Olson S-311

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Can I use this cabinets?
 

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huymdt said:
"...so I don't recommend building the Onken..."

Could you guide me clearly? Now I need a schema for Olson S-311 drivers. What can I use if not the Onken?

Greets!

Like I said, without any info I can't really help much, I just know that if it doesn't sound good in the Onken, it's not a user friendly cab for tweaking beyond stuffing the vents to roll off any 'boominess'.

WRT what appears to be a crude '50s era BLH cab in the pics, don't have a clue. Only one way to know for sure though without specs.

Really, for max performance you need to either measure them or have a local electronics repair shop/whatever do it, then get back to us. Otherwise the only suggestion I can make is to use this pre-T/S bass reflex rule-of-thumb for what was considered an optimum box volume (Vb) for a given effective piston area (Sd) where the port area (Ap) = Sd:

Vb = 2000R

where:

R = SQRT(Sd/pi)

Since a typical 12" has a ~78"^2 Sd, or ~4.983" radius:

Vb = 2000*4.983 = 9966"^3 = ~5.7674 ft^3

If it's tuned too high, reducing Ap to 1/4 will tune it ~1/2 octave lower and 1 octave if reduced to 1/16th, but it may 'chuff' enough to be audible on some music/movies at this size, though some vent damping will cure it.

As for shape, a tower design (aka MLTL) to get the driver up to near/at ear height, keep the footprint reasonable and construction simple is my preference:

L = ~57.06"
CSA (w x d) = ~174.68"^2 (I recommend ~16.82" w x 10.39" d)
driver down ~21.93" from top
vent near/at the bottom

All dims are inside (i.d.) and since you'll probably want to experiment with making the vent smaller, putting it on the rear seems best. Initially, just line the top, one side and back about 2/3 the way down with 1" fiberglass insulation.

GM
 
Thanks GM,

On your instruction, I imagine the cabinet with 27.93"(H) x 16.82"(W) x 10.39" (D) and driver space from top about 6", with vent near the bottom... This is the first project for cab and difficult without specs. Thanks so much for your recommend.

Huymdt
 

GM

Member
Joined 2003
Greets!

You're welcome!

?? Finished, this will be a ~5 ft tall speaker to take advantage of some 1/4 WL pipe loading and minimize its 'footprint', with L = length = height = ~57.06" and the driver is down from the top ~21.93", or ~35.13" up from the bottom if you prefer to view it this way. Again, these are inside dims. Obviously, if you have small children or pets big enough to tip them over a suitable base will be required.

There's been numerous posts WRT the pros and cons of different construction materials and bracing preferences, so a search should give you enough to decide what will probably work best for you.

GM
 
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