SLS 83668 10" as a woofer in a 3/4-way?


2019-07-31 3:49 pm
Hi guys!

How does this woofer behave when used higher up in frequency? I'm thinking of using a pair of them as woofers in a reasonably high sensitivity design.
The idea is to cross them over to the mid at the baffle step. Thinking of a baffle at around 32cm width.

What are your thoughts of this woofer used like this?

It should be a reasonably good performer, and probably really good for the price, especially if you want something with a dust cap instead of a phase plug. Has a shorting ring, very well-behaved frequency response, and has a pretty good xmax rating. Alternatives could be the RS270 family.

It starts to beam around 500 Hz so crossing over below that should be fine.

830668, by the way, in case you anyone wants to try to search for this thread later.
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Paid Member
2014-06-27 3:32 pm
Tarkus, by Paul Carmody uses this woofer, and some have built bass modules a la Jeff Bagby with it.

I have used them in a two-way with a 10f cheapie(plastic frame, Mad buyout from Japanese Stereo magazine project).
12" baffle,380hz cross. Nice and easy.


2019-07-31 3:49 pm
I missed the zero when writing on my phone.
Yeah, I know they are often used for subwoofers on the cheap, and have read about the Tarkus. The idea for the project is to build something that is fun and engaging to listen to at loud volumes. Maybe not the most correct speaker on earth. Something somewhat similar to the more successful models from CV.
The idea as it stands now is 2*830668 at the bottom in sealed boxes crossed over at the bafflestep to a 830875 and then to a DX25BG60+WG300 at a suitable frequency.
I might try the tweeter and wg + crossover from my Elsinores at the top, as they would be somewhat similiar to them otherwise.

There isnt that many options in this price class, i can only think of the 26W Discovery and RS270 in the same price class, but they are metal membrane woofers with break up, and seems to like bigger boxes. Im biased towards low order crossovers so they might not suit what im after. Their sensitivity is also lower and as such need another mid to be used.
With the 830668 i would be somewhere around 4-5dB of BSC, depending on gain from the bandpassed mid. That should be around what's needed.

The whole idea of the project is to build something different thats mainly fun and engaging with high spl capability for a fairly low price. I hope the SLS woofers would provide what i am asking for. Their suitability to fairly small sealed boxes is another plus, ive seen them used in as small as 40L boxes, with LT, but i think as a woofer instead of sub, LT might not be needed.

Unfortunately my pc, soundcard and measuring mic has been stolen, so i am not able to simulate any boxes at thia moment.. anybody interested in that? :) Would like to see what kind och curve a box around 40-50L would provide.
interesting driver, however slightly high Qts.
here is the 830668 in 40 L closed box, for 2Pi (floorstanding), Qtc is 0,94.
you would need 126 L for Qtc 0,71 ("max flat butterworth")


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If you use a pair of them per side, with one front-firing and one rear-firing, you can sort of get free BSC, plus of course the bass reinforcement down low (halves the excursion required for any given SPL, assuming the enclosure "size" is identical for each driver). Would need more box volume but you can make up for lost bass response somewhat with an LT as you mention, if you don't have enough space to double your enclosure size.
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Very good driver, especially for the price hard to find a better one. Used them long ago (2009 ?) in a very big transmission line with Monacor MSH116 midrange crossed over to at ~300Hz (and Seas 0,75" fabric tweeter with XO=3kHz), and had nothing to complain.

You would do nothing wrong with the SLS, it will give you very decent performance.

RS270 is nice too, as I don't like the higher mechanical losses / low Qms as I'm undecided if it comes from the aluminium voice coil eddy current losses (just loss of efficiency) or the mechanical suspension (which acts non-linear and promotes distortion) and I don't like the phaseplug design as it provides a leakage whith the risk of air flow noise at high output levels (but cools the voice coil).

My favorite price/performance 10" driver - especially for use as a "real 3-way woofer" with higher crossover up to 500 Hz - is the Scan Speak Discovery 26W4534G00 (4 Ohm) or 26W8534G00 (8 Ohm) in closed box alignment.

Found a test report by german hifi magazine:
(you can mark the text and give it to a translator, e.g.

I use two of the 8 Ohm type per side in parallel, driven by one channel of a Hypex FA123 (125W), which is by calculation excacly enough to drive them to datasheet mechanical Xlim by low-bass frequencies. I put them in ~65l CB with resulting Qtc = 0,85, applied linkwitz equalization to 30Hz / Q=0,71 and use them up to 300Hz LR4.

Bass and low-mids perform outstanding crystal clear up to Pmax, you can see that the woofers deflect to Xlim, but without the funny bouncing you observe from cheap car hifi soup bowls; they are just "visually blurring", with very, very few DC offset. A guy in a german forum, who developed the current speaker line for T+A mentioned a few times that he tested and very likes this driver too. Performance at very low levels is also excellent thanks to the very few mechanical losses.

In my opinion you can't get better with a 10" if you want undistorted sound and clarity, only a few dB louder when you spend multiple the money e.g. for a Scan Speak Revelator 28Wxxx which has relevant higher linear excursion/power capabilities with also very low distortion.

Sensitivity is above average, especially for the 4 Ohm type (much higher than typically subwoofer / long-stroke drivers).

This is my beloved system (which I decided will keep as reference forever because it sound so neutral and clean - no, no, this means not that I will not build more speakers, LOL) where I use them:


If you want a really very high sensitive woofer with "in your face" low-mid punch for small cab < 30l BR alignment I would go for a Faital Pro 10PR320 or Sica 10S3PL, but they will completely lack of low-bass by physics (never used them, but by data and assumed construction details they would be my choice for that application).

A good compromise of sensitivity vs. low bass capability and much higher electrical load capability than the Scan Speak may be the Sica 10SR2,5CP, which has very good reputation in Germany - but never heard or used them myself... Faital Pro 10RS350 which his praised by Troels Gravesen is in the same ballpark, but much uglier and the Sica simulates very few better.

Maybe you give us a few more information about the forseen midrange and tweeter, Xover frequency and desired application?

Best regards
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Good points. I would think that with a mid, though, no need to run the woofers too high, so having 2 SLS vs 1 26W/x534G00 would be more cost effective in terms of clean bass (I.e. same level of distortion). Plus, the free BSC as mentioned earlier.

where I live, the SS is more than twice the price of the 830668 and almost twice the price of the 830669


2019-07-31 3:49 pm
That Sica driver was interesting. Not the unusual high FS pro drivers tend to have. Sensitivity is also very good. If it were a bit lower than specified as usual, at 92dB then i could have a lot more 6" mid drivers to choose between, at around 88dB for some 4dB BSC. It wont be a high sensitivity design thou..

It isnt easy finding 10" woofers that fits in a reasonable sized box. Those who do, tend to be subwoofers. Im after a pure woofer, suitable for use higher up in frequency. And at a reasonable price. I might have to step away from using 2*10" as the box size without LT rises above 100L which is what i feel is maximum i could find place for.