Is the SB Acoustics SB34nrxl a Satori in disguise?

If you compare the "Feature" box in the Satori WO24 and the SB34nrxl specsheet, they seem to be identical … Is the SB34nrxl a "Satori" woofer, with under-cut pole piece, dual shorting rings, silver wires ++?

What do you think of the SB34nrxl?

I am tempted to use it in a JBL L-112 inspired 3-way monitor with a high-ish crossover around 800Hz, as its t/s-parameters is almost identical to the famous 128H in the L-112.

I am a bit worried, though, if the SB34's deep cone profile might be a problem with midrange frequencies (phase-distortion, early beaming, ragged response)?

Thoughts, anyone? Other L-112/128H alternatives in the same price range?
 
Feature set is pretty much consistent with the smaller SB**NRX drivers. The cone resonance causing a 5dB dip at 770Hz~ is going to be difficult to work around for an 800Hz XO. Theoretically a 12" woofer should start beaming at about 550Hz so I wonder if SB made an error in their measurements (nearfield measurement was ran up too high). Surely the frequency response is not free of nulls up to 1kHz and out to 60 degrees off axis?

Measurements here show low HD up to 1kHz:
Zaph|Audio - SB12.3 3-Way Tower

Le(x) is starting to become questionable at about 600Hz imo, so if you run it higher than that you will get intermodulation distortion with the bass.

Satori drivers are overrated imo. Their motors are a bit more linear than the NRX but their soft parts leave much to be desired with cone resonances galore.
 
Last edited:
Thanks for answering, and I mostly agree. I asked because the SB24nrXL with its under-cut pole piece and dual shorting rings, the same "symmetric-drive" that the Satori WO24 has (and that no other non-Satori SB woofers have?), seems to flatten the impdance quite well. The XL only increase with 8ohm up to 2000Hz, while the non-SD SB34nrX increases with 16 ohms in the same range. Isolated, a flatter impedance should make the XL better suited for bass and midrange?

Almost every SB Acoustic paper-woofer/midwoofer has this 4dB narrow FR-dip where the cone starts to become directional and starts to resonate with the soft and sloppy rubber-surround (MW16 at 1600Hz, MW19 at 1200Hz and SB34 at 700Hz), visible in waterfall plots as accumulation of energy. But I've read that this type of distortion is not as dangerous as it may look, and I have not heard anyone yet complain about the MW16's or the MW19's (or the Audio Technology 15H's, which has the same dip) midrange performance, so I'm not that worried about this 700Hz dip (but I admit that Zaph's measurements look pretty ugly).

Maybe the SB32nrXL's 1,20mH impedance will lead to too high IM-distortion above 500-600Hz, I don't know, but I remember that gurus like Lynn Olson gladly crossed a Tad 1601 15" with 1,60mH impedance at 800Hz.

I still think the SB34nrXL can be a great 40-700Hz midwoofer, with warm and powerful JBL-like qualities in the bass and lower midrange.

Not that many 40-800Hz 12" midwoofers around with low enough Qes to suit a 45 liter cabinet. …
 
Well depends.

For sub-bass (<60Hz) aka subwoofer use I’d take the SB34RNXL up to about 120Hz, maybe 200Hz.

For the a smaller box in bottom of a 3 way, or up to 1.x Khz for a 2 way I’d take the WO24

T
 
Last edited:
The independent measurements at hificompass seems to show the SB34 at twice the sd, comes close to but is not as low distortion as the WO24P.

SB Acoustics SB34NRXL75-8 | HiFiCompass

Satori WO24P-8 | HiFiCompass
Actually it's extremely close because the WO24P needs around 5.6V to equal the SPL of the SB34 at 2.83V, so you must compare HD at those voltages. Good example of how a larger woofer with simpler motor is just as good as a smaller woofer with superior motor if you don't need to cross it too high.

https://hificompass.com/sites/defau...x/public/zamer/afc315/wo24p-8_315mm_5v6hd.png
https://hificompass.com/sites/defau...blic/zamer/afc315/sb34nrxl75-8_315mm_2v83.png

SB23 also for comparison, which is clearly inferior >300Hz and <100Hz
https://hificompass.com/sites/defau...amer/afc315/sb23nrxs45-8_315mm_4v_hpf2-50.png
 
Last edited:
The SB34NRXL75 is a very organic and accurate sounding woofer that can be crossed higher than other typical 12 inch drivers, given you don't push it past 350 Hz with a 2nd order slope (staying away from that 700 Hz cone resonance dip).

