WBAL Betsy-K 'small' ~40 Hz MLTL

[GM]

'Parking' a design here, so I can link sims to this other forum thread:
Betsy K cabinet help? (Page 1) / FullRangeDriver Forum / Fullrangedriver Forum

Originally Posted by Greg B

For WAF, a TL or single fold TQWT can be disguised as a plant stand.

Originally Posted by KenR

I have space issues, I can only go 10 inch wide. about 15-20 inch deep and some 40 inches tall.

For a MLTL, etc., this driver wants to 'feel' at least a 4.4 ft^3 net Vb, so going back to the original max dims as overall, this equates to only ~2.5 ft^3 net.

Still, backed up against a wall, its relatively high F3 should work well if tuned to around 40 Hz and a heavy plant perched on top will sufficiently mass load the relatively skinny tower for a nice 'tight'/solid bass line once damped to 'taste' or even stuffed to semi-aperiodic if that's what sounds best.

Anyway, FWIW [15” deep/1st sim]:

L = 38.5"
w = 8.5"
D = 13.5"
driver centered at 5" down
3" dia. x 1.5" long vent centered at 30.8" down

All dims i.d. [inside] and approximate based on 3/4" [~19 mm] void free plywood or similar construction. Some ~1” dowels, vertically oriented 1x3 boards or plywood scrap tied together to form ‘X’ braces at ~1/4 [9.625”], 3/5ths [23.1”] down from the top is sufficient bracing to keep the column from ‘breathing’ if the potted plants are used, otherwise a full height riser tied to the center of the ‘X’ bracing is required.

I recommend the top, one side and back be lined with 1" acoustic fiberglass insulation or similar, though sim is based on 0.25 lbs/ft^3 of polyfil [~10 oz] evenly distributed along its length.

++++++++++++

Alternate [20” deep/2nd sim]:

L = 38.5"
w = 8.5"
D = 18.5"
driver centered at 5" down
4" dia. x 1.5" long vent centered at 30.8" down

GM

[IG81]

Sims look good, thanks for putting this up. Driven by low Z source I assume?

IG

[GM]

You're welcome! Yes, though should be OK with SET if away from the walls a bit and can be fine tuned with vent damping.

GM

[IG81]

Originally Posted by GM

You're welcome! Yes, though should be OK with SET if away from the walls a bit and can be fine tuned with vent damping.

GM

Only lately have I started to check out impedance from 0 to 8 ohm when simulating boxes; it's pretty enlightening to see how DF=1 can screw up a "warm" design. I also experienced it with the 49L/40Hz boxes I made for CG10T/AD9710, with a built-in 2-3dB hump on a low-Z drive, to battle baffle-step; it works well but did better on a low-Zout SS amp in my small room.

IG