Jean Hiraga 604 speakers

**Michael V** · August 8th, 2009, 11:13 PM

6moons article

"Hiraga has spent the last few years perfecting his take on what a speaker should be. The focus of this endeavor has been the equally legendary Altec 604 Duplex 15-incher with coaxial compression tweeter.* ....plans are underway to set up their own manufacturing of modern-day 604s built just like the originals and from the same materials including Alnico V. "

Just wanted to point this out for all the Altec aficionados. I've heard the GPA 604's (with their crossovers) and the response wasn't to my liking. Curious to see how the Hiraga design is received.

**stéphane Rame** · August 9th, 2009, 01:44 AM

Product links Hiraga - The magic of music

St?phane

**gortnipper** · August 9th, 2009, 04:34 AM

The GPA crossovers are not the greatest. I had some made a few months ago, and they are much, much smoother than the stock ones. I put the stock ones back in a couple weeks ago and they were almost unlistenable - all bright and irritating.

**baja** · August 9th, 2009, 06:07 AM

Originally Posted by gortnipper

The GPA crossovers are not the greatest...

yes, that's true.
with all due respect (I was in contact with hiraga a while ago) the hiraga 604 "only" pinpoints one more individual possibility of building a speaker based on the 604.
at least it depends on once own valuation if it's worth to go for a "manufacturers" built 604 concept or to dare individual preferences. there are more concepts, as the imperial (former music connection), the yamamoto or the wolf von langa 606i - and (surprise) all of them are around 16k. I don't believe in magic - but I believe in the 604 concept and it's potential to try out - and never forget, it's not only the driver itself - it's a package of crossover, enclosure, wiring, frontend and music-data ...
best,

**speakerdave** · August 9th, 2009, 03:53 PM

Interesting--thanks for the link.

**Panomaniac** · August 9th, 2009, 06:07 PM

Well if anyone know how to build a good crossover for the 604, it's Jean Hiraga. The man gets great results. He also said that the cabinet is some new bass design of his, but he won't say more. I'd love to hear a pair - hope they come to the US soon.

BTW, my avatar is a Hiraga rig that I helped him build about 25 years ago. Still my favorite speaker. He knows his stuff.

**chrismercurio** · August 10th, 2009, 01:18 PM

Originally Posted by gortnipper

The GPA crossovers are not the greatest. I had some made a few months ago, and they are much, much smoother than the stock ones. I put the stock ones back in a couple weeks ago and they were almost unlistenable - all bright and irritating.

David,

Glad to hear that you were finally able to implement the Selah Audio crossovers in your speakers and that you found them to be worth the investment. I also came up with a box design and size that my wife hasn't complained about (yet) that clocks in at about 110 liters. It's the 6th box I have built and I like it the best. Outside of making an attractive permanent pair of boxes, and upgrading crossover parts, I think the journey is over and is rewarding every time I sit down to listen.

Chris

**KBergsson** · August 11th, 2009, 04:21 AM

Hi Chris

Originally Posted by chrismercurio

David,
I also came up with a box design and size that my wife hasn't complained about (yet) that clocks in at about 110 liters.
Chris

Can you tell us more about your 110L boxes?
They have a high WAF, compared to most other 604 enclosures.
Regards
Kjartan

**gortnipper** · August 11th, 2009, 04:41 AM

Yeah, I really like Rick's crossovers. I found the GPA xo a bit harsh, and they were difficult for me to listen to for extended periods withoug fatigue.

I had a visit to the audiologist today, and except for a ~5 db dip at 4k (too much of EV horns, power tools and loud concerts without protection in my youth, I think!) my hearing is "excellent" and "totally normal", with only a "slight drop" above 14k. I am happy as a clam! But I did also have a 2 db peak at ~2k. I don’t know if this peak is exacerbated by the GPA xo or not, but I really do find the new xo's much nicer both on my PP KT88 and SE 45 amps.

There were times in the past year when I was not sure if I could keep the GPA 604s. But, I am glad I took the chance and popped for Rick's units, they were definitely worth it despite being bog-standard parts. I don’t regret buying the GPA xo's when I did, but if I were to do it over again I would get the III's with Rick's xo and upgraded parts. They have taken the drivers to a new level.

Now I just have to listen to them against some Alnico 604s….

David

**chrismercurio** · August 11th, 2009, 11:07 AM

Originally Posted by gortnipper

Now I just have to listen to them against some Alnico 604s?.

David

The won't play as low or as high...but might have more magic in the middle. Maybe we should buy all Duelund filters from Rick for Christmas? Probably not with my ever shrinking job!

As for the box, I made it up. This was the ~4 cubic foot sealed box I developed when I was trying to arrive at something compact that would not require a stand and raked the baffle back at about ~10 degrees so that it could be very short. The thing with the sealed box was that it didn?t have enough low end so I made the 10.5 cubic foot MLTL in the meantime, then finally cut a hole in the bottom of these to give better bass. (This is my 6th box variant)

I simulated it in Jeff Bagby?s spreadsheet using the 10.5 cubic foot MLTL as the first simulation to verify how well the software worked, then settled on 40hz in room as an F6 target knowing that room gain down low especially would make it mostly flat.

Here are the internal dimensions:

Those are vented out the bottom with a 4" x 3/4" hole. The woofer center is roughly 9? down from the top.

17"w x 34.75"h

top plate is 8.75" deep

bottom plate is 13.75? deep

Total volume is ~110.5 liters.

Best,

Chris