I have to point out that pushing a large woofer that high in a big enclosure creates quite an engineering challenge. You end up with a lot of problems related to enclosure panel resonances and interior standing waves, so proper enclosure design becomes a much greater priority compared to physically smaller designs. A larger driver can deliver much higher acoustic output levels in the lower midrange, which is a greater issue with ported enclosures with much of that excess rear radiated energy potentially leaking out through the port, smearing the sound. Even sealed boxes can create issues related to this problem and require alot of careful engineering to end up with clean and coherent lower midrange at higher playback levels. Sealed boxes generally are capable of delivering cleaner lower midrange than ported ones, given the driver and enclosure are optimized for each other. The midbass driver's resonance is another cause for concern and should be treated either with an impedance flattening LCR and/or with extensive enclosure dampening. If not treated properly, it can cause muddy sounding lower midrange and can even create midbass power handling and phase issues.

Anyways, this big SB driver is comparable to a few higher end 10 inch drivers. It does remind me alot of the good old Vifa M26WR09-08, which is likely one of the best 10" paper cone drivers ever made IMO.

With half space boundary gain, the SB 34NRXL75 can get close to 93 dB/2.83V when located on a tall/wide baffle close to the floor like in a big floor standing system. The Peerless NE180W-08 complements the big SB driver nicely and is my new favorite dedicated midbass with a LP of 1 kHz or lower - I'm currently working on a larger 4 way design with these drivers along with a ScanSpeak 3" dome mid and Seas T35C002 in a WG. Should sound really nice based on preliminary testing.
 
I agree with everything profiguy says. It is a great woofer. I use them in a 70 liter sealed box, with a + 6db Linkwitz transform boost at about 30 Hz. Even in a very well made box, I don't want to cross mine higher than 300 Hz. The very best sound, in terms of clarity and definition, comes from crossing them at 250 Hz or below. I don't know how much of this limitation comes from the driver, and how much comes from the box... probably a bit of both.

But when used from 20 Hz to 250 Hz, they have excellent definition, clarity, subtle detail, power, and punch.

j.
 
I have to point out that pushing a large woofer that high in a big enclosure creates quite an engineering challenge. You end up with a lot of problems related to enclosure panel resonances and interior standing waves, so proper enclosure design becomes a much greater priority compared to physically smaller designs.
So, brace it thoroughly and damp it well. Nearly every commercial and DIY design is lacking in this regard.
A larger driver can deliver much higher acoustic output levels in the lower midrange, which is a greater issue with ported enclosures with much of that excess rear radiated energy potentially leaking out through the port, smearing the sound.
Plan the build including the port location. I usually exit the port on the bottom (rear is option 2) and internally arrange the acoustic damping so that it does not impede flow to the internal port entrance and absorbs as much of the MF energy as possible.
 
Satori is just a label and the driver is labeled SB and it measures excellent. I'm not sure whats the point of this post.
@profiguy Have you compared it to other drivers? It measures so well and is pretty expensive I feel its a waste to use it under 300
Well, sure you can run it up higher but you get closer to that resonance blip around 700 hz, then you'll need a steeper LP, which IMO is not such a great idea at lower xover points, being the resulting phase shift is more invasive to the ear down there. It also makes a passive xover more expensive, but most guys will go active xover that low, unless they have a bunch of money to burn on huge coils and caps. If you do insist on a higher xover LP, i would do an active LR4 no higher than 500 hz, but BSC gets tricky and fiddly getting the system power response right. I'm assuming some of you CD + horn guys are looking at this driver as a viable option for a 2 way and that may work if done correctly.

