AR94S vs AR94SX

[Carlspeak]

I'm not a big fan of 'vs' threads, simply because they are so opinion based, and in this hobby - well, you know the rest....

This one has to do with physical differences and is for the historians. I found a schematic for the SX version in the library, but not the 94S version. However, I do know the S version has 4 uF tweeter cap, 100uF woofer parallel cap and a #9 coil.

Are the drivers any different?

[RoyC]

I'm not a big fan of 'vs' threads, simply because they are so opinion based, and in this hobby - well, you know the rest....

This one has to do with physical differences and is for the historians. I found a schematic for the SX version in the library, but not the 94S version. However, I do know the S version has 4 uF tweeter cap, 100uF woofer parallel cap and a #9 coil.

Are the drivers any different?

Hi Carl,

The AR-94 model is a puzzle. There were a number of versions. (I believe there was a "q" and and an "r' as well.) There were definite differences in the 8" drivers used as mids and woofers in at least one or two versions I have seen, and crossovers varied as well. In the 94sx, the 8 inch drivers appear identical. I have never seen any concise documentation regarding the differences. The one constant seems to be the tweeter and associated 4uf capacitor crossover.

Roy

[Carlspeak]

The 'SX' dwg in the library shows a 5 uF tweeter cap and two identical 8 inch woofer p/n 210067. The lower woofer series coil is 1.45 iron core that also doesn't match up with #9 coil mH spec. I thought the 'SX' version might just be a crossover change vs the 'S' or improvement but I guess that's not the case.

[RoyC]

The 'SX' dwg in the library shows a 5 uF tweeter cap and two identical 8 inch woofer p/n 210067. The lower woofer series coil is 1.45 iron core that also doesn't match up with #9 coil mH spec. I thought the 'SX' version might just be a crossover change vs the 'S' or improvement but I guess that's not the case.

Hmmm, so much for my tweeter theory. :-).

Roy

[Carlspeak]

Hmmm, so much for my tweeter theory. :-).

Roy

The AR94 puzzle continues! :-)

[DavidR]

The AR94 puzzle continues! :-)

This speaker sure is a puzzle. I was given a single AR94S (as depicted on the label by the binding posts). I was hoping to score a 8" LMR woofer for my AR90s as a spare; p/n 200027 (drwg # 153). I spent a while looking thru the drawings in the Library here on CSP. The standard compliment of drivers for an AR94 is: Tweeter: p/n 200038 (drwg #167); Mid: p/n 200027; Woofer: p/n 200001-1. I also came across drawing #164 which suggests the Tweeter p/n should be 200034 (drwg # 164).

My 94S has the crossover for a AR94 (drwg #480) with the 100uF on the woofer, 4uF on the tweeter, 2.85mH (#9) coil, 2 ohm 22W resistor which appears to be wired for both the Mid and Woofer.

Driver part numbers:

Tweeter: 1-2100380 K53TNJ

Mid: 1-2100450B K53TNG

Woofer: 1-2100370 L51TNE

Drawings in the Library have the #200038 Tweeter as belonging to the AR18S and 38S (drwg #167)

Tweeter #200034 belonging to the AR94 and 93 (drwg #164)

Mid #200027 belonging to the AR9, 90 and 94 (drwg #153)

Mid #200450B belonging to the AR9LS and 98LS (drwg #171 revB, drwg#076, rev A was stamped obsolete) The difference I could see was the surround was glued to the back of the cone and it is on mine.

Woofer #200001-1 (I only found drawings for the cone and VC)

Woofer #2100370 belonging to the AR18S and 28S (drwg #166)

So it would seem AR may have used drivers that were available and were close in design.

(Yes, I had nothing better to do today; or at least didn't feel like doing much else). I may be all 'wet' in my logic for all I know.

[JKent]

There were several different "94" models. I discussed the restoration of the "Si" version here: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8149&hl=ar-94si

The original xo had a 5uF and a 40uF cap, two 2 ohm resistors and a 1.37 mH coil.

The woofer and the mid are identical 8" drivers (part 1210067).

-Kent

[RoyC]

There still seems to be more questions than answers with these beasts, though I agree with David's conclusion.

It appears the 8 inch drivers were originally US made, and the model design changed somewhat when AR began using Tonegen drivers (identified by the "TN" in the part number). I'm aware of more than a few AR-94's dismantled for AR-9 mid drivers, woofers for smaller two-way models, and tweeters for a number of other models.

