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Alpair 7P & Alpair 12PW combination.

a simple two way A12bw + A7p

...almost ready....
 

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Hey guys!

I was thinking about trying the 12PW fullrange, in 3 ft^3 @ 23hz (-6dB Extended Bass Shelf). Xmax is completely fine down to 10hz at 3.5W/ 93dB @ 100hz in Box Sims. I was planning to use this with a 3.5 watt SET amp, so it works out perfectly!

20hz Xmax is exceeded @ 12.4 watts... but any rogue sub 20hz frequencies will probably destroy the thing, with cone travel up to 16mm at 10hz.

-3dB @ 60hz
-6dB @ 23hz!!
-9dB @ 20hz!

Enclosure dimensions would be 24" high, 18" wide, and 12" deep. Similar dimensions/look to the JBL L100 Classic, for that "retro" look.

What do you guys think?
 
frugal-phile™
Joined 2001
Paid Member
in 3 ft^3 @ 23hz (-6dB Extended Bass Shelf). Xmax is completely fine down to 10hz at 3.5W/ 93dB @ 100hz in Box Sims.

I am not a big fan of that kind of alignment. Something that came about with drivers that can’t actualy di decent bass. Scott's ML-TL get simialr extension (and i expect smaller)

And unles syou use 2, the sensitivity will not exceed the 87-88 dB 1w figure. And given that it is extended bass shelf something less than that (typicaly 3-6 dB less).

dave
 
How much do I need to adjust either the front-to-back dimension or the height to compensate for an internal baffle with approx 50% holes, and if front-to-back, what does that do to the upper section - I assume no baffle is needed there ?

Sorry if this is basic stuff, but I'm a basic beginner with no idea...!
Thanks for any help - its appreciated.
 
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I was joking zman - yup, clamps, glue and reasonable woodworking skills, although my knowledge of cabinet building stuff, such as aspect ratio's is nil.
I'm a property maintenance guy for a living, have hands that work, and a brain that maybe doesn't so well.............

..and I hardly ever use nails for anything !
 
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zman - nope. I'm just starting to cut up the ply, and am going to try to make a cross brace, the same as a pensil has, ie one full length of the lower cabinet, from front to back, and one that goes side to side, and slides onto the front to back one. It's only going to reach up to just below the port.
 
simplesteve,

When you are doing the side to side bracing piece, make sure that the back to front brace that slides in is not placed exactly in the middle, but slightly off center - an image attached below to give you the idea.

The drawing is done assuming that you will be implementing a similar brace to that of the "holey" brace advised by Dave.
 

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