipman725]

I'm presuming the 15G and 45G measurements are 15 degrees and 45 degrees respectively? if you took closer spaced angular measurments you can put them in Virtuax cad to generate polar plots.

 

[Mihai Cimpoeru]

Yes those are degrees. I need to make a measurement table to measure more precisely. Those degrees are set by using two rulers. I wanted to see the directivity of the drivers so i can match them at the crossover points.