Biamping 4430

Hi All,
I`m getting ready to set up the 4430s to run in biamp mode. My crossover is a Brooke Siren Systems model FDS 310 2 way stereo with variable 24 DB/octave Linkwitz Riley filters.


Attachment 57337
If memory serves me right, the JBL model 5235 active crossover with appropriate cards (12 DB?) was recommended for frequency dividing duties for the models 4430 /35.

My concern is that a fourth order filter may be too sharp a slope and negatively affect the polar/frequency/phase response.

Will this be an issue?

1khz / 12db

http://www.jblproservice.com/pdf/Stu...ies/4430LR.pdf
http://www.jblproservice.com/pdf/vin...5%20manual.pdf

Stéphane

Quote:

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Originally Posted by stephane RAME

1khz / 12db

http://www.jblproservice.com/pdf/Stu...ies/4430LR.pdf
http://www.jblproservice.com/pdf/vin...235 manual.pdf

Stéphane

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Je te merci pour les liens Stephane. 12db/8ve it is then. Aside from the selectable LF contouring via the dip-switches, do the cards offer any type of EQ or are they strictly low and hi pass filters?

http://www.audioheritage.org/vbullet...tage%20drive#4


If you can't get the 5235, go digital and mimic the voltage drive shown the link. I'm using an xilica dsp on my 4435's to achieve the crossover slopes needed to properly bi-amp the 4430/35. Hope this helps.


Al

Quote:

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Originally Posted by Mike F

Aside from the selectable LF contouring via the dip-switches, do the cards offer any type of EQ or are they strictly low and hi pass filters?

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The high pass card is a simple 6 dB/octave slope designed to complement the 20 uF series capacitor that is left in the passive filter after switching to bi-amp mode. Together the two create the 12 dB/octave slope. The passive high pass filter also provides the EQ for the horn/c.d. That portion of the high pass filter is not switched out in bi-amp operation, it remains functional.

Like Allen states, this can all be done with DSP now, although, arguably, that 20 uF series capacitor is kind of handy protecting the c.d. from DC.

Agreed, I chose to keep the passive components in my setup and go 6db on my dsp for the 12db effective when combined with the passive.

Al

Thanks Allen and 4313B. Well I`m a little bummed now. It seems the 24 db slope offered by the BSS is indeed too sharp:(
Would I be better off substituting it for say a Behringer DCX 2496 or similar? 5235s and cards are about as common as 3 legged ballerinas these days...

Try what you have, set it for 24 dB/octave at 1 kHz and see how it sounds. You'll either like it or you won't.

Quote:

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Would I be better off substituting it for say a Behringer DCX 2496 or similar? 5235s and cards are about as common as 3 legged ballerinas these days...

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If you have the crossover the cards are not all that hard to make if need be. Here are photo's of the 4430/35 card. They used the 18db card.

Rob:)

of course, you could always do what a number of us did - get an Ashly electronic crossover.
The Ashly XR 1001 Stereo 2-Way worked really well for a number of us (I used it with my 4341s for years.)
You can adjust the crossover freq, set the levels for the high out and the low out, and set the response ...

from their owners manual -

Response - adjusts the damping of the filter affecting the response shape at the crossover point. The dial calibrations refer to the amount of attenuation effected by the filter at the crossover frequency, i.e., a setting of 3dB means that the filter’s high-pass and low-pass outputs are each “rolled off 3dB at the crossover point”. This describes Butterworth filter response, or a gentle 3dB peak at the crossover point where the two filter output signals overlap. To obtain a flat signal, or “Linkwitz-Riley” response, set the Response control to “6”. To obtain a notch at the crossover point, turn down the response control past “6” to best suit your needs. The purpose of this control is to help offset the inaccuracies inherent in typical loudspeakers, helping you to achieve a flat system response. NOTE: The Response control is not a “slope” control. The Response control only affects filter response shape in the immediate vicinity of the crossover frequency; the ultimate crossover slope is a fixed parameter.

Quote:

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Originally Posted by hjames

of course, you could always do what a number of us did - get an Ashly electronic crossover.
The Ashly XR 1001 Stereo 2-Way worked really well for a number of us (I used it with my 4341s for years.)
You can adjust the crossover freq, set the levels for the high out and the low out, and set the response ...

from their owners manual -

Response - adjusts the damping of the filter affecting the response shape at the crossover point. The dial calibrations refer to the amount of attenuation effected by the filter at the crossover frequency, i.e., a setting of 3dB means that the filter’s high-pass and low-pass outputs are each “rolled off 3dB at the crossover point”. This describes Butterworth filter response, or a gentle 3dB peak at the crossover point where the two filter output signals overlap. To obtain a flat signal, or “Linkwitz-Riley” response, set the Response control to “6”. To obtain a notch at the crossover point, turn down the response control past “6” to best suit your needs. The purpose of this control is to help offset the inaccuracies inherent in typical loudspeakers, helping you to achieve a flat system response. NOTE: The Response control is not a “slope” control. The Response control only affects filter response shape in the immediate vicinity of the crossover frequency; the ultimate crossover slope is a fixed parameter.

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Thanks for your input Heather. IIRC, the Ashley unit is a fourth order filter as well differing only in the degree of attenuation at the crossover frequency (not sure how that feature would affect pass band phase response/coherency) and therefore present an identical dilemma.

I chose the BSS unit specifically for a number of reasons, build quality, reliability, operational flexibility and transparent sonics topping the list as well as the "period correctness" aspect.
There is no question newer digital processors offer much more all-around flexibility but I have a hard time believing they would meet or exede the previously mentioned criteria given this price point.

Let us know how it works out for you.