Light as Air Slot Loaded Band Pass Sub

[xrk971]

So, here is a first raw sketch according to XRK's dimensions, although in millimeters and "flattened":

That looks good. Maybe give the entrance to the wraparound vents a little more clearance at where they start inside the chambers.

 

[gkh]

That looks good. Maybe give the entrance to the wraparound vents a little more clearance at where they start inside the chambers.

Like folding it once more?

 

[xrk971]

Like folding it once more?

Yes that looks good. I would make a triangle cross sectional shape bar (height of slot) maybe 2in deep at the apex and 5 in wide at base and place at the common duct joint. This will give smoother air flow out and reduce noise. Two pieces of thin angled ply works. Does not need to be solid.

 

[gkh]

Yes that looks good. I would make a triangle cross sectional shape bar (height of slot) maybe 2in deep at the apex and 5 in wide at base and place at the common duct joint. This will give smoother air flow out and reduce noise. Two pieces of thin angled ply works. Does not need to be solid.

Done

 

[BP1Fanatic]

X is the man! Can't wait to see the build pics.

 

[gkh]

X is the man! Can't wait to see the build pics.

Absolutely!

Will order BB and Mivocs Today.

 

[xrk971]

Thanks guys. Looking forward to the build pics and sound check!

 

[Ear Wax]

Yes that looks good. I would make a triangle cross sectional shape bar (height of slot) maybe 2in deep at the apex and 5 in wide at base and place at the common duct joint. This will give smoother air flow out and reduce noise. Two pieces of thin angled ply works. Does not need to be solid.

Would Karlson slots be of any benefit?

 

[gkh]

Would Karlson slots be of any benefit?

Something like the attached? Just christened it KarlMivoc...
I really wonder what XRK and Freddi will have to say.

 

[BP1Fanatic]

The tuning would change. You need to calculate that slot area.

 

[gkh]

The tuning would change. You need to calculate that slot area.

That's why I wonder

 

[xrk971]

There is no benefit of a Karlson aperture in this case. It's needed to help disperse midrange to higher frequencies as an acoustic lens and to serve as a gradual impedance matched exit port on a transmission line. Neither of which you need here. It would just restrict your bass output.

 

[gkh]

My build will - unfortunately - take some time, as the company who did cutting and CNC routering for me closed down from one day to the other. Finding an equally good and reliable company seems to be a major PITA.

 

[xrk971]

Sorry to hear that. So you don't cut wood yourself? I don't have a proper workshop either and every time I make a speaker out of wood it is major hassle. Hope you find a replacement soon.

 

[carlosdelondres]

Hi there, interesting thread!

Came across it while pondering what to do with 4 TB W5-876SD I have lying around. I've been wanting a nice portable system for outdoor use for a while, a pair of these should fit the bill. However for use outside I wanted to tune a bit higher, and maybe with a peak before roll-off.

I have never got to grips with Akabak and can't really figure out how the plenum dimensions affect the tuning of the box. BassBox and Hornresp don't seem to be able to sim it? Any chance of taking a look at these dimensions and checking they're not massively far out? Just over 8 litres in each chamber...Build will be 12mm ply...

Thanks very much

 

[xrk971]

Hi there, interesting thread!

Came across it while pondering what to do with 4 TB W5-876SD I have lying around. I've been wanting a nice portable system for outdoor use for a while, a pair of these should fit the bill. However for use outside I wanted to tune a bit higher, and maybe with a peak before roll-off.

I have never got to grips with Akabak and can't really figure out how the plenum dimensions affect the tuning of the box. BassBox and Hornresp don't seem to be able to sim it? Any chance of taking a look at these dimensions and checking they're not massively far out? Just over 8 litres in each chamber...Build will be 12mm ply...

Thanks very much

View attachment 612365

What's the gap dimension on the wraparound vents?

 

[gkh]

Sorry to hear that. So you don't cut wood yourself? I don't have a proper workshop either and every time I make a speaker out of wood it is major hassle. Hope you find a replacement soon.

Unfortunately, there's no place in my 50m² appartment

 

[carlosdelondres]

ah sorry, they're 0.5", as in your original. cheers

 

[NegativeGhostrider]

I know it's been a long time since anyone's posted in here but I am digging this design and am wondering about a version using one of these since the Tang Bands are discontinued.

Peerless SLS-P830945 5-1/4" Paper Cone Woofer 4 Ohm Pretty similar to the originals and that 5mm xmax.

Dayton Audio DC160S-4 6-1/2" Classic Shielded Woofer 4 Ohm Larger driver and much lower Fs but lower xmax. Not sure how that would translate to SPL extension.

FaitalPRO 5FE100 5" Professional Midbass Midrange Woofer 8 Ohm 5.25 xmax but the Fs and Qts are a bit high.

Thoughts or experience on any of these? Thanks!

 

[freddi]

if you could tolerate the weight and size then this speaker made popular by BFM could make a sub of sorts

https://www.newark.com/mcm-audio-select/55-2421/8-high-excursion-woofer-120w-rms/dp/88C7835