Regarding comparison to other similar drivers, I looked at some other higher compliance pro drivers, but I can't find anything else that has the best of both worlds regarding low end reach combined with upper bass clarity and low IMD. Its kind of an oddball driver if you ask me. Most drivers with this much xmax are dedicated subwoofer drivers. Even the cheaper SB34NRX75-6 optimized for a sealed box sounds similar to the NRXL but it doesn't play as clean that far up, plus the efficiency is lower. The fostex FW305 is a good contender, but power handling isn't on par with either of the larger SBs and not worth the cost either.
 
Last edited:
Well, sure you can run it up higher but you get closer to that resonance blip around 700 hz, then you'll need a steeper LP, which IMO is not such a great idea at lower xover points, being the resulting phase shift is more invasive to the ear down there. It also makes a passive xover more expensive, but most guys will go active xover that low, unless they have a bunch of money to burn on huge coils and caps. If you do insist on a higher xover LP, i would do an active LR4 no higher than 500 hz, but BSC gets tricky and fiddly getting the system power response right. I'm assuming some of you CD + horn guys are looking at this driver as a viable option for a 2 way and that may work if done correctly.

Regarding comparison to other similar drivers, I looked at some other higher compliance pro drivers, but I can't find anything else that has the best of both worlds regarding low end reach combined with upper bass clarity and low IMD. Its kind of an oddball driver if you ask me. Most drivers with this much xmax are dedicated subwoofer drivers. Even the cheaper SB34NRX75-6 optimized for a sealed box sounds similar to the NRXL but it doesn't play as clean that far up, plus the efficiency is lower. The fostex FW305 is a good contender, but power handling isn't on par with either of the larger SBs and not worth the cost either.
The reason I asked is because I did consider this driver for my set up and I think for under 300hz the NRX (non L) is probably almost as good and is much cheaper. I went the PA way as I want 15’ and the SB42 is too “subwoofery” for my taste but anw thanks for sharing.

On another note, Im finishing the cabinets for my 3 way active speakers and Im curious of what you and @hifijim said about crossing a big woofer at higher frequency. Intuitively, I think box resonance is of a bigger concern at lower frequency and high volume (ie high excursion) no? For higher hz, the big woofer’s cone only need to move very little to generate desired SPL so I wonder what makes the box resonance concerning crossing a big woofer high up there. Thx
 
Just to clarify, my experience is with the SB34NRX75-6, not the NRXL version.

I'm curious of what you and @hifijim said about crossing a big woofer at higher frequency.

Regarding cabinet resonances: The most troublesome region, in my opinion, is from 200 to 600 Hz. Unfortunately, this is exactly where a lot of ordinary cabinets have a resonance. If we can push the resonances up above 600 Hz with lots of stiffness (bracing) and thick walls, the resonances tend to become high Q, which makes them less audible and less likely to be activated by program material (music or film soundtrack). Also, there is much less energy available at higher frequencies to activate the cabinet resonances. Going the other direction, getting the resonances below 200 also seems to work. This is done by adding structural damping and mass. This drives the resonance frequencies lower, and lowers the Q of the structural resonance. If the structural resonance Q can be driven down to 1 or lower, then there will be no resonance at all. This is practically impossible. In theory, driving the structural resonance down in frequency and lowering the Q would make the resonances more audible, until the Q can be lowered to 1 (which is virtually impossible) at which point the resonance goes away ... However, the physics and psychoacoustics involved here must be more complicated than simple theory, because there are several CLD techniques which seem to produce a very low signature cabinet, even though the Q is very much higher than 1 and the structure does have resonance. So whatever is going on with lightly braced CLD cabinets, it works. There is no arguing with success no matter what the theory says. So in short, both methods work, but we have to do one or the other. If we do nothing, a typical cabinet will have audible resonances.

