Now that's a manly man's horn! 🙂
On a completely unrelated subject, I'm not quite sure how I did it, but I just had a message pop up saying I had unsubscribed from all my threads! 🙁 Is there a way to get them all back?
On a completely unrelated subject, I'm not quite sure how I did it, but I just had a message pop up saying I had unsubscribed from all my threads! 🙁 Is there a way to get them all back?
Hi,
Trying not to hijack this thread, but i acquired a couple 288c (24 ohm) and 805b horns
Any recommendations on bringing them to life? (ill try to post some pics later)
greg
Trying not to hijack this thread, but i acquired a couple 288c (24 ohm) and 805b horns
Any recommendations on bringing them to life? (ill try to post some pics later)
greg
Greets!
If the diaphragms are blown, then obviously they will need replacing and due to their age and probable work history, a good zapping of the magnets is required, so either find a relatively local prosound re-coner with the credentials to do this or send them back to GPA. If done locally, make sure they use either GPA's diaphragms or at least Altec NOS (new old stock):
http://www.greatplainsaudio.com/
http://stores.ebay.com/Great-Plains-Audio
GM
If the diaphragms are blown, then obviously they will need replacing and due to their age and probable work history, a good zapping of the magnets is required, so either find a relatively local prosound re-coner with the credentials to do this or send them back to GPA. If done locally, make sure they use either GPA's diaphragms or at least Altec NOS (new old stock):
http://www.greatplainsaudio.com/
http://stores.ebay.com/Great-Plains-Audio
GM
nice horns cal! i love the big horn sound..somehow, to me, my large format 300hz cycle horns sound very precise and clean. its funny throuhout the web, most of the pics i see of folks listening rooms, look "lived in" wires and amps and equipment and cd's and albums everywhere..a dedicated sweet spot. glad its not just me.
cyclotronguy
Here is a site in French only .It should give you a good idea.
I've seen it a couple of times over the past few years.
http://www.melaudia.net/remOnken.php
Here is a site in French only .It should give you a good idea.
I've seen it a couple of times over the past few years.
http://www.melaudia.net/remOnken.php
Attachments
CONVERGENCE said:
If you need help with the site or the W, let me know. I know the cabinet well. The double wall sand filled Onken-W is a beast. But very, very, clean. Very top notch stuff.
GM said:
Thanks GM for the advice, i'm not too sure of anyone local to be able to do it. As for sending them to GPA, it might be a bit costly and ill have to check with customs here to see if they will even allow to me do that... (customs in Australia aren't at the least bit helpful
)tomtt said:
an amp is a good start too!, any recommendations for votts in i guess a not too expensive setup always diy if its cheaper
(things that can be found in Aus please list 😀)all thats missing is the woofer, i assume a 515b fits this criteria. Any recommendations of working crossovers for the two? (with the right crossovers does the 24 ohm horn work with say a 16 ohm woofer?)
Thanks
Greg
There are some crossover schematics floating around this forum that involve the 288 drivers, but not on 805 horns, IIRC. I'd love to hear the 805s.
You would need to scale the crossover values for 24 ohms, or replace the diaphrams with 8 or 16 ohm models if that is possible. GM, do you know?
The lowpass part of the crossover is also going to depend on the box and the LF driver. What did you have in mind?
You would need to scale the crossover values for 24 ohms, or replace the diaphrams with 8 or 16 ohm models if that is possible. GM, do you know?
The lowpass part of the crossover is also going to depend on the box and the LF driver. What did you have in mind?
W-onken
OK, now I confused: I thought I understood Onken cabinets. In the classical sense I've always understood them to be a reflex with a port area equal to the Sd of the driver. The cabinet in the photo (unless some more ports are hiding somewere) looks to be a reflex with small ports and rather high tuning frequency.
My current single 416 cabinets looks to have at least 2X the port area of the one in the french photo.... from personal experience on my cabinet the ports are too small under large signal conditions.
Cyclotronguy
OK, now I confused: I thought I understood Onken cabinets. In the classical sense I've always understood them to be a reflex with a port area equal to the Sd of the driver. The cabinet in the photo (unless some more ports are hiding somewere) looks to be a reflex with small ports and rather high tuning frequency.
My current single 416 cabinets looks to have at least 2X the port area of the one in the french photo.... from personal experience on my cabinet the ports are too small under large signal conditions.
Cyclotronguy
panomaniac said:
The 288C can have either 8, 16 or 24 ohm new diaphragm. If they are original, they also require an adaptor kit for the new diaphragm. The cost is $100.00 ea which includes a re-mag zap.
Guess where mine are headed. 🙂 I chose the 8 ohm
mafusha said:
Greets!
You're welcome!
Considering WE/Altec's decades long impact world-wide, I find it hard to believe that repairing early Altec gear is a lost art in Australia, though it seems reasonable that you'd only find them in the oldest major cities.
Don't have a clue what your amp selection is like, but I assume you can build chip amps if the new/used market choices suck. Bottom line, compression horns want to 'feel' a matching impedance load, so one way or another a high output impedance that ~matches the horn's yields the smoothest response and if no super tweeter is used, then a HF by-pass cap is required to flatten its response out to the driver's practical limit.
