Giant Subwoofer?

[infamousJ]

Originally posted by tvi


I thought the Carver ribbons used cone drivers for bass.



Heres the patent for the above speaker
Carver Patent EP0267650

Regards
James

a few years ago my boss at a local electronics shop gave me 3 of the ribbon drivers sans boxes, two were nearly mint, one was taken apart, the good ones were alittle worn out but sounded so very good even without boxes..... sadly the two working ones were 'taken' off my hands when I lost a storage locker for non-payment... I still have the disected one in my dad's basement... does anyone have information that I could use to resurrect it and maybe build it a mate? I know this is wrong post for this but I have been searching high and low for info for these drivers

[Doedolf]

http://www.royaldevice.com/custom.htm

[TravisDigital]

Clairion and Kenwood both make a 32" driver but is it needed?

If you just want to reproduce 8hz You could build a transmission line enclosure for an 18" driver and that should achieve frequencies far too low for human hearing such as 8 hz!

On the other hand you might just want to have a bigass sub! does this have to be a "conventional" subwoofer? you can get a servo motor and build a woofer to be 99" if you want, check out the Adire audio Parthenon. I think that one was 44" I'll post a pic of it below

[AndrewT]

any size of driver can produce any frequency.
The weight and size of the driver limits the high frequency.
The weight and size and Xmax limits the SPL of the low frequency.

[TravisDigital]

Originally posted by AndrewT
any size of driver can produce any frequency.
The weight and size of the driver limits the high frequency.
The weight and size and Xmax limits the SPL of the low frequency.

In my experiences hand building high end drivers for the last several years, when dealing with subwoofers, the voice coil it's self limits high frequency. subwoofer coils generally have more windings than a mid or even a full range driver, these extra windings act as an inductor and in return you can't get really high frequencies from a subwoofer, the cut is often around 6k for the average every day entry level woofer.Really high excursion woofers can be as low as 1k or lower.

[TravisDigital]

Have you considered variable mass passive radiators?

You could run 1 driver and put it in an enclosure with several passive radiators to conserve amplifier power, as well as achieve extremely low frequencies at moderate SPL levels. Oh and the variable mass p.r.'s you can tune them yourself by adding weight to the rear of the cone, so it shouldn't be very difficult to get 8hz.
Here's the specs from audiopulse on their passives, and it looks like all but the 10" are capable of 8hz or lower!!!

10″ 12″ 15″ 18″
Qms Variable Variable Variable Variable
Mms 0.5 - 2 kg 0.5 - 2 kg 0.5 - 2 kg 0.5 - 2 kg
Fs 10 - 24 Hz 8 - 22 Hz 7 - 20 Hz 7 - 20 Hz
Sd 0.032 m² 0.052 m² 0.083 m² 0.110 m²


you can learn more about variable mass passive radiators at www.audiopulse.com