I dont have the actual frequency but the WJ XOs have some adjustability ie the cutoff for the horn can be adjusted slightly. I expect it crosses at c.a. 5-600.Quote:
Originally Posted by endeeinn
Printable View
I dont have the actual frequency but the WJ XOs have some adjustability ie the cutoff for the horn can be adjusted slightly. I expect it crosses at c.a. 5-600.Quote:
Originally Posted by endeeinn
Thanks for helping out Pano ! :Thumbs up:
Thanks, nice to know it's not the original as it made no sense to me how it could be considered great as I previously noted and been told by quite a few folks that I was clueless in various [not so] polite ways. That, or a once common way to protect one's intellectual property, and still is in certain areas such as advanced auto design [smog, etc.], though forums like this one is slowly 'pealing back the veil of ignorance' [as Tom Danley likes to describe it] and the seemingly endless 'flooby dust' that certain types of folks keep infesting us with.Quote:
Originally Posted by Panomaniac
GM
Yeah GM - It's all a mystery to me. The published crossover seems to do some of the right things; crossover point in about the right place, HF shelf filter for the horn, big dip around 3K to tame the horn hump. However it just did not work well with my set-up, so I would think that it would not work well with any other setup except the original. I can't remember what was the woofer we had in it - at one point it was a Westrex frame with an EV cone, IIRC. The 1505 was lit by that 50s vintage Westrex compression driver. A couple of different JBL tweeters were rotated thru. Different drivers and horns will need a different crossover. On my set-up the published crossover was too midrange heavy and felt unbalanced. Not awful, but not anything I wanted to keep.
As to midrange attenuation, I don't see any in the schematic I posted, so maybe i did some shaping with my DEQ2496. I went thru so many iterations of the crossover it's hard to remember. I don't have the A5s any more, but I do have the final version of the crossovers (it just occurred to me). I can double check those to see if they match what I posted.
Crossover to the Fane bullet tweeter was at ~7200 Hz. That's about as low as they would play, and an easy roll-off to do on my 288+1005 horns. I tried to work with the natural response of the drivers, gently coaxing them into blending together. It worked rather well.
"Slowly" for sure at times.Quote:
Originally Posted by GM
Remember the baboons that could hear to at least 60KHz posted on this forum to justify an opinion. The youngest of the most hearing capable baboon species tops out at 43KHz. The bulldust is still being put forward elsewhere.
Yeah, Jeff is pretty conservative compared to so many I've 'crossed swords' with around the net and at 'audiophile' retail outlets.
GM
so reading this thread has be doubting my idea to try to build a set of these crossovers. And definitely before I go down the road, id want to try to demo it out at different crossover points before committing.. Any reason i should buy one of these to try out different cross points before committing?
ART CX311 Stereo 2-Way Crossover with Sub Out
And i am running a sub already so this would be an interesting way to play with that as well
Another link with Hiraga content, although it is for A7-500.
Altec A7 Voice Of Theatre Speakers
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.
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.