SS 7" Illuminator

[JonMarsh]

Trying to pick up the pieces before work went monster on me the beginning of November - these measurements were done earlier, but I hadn't found time to post.

These are just some very preliminary tests on SS Illuminator 18WU/8747T-00; they caught my eye as a possible woofer retrofit/modification to the as yet incomplete Ardent project. I've been interested in converting that system to sealed, if I could find the right driver, after my listening time this year with the Modula Xtremes, which are sealed. There's an articulate, dry but harmonically rich character to the bass that I rather like (by harmonically rich, I mean the real instrument overtones, not woofer generated distortion), and I'm hoping to replicate that in the smaller system.




The construction of this woofer should also work well with the issues around the Ardent Baffle.


To that send, some basic measurements were done for one driver in a 22L test cabinet, as this is 1/2 the woofer volume available in the Ardent enclosure. 6" nearfield looks very usable in the required operating range up to 1 kHz (considering -18 dB with a Duelund crossover)





The SS uses an underhung neodymium motor; it appears to have remarkable symmetry, with 2nd order lower than 3rd order at 2.83VRMS drive level. Distortion is steadily dropping all the way to 1 kHz, a good sign of low inductivity modulation.



Looks like something worth taking to the next step...

[Silversmoky]

Hi Jon. Glad to see you're back again! Those Scans look like they will work nicely in your Ardents. Should look very nice too! Distortion is pretty impressive.

[Jed]

Looks good... just wish they had about 3db more sensitivity. But you can't have it all I guess.

[JonMarsh]

Looks good... just wish they had about 3db more sensitivity. But you can't have it all I guess.

Yeah, but that's kind of a side effect of the overall magnetic structure and actual T/S parameters- if my measurements are correct, that's why they'll work well in this configuration.

Proof's in the pudding, of course- we'll have to see.

[Jed]

What are you getting for actual T/S parameters? The tests in Voice Coil were fairly close to manufacturer specs IIRC.

[peepaj]

welcome back Jon

[JonMarsh]

Hey, thanks- it's been crazy of course at work, was on business travel all of November and December except Thanksgiving week, and now it looks like I'm being drafted for a new interesting position- have to fly to HQ this coming weekend re that.

Jed, you know how it is about SS T/S parameters; controversial to some degree for years- I'm not making any credibility claims for my measurements versus VC, but for the samples I have, they look a skosh less sensitive, and Qts more like 0.45 than 0.31 as in factory spec. I'm good with that; they work better for what I want to do as they are, not as the spec sheet is.

Of course, these aren't exactly bargain basement woofers, but it's interesting that the aluminum cone versions are so much less expensive than the paper cone.

[claudius]

Hi Jon,
Welcome back,you seemed to have fallen of the edge of the earth there for a while....it's good to have you back.This is my first post but i have followed youre various projects with interest and admiration for a long time now.Just a few questions if i may, What happened to the ModulaXtreme thread,It's disappeared altogether.While on the subject, is the crossover schematic on(https://www.htguide.com/forum/showthread.php?t=36370) of the then Modula Xtreme thread final or have you been developing it further.I have built a pair using 26W/8861T the paper cone version that i had and they sound gorgeous.Having in the past built theTony Gee's Humble Statement i was convinced that only Accuton C220 could really match the recalcitrant C173-T6-90.Modula Xtreme have forced me to change my mind, Side by side with H Statement the M Xtreme have stronger more dynamic bass that somehow manages to be better integrated tonally, with the difficult T6-90 than Accuton's own C220. The only problem is that26W8861T in parallel must present a rather punishing load to the amplifier because my old FPB300 tends to get very hot, no, i mean really really hot when i listen at loud volume and the other amp Rotel Rmb 1095 just switches off.The only deviation from you're crossover is the use of Mundorf 3.5mm wire transfomer core inductors for bass and the supreme cap's for T6-90. Oh... did i mention welcome back.

[JonMarsh]

Hello Claudius!

I'll have to check out where the thread is- I didn't delete it, so it should be around-

I'm trying to get back into the swing of things with all things audio, work has been tough, even now I'm writing from Austria after finishing up a organizational workshop here and some additional side meetings regarding new products getting close to release, and our cooperation with key US customers.

