isobaric bass cabinet

[mayfly]

That is very very cool!  I love it when people get off the tried and true path and explore new territory  :icon_thumright:

 

[kboman]

That's so cool I'm getting frostbitten.

 

[Super Turbo Deluxe Custom]

This has become my primary cab for quiet, indoor small gigs and uber loud outdoor gigs where a rig is just for stage volume and the direct out of the head is used.  I played with it Saturday night with a full PA and it sounded great.  With my amp set flat and using the BBE Sonic Max to tweak highs and lows, it sounds great.

Middle sized gigs where my stage volume is the room volume, I still use my Ampeg and sometimes both.

It has (2) 400w 12" speakers which were absudly cheap.  Combine that with (mentioned in earlier posts) the inefficiency of the design, it just does not get very loud.  This is actually the only cab I can peak my head, and still be close enough to it to not be deaf.

The sound of it is amazing.  Much better than it should be.  The sound is definitely very bassy and not articulate, but it doesn't have those spots like other cabs I've used where a few notes on the neck will rattle your teeth.  You feel and hear the bass around you, but can't really trace it's origin, so if the band gets louder, I don't have too.  In this sense, it's not very room sensitive.  It's very consistent from venue to venue.  I made this as a what if, almost as a joke, and had the time to experiment with it.

After Thanksgiving, I have plans to make another one from the ground up.  This one was originally a GK 2x10 that had been gutted.  My next will probably use (2) 10s on the inside and (2) 12s on the outside.  It's probably going to be that way out of convenience.  The construction of it won't allow me to put a same size speaker in once the cab is built.  They have to go in from the front.  I can't think of a way to put a 12" speaker through a hole that another 12" speaker will mount to, not without building the cab around it.  

 

[tubby.twins]

My next will probably use (2) 10s on the inside and (2) 12s on the outside.  It's probably going to be that way out of convenience.  The construction of it won't allow me to put a same size speaker in once the cab is built.  They have to go in from the front.  I can't think of a way to put a 12" speaker through a hole that another 12" speaker will mount to, not without building the cab around it.  

Not meaning to rain on your parade, but I'd be concerned that this dual-size approach might cause problems.  Your first isobaric cabinet works (i.e. reduces the Vas by half) because both 12" drivers have the same parameters, and displace the same amount of air given the same amount of power applied to the terminals; hence there is zero pressure differential in the intermediate area between the two drivers.  What happens if your 12" and 10" drivers don't displace the same amount of air?  What will a pressure differential in the intermediate area do to your drivers (or to the sound)?

 

[Super Turbo Deluxe Custom]

I thought about that as well.  With the same speaker, and in phase, there is (in theory) no pressure difference.  With a single speaker in a sealed cabinet, there is a pressure difference.  With 2 different sizes, the pressure should be somewhere between zero and sealed.  I had to convince myself to do the different size thing because I had the idea of the cabinet before I considered how to put speakers in it.  I may have to reevaluate the construction, atleast the front, just to use the same sized speakers.  I'll be the first to tell I really don't know what I'm doing.  I may have just lucked out with the first one, and this one may crash and burn.  But, I've got a router, time, and gumption.  The Orange cabinets would be ideal, but I don't want an 8 ohm cab.  Their only 4 ohm cab is a 4x10.