Isobarik requires the cones to be closely coupled which effectively halves Vas. So you can halve the box size. Usually the drivers are mounted clamshell or back to back via a small tube.
A simple push pull box would have both drivers visible and be four times the volume.
A simple push pull box would have both drivers visible and be four times the volume.
Thanks for answering. So a push pull doesn't suffer the loss in sensitivity and keeps the same vas as a conventional box.
Yes, the isobarik trades sensitivity for smaller box size.
With simple push pull box its just two drivers basically, just that even harmonic distortion is cancelled.
With simple push pull box its just two drivers basically, just that even harmonic distortion is cancelled.
A further question re push pull, if one driver is facing forward and one behind, does it matter which way round? Ie if one decided to have the inverted driver facing forward.
Hi,
Not really. On opposite panels you will get some box force cancelling.
rgds, sreten.
True, though you'll lose some of the cancellation of harmonic distortion. I'd try and keep them close together.
Chris
Chris
If one were to go front and back, to the question of which driver faces forward, would it matter?
"Hi, I don't see why that would happen for a subwoofer"
PP cancels 2nd and 4th harmonics, so what is the 1/4WL of the 4th harmonic of 100hz?
(this tells you the spacing required)
PP cancels 2nd and 4th harmonics, so what is the 1/4WL of the 4th harmonic of 100hz?
(this tells you the spacing required)
For a push pull with one driver on the front panel facing outward and the other driver underneath facing inward, how should one wired it to the plate amplifier?
Thanks in advance.
Thanks in advance.
The driver mounted magnet-side-out needs to have its polarity reversed in order to operate in phase with the other driver. Wire the 2 drivers in parallel, if the impedance isn't too low for your plate amplifier.
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Thanks for the reply.
Am building a pair of M&K Clone using 300W Oaudio Plate Amp with 8in Peerless 830586 drivers.
I'd like to see that. Coming from diymobileaudio, i was told of the benefits of the M&K set up in a car audio setting.
Sorry to keep asking, does it matter what side the magnet side out driver is facing?
AIUI, the magnet and frame assembly will be invisible to subwoofer frequencies due to their wavelengths just wrapping round the objects in question, so no, it doesn't matter whether you have the speaker cone front or the magnet assembly facing you.
Only thing to take account of is that when running near Xmax (if designed to do so), there might be some mechanical noise from the large movement of the cone and suspension components, or some noise from any cooling vents in the pole/magnet assembly, so you might want to orientate the box so the driver that has its cone facing outside the box is towards you if you have a box with drivers on opposite sides. (If the box is an M&K clone, mount the reversed driver underneath so that higher frequency mechanical noises from large excursion could be masked by a carpet or rug, perhaps?)
That said, I rarely hear any mechanical noise from my PPSL subwoofers (you should be able to find my build thread through my profile page) and would highly recommend them for their 'transparent' bass sound (presumably from the cancellation of the even order harmonics, as mentioned above) so if you have the space available, consider making a PPSL box yourself 🙂
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