Double Advent crossover

[Dchristie]

Hi folks, over the years I have accumulated several pairs of Large Advent ( Original series not the New series) drivers including tweeters, bass drivers and of course the crossovers. As you all are aware, the Double Advent system was simply running a pair of Large Advents in parallel on each channel ( also referred to as stacked Advents) with each speaker sharing the crossover with the other speaker and the amp. I am currently building a Double Advent system from scratch and want to place the drivers for each channel in a single cabinet ( compensating for the correct volume for the doubled up bass drivers) but would like to have the appropriate crossover values for the dbl system (not separate crossovers for each single system in parallel as per the original design). I am going to rebuild the crossovers with better components eliminating the frequency switch so looking for some help on what the inductor, and cap values would be appropriate for such a system.

I seem to recall that the single Large Advent had a 1.6 mh inductor in series with the bass driver ( 1st order slope) and a 16 uf cap in series with a 3 ohm resistor with a 0.45 mh shunt on the tweeter ( 2nd order slope).

If I remember my basic speaker building principles, a change from an 8 ohm system to a 4 ohm system doubles the inductor value for a 1st order crossover ( in this case for the bass drivers) and halves the inductor and doubles the capacitior values for a 2nd order crossover ( tweeters).

So, can anyone ( Pete or Carl, or?) give me some guidance - would simply applying the basic 8 to 4 ohm principles outlined above be appropriate for my Double Advent rebuild?

And, if not can anyone supply the correct values for a single crossover in a Dbl Advent system?

Thanks

Dean

[Pete B]

Imagine that you just put all the components in the crossover in parallel, this is exactly how it works:

1.6 mH goes to .8 mH at half the DCR

16 uF goes to 32 uF

.45 mH goes to about .22 - .25 mH

3 ohms goes to 1.5 ohms

You have Rev 2 crossovers?

http://baselaudiolab.com/ADVENT_LA_XO.html

[Dchristie]

Thanks Pete.

Yes, I have revision 2 (later Original Large Advent crossovers) as per your baselaudiolab info.

Dean

[giovanni56]

On 14/9/2015 at 20:48, Pete B said:

Immagina di mettere in parallelo tutti i componenti del crossover, funziona esattamente così:

1,6 mH va a 0,8 mH a metà del DCR

16 uF va a 32 uF

0,45 mH corrisponde a circa 0,22 - 0,25 mH

3 ohm vanno a 1,5 ohm

Hai crossover Rev 2?

http://baselaudiolab.com/ADVENT_LA_XO.html

16 uF va a 32 uF ?? 

I don't understand, with the switch in INCREASE, C1 and C2 are put in series and in this case, the capacitance is halved and becomes 8uF. Am I missing something?