SB Acoustics Satori MR13TX-4 5" Textreme Midrange
MAY 12, 2024
I this post I test the SB Acoustics Satori MR13TX-4 5" Textreme Midrange. This is midrange only version (MR) of the Mid-woofer (MW). This is a new product for 2024 and Mark from SB was kind enough to send me a pre-production sample by request. I have been looking for a good all-around 5" midrange for a variety of projects which I will get into at later blog posts. But for this blog post I want to focus on the the raw test data.
Features
- Advanced TeXtreme® cone
- Inverted soft low damping rubber surround
- The mid-woofer version has a non-inverted surround
- Extended copper sleeve on pole piece
The most interesting feature of this driver is the textreme diaphragm. I was curious to see just how high the breakup region is which should be well past the typical surround breakup.
Besides the diaphragm, how does the motor perform in terms of distortion? Let's find out!
Test Setup
I decided to test the MR13TX-4 on my 90cm x 90cm IEC test baffle which in addition has a 8.6L sealed rear chamber measuring 13cm deep x 24cm wide x 24cm tall. I first measured the driver using a 30cm mic distance gated to 7cm where the first room reflection occurs. I then measured using a 5cm mic distance and spliced this ungated measurement in at 575Hz for the low frequency portion of the measurement. I applied 1/24dB octave smoothing for above 275Hz and 1/3 octave smoothing for below 275Hz. My measurement mic is an ACO Pacific 5012 running into a Scarlet Solo Mic Preamp.
Measurements
Let's start by looking at the manufacturer's published frequency response. High level we see an average sensitivity of 90dB through the midrange along with a breakup mode at 5.6kHz. The driver starts to become directional starting at 4kHz.
Showing the same zoomed in...
Below is the MR13TX-4 frequency response (red) with the impedance (green) overlay for reference. My measurements show a very linear response right up to breakup at 5.7kHz.
I then extended the same measurement out to 50kHz. It's interesting to note that we see output all the way up to 22kHz. This means two things...that the diaphragm is likely not breaking up and what we are seeing is simply surround breakup effecting the response, and secondly, that the motor has very low inductance. We can see this in the impedance sweep where there is very little inductive rise into the upper treble. Very interesting!
Moving the mic back from 30cm to 100cm to conduct off-axis is shown below. I measured at 0,15, & 30 off-axis. (SB measured at 15, 45, and 60). Below 500Hz I spliced in the ungated response of the same measurement. At the 1m mic position there is a slight bump in the response centered around 250Hz which is likely the result of the 90cm x 90cm test baffle.
With my results, directivity starts to narrow at 5kHz which is a little higher up than SB's off-axis results at 4kHz. So my results are actually a little better than published. This means that you can push your crossover point just a little higher if needed. Side note... This almost is a candidate for a wide band full range driver and appears to only need a super tweeter coming in at perhaps 8kHz?
Impedance
Looking at the impedance mounted in the 8.6L enclosure is shown below. This raises the FS from the factory 44Hz to 76Hz.
Time Domain
General comment on Time DomainThe time domain aspect shows the midrange driver's behavior after the signal has ended. The CSD plot looks at the behavoir in terms of time. We can see below that the 200Hz region takes around 3ms to fully die down below -25dB. The burst decay shows how many cycles are required for the signal to die down, which is a more relevant metric in terms of audibility. For example, the 200Hz region shows no issues in the Burst Decay, since 3ms is only a fraction of one cycle at the 200Hz frequency.
Another way of examining this result is to look at the 1kHz region on the CSD. We see that things die down quicker than 0.80ms for this frequency region. Since 1kHz takes 1ms to complete a full cycle, we can conclude that the woofer is able to die down within the time it takes for the woofer to complete one cycle.
Below is the CSD waterfall plot showing excellent behavior across it's usable bandwidth.
The burst decay is shown below, again an excellent result.
Distortion
I started with harmonic distortion placing the mic at 5cm from the diaphragm. The driver required 1.5V to produce 85dB at 1m. Distortion is below 0.10% with the exception of the resonant peak at 4.7kHz. Distortion is still very low even above this region. If the peak was EQ'd out then the distortion would in this region would also disappear.
Increasing the test SPL to 95dB requires 4.60V and we see a slight rise in H2 for the upper midrange. Otherwise H3 and H4 remain very low. (below 0.10%)
Intermodulation Distortion
I then produced a 12 band per octave test signal ranging from 200Hz to 20kHz which required 0.80V to produce the 85dB at 1m test signal. Generally we see around 65dB of dynamic range with surprising clarity in the upper treble as well. Again, if the peak at 4.7kHz is notched out with an EQ, we would see a very good result indeed.
Increasing the test SPL to 95dB required 2.73V and reduces dynamic range to a correlated amount of 55dB. Generally we don't see any stressing behavior at this elevated SPL.
Gedlee Distortion (Gm)
The Gm distortion is shown below for the 85dB and 95dB sweep. Gm uses a dual tone test signal and weights the distortion product (Gm) towards types of distortion that we find more offensive than others. Generally we can conclude from this result that the driver is slightly stressed in the upper midrange at the higher SPL, but the overall result is quite low.
