Page 4 of 4 FirstFirst 1234
Results 31 to 36 of 36

Thread: Hiraga A5 crossovers - 1st hand listening experience sought

  1. #31
    Senior Hostboard Member
    Hiraga A5 crossovers - 1st hand listening experience sought


    Geekstar's Avatar
    Join Date
    July 9th, 2006
    Posts
    189
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: Hiraga A5 crossovers - 1st hand listening experience sou

    Quote Originally Posted by horndawg View Post
    Thank you Mr. Roberts for the useful info. I'd tend to give more weight to what you say re this crossover since you are probably one of the few who have direct experience with both 1005B and 1505B horns. I've been wanting to try the onken cab for a while now - maybe I'm getting closer to doing it. I'd appreciate it if you could share the modifications of your Onken box relative to the one published in Sound Practices issue 4, Koizumi's original design that was introduced to the West by Hiraga.
    Frankly, I don't remember everything I did with the Onkens except that I blocked off some of the port. Mine were built with three different sized slots on each side of the box and I blocked off the shortest one by stuffing it with felt. I also experimented with a layer of paper insulation (Kimpak type, recycled from WW II tube packaging) over the port exits on the inside of the box because there was a lot of chuffing and puffing going on due to air acceleration. There is also a LOT of sound coming out of those ports and I wanted to reduce that a bit. Eventually, I quit experimenting with it and just listened., but that felt blocked port and the paper layer over the entry to the port stayed in for as long as I had them

    Maybe some fiberglas in the ports or the old trick of filling the ports with drinking straws to create a honeycomb looking air channel would reduce turbulence.

    I found that the box is somewhat underdamped and doesn't shut off too quickly. There is also a lot of panel area on that thing which can add resonances if not braced well.

    Ol' GM recognizes some of these problems with the Onkens and can probably add a few more. it is a weird cab. I have to wonder why Mr. Koizumi picked this particular design to resurrect from the ashes of time.

    I'd say it is a good box but can't really argue that it would be better than a reflex box of more conventional construction. Bass was fat and bouncy rather than super tight. Overall, a good sounding box and I enjoyed it a lot. The whole combo with the 1505s and Hiraga xovers was good enough that I stayed with it for a long time, even though I tried many many other things temporarily.

    I also had a Petit Onken with 414As for two years recently and that was also quite nice. Perhaps less boomy and more controlled than the stock big Onken. I matched that with various small format horns and 802s. Had to sell it because it was ugly unfinished plywood and my wife hated it. This is the woman who drew the Onken plans for SP and wrote the WAF column...now Joyce is beating ME up on WAF issues! The irony!!

    After the buyer auditioned it, I set up 32 horns with the Petit Onken, letting the 414 run full range and cutting in the horn at 7-8k first order, and it sounded so good I hoped he would not come back to pick it up...but he did.

    My Onken adventure was so long ago that I used an HP tube oscillator and an RCA tube VTVM to tune the box. I can barely remember what I had for dinner yesterday, so I am light on some ancient details, but at least I have sound card software now.

    Anyway, the Hiraga xover is not a genius innovation, rather basic textbook filter stuff, but it works very well when used as intended, in my experience at least.
    Whereof we cannot speak, thereof we must remain silent --Wittgenstein

  2. #32
    Hostboard Member kwingylee's Avatar
    Join Date
    May 1st, 2010
    Posts
    98
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: Hiraga A5 crossovers - 1st hand listening experience sou

    Quote Originally Posted by Geekstar View Post
    I published that article and I built the crossovers before publication. I then listened to them every day for 15+ years. I used 288C, 1506, and 416Z in an Onken enclosures, not a VOT cab. I liked Onkens a lot more than the VOT bins, especially after retuning the ports and internal volume, so I scrapped the 828s before I even moved to Texas.

    I thought the whole setup was totally great. I still miss that speaker dearly, but it would not fit onto a moving truck when I left Texas for the East Coast. Had to sell it off quickly and cheaply, like a white van speaker transaction.

    I would verify that people who say this xover does not work actually tried it with 288/1505s, as intended. It may require retuning with different horns.

    After a few years I modified the shelving network for a bit more attenuation, based on measurements, brought out the HF a bit more.

    Rich, vivid, and realistic sound day in and day out, 10-12+ hours a day, for decades. I thought that systems was one of the best things I ever had in 30 years of audio.

    Although I got to play with literally tons of top theater systems for weeks every year. I never felt deprived when I returned home to my Altecs, although I'd concede that WE Mirrophonic is better (yet completely impractical.)

    Dozens of very serious and some famous audio guys visited my home through those years and nobody ever said, "Hey, Roberts, this crossover sucks!"

    In my mind, Hiraga is truly the master of the Altec crossover and maybe Altec implementations in general. His 604s were the best I have heard by a large margin and he got an 825 cabinet to sing like I never heard before with that Westrex 15" (2080?). Seriously, in competition with the best midbass I ever heard, I think he had a Zobel across the input terminals on the back of the cab. Maybe that Westrex woofer is just insanely good. M. Hiraga is an extremely careful designer and listens super hard with a very picky ear. I learned to trust that guy on Altec.

