Hiraga A5 crossovers - 1st hand listening experience sought

Happy New Year to all!

This Holiday I finally carved out some free time to build a set of the highly taut Hiraga A5 crossovers for 8 ohm drivers using published schematics.
Point to point wiring, Air core inductors (including ALPHACORES on the woofers) and Sonic Cap capacitors were used in the direct signal path.
I hand measured every components to ensure the values are per spec'd.

My components :
Altec 515-8Gs in 828 cabinets.
Altec 288-16Gs with new GPA diaphragms and 16 ohm resistors in parallel for compression drivers
Altec 1005B multi-cell horns
Altec 1285-8B crossovers set to 500Hz.

The system sounded really good as is.
I replaced the 1285s with Hiragas ... I fired them up. I was expecting improvement. Instead, the sound was underwhelming. I understood that Hiraga used 1505bs that were 2dB more efficient, so there maybe a balance issue. But having a lot of experience with active crossovers and knowing what driver imbalance sounds like, what I heard was not a balance problem, it sounded like there is a huge suck out in the frequency response. Songs that I am familiar with, entire sections of the musicians went AWOL.

Yes, I made sure polarities on the highs are reversed... as Hiraga designed.

I checked the connections on the crossovers, nothing obvious. I will double check. Hard to believe I screw up the same way on both sets.

Right now they are back on the 1285s, which in my humble opinion, are really good sounding crossovers, even though they are completely stock.

Just wondering if anyone here has heard the Hiraga A5 crossovers first hand? and provide a description on what they are suppose to sound like. I search the forums but surprisingly cannot find a subjective description of what the crossovers sound like. I read the hype and been to many shows where systems sounded great when playing carefully selected demo music, but when played stuff people actually listen to, not so much. Just want to know the real story here. I would real happy if it turns out the bad sound is due to my mistakes.

Cannot comment on the Hiraga crossovers as I have no experience, but in general... crossovers with driver polarity reversals are no good. Put high and low frequency drivers in opposite phase and imaging dies a cruel death. I have long built crossovers with simple first order filters and luckily have never lost a diaphragm.

I used to run into this with the Lansing Iconics. Connect the drivers as indicated by these second order networks and the imaging was vague, although the power through the crossover frequency was fine. Put the drivers in the same polarity and the imaging was great although there was a hole at the crossover frequency. I always preferred the in polarity connection overall.

The two Hiraga A5 crossovers schematics I have seen which are included in the "La Voice of the theater Chez Nous" by John Stronczer, which may not be the only schematics out there were for matching impedance drivers. The article included the original design for both an 8 Ohm woofer and an 8 Ohm compression driver, with the second crossover schematic in the article scaled for the the use of a 16 Ohm woofer and a 16 ohm compression driver. You indicate you are using a combination of 8 Ohm and 16 Ohm components. Was the schematic you used designed for matching impedance drivers?

Where's Pano, he ~ lived with the originals for years, helped build them IIRC.

Personally, when I saw the XO schemes ages ago, I just shook my head and moved on. That said, if driven with a matching impedance with variable DF tone controls, then the XOs only need to protect the drivers.

GM

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Quote:

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Originally Posted by Steve Schell

Cannot comment on the Hiraga crossovers as I have no experience, but in general... crossovers with driver polarity reversals are no good. Put high and low frequency drivers in opposite phase and imaging dies a cruel death. I have long built crossovers with simple first order filters and luckily have never lost a diaphragm.

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+1

GM

Quote:

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Originally Posted by wweigle

The two Hiraga A5 crossovers schematics I have seen which are included in the "La Voice of the theater Chez Nous" by John Stronczer, which may not be the only schematics out there were for matching impedance drivers. The article included the original design for both an 8 Ohm woofer and an 8 Ohm compression driver, with the second crossover schematic in the article scaled for the the use of a 16 Ohm woofer and a 16 ohm compression driver. You indicate you are using a combination of 8 Ohm and 16 Ohm components. Was the schematic you used designed for matching impedance drivers?

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I built the 8 ohm version of the crossover for the highs and lows. I didn't have 6.6mH Inductors available and didn't really want to spend the money until I at least hear what the crossovers would sound like.. For the 288-16G compression driver, I placed a 16 ohm resistive cluster in parallel to make it "look" like a 8 ohm driver.

I reckon I can add LPADS to the notch filter leg so I can adjust the amount of attenuation of the notch, as has been done by people in the audioasylum and DIYaudio forums and see how that would work. Or simply go back to active as I have several old EV active crossovers I can play with.

Any new news here? I was hoping you would get more real world user comments on these xovers... Pano??

I acquired a pair of 825 cabinets and am about half way with assembling the components for a well equipped VOTT.

So, unfortunately, I have nothing to add but am very interested in this subject.

Pano is a mod and online earlier today: diyAudio - View Profile: Pano

GM

I am interested in comments on the Hiraga crossovers as well. Especially with horns other than the 1505. I was considering building a pair for my 805 horns and 828 cabs. I have spoken to a few people who have used these with the 1505 horns who liked them. And was also warned about using the less efficient 805 horns.

I have been using these speakers active biamped with HF EQ, and am worried about being underwhelmed with the Hiraga like the OP.

Hmm, in theory and all else equal, the wider the pattern, the lower the efficiency, so the 805 should be the most efficient and according to Altec it measures this way too ;), ergo needs more shelving, lower frequency bypass cap: https://greatplainsaudio.com/wp-cont...ell-Horns2.pdf

GM

'mr ed' offered to help with Hiraga/805: http://www.diyaudio.com/forums/full-range/317407-altec.html

GM