I've updated the driver quantities available in the spreadsheet.
We'll be adding two highish efficiency woofers soon. An AR 12" woofer used in the Limited model 3 loudspeaker and a Jensen 15" woofer used in their Cerwin Vega clone line from about eight years ago. Parameters for the AR 12" are already up. Parameters for the Jensen 15" should be up within a week.
We'll be adding two highish efficiency woofers soon. An AR 12" woofer used in the Limited model 3 loudspeaker and a Jensen 15" woofer used in their Cerwin Vega clone line from about eight years ago. Parameters for the AR 12" are already up. Parameters for the Jensen 15" should be up within a week.
The numbers for the 12-inch from the Limited #3 have me interested.
I am wondering about sizing a sealed chamber for it. That Vas is shown at 269 l ... maybe a Vas that big is normal for the driver's build and purpose and a much smaller box will do. For sure that original cabinet looks a well short of, say, 9 cubic feet, if I have the size converted correctly. Any ideas?
Also, I am wondering if anyone might recall the frequency that this one was crossed in the original LTD. Was this one used like other ARs I remember with rather high and gentle glide points? I have not turned up anything other than pics of those pretty boards.
patch
I am wondering about sizing a sealed chamber for it. That Vas is shown at 269 l ... maybe a Vas that big is normal for the driver's build and purpose and a much smaller box will do. For sure that original cabinet looks a well short of, say, 9 cubic feet, if I have the size converted correctly. Any ideas?
Also, I am wondering if anyone might recall the frequency that this one was crossed in the original LTD. Was this one used like other ARs I remember with rather high and gentle glide points? I have not turned up anything other than pics of those pretty boards.
patch
The brochure for the AR Limited 3 speaker can be found here:
http://www.classicspeakerpages.net/ar/Classic&Limited/Limited_3_Speakers_Brochure.zip
The pictures aren't very good. The bass enclosure goes from the the bottom of the grille up to the break in the front baffle just below the bottom midrange dome. The bass enclosure was probably around 70l (2.3 cu ft)total volume. No where near as large as it could be given the overall size of the speaker.
The woofer was crossed over at 300Hz at 12dB/octave. The combination of a 0.2 Qts, Fs of 20Hz and cabinet volume of 70l all combine to give the woofer an f3 of about 55Hz. A woofer with this low a Qts has no place in an acoustic suspension enclosure. It must be a ported enclosure to get any bass out of it.
In a vented enclosure I would use around 35l tuned to about 37Hz. This will give you an f3 around 45Hz. If you have eq available, you can put it in a 45l enclosure tuned to 32Hz, add a 2nd order HP filter with an Fs of 30Hz and Q of 1.2. That will give you an f3 of about 35Hz.
The easiest way to get more bass extension out of this driver is to add a high power 0.5 to 1.5 ohm resistor. This will raise the Qts quite a bit. Then just calculate the enclosure parameters based upon the new Qts.
This speaker was NOT designed by AR employees. It was designed by people from another company that International Jensen also owned at the time. It is very clear that they had no clue about acoustics or electronics for that matter.
http://www.classicspeakerpages.net/ar/Classic&Limited/Limited_3_Speakers_Brochure.zip
The pictures aren't very good. The bass enclosure goes from the the bottom of the grille up to the break in the front baffle just below the bottom midrange dome. The bass enclosure was probably around 70l (2.3 cu ft)total volume. No where near as large as it could be given the overall size of the speaker.
The woofer was crossed over at 300Hz at 12dB/octave. The combination of a 0.2 Qts, Fs of 20Hz and cabinet volume of 70l all combine to give the woofer an f3 of about 55Hz. A woofer with this low a Qts has no place in an acoustic suspension enclosure. It must be a ported enclosure to get any bass out of it.
In a vented enclosure I would use around 35l tuned to about 37Hz. This will give you an f3 around 45Hz. If you have eq available, you can put it in a 45l enclosure tuned to 32Hz, add a 2nd order HP filter with an Fs of 30Hz and Q of 1.2. That will give you an f3 of about 35Hz.
The easiest way to get more bass extension out of this driver is to add a high power 0.5 to 1.5 ohm resistor. This will raise the Qts quite a bit. Then just calculate the enclosure parameters based upon the new Qts.
This speaker was NOT designed by AR employees. It was designed by people from another company that International Jensen also owned at the time. It is very clear that they had no clue about acoustics or electronics for that matter.
Jack, thanks for that.
Gads, what a mis-match, sounds like a real waste of potential. I can imagine the owners back then didn't sell all that many at $6,700/pair.