For bass bins it's more about having plenty of clean power so that it can handle the high power transients in the ~250-500 Hz BW and the EQ required to flatten its in-room response if not either BW limited to the mid-bass and/or loaded by a large, low tuned BLH. Bottom line, if a single amp is used, it needs sufficient current handling for the lows and a 'stiff' enough power supply voltage wise to handle high impedance loads or it will 'lay down', clipping fast transients, so try to find an older SS amp (preferably straight Class A, but at least A/B) that's rated for at least 4-16 ohms with a low DF and enough power to handle the transient peaks without clipping, unless you prefer the euphonic clipping of tubes amps.
515Bs have been my driver of choice since '69, but depending on the app the AlNiCo 803/416 series can be the better choice.
Short of designing an optimized XO based on measured in-room results, adapting the M19's XO to whatever driver impedance complement (they don't need to be the same) you wind up with is good enough for most folks IMO: http://home.earthlink.net/~jmarkwart/id7.html
GM
post script: I just remembered there's an SS amp builder in Aus. that some horn owners swear by: http://www.aksaonline.com/products_2_3.html
Re: W-onken
Greets!
If I were to recount all I've read/heard on this subject, you'd really be confused! Regardless, the Jensen Ultraflex derived 'Onken' is the most famous, but doesn't define 'Onken' per se. FYI, it's designed based on Thuras' original bass reflex cab patent: http://www.google.com/patents?id=MS1bAAAAEBAJ&dq=1869178
Anyway, can't comment about your cab's alignment, but IIRC the vents in the 'W' are tuned to ~ the driver's Fs and has sufficient CSA for a low < 5% vent mach at the driver's 75 W power rating (150 W total).
GM
cyclotronguy said:
Greets!
If I were to recount all I've read/heard on this subject, you'd really be confused! Regardless, the Jensen Ultraflex derived 'Onken' is the most famous, but doesn't define 'Onken' per se. FYI, it's designed based on Thuras' original bass reflex cab patent: http://www.google.com/patents?id=MS1bAAAAEBAJ&dq=1869178
Anyway, can't comment about your cab's alignment, but IIRC the vents in the 'W' are tuned to ~ the driver's Fs and has sufficient CSA for a low < 5% vent mach at the driver's 75 W power rating (150 W total).
GM
Re: W-onken
I can understand why! 🙂
The so called "Onken Cabinet" isn't Onken at all, it was Jensen who popularized it first. They called it the "Ultraflex." They came in several shapes and sizes.
Onken in Japan later picked up the design and tweaked it for their own drivers and special plywood. In about 1979 Jean Hiraga published an article in French magazine "Revue de l'Audiophile" on the Onken cabinet. The design was adapted to the Altec 416 driver which Mr. Hiraga felt to be the closest match for the Onken driver.
Many of these were built and it became a popular design. A smaller version was built with a Focal driver, sounded pretty good, as I recall. I had planned to build one years ago, never did.
But then there is the Onken-W. It is an Onken design, but NOT of the Jensen Ultraflex type. The Onken-W is a large box with 2x15" drivers and 2 small ports in the corners, as you see in the photos. The box is generally double walled, sand filled. Not much damping inside, just some wool felt.
The Onken-W is an amazing bass box. Done right, it sounds beautiful. Big, deep, articulate. With the right amp, it can be stunning.
I would imagine that calculations and simulations of the Onken-W would not be very impressive. But it certainly is in person!
cyclotronguy said:
I can understand why! 🙂
The so called "Onken Cabinet" isn't Onken at all, it was Jensen who popularized it first. They called it the "Ultraflex." They came in several shapes and sizes.
Onken in Japan later picked up the design and tweaked it for their own drivers and special plywood. In about 1979 Jean Hiraga published an article in French magazine "Revue de l'Audiophile" on the Onken cabinet. The design was adapted to the Altec 416 driver which Mr. Hiraga felt to be the closest match for the Onken driver.
Many of these were built and it became a popular design. A smaller version was built with a Focal driver, sounded pretty good, as I recall. I had planned to build one years ago, never did.
But then there is the Onken-W. It is an Onken design, but NOT of the Jensen Ultraflex type. The Onken-W is a large box with 2x15" drivers and 2 small ports in the corners, as you see in the photos. The box is generally double walled, sand filled. Not much damping inside, just some wool felt.
The Onken-W is an amazing bass box. Done right, it sounds beautiful. Big, deep, articulate. With the right amp, it can be stunning.
I would imagine that calculations and simulations of the Onken-W would not be very impressive. But it certainly is in person!
Cal Weldon said:
Instead of an adjustable pot to attenuate the HF, there's four 1 dB attenuation taps, so if you want 4 dB of attenuation, then relocate the shorting bar currently attached at 0 dB to the #4 taps.
I've never torn apart any potted XOs, but if I were to, I'd fire up my 1 kW heat gun and start melting. 😉 After all, they had to heat it up to pour it in, so it seems reasonable to me the components can take the heat required to melt it.