DIY multicell horn

I saw a wooden 1803b multicell horn in a web site. That owner collected a lot Altec multicell horns and then he made the replica with wood.

Did anyone in here tried to DIY the Altec multicell horn?

To build a 15cells horn looks thing or similar object is not a hardest job. But this horn can repoduce great sound. I will have a lot of questions.

I have collected some wooden horns design books. usually, a single horn from design to completed at least needed 3 months or more, some even few years.. Cause it needed more tested with instruments. As same as manufacturers to devolop a product.

To look is simple, to build is difficult.

To build a 511 replica is not simple. Usually, size would bigger then source too many. A 15cells horn with plain or soild wood .... ????

If this is more simple as your imagine. Westlake will be close. Why such many peoples(included you and me) still looking for the VOTT? Don't DIY the king of king horns by yourself. why?.. Westlake can stand right there, then products selling such high. I believed that you saw that on some private/online shops homepage or in hifi magazines...right?

I will be a Altec Second If there is such simple.

Just a joke. http://www.hostboard.com/forums/

to remind; I know metals welding and i was a leader of wood work club when I was a student. http://www.hostboard.com/forums/

Speaking as a manufacturing guy, there is a lot of production, CNC and other rapid prototyping equipment out there that can produce a horn today very quickly.

And, unfortunately, around the U.S. there are plenty of machine shops with advanced equipment and lots of open time.

To avoid using very specialized and expensive machine time, it may have to be machined in sections, then assembled, but that's no problem.

The software to program these things is dirt easy, if you can design a horn you can certainly run the software. With the right output, you can simply email it to the shop. Many of the new CNCs will do the programming themselves, determine the tool path, etc., all you have to do is sit back and watch.

If you want to duplicate an existing horn, you can simply have it put on a CMM (coordinate measuring machine) that makes a digital copy. On our shop floor, you could feed the output of the CMM right to the CNC, but you could just as easily save it on disk and tweak it on your PC.

I've never machined wood, but if you have a nice solid hunk to work with, it shouldn't be that much different than aluminum or any other soft material.

We've prototyped model cars, etc., out of giant hunks of brass because you can just sell the scrap right back to the place you got the billet.

Good luck!

I've seen that same picture of the wooden multicell
I think it was made by Michael Christ.

Multicell would be very difficult to replicate but
the good news is you don't really want a multicell
as it is not the ideal horn - they are designed to
get HF to difficult seats in a cimena but have their
own problems (lobing etc).In fact I don't like the
sound of any of Altec's multicells.

I made a replica of the WE 24A - the best sounding
multicell known - without the internal cells and it
sounds great !

Okay, my wife was looking over my shoulder and said that's as clear as mud.

Imagine you take a 10" loaf of stale bread and carefully cut your horn design into it.

Then cut the loaf of bread into five 2-inch-thick slices. Now you have five cross-sectional pieces. Put them back together, you have your horn.

Each 2-inch-thick "slice" is what you'd have machined (we're using five as an example, but the number of slices is determined by how deep your tooling can machine). Assemble them all together like your loaf of bread and you have your horn. Even better, you can have the CNC machine in some locating holes so you can put pins in there and the pieces will line up perfectly.

The end product I'm describing gives you a giant hunk of material with a horn inside. There's alot of excess material there which could be cut away to reduce the weight, but you could leave it there and eliminate all your resonance worries.

HTH.

Of course, I known machine can duplicate more difficult objects.

For exsample: NASA can duplicate 288s & 515s easily. Some people even can duplicate all Altec's speakers if he own same materials and machines. But there is more different to a DIY people who love to his(DO IT YOURSELF)hobby.

Anyway, I'm not meant that no one can do that. I just emphasize not everyone can easy to build his (DIY)replica horns. And then the soild wood material needs placed a long time before use.

altho you can usse cnc machine to duplicate a 18cells wooden horn. But I don't think that horn can be soild and durable. Cause metal horn can built with under 1CM thickness metal plate. But can you use under 1CM thickness wood to build a replica horn in same size with no resonance. You should know if the thickness of meterials are not same. the diameter of the horn mouth would not same...

Howevver, to replica a wooden horn throat that I would agree is a simple job. http://www.hostboard.com/forums/

Yes, the wooden 1803b was made by Michael Christ. I wondered that the sound of the replica horn??? In fact, I think to replica the Altec 1803b is a very difficult job except having a lot tools (I means DIY at home, I also know welding and wood work). Of course, it can be done in a simple way, just do it using BACarr?s method.

