Red Logo Concert Series Component Crossover

[Anonymous]

i saw a crossover unit in a concert series case that had 2 big "3 corner" knobs for selecting crossover point frequencies.
 
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2555432993&category=10171


it resembles the Dahlquist DQ-10 Subwoofer Crossover of the same era.

when i started comparing the 2 units visually, i noticed a lot of similarity in the knob spacing, type, and crossover frequency positions on the dials.

here's my technical puzzler for the day:

is this a Dahlquist DQ-10 Crossover adapted by Hartzell into a Sunn Concert Crossover?

i have never seen any tech sheets on this unit and have never seen one used in sound reinforcement systems in 30 years of avidly following the technology.

best regards, tube

[Anonymous]

i have no idea what this is but it's pretty so i bought it.

any help in identifying the thing would be appreciated.

best regards, tube

[Betta Sunn]

Passive Crossovers Sunn SPL 8720 ,SPL 8730
Features:
The Sunn SPL 8720 and SPL 8730 are professional quality passive crossover networks . Their individual butterworth filters are optimized for typical 8 ohm speaker impendances , not just resistive loads . The 8720 is a two-way with a crossover at 1000 hz . The 8730 can be employed as a two-way system with crossover at 1000 hz , or a three-way system with crossovers at 1000 hz and 5000 hz . Built to handle high power levels of up to 400 watts program , both of these units exhibit low insertion losses through the use of high quality capacitors and low resistance inductors .
I will e-mail spec info to you soon . I need to borrow a camera .
                                                              Art...[Beta Switch III]

[Anonymous]

 thanks art!

 the pic on the auction page was fuzzy but i believe this is the 8730, 2 knobs, 2 knee points, 3 pass bands.

i have no idea what i'll do with it but it looked cool!   and it'll add another 10" to my stack, hehe!  

best regards, tube

[Beta Sunn]

Tube ,

I almost forgot about this . Specifications : SPL 8730

Crossover Freqeuncies : 1000 hz & 5000 hz - Three way operation
                                     1000 hz - Two way operation

Crossover slopes : 12 db/octave - Butterworth Response

Insertion loss : Less than .75 db

Power Handling : 400 w program/200 w RMS continuous *

Level Controls : L - Pads Mid & High

Protection : Circuit Breaker & overvoltage

Load : 8 ohm

*RMS - Thermally limited continuos RMS power
Program - Recommended amplifier power to provide adequete headroom for reproduction of program peaks .

[Anonymous]

 thanks beta sunn!

i took a good long look at this when i got it. i plan on using it to heat my practice room this winter  

i've always be a firm believer in active electronics for eqs and crossovers. this "massive passive" unit defies modern logic!  

it looks good in my stack, though.  

best regards, tube