Reccomend a box for this driver

[greg_mcquaid]

Hi,

I would like to know what box you guys would reccomend that would get me down to 20hz using the following driver:

Re: 3.7 ohms
Le: 1.30 mh
Fs: 23.5 Hz
Qms: 2.73
Qes: 0.416
Qts: 0.361
Vas: 61.6 Ltr
Mms: 232 g
Cms: 0.35 mm/N
Sd: 468.7 Cu Cms
Bl: 17.46 T-M
Xmax: 15mm

I hope the driver is pretty good as it is cheap and available on my side of the pond.

atb,
greg

[sreten]

Hi,

what is the driver ? some very good numbers there, may not be right.

/sreten.

[greg_mcquaid]

Its the driver from this subwoofer that bk electrnics produce:

http://www.bkelec.com/HiFi/Sub_Woofers/monolith.htm

The driver is based around a lab12 i think.

greg.

[sreten]

Hi,

well according to the numbers its an excellent driver - but who
sells it ?- I can't see anywhere on Bk site where you can buy it.

/sreten.

[greg_mcquaid]

sreten here's the link:
http://www.bkelec.com/HiFi/Drive_Uni...onolith_du.htm

Ive come up with a design in unibox, il post the graphs to see what you think (it probs needs improving).

Here's some stats on the design:
VB: 65l
FB:21.00
F3: 20.32

2 ports (8.00cm Dia) with a total length of 99.56cm.

106db at 20hz

Here's the graphs:

Response Graph - http://img59.imageshack.us/img59/727...thdrivean4.gif

Excursion Graph - http://img59.imageshack.us/img59/993...ithdrivfv5.gif

Am i on the right track?

Thanks,
Greg

[GM]

Greets!

It may be OK, but the long vent's pipe harmonics won't be completely damped by flaring the ends, so they may need additional damping, which will lower output somewhat, so I'm thinking a lower tuned ML-TQWT may be a better alignment overall, though a bit larger:

L = 101"
SO = 200"^2
SL = 19.635"^2
zdriver = 6"
zport = 98.5"

Folded up, both the driver and vent cutout will be at floor level for max boundary gain. Sim shows minimal stuffing, so adding more further smooths it and rolls off the bottom end if it sounds too 'boomy' in-room.

GM

[GM]

As opposed to this 45" high bottom firing sim using your alignment with the same amount of stuffing, though it doesn't show any damping due to any vent flaring:

[sreten]

Originally posted by greg_mcquaid
s
Am i on the right track?

Thanks,
Greg

Hi,

Just my opinion but flat alignments can sound boomy, I like to tune
the ports lower than that that gives flattest response, but each to
there own - possibly get an adjustable port and try in situ.

/sreten.