Roy

[DavidR]

There were several different "94" models. I discussed the restoration of the "Si" version here: http://www.classicspeakerpages.net/IP.Board/index.php?showtopic=8149&hl=ar-94si

The original xo had a 5uF and a 40uF cap, two 2 ohm resistors and a 1.37 mH coil.

The woofer and the mid are identical 8" drivers (part 1210067).

-Kent

Very nice thread Kent. Those Madisound surplus film caps sure find their way into a lot of restorations. I used some of the 10uF and 2uF mylars in a small 3-way Yamaha speaker. Can't go wrong with the price.

[DavidR]

<edit>

[JKent]

Has anyone thought about making the mid range, which is wired as a full range, a true mid range driver? I would like to know if this is a good or bad idea and if its a good one can anyone guide me on the proper shunt cap size and coil needed.

I'm no expert on these but as discussed above there were several versions of the 94S. I restored/modded the Si version. I'd suggest you consult Roy on the xo as there were a number of xo changes and maybe he has an opinion on which was "best." Another thought: The 94s series used two identical 8" drivers as the woofer and mid but the mid was placed on the bottom. Roy suggested trying a simple mod: Wire the bottom driver as the woofer and the top as the mid. I had already completed mine and did not plan to keep them so I left the mid on the bottom but it's worth a try.

-Kent

[DavidR]

Thanks Kent. I had read that Roy suggested moving the woofer to the bottom. The ones I have are 94S and have the first iteration of the xo; however, the mid and woofer drivers are different. I believe in the 94Sx the mid and woofer were the same driver - at least it shows that on the xover schematic in the library. I can still easily swap the wires and relocate the drivers as I plan on recapping them and changing the spring loaded type speaker connections to 5 way binding posts.

I've read your thread on the mod to the 94Si. Very nice.

Any idea about sources for surrounds: Rick Cobb, John at MSound, etc. On the mid driver the surround mounts to the underside of the cone and is different than the woofer surround.

[baco99]

Hi all!  I'm new here, but ran into a set of AR94SU and another set of AR94SX/Si speakers.  Both are getting reborn, but I wanted to show some images of some if the differences in the drivers and the crossovers.  I lumped the AR94SX and AR94Si together because they look exactly the same and are made from the same components.  Not sure why the nomenclature change.  The -SU are definitely a different animal with different mid and woofer and crossover.  

Hope this is helpful.

1) Both models use the 1210138-0 or 1310138-0A tweeter.  Made by Tonegan, with the curved tinsel leads.  They are a very good sounding tweeter. 

2) The -SU model uses two different drivers. The mid-bass driver is an AR branded Tonegan 1210045-0 8" paper cone driver very similar to the AR9 midrange as others have mentioned.  It has a big magnet and thick stamped frame.  The cone diameter is a hair smaller than the upper-mounted low frequency woofer so a slightly thicker foam surround roll/edge is needed to make it fit properly under the cone as that's how they were mounted originally.

The upper low frequency woofer also has a very stout frame and large magnet with model # 1210037-0.  The suspension is much more compliant than the mid-bass driver and a standard 8" foam surround fits the cone profile perfectly.  The cone material is thick paper and left untreated.

The crossover uses a lower frequency cutoff for the tweeter and is slightly more complex than the SX/Si version.  Here's where the 4uf cap can be seen.  The midrange uses a 100uf cap as a high pass filter.  I measured the caps to be within spec, so I left them alone.

In terms of finish, the SU model uses vinyl covered top caps vs real wood on the SX/Si.  These SUs had brown cloth socks.  

3) The -SX/Si models used two of the same drivers for the woofer, model # 1210067-0B.  This woofer has a noticeably smaller magnet and thinner frame.  The cone is coated in a thick "membrane" of sorts.  It looks like a sprayed on dampening material.  

The crossover was simplified and here's where the crossover point was raised, presumably to allow for greater power handling to the tweeter.  The 5uf cap can be seen here on the tweeter, and a 40uf for the midrange, which is used to control the slope of the midrange low-pass, NOT used as a high-pass.  Seems the crossover points were dramatically changed.

The real wood tops are a nice touch on this model.  Otherwise the construction is exactly the same as the SU model.  The socks are black on this model, not brown.

 

I haven't completed the refoam on the SX/Si yet, but when I do I'll post my impressions side-by-side.  I'me really curious as to how they will perform compared to the SU which has seemingly much higher calibre components inside.

I'd also really like to know how/who thought to put the midrange by the floor. Somehow, the system is very coherent even with the lower midrange so far away from the tweeter.  The low crossover point probably plays a role as well.  

