Multiple drivers vs. single driver sub

[planet10]

Originally Posted by AJ34

Exactly what I'm thinking of doing. I could even mount each driver compliantly on the cabinet and brace the drivers securely back-to-back to further minimise transfer of driver vibration into the cabinet.

I would not compliantly mount the woofers. It would reduce the push-push coupling (in most cases) leaving energy in the basket reducing the system's DDR.

dave

[Rullknufs]

Originally Posted by planet10

The cone moves. The basket has an equal and opposite reaction. This is all loaded into the box. If you have 2 tightly coupled push-push woofers most of the reactionary energy is canceled and you dramatically reduce the energy input into the box.

dave

Okay, and the noticable sound improvements are ...?

[Etocynned]

There is a review of the TRW17 rotary woofer here:

Home Page

It speaks at length on the very concept of subwoofer output limitations due to impedance matching of the driver to the air.

I've read the review over and over again and each time learned something new.

I'm a big fan of Tapped Horns and their cousins Tapped Tuned Quarter Wave Tapers(correct name?) Because of the concept of impedance matching.

When i can i will buy and install 2 TRW-17's in my listening space to augment whatever system is running.

[planet10]

Originally Posted by Rullknufs

Okay, and the noticable sound improvements are ...?

Much less box, more DDR.

dave

[Rullknufs]

Originally Posted by planet10

Much less box, more DDR.

dave

Less "box-sound"? What is DDR?

[planet10]

You are putting dramatically less energy into the box, much less then available to excite box resonances.

DDR = Downward dynamic range.

dave

[Rullknufs]

Originally Posted by planet10

You are putting dramatically less energy into the box, much less then available to excite box resonances.

DDR = Downward dynamic range.

dave

Alright, so for my future project including the CSS SDX10 you would recommend a push-push box of what size and tuning?

[planet10]

We built page 1, page 2 was version 1, i decided it was too big for my room.

http://www.p10hifi.net/FAL/downloads...oof-230712.pdf

dave

[weltersys]

Originally Posted by planet10

The cone moves. The basket has an equal and opposite reaction. This is all loaded into the box. If you have 2 tightly coupled push-push woofers most of the reactionary energy is canceled and you dramatically reduce the energy input into the box.

dave

The dramatic reduction of energy input to the "box" is especially helpful when the box is part of an infinite baffle installed the floor or ceiling, where the mechanical transmission can show up as rattling parts of the house.

[adason]

I experimented with subwoofer with two 15" woofers on opposite sides, and heard big improvement in push-push (dipole) configuration in comparison to push-pull (bipole). Even decided to take some measurements.
keele line array, bad start...
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