model 3156

[pipe]

Can anyone help me with the correct cabinet sizing for the model 3156 drivers. I can not find any information on these drivers.
Thanks!

[[email protected]]

http://www.greatplainsaudio.com/Thiele-Small.html

[GM]

http://www.greatplainsaudio.com/Thiele-Small.html

Using the specs from this page and the dims of an 8156 sub, I get a slightly underdamped alignment with a potentially 'whistling' vent at higher SPLs, but prodigious amounts of LF down to 60Hz/F10 of ~25Hz at half power. For band/PA it should be fine though.

28.5"h
17.5"w
13.25"d
4.93"dia vent assuming a 0.75" thick baffle

A larger cab tuned lower (6.69ft^3 net/~34Hz Fb) should sound much smoother/tighter in a typical HIFI room, covering all musical instruments except 16Hz stopped pipes, with less peak SPL down low as the tradeoff of course.

34"h
23.68"w
14.75"d
6"dia vent x 5.25"L

All dims are inside.

GM

[[email protected]]

The Altec design of the 8156X cabinet for the 3156 woofer (ref. AN #5, pg.5, inside dimensions):

28.5"h
17.5"w
12.25"d
5"dia vent in a 3/4" thick baffle

Woofer C/L 18-3/4" from cabinet floor
Vent C/L 12-1/4" below woofer C/L

[GM]

Hmm, somewhere along the line they changed the design from the early one I measured, probably for manufacturing reasons. Regardless, the performance of either set of dims is audibly identical for a given driver.

Thanks for the info! I don't have a copy of this particular AN, is it posted on the net?

TIA,

GM

[cineserv]

Hi

I have recently acquired 4 3156 drivers so am thinking about building some cabinets for them. I am completely new to speaker cabinet building, so any tips appreciated, but my first question is: are the dimensions listed above internal or external cabinet dimensions?

I have also picked up an 18" driver, but have not got a note of the model number so may come back for more info soon.

My primary use would be home cinema, so from what I've read these may not be ideal drivers, but they were free and I like experimenting so in the end it's really just for fun... I may try 1 3156 to handle bottom end of left/center/right channels with x-over, then use the 18" as the dedicated sub-woofer...
Any thoughts?

Cheers,
Ian

[LICORNE]

The dimensions of 2 3156 for a ducted port would be closer to.

41" H
26.5 " W
26 " D

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<font color="#FFFFFF" size="1">[ March 29, 2008 08:58 PM: Message edited by: CONVERGENCE ]</font>

[Old Guy]

http://www.cpcproductions.com/altec_..._resources.htm

[LICORNE]

There's a different set of cabinet size for the A-10 and A-15 produced for cinema applications THX. The plans are not available. These units were shiped with 3154 woofer inside and the cabs were sealed.

But for 2 3156 woofers it's more than 16 inches deep that is for shure.

The 8000 series of cabinets are low frequency cabs
that do not correspond to the A-10 or A-15.

Tough banana.

.................................

[Vince G]

I use the 3156 woofers in 6.5 cubic foot cabinets
tuned at 40hz with 909 hf drivers. They have lots
of midrange output to about 50hz max. I cross
them over at 60hz to 3154s in 8 cubic foot cabinets tuned at 30 hz. They sound close to a
416 but with much lower volume compliance and
a lot more power handling.