    His A5 creation was super good at the European Triode Festival in Berlin a few years back. He set it up with a ruler and playing bell sounds and listening for harmonics, then moving things a few mm. Careful, meticulous. In the time he took to do this, I would have been on my third LP and third beer.

    I can't help but thing that if a Hiraga crossover sounds bad on 288/1505s, the builder is doing something wrong. Maybe parts come into play. I strongly preferred oil caps and used WE and a few Sprague caps. And Alphacore foil inductors since they were an advertiser and I could trade ads for copper. I first built it with polycaps and wire air coils then built a better, much heavier one with the swank parts.

    And I must say that with decades of opportunity to hear feedback, I have heard lots of positive responses to this design and few if any negative responses, except for this thread.

    I must conclude operator error or misapplication is in play.

    I'll add that I had sheet metal and tar filled 1005s and 1505s. Later sprayed sheet metal versions were better, richer and this especially helped with the 1005. There is a huge presentational difference between 1005s and 1505s. 1005s are rather hot on axis and if you stand up and sit down through the on-axis sweet spot, significant vertical beaming is apparent. The 1505s doesn't do this. It sounds richer, fuller, and more evenly dispersed, to me at least. In typical size listening rooms and at typical distances, there is a major difference between these two horns and I don't see them as sonically interchangeable.

    In theory, the general notion of midrange shelving and HF peaking should work for both 10 and 15 cell horns but circuit adjustments might be mandated and results subjected to prolonged listening enjoyment testing and maybe a calibrated mic. A standard Altec crossover without EQ is way more generic and interchangeable than the Hiraga unit.
    Roberts, thanks for rebutting my comments. To set the record straight I used 1005B/288-16G combo. Perhaps that is the cause for the difference in the results. The "Hiraga" crossovers I made sounded a lot better on my A7s with 511B/808-8As... I don’t recall what pano used but it seems some modification to the published crossover is needed if noon-1505 horns are used. I can install a LPAD on the mids and reduce the level a bit....before trying them again on my A5s but as I recalled. , for the set of crossovers I built, it sounds like the midrange dip needs to be adjusted as well. My point is, the publish crossovers should have some caveats attached to them.
    Last edited by kwingylee; March 15th, 2018 at 10:38 AM.

  3. #33
    Senior Hostboard Member
    Hiraga A5 crossovers - 1st hand listening experience sought


    alancohen's Avatar
    Join Date
    October 26th, 2012
    Location
    Hunterdon Cty, NJ
    Posts
    684
    Follows
    0
    Following
    0
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    3 Post(s)

    Re: Hiraga A5 crossovers - 1st hand listening experience sou

    It's hard to believe it's been almost 5 years since I set up my A5s with Hiraga x-overs. Still listening to them every day. Unfortunately, my audio hobby ended as soon as I heard them. I was done.

    Bringing 828 cabs up to snuff...

  4. #34
    Senior Hostboard Member
    Hiraga A5 crossovers - 1st hand listening experience sought


    Geekstar's Avatar
    Join Date
    July 9th, 2006
    Posts
    189
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    0 Post(s)

    Re: Hiraga A5 crossovers - 1st hand listening experience sou

    My point is, the publish crossovers should have some caveats attached to them.

    The first caveat that I would offer is "Don't blindly believe anything you read anywhere!"

    The second is "Don't make wild assumptions just because the article doesn't caution against it."

    The third is "Read what is actually printed."

    That article didn't suggest anywhere that this design was a universal Altec solution. It was a very specific, tailored application.

    If you built a 2A3 amp and decided to plug in a 50 tube instead and it didn't work, is that the article's fault?

    in any case, it worked for me and many others in the proper setup with 1505 horns. I have seen a few negative comments online but who knows what they actually did with it. Maybe they just didn't like it. That is still legal, for now at least...
    Whereof we cannot speak, thereof we must remain silent --Wittgenstein

  5. #35
    Junior Hostboard Member ckp's Avatar
    Join Date
    December 23rd, 2003
    Location
    Missouri
    Posts
    20
    Follows
    0
    Following
    0
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    1 Post(s)

    Re: Hiraga A5 crossovers - 1st hand listening experience sou

    Hello,
    Dragging up this oldie but goodie. I built a variation of the Hiraga network and like it quite a lot. Installing a HF attenuator made a world of difference to me. Auditioning them on another similar system was positive also. My network is built for 16 ohm drivers. I would like to build the network for 24 ohm 288s and 20 ohm 515s. I've been trying to figure out what values to change the components to, but I'm having trouble. Would I multiply/divide the HF by "x" and the LF by "x1" somehow? I'm a bit out of my league. Thank you.

  6. #36
    Senior Hostboard Member GM's Avatar
    Join Date
    December 26th, 2002
    Location
    Chamblee, Ga.
    Posts
    4,930
    Follows
    0
    Following
    0
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    43 Post(s)

    Re: Hiraga A5 crossovers - 1st hand listening experience sou

    Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.

Page 4 of 4 FirstFirst 1234

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
This forum has been viewed: 20762827 times.