Thank you for your comments regarding the Modula Xtreme and your experience with the design. I'm very impressed with the Revelator motor and the performance possible with their 8" and 10" woofers, but as you note, the impedance can be a bit of a challenge with many amplifiers. A key change was putting the initial two woofer modules up on a third and re-locating the crossovers. Their are some minor tweaks I was considering in June but haven't gotten around to, plus a cabinet rebuild switching to piano black but retaining the laminated bamboo lumber. I also have some new Jantzen waveguide assemblies and a pair of Ciare MT320 to evaluate with them- even have the test baffle fabricated, but stalled due to travel and other personal commitments. But this should change soon, I think... that or I just need to take some vacation and make it happen! :W

I'm also planning on working on the room a bit, some treatments and new seating.

I'm in transit to back home, sitting in a Starbucks at the Vienna airport this Saturday morning- unfortunately my return schedule was optimized for price, not for timeliness, so I won't be arriving back in SF until Sunday afternoon- after a stay overnight in Frankfurt. This is crazy- and I know I'm coming back here in March at least, if not sooner.

I'll check out the status of the original thread post, and update it from at home soon, where all the data is- this is a new MacBook, and mostly just work stuff is on it for now. That needs to be updated! :W

[jkrutke]

Hi Jon, welcome back. I have to say, I like the aluminum better that the paper version. Almost seems like the driver the Illuminator was meant to be. Nice. Higher breakup and smoother in the upper treble. Could do great in a 2-way.

[JonMarsh]

Funny you mention that, it's something I'm looking at besides the Ardent application, probably a WG two way, or 2.5 way. And on top of it all, throw in the lower price...

Just got back from Austria- shouldn't take two days to get back from there with the cheap flights, but it did. Ugly.

[tktran]

The SS datasheet shows 7-10KHz break-ups that look even more fierce (+15dB)

Waiting for the 8-10" Illuminators...

[Face]

The SS datasheet shows 7-10KHz break-ups that look even more fierce (+15dB)

Waiting for the 8-10" Illuminators...

Are there any plans for such beasts?

[kevinlin1013]

SS 7" Illuminator seems be nice but expensive. The price is close to accuton.

[Rick Craig]

Are there any plans for such beasts?

Maybe :W

[Face]

SS 7" Illuminator seems be nice but expensive. The price is close to accuton.

Yes, but just a little more durable. :B

Maybe :W

:T

[kevinlin1013]

Yes, but just a little more durable. :B


:T

Because accuton is a little fragile? I also am considering the 7" woofer match with accuton tweeter/mid because the cabinet of two 8" woofer might be too large in my room.

[Bear]

SS 7" Illuminator seems be nice but expensive. The price is close to accuton.

I'm not so sure when you are looking at comparable performance in the hard cone versions. The -95 or -95E are close to $400/driver, and the FR and distortion performance doesn't look as good as what Jon is posting here (insert disclaimer here about lack of comparable test conditions). The -90, -96 and -96E are pretty special, but then you are >$600/driver. From an application standpoint, the Accuton drivers have uniformly higher sensitivity but a lower Xmax (and presumably Xlim).

[kevinlin1013]

Thanks bear for information.

I am looking for the drivers crossed about 250Hz(2LR electrical)

The tweeter and mid are already accuton but the woofers will be too much cost if using accuton's.

So I am finding something can sound well with accuton's tweeter and mid (clean and fast sound) for example the ScanSpeak or Seas Excel might be good choices.

Please giving me some suggestions. Thank you very much.

[Bear]

Thanks bear for information.

I am looking for the drivers crossed about 250Hz(2LR electrical)

The tweeter and mid are already accuton but the woofers will be too much cost if using accuton's.

So I am finding something can sound well with accuton's tweeter and mid (clean and fast sound) for example the ScanSpeak or Seas Excel might be good choices.

Please giving me some suggestions. Thank you very much.

I think one of the gurus here would be able to give you better information. If you are looking for something to be the bottom of a three-way, then there are a lot of options that will be good with a 250Hz Fc, especially with LR2 electrical (for high-end drivers like what you have, many folks would probably encourage LR2 acoustic slopes). The question becomes, really, how do you want to work Hoffman's Iron Law (efficiency vs. reach vs. cabinet size) and what are your budget constraints. Also, would you consider a 10" driver (26cm) instead of an 8" (22cm)?

Zaph's site has some comparisons of various 22cm and 18cm drivers which would be a good starting point.

[Rick Craig]

So where do you think Jon first listened to this driver in a sealed box? :W