Plans for this lascala mod

[bliss53]

Does any one have plans/drawing/measurements/listening experience for the slotted base bin modification in the picture? I do not know who owns these to ask directly.

Thanks,

[djk]

Those belong to Les Hudson at Audio Asylum.

[jambandfan]

I like that look a lot. What horn is that on top? -marc

[djk]

It looks like an Oris 150 with a Lowther driver.

Les has made some horns like that from scratch, so it may be his version of same.

Various projects:

http://gallery.audioasylum.com/cgi/view.mpl

10" Audio Nirvanas in a 150hz Tractrix Front Horns on top of Double 12" Push-Pull bass cabinets

I think that this is the worlds best subwoofer design. This is a Double 15" Push-Pull. I'll never build a bass horn again.

[moray james]

Dennis: how high up could you run a pair of tens in a cabinet like this? I am shooting for a crossover point between 350 - 400 Hz so could this get me there? Driver with a Qts of atound 0.3 or so? Thanks for the help. Best regards Moray James.

[djk]

Sure, 400hz for a pair of 10s should be no problem.

Keep the depth of the mounting plenum to a minimum for maximum bandwidth.

A Qts of around 0.3 is best for minimum box size vs efficiency vs bass extension, although any value can be used with the appropriate cabinet design.

A PPSL dual 10 Linkwitz open-baffle design.

[moray james]

Thank you Dennis: as for the box design are there any special adjustments required when designing with a pair of driverrs in a plenum or is working the model for two identical drivers all you need to do once you have made volume adjustments for the plenum volume? For future reference what would be the useful cut off frequencies for a 12 inch driver and a 15 inch driver?

In the posted photo are the drivers simply in an open W baffle? Could you comment on bass exetension with an open baffle and when using a box in conjunction with the plenum? Thanks for the information best regards Moray James.

[tigerwoodKhorns]

Does any one have plans/drawing/measurements/listening experience for the slotted base bin modification in the picture? I do not know who owns these to ask directly. Thanks,

Same question here. My guess is to simply take the area and depth of the two recommended 4" x 7" deep circular ports and make one square port.

So we have (4/2)^2 x 3.14 x 2 = 25.12 sq. in.

OK, the top (er, bottom) of the La Scala is 10" tall, so it looks like the port is 10" x 2.5" x 7" deep by my coctail napkin calcs.

Vary as required (meaning if you build an actual port from 3/4" wood, it is now 8.5" x 2-15/16" x 7" deep)

Sound good??

[tigerwoodKhorns]

Geeze, I feel like Kryptonite in this thread.

Can anyone verify if this is correct? Please.

[moray james]

If I knew how to calculate that kind of thing for you I would sorry but I am not the guy to ask. I know there are guys here wo have their pilots license for box response programs though perhaps one of the tech guys will answer. This is whyI really want to learn how to fly HR. Still looking for someone to give me a hand with that. Good luck and best regards Moray James.

PS: for what it is worth from my observarions most of these cabinets have little actual cabinet volume so I think that a test box and some experimenting would get you where you want to go. Another area I have found wanting is understanding how slot reflex vents are designed, I know that they have a wider range of response (band width) compared to round or square reflex vents but try and fine a program to design one. (like the vents on an Onken cabinet.

[Guest " "]

Does any one have plans/drawing/measurements/listening experience for the slotted base bin modification in the picture? I do not know who owns these to ask directly. Thanks,

Same question here. My guess is to simply take the area and depth of the two recommended 4" x 7" deep circular ports and make one square port.

So we have (4/2)^2 x 3.14 x 2 = 25.12 sq. in.

OK, the top (er, bottom) of the La Scala is 10" tall, so it looks like the port is 10" x 2.5" x 7" deep by my coctail napkin calcs.

Vary as required (meaning if you build an actual port from 3/4" wood, it is now 8.5" x 2-15/16" x 7" deep)

Sound good??

Well, just to throw a wrench in the works... if they are wired the same....quasi isobaric rules apply.....box volume basically becomes bigger as the woofers move closer together.....max bigger is twice the size if the woofers are clam style. So, you have to account for the effective volume based on isobaric concepts then calculate slots based on that. So a 1 cubic foot box with clam shell style woofers becomes a 2 cubic foot box. woofers that align train style are influenced by this isobaric effect the closer they are to each other and wired in the same phase orientation. There may be another unique term for this relationship from a cubic foot perspective.

[tigerwoodKhorns]

But seriously, the port volume cannot just be maintained? I know that Gothover built a set with one slot port on the bottom of each facing forward.

[Guest " "]

But seriously, the port volume cannot just be maintained? I know that Gothover built a set with one slot port on the bottom of each facing forward.

Same question here. My guess is to simply take the area and depth of the two recommended 4" x 7" deep circular ports and make one square port.

slots and ports use as one of the computation elements the volume of the box. in the first picture we do not know the volume of the cab, the FS data for the woofer, the target frequency for tuning the slot, and in later pictures that show a front to back isobaric arrangement....we do not know how the orientation of the woofers effects the cabinet volume.

I know that Gothover built a set with one slot port on the bottom of each facing forward.

you can add slots easy once you calculate the total internal volume (doghouse plus the volume of either the sealed off top section or the volume of the new added bottom section) and size the slot using a slot calculator.