So how do we use this information in a practical cabinet? A big woofer has a lot of capability to pump energy into the cabinet. The larger the cabinet, the more complicated it is to make it stiff and to get the resonances above 500 Hz. The combination of a powerful woofer motor, a large cabinet with a lot of surface area, and the necessary large hole where the woofer sits, starts to really complicate the cabinet design. If we know the big woofer in the big cabinet is only going to be used up to 250 Hz, our job becomes easier, and we are more likely to achieve a low signature cabinet. Small cabinets are naturally more stiff, so it is easy to get the resonances well out of the troublesome region. Alternatively, a small cabinet can be made as a CLD box. By assigning the middle range from 250 Hz up to a small driver in a small cabinet, we can handle the troublesome region in a manageable way.

I have never really been satisfied with the sound of a big woofer running up high, such as a 12" or 15" driver crossing at 700 Hz. I am not sure if the blame lies in the cabinet or the driver. I think it is probably both.

j.
 
So, brace it thoroughly and damp it well. Nearly every commercial and DIY design is lacking in this regard.

Plan the build including the port location. I usually exit the port on the bottom (rear is option 2) and internally arrange the acoustic damping so that it does not impede flow to the internal port entrance and absorbs as much of the MF energy as possible.

The reason I asked is because I did consider this driver for my set up and I think for under 300hz the NRX (non L) is probably almost as good and is much cheaper. I went the PA way as I want 15’ and the SB42 is too “subwoofery” for my taste but anw thanks for sharing.

On another note, Im finishing the cabinets for my 3 way active speakers and Im curious of what you and @hifijim said about crossing a big woofer at higher frequency. Intuitively, I think box resonance is of a bigger concern at lower frequency and high volume (ie high excursion) no? For higher hz, the big woofer’s cone only need to move very little to generate desired SPL so I wonder what makes the box resonance concerning crossing a big woofer high up there. Thx
The sb34nrx75-6 is optimized for a sealed enclosure and crossed around 300 hz sounds very close to the nrxl version. Other differences are lower efficiency, higher Le and Qts, which make it easier to pair with your average mid cone driver and not needing as much (if any) BSC on a 15" baffle width crossed lower thanks to the higher Le. Having the xover point close to where the driver starts beaming and going non-pistonic isn't a good idea. Ideally you want to have close to an octave of predictable response past the xover if using a 2nd order slope (which is as steep as i would go in the lower midrange).

I've used all three versions of the SB 12" , including the SW sub version (very high Le with a 4 layer VC). They sound very similar in character under 100 Hz. The nrxl version sounds much tighter in general thanks to its higher BL and lower Qts, plus its the only version I would use in a ported enclosure. I run it in a sealed 90 liter box with EQ. The low end is very natural, linear and resolving compared to other similar non-pro audio 12s. The closest drivers I've used that sounded as good overall were the older SVI 12 and the smaller Vifa M26WR09-06. Under 100 Hz the SVI 12 was just a hair better, but it couldn't go higher than 120 Hz without announcing its bad traits. The M26WR09-06 is in a class on its own in a ported box, but not so much sealed.

I attribute the character of all 3 versions of the SB34 to the cone composition, high compliance suspension and generous VC venting. The VC former is fiberglass, which is stiff and non-damping compared to aluminum, but makes it more susceptible to power compression and non-linear VC heating related distortion. Its not really an issue under real world conditions but in a smaller sealed box under sustained high power levels with a good amount of low end EQ, it can become a issue. I'd say the 200 W continuous power rating is conservative under average conditions. I run a pair of the SW versions, each in a larger aperiodic dampened box, powered by a SpeakerPower 400W class D plate amp. I've never had any issues, even under harder use at 110 dB+ levels, also employing them a few times for small outdoor acoustic jazz gigs with mic-ed hand drums, Fender Rhodes and upright bass. You could still feel the low end 10 ft away from the subs and I got lots of compliments, specifically regarding how full and natural the upright bass sounded, plus they couldn't believe it was just a pair of home audio 12 " subs.
 