I'll also plan to measure each of the drivers T/S specs in case anyone is looking for aftermarket replacements.  

 

Thanks!

 

 

EDITED TO CHANGE THE CROSSOVER SWAP FROM THE ORIGINAL POST.

 

 

[jason4300]

Good info. I'm also curious to hear your thoughts on how they sound side by side. I've found my SI's to sound very full, except for the mids, which are strangely lacking. I'm guessing the SU won't have this problem. They do pair perfectly with a set of Rock Partners which fills out the mids very well.

 Also seems I found the only pair of SI's that didn't have a real wood cap. Mine were vinyl covered particle board.

[jason4300]

Also, I think you have your crossovers switched in the description. IIRC, the SI should have the 5uf/40uf caps. I believe JKent modified his to be closer to the SU's specs when he restored his SI's.

[bjmsam]

4 hours ago, baco99 said:

2) The -SU model uses two different drivers. The mid-bass driver is an AR branded Tonegan 1210045-0 8" paper cone driver very similar to the AR9 midrange as others have mentioned.  It has a big magnet and thick stamped frame.  The cone diameter is a hair smaller than the upper-mounted low frequency woofer so a slightly thicker foam surround roll/edge is needed to make it fit properly under the cone as that's how they were mounted originally.

I'd also really like to know how/who thought to put the midrange by the floor. Somehow, the system is very coherent even with the lower midrange so far away from the tweeter.  The low crossover point probably plays a role as well.  

The kit I ordered came with identical surrounds for both drivers.  The mid-bass drivers were certainly trickier, but there was just enough overlap for installation over the cone.  I am curious about the driver placement as well, which seems at odds with the rest of the 9 series.  Regardless, the speakers sound great in a bedroom system!

[baco99]

11 hours ago, bjmsam said:

The kit I ordered came with identical surrounds for both drivers.  The mid-bass drivers were certainly trickier, but there was just enough overlap for installation over the cone.  I am curious about the driver placement as well, which seems at odds with the rest of the 9 series.  Regardless, the speakers sound great in a bedroom system!

 

Yours look great!

i saw that the kits use the same foam but when I measured the cone diameter, the lower mid cone is definitely a touch smaller than the top one. The foam roll has a 5/8 roll instead of a 1/2 roll IIRC. 

 

[JKent]

15 hours ago, jason4300 said:

Also, I think you have your crossovers switched in the description. IIRC, the SI should have the 5uf/40uf caps. I believe JKent modified his to be closer to the SU's specs when he restored his SI's.

My Si had a 5yF and a 40uF. It's the one shown in your 1st photo (with the two 22 ohm resistors). Roy recommended changing the 5uF to a 4uF and the 40uF to "greater than 70uF". He also recommended putting the low-range woofer on the bottom. If you haven't tackled the Si yet you may want to try these mods.

-Kent

[baco99]

You guys are right.  I got the pictures swapped, will fix it.

The SU uses the simpler 1st order crossover.  There's a 2 ohm pad in front of the top woofer, and a choke and filter in front of the bottom one so it' acts like a "bandpass" lower midrange.  The tweeter uses a 4uf on the SU, 5uf on the SX/Si.

 

Bringing the 40 uf cap on the SX/Si bottom driver down to 100uf will change the slope of the cutoff at the top end of the driver, but not the frequency, correct?

[baco99]

16 hours ago, jason4300 said:

Also, I think you have your crossovers switched in the description. IIRC, the SI should have the 5uf/40uf caps. I believe JKent modified his to be closer to the SU's specs when he restored his SI's.

 

Yes, fixed.  Thanks!

[DavidR]

I've seen that lacquered woofer, model # 1210067-0B, before but can't recall what other speaker(s) AR used it in. I took a look in the Library but could not locate it. I may try another search.  The dark, split cone woofer came in the AR9LS and LSi and even found its way into some AR9's.

I'd be very interested in your thoughts on the comparison between the two 94 models. I've rebuilt 2 pair of the 94S for my brother in law. They sound very decent with his Pioneer SX-1250.

[baco99]

IIRC, the SU top paper cone woofer was also used on the TSW series before they went to rubber surrounds.   Not 100% sure 

[DavidR]

The TSW series used poly cones.

[baco99]

56 minutes ago, DavidR said:

The TSW series used poly cones.

Ah, that's right.  The dust caps are the same.

[baco99]

56 minutes ago, DavidR said:

The TSW series used poly cones.

Ah, that's right.  The dust caps are the same.