Hi Mirrophonic Sound System (it seems your nickname came from the WE?s sound system), I never seen a WE24 horn (even a photo), what material you are using on your DIY horn? Why you choose to DIY (not purchase it)? You seems to built a DIY horn successfully and having a great sound.

On the other hand, i must mention that using a wooden horn throat is good. It is better than using the original throat. I read an article before, the author is made a replica Altec horn throat with wood and then he measured it with the Br?el & Kj?r, the data proved that it is good.

Thank you guys, you let me find that web page again. I was lost this website path too long.
His opus still makes me feel wonderful. A real expected horns builder.

Hi Larry & B.A.Carr

Larry to see a Western Electric 24A horn, click on "rate member" to the
left and it will give a blow-up of the photo.

I made the copy 24A out of sheet metal damped with glued on rubber with cast alloy throat coupler
but it is for 2" drivers - not altec. Tomorrow I'll change the picture to show this homemade horn.

For 288's I once made Edgar's 300 hz wood horns and adapted
Altec alloy throat couplers to them - sounded great !
This Edgar horn project was in Speaker Builder magazine 1/86.

BA Carr: Your CNC ideas are good I think Edgar's 300hz round Tractrix horns are
produced this way. They seem to be machined from a solid
piece of a glued stack of hardwood sheets.

Now the picture is of the cloned 24A horn without internal 'multicells'
- which are unnecessary for home systems.

It has the exact same dimensions, flare-rate, cut-off freq, etc.

Hi Mirrophonic Sound System, i think that you are a very good horn player. Now, i have a lot of questions.
From other topic, you mention that
Western Electric 24A: 35.5" x 26" = 923 sq in =120HZ cut-off
JBL 2390: 35" x 7.5" = 262.5 sq in = 235HZ cut-off (use adapter for Altec drivers)
Altec 511 is 23" x 9" = 207 sq in mouth area = 265HZ cut-off frequency
If i know the mouth area. How to know/calculate the cut-off frequency?
I wondered that i saw a vitavox 220Hz horn before and the cell mouth is so small(around 8"x 8"). Why the vitavox horn can have a such low cut-off frequency?
On the other hand, Can you explain why the internal 'multicells' is unnecessary?

Thanks

The picture at left now is a home constructed 300hz Tractrix-contour wood horn
designed by Dr Bruce Edgar - details of construction are in Speaker Builder 1/86.

Construction is super easy and design was truncated towards throat end
to match exit of Altec 288 throat coupler.

It is sitting atop an Altec 620 enclosure with a 416 for bass -
crossover was 400hz 24db/oct bi-amp

My home-made 1505, may it rest in peace.

Years ago I constructed a replica Altec 1505 out of paperboard and tape! Now wait, this thing actually worked like a charm because I filled it with beach sand. The horn was easy and fun to build using 60 identical panels (modeled after one cell of my existing tar filled 1505) which resulted in 15 cells that all converged at a plaster-cast throat assembly. I then enshrouded the horn in the same heavy-gauge paperboard and filled the unit with sand for non-resonant mass, adding duct tape here and there to stop the handful of sand leaks that ensued. The finishing touch was the addition of my trusty 902 drivers (adapted of course) to the two 1505s. The result was excellent. Unfortunately the more I hauled the 'sand monster' around the the more it collapsed under its own weight springing numerous leaks. I don't think a day went by when I wasn't applying duct tape and/or sweeping up sand! Nonetheless, that horn found its way into a number of live music productions performing valiantly and it always proved to be a good conversation piece as well. At last, though, the horn was beyond any help that duct tape could offer and the unmanageable beast was eventually buried in the back yard like an expired pet. This seemed appropriate since it was mostly sand anyway. The thing that really amazed me about the horn, even in it's last days of applicable life, was that even in its physically distorted state the sound quality was still excellent and in A to B comparison it seemed identical in sound to its tar filled brother.

Someday sombody is going to dig that thing up and scratch their head.

