New Heathkit AS101 owner - First post.

[alancohen]

I built this speaker before discovering the wonderful world of Altec horns. It utilizes an 8" Tang Band full-range driver. I assume you mean this style where the port is separated from the driver. I used a $5 4" port tube from Parts Express an cut it to length to tune.



I also saw this on 6 moons 6moons audio reviews: Steph?n's Altec 604 Dream Speaker where he does a similar thing with a 604. I guess I would be mounting my 811 on top. His dimensions are deeper than wide. I think I would go the other direction as you suggest, ~30" wide by ~21" deep which would accommodate the horn better. I'd like to avoid the freakish, appearance-wise.

The speakers I built are 3/4 MDF and weigh quite a bit. I can only imagine what the cab would weigh of the size I would need for the 416s. I think for that reason I would build a separate cab for the 811. Not that I'm planning on moving again soon. But the experience is still very fresh in my memory (arms and back). My current sentiment is to be buried in this house, but who knows?

Since I'm bi-amping w/ active XO, should I be considering an open baffle design?

[alancohen]

Not easy to find, but I came across these Thiele small parameters for the 416A:

Model Number: 416A
Xmax (inch): 0.6
Xmax (mm): 15
Re (ohms): 12.54
Fs (Hz) 21.4
Vas (cu. ft.) 36.8
Qts 0.272
Le 2.5
BI 18.01
Cone Dia 12.7
Cms 0.001124

Plugging in to this calculator Speaker Box Enclosure Designer / Calculator I get 10.02ft3 for volume. 6" x 2.57" length port for the 416A.

That would give me a box OD 28" wide, 21" deep and 36" high made from 3/4 MDF with 3/4" battens and leave room on top to get the 811 to ear level.

[valhallax]

[QUOTE=alancohen;1845970] His dimensions are deeper than wide.
whose dimensions?

[alancohen]

[QUOTE=valhallax;1845989]

His dimensions are deeper than wide.
whose dimensions?

Follow the 6 moons link to the article.

[alancohen]

So...this weekend I'll be getting moving boxes organized in my garage and my shop up and running. I have two projects in the queue:

1) acoustic panels for my listening area and

2) designing my new cabinets

I just picked up some of this stuff for both:

16 in. x 48 in. UltraTouch Denim Insulation Multi-Purpose Roll (6-Pack)-60306-16482 at The Home Depot

It's 2" thick insulation that I hear makes a pretty good sound absorber. Since it's 16 x 48" I'll be making some 16 x 48" acoustic panels as well as some 32 x 48" panels to mount on the ceiling, fireplace and back walls.

But I think I'll also use it to line my cabinets.

That brings me to cabinet design. I've poked around and found quite a few threads on the subject. Basically I'm thinking along these lines:

http://www.hostboard.com/forums/f700...tl-416-8b.html

I like the idea of an MLTL cab, but do I have to go 52 3/4" high? I'd like to mount the 811s on top and have their centerline at ear level...maybe 38-40" off the floor. I could make the cabs taller and angle the horns down, but I think I'd prefer them on plane together.

Also, I see internal volumes all over the place for 15" Altec speakers...from 6.5 cuft for model 19s to 16cuft and up. I'd like to stay with about a 9 cuft at most.

We don't need to rehash everything here. Can someone distille the past fews years cab threads and direct me to a few that might fit my siituation?

[GM]

IME, the denim?s specs implies it?s too absorbent for a MLTL. O-C 703 1? duct board same as what Altec sometimes used works well, while others prefer to stuff with loose polyfil. If you can split the denim in half it would probably be OK.

The M19 is ~ 8.35 ft^3 net. To get more bass extension requires more net Vb, so to get down to a low Fs with authority and/or to keep from having a ?boomy?/?flabby? bass with a high output impedance requires a huge cab due to the 416?s specs.

This is why I always recommend building the largest cab one can ?afford? if for no other reason than it allows some extra tuning flexibility.

A MLTL?s path-length is restricted not by it height per se, but by its height x its depth and any adjustment required to fit the driver in, but to fold it in half with a divider/vertical brace, it needs to be 23.25? o.d. deep for the 416A and dictates the dual 4? vents will normally exit the rear side corner[s] or back 13.1? i.d. up from the bottom.

If we split the difference and design based on a 39? ear height, a 34.25? o.d. MLTL height equates to a ~65.5? one fold path-length based on a ?? thick panel construction.

Combined with the M19?s 30? o.d. width, it will be near 11 ft^3 net.

All dimensions are approximate and sims are minimally damped.

1^st sim = ~30 Hz tuning/0.75? long vents, 2^nd sim = ~24 Hz [Fs]/4? long vents, so this is the typical tuning range.

GM

[alancohen]

I'm confused. Plans on the net show the Model 19 lower cab to be 30x24x19. If I plug those OD dimensions into this volume calculator, and assuming 3/4" panels you get 6.49" of internal volume.

Speaker Box Volume Calculator / Designer

What am I doing wrong?

[Earl K]

I'm confused. Plans on the net show the Model 19 lower cab to be 30x24x19. If I plug those OD dimensions into this volume calculator, and assuming 3/4" panels you get 6.49" of internal volume.

Speaker Box Volume Calculator / Designer

What am I doing wrong?

Here's a clue ;

This is a look at the bottom of an M19 horn module .