1215A building plans

[bowtie427ss]

OG, i'm also looking over the tuba 36's with great interest, but am stuck in a bit of a rut with the drivers i want to employ.

I have four NOS Emilar EW15's that i'd like to use for subwoofers. I'm unable to find any T/S parameters on these woofers. With my limited knowledge I've been able to only determine the very basics including an Fs of 21hz.

I suspect this is lower than ideal for an enclosure like the T36. I'm only interested in using these below 100hz as subwoofers for use with A7's, and possibly 817 or 815's in the future.

Opinions and suggestions for a foolproof box design for these are invited and welcome as well as appreciated.

[Old Guy]

Wow, 21 hz. Yeah that's not gonna work well in the T36.

Best Altec candidates would be probably 421 or LF, or maybe the 515 GHP. I haven't modeled any of them yet. I have a pair of Eminence I got as samples that are basically the 3015 LF with a couple of tweaks. They work well in that box.

With the emilars you probably want to go ported or maybe even a large IB.

You might want to check some of the high efficiency boards, you may find a geek close to you who could measure them for you.

[Old Guy]

Isn't there a guide in one of the Altec enclosre books on the "old style" tuning method? Maybe that would work for Bowtie...

[bowtie427ss]

Yes, large ported box seems to be the consensus for these. I played with a pair in some ~9cft boxes with 6in dia 8 inch long ports and they seemed to perform quite admirably down in the 30 hz region, i'd like to get lower and am confident these are capable.

These seem to by all appearances demonstrate a lot of influence from the altec designs, no doubt from Renkus' tenure at Altec working directly under Mr. Hilliard. They even sport a 16 inch frame quite similar to the Altecs.

Any experience or info out there on these?

[GM]

Greets!

Nope, have you queried the HE asylum members? They know a lot about their horns, so maybe: http://64.154.92.195/scripts/etv.pl?forum=hug

GM

[Old Guy]

I haven't actually tried this.
http://sound.westhost.com/tsp.htm

Have you tried the folks at Plus One Engineering?

They have some old Emilar docs. I know at one point they were considering marketing recone kits for these.

[LICORNE]

I found this drawing ,looks similar to Altec 1215A.




...................................

[Old Guy]

Hi Convergence- that's a lot bigger. I think that is the Shearer horn with space added to square off the ends. I have that print, been meaning to compare it to the Shearer print but just haven't had a chance.

[Audio_by_Goodwill]

Originally posted by Old Guy:
Hi Convergence- that's a lot bigger. I think that is the Shearer horn...

<font size="2" face="Verdana, Helvetica, sans-serif">The Shearer, was my first thought too.

...with space added to square off the ends.

<font size="2" face="Verdana, Helvetica, sans-serif">The Shearer pictures that I have from the Lansing Heritage site look to have squared ends, although they are open on the back side, so you can see the angular pieces of the horn flare.

I have that print, been meaning to compare it to the Shearer print but just haven't had a chance.

<font size="2" face="Verdana, Helvetica, sans-serif">Is the Shearer print online someplace?

[Old Guy]

All the Shearers I have seen have had angled ends- at least several dozen, maybe over a hundred. They were widelu used in SR in the late 70's.


The only Shearer print I know of is in the Audio Cyclopedia- mine is packed away. I should scan it and put it online somewhere- I don't know of any place where it is.
Btw the print shows angled ends too. It's credited to Olson.