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leedh
09-12-2010, 02:47 PM
Hello,

Sorry for my english! I come from France and usually just speak French. But when you are a fan of altec system, you are obliged to do some improvement!

I try to build an A5 system based on Hiraga’s A5 system in the Nouvelle Revue du Son. To built them, I use the article coming from sound practices and written by John Stronczer, the boss of Bel Canto Design. I use a pair of 828 cabinets with two supravox 400 GNB for the bass and a pair of 288C and 805B for the high-medium. I have a problem concerning the crossover: in the article of John Stronczer, it is said that the original network (as shown in the article) is for 8 ohms drivers. http://web.archive.org/web/20050206015233/www.soundpractices.com/images/HiragaA5.pdfI am really surprised because Hiraga in his system used Westrex 2080 drivers (identical as altec 288C) and a woofer westrex with electrovoice membrane. I suppose that these drivers were respectively given for 24 ohms and 16 ohms. Is it a mistake in the article? Jean Hiraga gave a recalculate crossover for 8 ohms? I don’t know if I can just use the schematic of the Xover as is or if it is necessary to recalculate.

Thanks for your help!
Olivier

Zilch
09-18-2010, 01:33 AM
Your link does not work because you didn't put a space after it and before your "I".

http://web.archive.org/web/20050206015233/www.soundpractices.com/images/HiragaA5.pdf

Component values are provided for both 8 Ohm and 16 Ohm drivers. Recalculate based on those values for 24 Ohm drivers if that is what you have....

Google took me to my own post on this matter in another forum:

http://www.audiokarma.org/forums/showthread.php?t=185600&page=6

[What did I do to deserve this...? ;) ]

Altec Best
09-19-2010, 12:18 PM
Google took me to my own post on this matter in another forum:

http://www.audiokarma.org/forums/showthread.php?t=185600&page=6

[What did I do to deserve this...? ;) ]

Thoose "Bot" Spiders cover a lot of ground in a hurry don't they ! :) Especially if there are a couple of them working a forum !

sanpablo
11-01-2010, 03:31 AM
Hello Olivier,

Je pense aussi construire une VOT. J'ai cherché l'article de Sound Practices mais impossible. Tu aurais un scan de cet article ?

A+

sanpablo
11-03-2010, 12:57 PM
Merci qui ? :applaud:

sanpablo
11-03-2010, 01:00 PM
2ème partie

sanpablo
11-03-2010, 01:02 PM
3ème partie

sanpablo
11-03-2010, 01:03 PM
4ème partie

Altec Best
11-03-2010, 07:17 PM
Hey Oliver, There is a gentleman over at the Altec board/DIY Audio named "Panomaniac" who helped build those A5's with Mr Hiraga you may want to ask him as he would be the best person to ask about that system other than Jean Hiraga himself . Regards !

Pano
11-04-2010, 08:04 AM
I'm here now too. Been a reader, now signed up to post.

Yes, I built those A5s with Mr. Hiraga. Circa 1986 He supplied the brains, I supplied the brawn. As a trade for the help he let me borrow them for Jazz PA use. They were great, still are. My favorite speakers.

I'll try to answer whatever questions I can.

Pano (aka Panomaniac)

louped garouv
11-04-2010, 08:20 AM
I'm here now too. Been a reader, now signed up to post.

Yes, I built those A5s with Mr. Hiraga. Circa 1986 He supplied the brains, I supplied the brawn. As a trade for the help he let me borrow them for Jazz PA use. They were great, still are. My favorite speakers.

I'll try to answer whatever questions I can.

Pano (aka Panomaniac)

Welcome Aboard!

:applaud:

Altec Best
11-04-2010, 10:11 AM
Welcome Aboard!

:applaud:

+1 Welcome Aboard Pano ! Do you remember the Crossover on those Beauties ?


@Sanpablo Thanks for posting those old "Sound Practice Articles" very cool ! :applaud:

allen mueller
11-04-2010, 02:41 PM
I'm here now too. Been a reader, now signed up to post.

Yes, I built those A5s with Mr. Hiraga. Circa 1986 He supplied the brains, I supplied the brawn. As a trade for the help he let me borrow them for Jazz PA use. They were great, still are. My favorite speakers.

I'll try to answer whatever questions I can.

Pano (aka Panomaniac)


Another +1 here as well.

So dose any one know what the tuning of the enclosure is. I've read about what port areas work well, but what does the tuning work out to be?

Allen

Pano
11-04-2010, 05:04 PM
Hi guys, thanks for the welcome.

I will try to put together what I remember about the speakers and what I've learned with my own pair.
Also a big thank you to Sanpablo for the article. I had searched and searched for it, was about to phone Stronczer and ask him for it. Nice to finally read it.

I suggest everyone read it, he really hits it on the head. "I confess it was love at first listen with the A5s. I mean I listened to a single bar and I knew." Yep, that's those speakers. One thing he does not talk about is much is the box rework. Since I did that, I can fill in the blanks.

More to come.

Altec Best
11-06-2010, 12:06 PM
Hey Pano, Did you actually build those A-5's in Paris or were they built here in the States ?

Pano
11-06-2010, 05:38 PM
I don't know where the cabs were originally built. Likely in Europe. The horns were USA built, I assume.

The mods were done in Paris at #1 Boulevard Ney, the old offices of the Nouvelle Revue du Son. Circa 1986. There was a funky concrete storage room beside the loading dock near the giant rolls of newsprint were I did the work. Just me, some Nantex plywood, a few tools and some tar.

sanpablo
11-07-2010, 05:40 AM
Dear Pano,

First, thank you for your help.

At present, i'm building a 828B cabinet... with autocad.

I had many problems with the vintage drivers, so, i want to use :
- 515-8G
- 902-8A
- 511B (i don't found altec's horns drawings)

In the article, page 12 : "the other horn is an old 806 C" I found nothing on @, non-existent...
Page 6 : "a JBL ring type tweeter" On the crossover, we haven't the components.

Thanks & A+

Pano
11-07-2010, 09:27 PM
Hey sanpablo. I think he means an 805 multicell horn. I've never seen an 806, which would be 8 cells/600Hz. I started with the big 803 horns (8 cells/300Hz) but moved to the 1005 which I like better. One of the JBL 2402-2405 can be used as a tweeter.

About the crossover. I don't remember! :blink: It was a long time ago and I did not know much about crossovers then. It was passive, it was 2 way + super tweeter, but that is all I remember. I certainly do not remember the part values. As many times as I connected those things, I ought to remember, but I don't, alas. however the values are all there in the article. You'll still need to tune it to your room.

The 511A is OK, but does not have the magic of the multocell horns. It will get you started, tho.

The cabinet is super important. I doubled the inside of it with Nantex plywood. The most insane, heavy, dense, hard wood I've ever seen. Like iron. (The French Onken cabinets were also built of it.) Also I put a heavy layer of tar behind the horn flares. This is important. I did the same this year with my A5s. And added bracing to the curves. And braces inside the cabinet. With all that, it is super heavy but has NO box sound. Really amazing.

I get at least 1 email a week about the crossover and the box tuning. The crossover was published, but the box tuning remains a mystery. The port was made smaller, for sure. We might be able to figure it out from the photos on the Melaudia website.

Edit. Looking at recent photo it looks like the port has an area of ~330 cm^2. That should put the tuning at about 52Hz, if the port has no more depth than the box wall, which is what I remember.