MP

Hi Mirrophonic Sound System
Thankyou, very detail explaination ^_^. I saw the Vitavox horn in the Vitavox web site. Sometimes, it can be found in the ebay(Of course, the brand is Dukane). I think that Vitavox horn structure is similar with the early Altec horn and seems no other maunfacturer produce the 220Hz horn.
Hi thevott, I am very interested on your homemade 1505. I understand that you can copy one cell from the original 1505 and so you can make all 15 cells with paperboard. But, I wondered that the part between the 15 cells and the throat, how can you made it??? I think that a leakage will be happened at that part. On the other hand, i heard that when the 1505b is filled with sand, the resonant will be reduced

LarryLarry,
The short section between the cells and the plaster throat was also paperboard and was permanantly fastened to the throat by duct tape. The sand cavity extended to the throat as well. Duct tape is very effective at sealing up leaks and once the sand is present there is virtually no absorption of sound energy into the light weight paper and tape materials. The whole thing was mounted to a plywood skid which prolonged it life by months I'm sure. This was obviously a fun (if not laughable) experiment that proved surprisingly successful, however a more permanent assembly could be easily made of hardwood (throat assembly) and perhaps thin flexable plywood panels for the cells and outer shell. The unit could then be filled with concrete. But don't plan on taking it anywhere, that's what 511Bs are for!

Vott:
Is that drawing depicted in your avatar represent an actual system
or just a fantasy drawing ?

I'd like to hear one of those monster concrete bass horns that
you read some experimenters have actually built !

Larry:
It's funny that you mention the 220 hz Vitavox horn as I
have one of these ! It says DuKane model SA-325 - made by
Vitavox for DuKane of St Charles, IL. (St Charles is where
they have the big jukebox & antique shows - 40mi W of Chicago)

Is the other DuKane/Vitavox a single or pair ? I would like
to sell this one or buy another to make a pair.

The cells of the Vitavox are indeed 8"x8" but the cut-off freq
is the TOTAL or SUM of the cells in a multicell.

To find the cut-off frequency then we take the total mouth
area and find the radius of an equivalent circle :
which is the square root of area/pi= R
Now divide the speed of sound,13500,by 2.pi.R

With an eponential horn, the higher frequencies will tend to
beam. Western Electric solved this problem in the early 30s
by making the horn a composite of many smaller horns (with
higher cut-offs)that would direct the higher sounds in a
wide arc required for those 5000-seat movie palaces.
For home listening we don't mind having a little HF narrowing
(511's narrow the HF because they are exponential)
because it is a "sweet spot" listening situation and we
might also be using a supertweeter . Just like projection TV
screens beam light - OK for home but unsuitable for public exhibition.

Hi Vott,

Your idea is very good, hardwood used in the part of throat and thin plywood used in the part of cells. I think this is a funny experiment and i want to try. I haven't an original Altec 1505 so i cannot measure the actual dimension -_-.


I heard that concrete speaker cabinet is very common in mainland China. They also like to built woofer system in the ground/underground and all the material are concrete.

Hey Mirro,

You're in luck (Unless you're actually the seller); there is a single Dukane 325 horn on ebay now.
Dukane (Vitavox horn) http://www.hostboard.com/forums/

Thank's Datubie, The DuKane is a fairly neutral sounding horn
that will do 300hz easily and is built like a brick *********

A VERY GOOD CHANCE FOR YOU!
YOUR DREAM WILL COME TRUE!! http://www.hostboard.com/forums/

A very nice single 1505B multicells horn up on ebay auction( no reserve). Good chance for your 1505B multicells horn replica plan. http://www.hostboard.com/forums/

To ful fill your woodworkings ability now. http://www.hostboard.com/forums/

Larry

I should bid on it but I just know the bidding is going to go
ballistic - in which case I'll sell mine because it's more fun
to build your own.

I saw a whole cluster of Dukane multicells pulled from a university basketball arena about 10 years ago. They sold---along with 4 dual-15" bass horns---very low at auction and, like a fool, I wasn't there. http://www.hostboard.com/forums/

By the way, just for the record my 815s bass horns are currently loaded with my end cuts: two 418's from an Ampeg fliptop, one 515 (A) reconed to a 515-16G and one hornless 602 that (remarkably) made it through high school and college. The sound of these horns is solid Altec goodness regardless of the mismatches. I'd would like to get a hold of a full set of the new model 164-8LF Iconic Manufacturing woofers. Sounds like they will really flourish in the 815s!!

MP

Mirrophonic Sound System,
The avatar is in fact a fantasy system though I have have every intention to build the plywood beast. I do have the 815s, however, whose cutoff is at about 75 Hz according to Altec literature. My 815 horns are modified/opened up into psudo-Voice of the Theatre bass reflex enclosures. They sound very good and rolloff around 40 Hz with a 'nice' bump at 45 Hz.
Don't ask what drivers are in there but they are all Altec!

MP

Hi Mirrophonic Sound System

You are really lucky, in the ebay, that Dukane horn are 5A325, 10 cells and 220Hz cut-off.