Really helpful information on using this driver. I think everyone marvels when a good designer brings out an exceptional result from raw material - seeing the flash just sitting in there latent (or that could be sitting there) and finding a way to pull it out. Teachers, audio engineers, gardeners, etc.
Gads, what a mis-match, sounds like a real waste of potential. I can imagine the owners back then didn't sell all that many at $6,700/pair.
Really helpful information on using this driver. I think everyone marvels when a good designer brings out an exceptional result from raw material - seeing the flash just sitting in there latent (or that could be sitting there) and finding a way to pull it out. Teachers, audio engineers, gardeners, etc.
Wooo. I'd want to distance myself way far away from the project manager on that one. Three floors up.
I wonder why someone picked that particular 12" speaker, its parameters, and the original main application target for the unit. I am guessing, was it something tweaked up from off the shelf, maybe mostly intended for PA, theater, instruments?
I wonder why someone picked that particular 12" speaker, its parameters, and the original main application target for the unit. I am guessing, was it something tweaked up from off the shelf, maybe mostly intended for PA, theater, instruments?
I've just added two more woofers to the sale website. One is an AR 12" cast frame unit. The other is a Jensen/Foster 15" cast frame unit.
Wow: that 15" looks spectacular (for $60), very functionally similar to Eminence Magnum 15HO, a much more expensive speaker used in Dick Olsher's "Basszilla"
Mr. Hadley,
any idea what the upper end of the Jensen woofer is? I'm thinking two of these crossed to a horn open baffle. The Qts is a little low for ob but a little EQ might work. Also couldn't I add a resister across the terminals of the woofers and change the Qts?
thanks,
Mordikai
any idea what the upper end of the Jensen woofer is? I'm thinking two of these crossed to a horn open baffle. The Qts is a little low for ob but a little EQ might work. Also couldn't I add a resister across the terminals of the woofers and change the Qts?
thanks,
Mordikai
The VT3 amplifiers are 115V only. The transformers are not multi voltage. There is only one primary winding.
I don't know how high the Jensen 15" will go. I'm sure it goes to at least 500Hz. Yes, you can raise the Qts of the driver as high as you like by adding a series resistor with it. Of course, you will lower the sensitivity at the same time.
I don't know how high the Jensen 15" will go. I'm sure it goes to at least 500Hz. Yes, you can raise the Qts of the driver as high as you like by adding a series resistor with it. Of course, you will lower the sensitivity at the same time.
A request for information: who might have the crossover pattern(s) for the M3.3 or the 2.9? Or did I miss them somewhere on this forum or the web?
I have been focused on jiggering the 025/070 balance on my test mule - and these two drivers have feathered up a nice baritone/tenor duet in several combinations. But I'm driving in circles in another part of town not finding that right middle of the original.
The 025s and 070s are hugely good deals all around, fine product, doubly the same for the 077s. Thanks to Jack and NHT for making this happen, and to SY and Variac also there in the north bay for letting rest of us know.
Thanks! patch
I have been focused on jiggering the 025/070 balance on my test mule - and these two drivers have feathered up a nice baritone/tenor duet in several combinations. But I'm driving in circles in another part of town not finding that right middle of the original.
The 025s and 070s are hugely good deals all around, fine product, doubly the same for the 077s. Thanks to Jack and NHT for making this happen, and to SY and Variac also there in the north bay for letting rest of us know.
Thanks! patch
Spasticteapot,
Oh, do it. I'm sure a local pawn shop would be delighted to help out in any way they can. As they might correctly say: pawns produce cash faster than ebay or the driveway 😀
No need to cash out your gold, as SY said earlier these drivers are silly-cheap.
Tip: buy by the case - Jack will ship the 070s from the original sealed box (6 speakers). They arrive in perfect condition. And Jack ships quickly.
patch
Oh, do it. I'm sure a local pawn shop would be delighted to help out in any way they can. As they might correctly say: pawns produce cash faster than ebay or the driveway 😀
No need to cash out your gold, as SY said earlier these drivers are silly-cheap.
Tip: buy by the case - Jack will ship the 070s from the original sealed box (6 speakers). They arrive in perfect condition. And Jack ships quickly.
patch
Patch, I'm doing a set of mods on the 3.3s suggested by Jack and will post them here soon. Drop me an email and I'll send you a scan of the stock 3.3 schematic.
By chance, has anyone tried using any of the larger drivers for PA work? If so, how did they work for you, how you arrange them?
Thank you SY for the schematic for the M3.3!
Thank you SY for the schematic for the M3.3!
No one has purchased any of the 12" or 15" drivers yet, so I think it's safe to say that no one has used them yet.
Yes, all of the products on the sale site are still available. Just look at the spreadsheet to see what the quantities are.