using paradigm 15 drivers for car high SQ

[muddasirwaheedmalik]

hi everyone.

just got a chance to have a hand on pair of paradigm servo drivers 15 inch, i intend to use them in car trunk in a pair. each drivers has rms power rating of 400 watt with xmax of 1 inch.

with the single sealed design the sub can reach 17 hz -db, not sure if it is equazlized but could get advantage of cabin gain.

Paradigm Reference Servo-15 powered subwoofer | Stereophile.com

Paradigm Servo 15 Subwoofer | Moe's Home Theater

now my intention is to get deeepest bass with this pair, high SQ only whereas SPL is not requirement, have amplifiers to provide 400w rms using pull push desing to reduce the box volume requirment to be small enough to be filled in trunk even at the cost of reduced output and efficiency but lower frequency extension.

Requested Question: the internal volume in the paradigm design is 3.4 cubic feet for closed design , i intend to use them in pull push configuration (both facing out and magnets facing each other) what volume should i be using ?twice the 3,4 , same or half ? Think

is it a good idea or should i just get two individuals

 

[richie00boy]

Push-pull mounted as you describe you would not do as they just cancel each other out. Push-push would require double the volume. If you mount them clamshell and drive them push-pull you will need half the volume.

 

[muddasirwaheedmalik]

i agree , but they woule be wired out of phase , so when one woofer is moving out the other is pushing air in, they would complement not cancel each other??/

woul id not not reduce Vas? any gain in SQ?

 

[revboden]

Push pull isobaric, would complement by doubling the motor strength, What you descrive would be isobaric open baffle.

reference: Audio Innovation - by Dan Marx www.danmarx.org

 

[Michael Bean]

Like richie00boy said, if you mount them in a sealed box face out, and wire them out of phase, you will get cancellation and litte sound output.

Mike

 

[muddasirwaheedmalik]

ok. so an i put them on same side one faing out , ohter inside, with phase out with twice the Vas. not its two drivers, double box volume , same Fb but cancellation of harmonics. btw i am suprised how does the following work. ?
Paradigm Signature Sub 2 review from TechRadar UK's expert reviews of Hi-fi and AV speakers

and this one has two drivers :::
Experience the B&W DB1 - Bowers & Wilkins | B&W Speakers


i am quuite confused, i know two drivers inopposite direction make bipolar, make their output more directive ....but is that not we want unwanted difussion in other directions that muddy the sound?

 

[Trevor White]

ok. so an i put them on same side one faing out , ohter inside, with phase out with twice the Vas. not its two drivers, double box volume , same Fb but cancellation of harmonics. btw i am suprised how does the following work. ?
Paradigm Signature Sub 2 review from TechRadar UK's expert reviews of Hi-fi and AV speakers

and this one has two drivers :::
Experience the B&W DB1 - Bowers & Wilkins | B&W Speakers


i am quuite confused, i know two drivers inopposite direction make bipolar, make their output more directive ....but is that not we want unwanted difussion in other directions that muddy the sound?

If you mount them in a compound arrangement you will get a halving of the Vas. If they are mounted so the cones are facing each other then an added bonus is a reduction of 2nd harmonic distortion but each driver must be wired out of phase to each other as in the following diagram.

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