  • Like
Reactions: IamJF and dkxdn
@profiguy ,

Have you comparer your sealed SB34-RNX-L with a vented one à la SC4 load, please ?
The low end group delay was better sealed despite the Linkwitz transform ? Did you also EQ it in your room or was it passive ?

I am looking for a 10 or a 12 thatt goes lower than a PA one (I know the 12RS430 is an option though) . I woulld like a f3 that goes 35 to 40 hz but a F10 a little stronger than most PA vented exhibits (often F10 aroundd 32 hz in my sims, for instance the 12PR320 which is more a big mid than a bass driver but some use as a woofer in a 3 Ways but imo with too much big cabinets for me (Humblehomemadehifi) or too much weak bass in load < 80 L.

In fact looking for a not too much huge bass cabinet (<60 L) without too much sacrifice the good sound. I am not against a force cancelling push push design btw as far it is not too much huge. I saw some 10" can do it, but 12" subjectivly seems to me the good size for a living room and home hifi but the huge cabinets.
 
I can tell you running a DSP based EQ on any of the SB34s in a sealed box is very effective. The NRXL version works the best having a lower Qts in roughly a 60 to 70 ltr sealed box. Obviously the biggest drawback would be the lower compliance causing some non linear behavior under Fc. There's a slight increase in 3rd order HD (to be expected) which isn't very audible around those frequencies.

The other SB34 versions need more volume to operate in a sealed EQed situation to get close to the lower distortion of the NRXL version. The suspension is inherently very linear on all versions of these drivers, but it greatly benefits from a larger sealed enclosure and lowers odd order HD thanks to enhanced compliance linearity of the sealed air volume.

The sub 100 hz THD is already very low on all versions with the NRXL having a clear advantage of a stronger motor with inductance control. I've seen THD less than 1% under 200 hz above 90 dB and the other models are about 2% - still very good IMO for a reasonably price driver and exceptional in the case of the NRXL.

Without copper in the gap on the base model SB34s, the practical upper cutoff limit is in the 200 to 250 hz range, compared to 300 - 400 hz on the NRXL. The main limiting factor on upper cutoff is otherwise the response wiggle at 700 - 800 hz. I'd stay well clear from that in a 3 way design and make sure its at least 15 dB down in the final FR. The phase swing is substantial there being the main Achilles heel of this driver family. If you plan on a larger sealed box with cutoff under 250 hz, there's not much difference to be heard among all SB34 versions. You wouldn't want to go above 100 ltrs sealed on the NRXL anyways, making the NRX a better choice for a more manageable Qtc. If you want to use a smaller sealed box of about 50 to 60.ltrs with EQ, the NRXL is the clear choice.

Doing a force cancelation design with magnets back to back lowers the Qts slightly due to an increase of shared magnetic flux between both driver magnets sitting close to each other. You could get away with the NRX version if you're ok with a Qtc of .80 to .85, but EQ will be less effective with F6 and F10 being lower than with the NRXL. The increased Sd of two drivers makes this more forgiving including the room gain.

You'd have to model these scenarios to see if these variables are acceptable for your needs. There isn't much difference in discernable sound between the NRX and NRXL in sealed enclosures. I would however choose the NRXL if you're looking to go with smaller sealed enclosures, especially if pushing the upper cutoff. Thats where you'll notice most of the difference between versions.
 
  • Like
Reactions: frangus and IamJF
Many thanks profiguy for the feedback.

200 hz should be ok with two NE149W.

I am looking for liw and good enough low end for music only.. but not too much 70 to 100 L cabinet. So the SB34 should work best here than the 12" Faital I have
 
Anyways, this big SB driver is comparable to a few higher end 10 inch drivers. It does remind me alot of the good old Vifa M26WR09-08, which is likely one of the best 10" paper cone drivers ever made IMO.
This comment makes me think I REALLY need to get off my *** and make some decent cabinets for my M26WR09-08's which I've been saying I was going to do for about 15 years now.... 😀
 
  • Like
Reactions: Moondog55 and IamJF