Hi Vott,

Could you tell me the 1505 horn dimension of the cell mouth?(or the single cell dimension). I want to calculate the actual cut-off frequency of Altec multicell horns.

If you know the size of other Altec multicell horns mouth. Please let me know.

Thanks

All are inside measurements
311-60~= 20 1/2 x 11 1/16h

311-90~= 31w x 12 1/8h

511~= 23 7/8w x 8 15/16h

811~= 18h x 6 3/4h

1005~= 32 1/2w at top and bottom
34w at middle
12 11/16h
Each cell of the 1005 measures 6 5/16w x 6 1/4h

Has anyone seen this:

http://jipihorn.free.fr/Chaine/Jerom...l/DSC00167.jpg

The main page is

http://jipihorn.free.fr

Look under "Nos systemes"! Looks like excellent work to me! I whish my french was good enough to understand a bit more as the authors seem to be very competent!
Seems this is a variant of the "Le Dauphin" horn? Maybe there?s some french members on this board who could comment?

Regards

Claus K

ClausK,
Cool link. I'm sold. Primarily because my wife actually likes it. She said: "I'd have that in my livingroom". But then she came to her senses and clarified the issue: " ...as long as it isn't too big". Nevertheless, it sounds like wood (no pun intended) is the ticket to marital harmony!

LarryLarry,
I no longer have my 1505 but I have a nice template of one cell panel. It fits nicely on any side of any cell throughout the horn and extends the full length of the cell. I would like to post a scan but I'm not sure how to on this site. Any suggestions will be appreciated.

Also, I have always assumed that 1505 cell size is the same as other 500 Hz horn configurations. Can anyone verify or dismiss this assumption?

MP

Charles has provided 1005 horn size. To get a single cell dimensions is enough (open mouth & length) to build your yearning 1505 replica by your woodworkings ability. You can also buy one 1505 from ebay auction if you want to get an exactly size. Ebay has one beautiful 1505 is waiting for you to own it. So, all your worries are disappeared. I think you should decide to start your project. Don?t let it (1505) goes easily. Cause I think that you are a multicells horn enthusiast.

To make your dream come true that is nothing can pause your motivate. Now, try to imagine that your 1505 horn replicas are reproducing smooth sounds in your home. WOW! WONDERFUL!

Anyway, don?t be hesitating any more if you are seriously.

Hi Mirrophonic Sound System

I agreed with you, It's more fun to build your own horn and sell out your horn.

Hi Charles Chance, thankyou for your data.

I calculated the actual Altec horns cut-off frequency which are shown below:

311-60 = 254Hz cut-off
311-90 = 197Hz cut-off
511 = 261Hz cut-off
811 = 346Hz cut-off
1005 = 192Hz cut-off http://www.hostboard.com/forums/

ClausK, that wooden horn is very good and look like a 311-90 horn

Vott, i don't know how to post on this site. May be you can post the scan on other site and then leave the address/path on this site. In fact, i really want to have it. Could you mind send a scan to me via email?
On the other hand, i think the 1505 cell size is not the same as other 500 Hz horn because the size of the cell mouth.

HiFiplayer, i saw that beautiful 1505 horn on ebay but that seller is ship to US and Canada only. On the other hand, if the cost plus shipping is too high, i cannot afford.
In fact, from the actual cut-off frequency results, the multicell horn has a lowest cut-off frequency, may be the 1803 horn is the best.

Thankyou very much

Anyway, I will very happy to hear that you have completed your multicells horn planning. Every man would loves his dreams come true. Don't forget to share with everyone here. http://www.hostboard.com/forums/

LarryLarry,
I'm happy to email a scan of the cell template. Send me your email address in a private message and I'll email a scan to you when I get a chance.

The 1505 is truly an excellent horn with an unbeatable 105? by 60? uniform dispersion pattern (unlike the sectoral horns). I personally had no problem with HF lobing when using my 1505s---that must only be a significant issue at great distances. I used my in a 1200 seat auditorium with a balcony and the result was very good.

MP

Hi Vott,

I sent my email address in a private message to you.

On the other hand, do you have other Altec multicell horn before? Say, 803b, 1005b..etc.
In fact, i want to know which one is more better(I means that the 300Hz, 500Hz or 800Hz horn). In fact, the 1803 is the most larger multicell horn and i wondered why Altec do not produce 18 cells 500Hz or 800Hz multicell horn.

Thanks

Vott:

What is the difference between a 210 horn and the 815 horn cabinet ?

Are there drawings of these with dimensions ?