H805 adapter

[Boli46]

After 30 years I am in the process of upgrading my A7-500s to something more like A5s. For multicells I will be using a pair of old H805s I acquired at a reasonable price some time ago. These came out of an Aga-Baltic cinema speaker system (dismantled long before I got my hands on the horns). The Swedish AGA-Baltic company used Lansing Mfg. speaker systems for their cinema installations from the late thirties on. There were three types, Type 1 was the Shearer horn, Type 2 the Monitor 500A in a large baffle and Type 3 the Iconic. They were probably manufactured in Sweden under licence. A Japanese aquaintance of mine who used to sell high end Japanese audio in Sweden has told me that Japanese audio fanatics actually prefer AGA-Baltic manufactured drivers to the original Lansings. There can't be many people in a position to make that comparison! Now to my problem. My multicells have the 2 1/2" inch threaded throat. To use 288s I will need an adapter. I have read that such adapters were made in the distant past, but they are presumably very thin on the ground these days. Does anybody here know of a source? Otherwise I will have somebody make me a pair, but I would prefer originals.

[BillWojo]

I have never seen Altec horns with a threaded throat, not saying they don't exist but I think in the USA they were probably all made with the flange end. Does your horn have a bolt on adapter? Rectangular where it meets the horn, held on with 4 bolts. If so replace them with 30162 adapters. I'd keep an eye out on ebay for a set. Stuff like that always pops up. Actually, there is a couple listed right now. You can't get them made for that price.
A picture of what you have would be interesting.

BillWojo

[Boli46]

I have never seen Altec horns with a threaded throat, not saying they don't exist but I think in the USA they were probably all made with the flange end. Does your horn have a bolt on adapter? Rectangular where it meets the horn, held on with 4 bolts. If so replace them with 30162 adapters. I'd keep an eye out on ebay for a set. Stuff like that always pops up. Actually, there is a couple listed right now. You can't get them made for that price.
A picture of what you have would be interesting.

BillWojo

Lansing Mfg. horns were built with the threaded throat until 1940 (except for the H808 that had the flange end from the beginning), but the horns were of course used long after that. When replacement drivers were needed an adapter had to be used and I have read that such adapters were made. AGA-Baltic probably used the threaded throat longer than Lansing. The threaded throat is bolted on, but the 30162 will not fit, unfortunately.

I'll be going away for a couple of weeks tomorrow morning, but I'll try to post pictures when I get back. I'm a computer illitterate, but I'll do my best.

[Phil-G]

what are the chances of fabricating your own female threaded flange adaptors?

[Earl K]

Hi Boli46,

No doubt you are aware that Steve Schell is one fellow who would know about a possible adapter existing .

In the meantime, a measurement ( made in inches I suppose ) of the rectangular entrance into your version of the H805 would be useful info for all involved.

I'm pretty sure that Vitavox ( among other European suppliers ) adapted some of the Lansing technology post WWII.

They made ( for export to N.A. at one time ) a range multicells that were able to be equipped with either the large threaded adapter ( typically used in the U.K. & other Commonwealth nations ) & the typical bolt-on adapter used by Altec & JBL, post-war .
- You might get lucky and find that the British adapter is compatible with your Lansing era 805.



PS ( some pics )

[BillWojo]

"The threaded throat is bolted on, but the 30162 will not fit, unfortunately"

Maybe an adapter plate could be made. Pictures and possibly dimensions of the internal rectangular port with the bolt hole lay out would be helpful. After we have this the same dimensions from the 30162 adapters would tell us if a simple plate could be used to adapt 30162 to your existing horns. But due to Murphys law, that would be much to simple.

Or due you mean that there is no adapter from the horn to the thread mount? That the end of the horn is threaded? If that is the case, making the adapter gets much more complicated.

Like I said, a picture would be very beneficial.

BillWojo

[Boli46]

what are the chances of fabricating your own female threaded flange adaptors?

What I need is an adapter with a male thread at one end and the usual 288 three bolt flange at the other. The threaded throat on the horn is female.

Me fabricating? Zero knowledge, zero experience and zero equipment are factors against this course of action.

- - - Updated - - -

"The threaded throat is bolted on, but the 30162 will not fit, unfortunately"

Maybe an adapter plate could be made. Pictures and possibly dimensions of the internal rectangular port with the bolt hole lay out would be helpful. After we have this the same dimensions from the 30162 adapters would tell us if a simple plate could be used to adapt 30162 to your existing horns. But due to Murphys law, that would be much to simple.

Or due you mean that there is no adapter from the horn to the thread mount? That the end of the horn is threaded? If that is the case, making the adapter gets much more complicated.

Like I said, a picture would be very beneficial.

BillWojo

There is a flange on the threaded throat that bolts to the horn. But this flange is much smaller than the flange on the 30162. I have a pair of 30162s and there is no way they could be adapted to fit the horn.

It's 10:40 pm here in Sweden and I am leaving early in the morning. Pictures will have to wait.

[BillWojo]

Well that could be a lot easier to have made up. Your looking for a flange to flange adapter. Am I correct in assuming that the flange that bolts to the horn has a rectangular hole? The tricky part is making the transition from 1.4" diameter to a rectangle. Unless you have someone with 3D cam software to model the transition and run that portion in a CNC machine it will be costly.
Since the threaded portion unbolts from the horn it may be easier to just use that and have a set of adapters machined on a lathe. They can use your existing adapter as a thread gauge.
Hopefully you have some machinist friends as any of this can get costly.

BillWojo

[Boli46]

Hi Boli46,

No doubt you are aware that Steve Schell is one fellow who would know about a possible adapter existing .

In the meantime, a measurement ( made in inches I suppose ) of the rectangular entrance into your version of the H805 would be useful info for all involved.

I'm pretty sure that Vitavox ( among other European suppliers ) adapted some of the Lansing technology post WWII.

They made ( for export to N.A. at one time ) a range multicells that were able to be equipped with either the large threaded adapter ( typically used in the U.K. & other Commonwealth nations ) & the typical bolt-on adapter used by Altec & JBL, post-war .
- You might get lucky and find that the British adapter is compatible with your Lansing era 805.




PS ( some pics )

Yes, I know that Steve Schell is a fountain of knowledge about all things Lansing/early Altec Lansing. In fact, most of what I know on this subject I have learnt from his posts on various fora. I would love to hear what he has to say about this.

I looked at Vitavox some time ago and I found that there are small differences in size between Vitavox and Lansing throats. A suspicious mind might think that this was deliberate on the part of Vitavox to avoid interchangeability.

- - - Updated - - -

Well that could be a lot easier to have made up. Your looking for a flange to flange adapter. Am I correct in assuming that the flange that bolts to the horn has a rectangular hole? The tricky part is making the transition from 1.4" diameter to a rectangle. Unless you have someone with 3D cam software to model the transition and run that portion in a CNC machine it will be costly.
Since the threaded portion unbolts from the horn it may be easier to just use that and have a set of adapters machined on a lathe. They can use your existing adapter as a thread gauge.
Hopefully you have some machinist friends as any of this can get costly.

BillWojo

I haven't removed the throat so I don't know the shape of the hole below. All I can say is that the outside of the flange is rectangular. The hole in the throat is circular. Removing the threaded throat and using it and the 288 end of the 30162 as a template for adapters machined on a lathe has been my fallback position. As i have no machinist friends, this can get costly, as you say. That is one reason I wanted to find out if there was an easier and cheaper way out.

[Steve Schell]

Adapters do exist to match the early threaded horns to the later 3 bolt (287/288) drivers. I have not seen any in some years though, so good luck in finding a pair! I have seen them in both steel and aluminum versions.