I tested the MFC 5" woofer from SB (shown below) and the result was slightly higher Gm for both test SPL's. So the MRX woofer excels in Gm compared to SB's more affordable woofer models. Please note the result below should only be looked at below 2kHz since my quick test was conducted with the woofer mounted in the the 1159 stand mount 2-way speaker.
Conclusion
The MR13TX-4 is an exciting new product from the SB Acoustic Satori line up. The driver exhibits a very flat frequency response which indicates excellent time domain performance. The distortion profile is consistent in terms the H2,H3, & H4 ladder effect where we see H2 dominant at elevated SPL with H3 and H4 lower down respectively. I personally find this this ladder attribute remains a consistent metric to correlated sound quality. And lastly the Gm metric is very low when directly comparing against the more affordably priced MFC woofer from SB Acoustics. SB Acoustics has done its homework on producing an excellent dedicated 5" midrange.
I suspect the harmonic distortion plot has two y-axis. The left y-axis is in units of dB SPL and applies to the fundamental, the right y-axis is in units of % distortion and applies to the distortion curves. If my suspicion is true, then at 500 Hz the D2 is about 0.15%.
Any 5" driver, even a very low cost one, which made 10% THD at 500 Hz would be broken or damaged. Even cheap drivers can do 2% THD.
Thank you @Joseph Crowe, I have been looking at this driver with great interest since it was announced.
SBA has achieved nothing in case of their MR13TX-4 , a 9dB resonance at 5600Hz is not acceptable!
So the introduction of the Fancy Dish Saucer Satori (FDSS) - is another assault on our (small) hobby budget!
And then an unknown new method of determining distortions (Gm metric) - a further attempt to trick us into buying expensive & unproven things ...
To SBA - the money lords down there in Asia :
Why not offering an introductoring price for the first 30 pieces , for 60% of the original price? (MR13TX-4/8)
The world is full of gangsters , do not let Kharma decide about your fate & future 🙂
The CAB is still a mystery to us , the cone/dish vibz too .. and what about the room?
Hell this is a murderous hobby!
There are tonz of killaz out there looking for my wallet 🙂
So the introduction of the Fancy Dish Saucer Satori (FDSS) - is another assault on our (small) hobby budget!
And then an unknown new method of determining distortions (Gm metric) - a further attempt to trick us into buying expensive & unproven things ...
To SBA - the money lords down there in Asia :
Why not offering an introductoring price for the first 30 pieces , for 60% of the original price? (MR13TX-4/8)
The world is full of gangsters , do not let Kharma decide about your fate & future 🙂
The CAB is still a mystery to us , the cone/dish vibz too .. and what about the room?
Hell this is a murderous hobby!
There are tonz of killaz out there looking for my wallet 🙂
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You’re welcome. I’ve tested a few 5” midrange drivers recently and I wasn’t able to publish due to issues related to the driver’s performance. This brand/model seems to do well.
Well here is the mysterious method how to extract more subjectively related information regarding how our hearing system works :
https://www.diyaudio.com/community/threads/the-gedlee-metric-demystified.287291/
https://www.diyaudio.com/community/threads/the-gedlee-metric-demystified.287291/
Would be interesting how good/bad the Dayton Sig180-4 performs regarding Gm-metric , because this driver has also an inward bowed "cone" .... as the SB-Acoustics TX wonder-woofer with that upper-class price 🙂
@Marveloudio - I can't tell if you are being comedic, or if you are making a serious point. I am assuming you are serious, so I will offer some comments on your statements.
I think they accomplished something quite nice. As a user of the MW16TX midwoofer, I have been hoping they would introduce a dedicated midrange driver with the TXT cone, similar to the MR13P and MR16P
Sorry to hear about your money problems. There are plenty of nice options which cost less, so no one is being assaulted.
Unknown to you, perhaps. The Gm distortion metric is known to those who read Dr. Geddes's material
Why? Would you be willing to work for the next 60 days without pay? I am not sure what a "money lord" is, but if it is someone who wants to be compensated for their time, effort, and knowledge, then most of us are "money lords".
In the 3" dome mid thread our fellow member Profiguy claims coned midranges cannot keep up with the better 3" domes such as e.g. ATC under more stressful conditions. The acid test therefor would be to send Profiguy a pair of these in order to be evaluated. I for one would curious about the outcome, even if that might be largely subjective.
I think the community would benefit (more?) from knowing what the bad ones are.
The atc is over $500 us and thats each. They should perform absolutely marveluosly. Thankyou to joseph crow for his dedication to diy horn speaker audio.
Afaik - $200 a piece with stunning basket design , but not a true beryllium inward dome :
https://usheraudio.com.tw/portfolio-item/0541a/
https://usheraudio.com.tw/portfolio-item/0541a/
You should contact Adam at Madisound. I don't think they are released yet but he may have pricing.
Hi Joseph,
thanks a lot for this great review. This is really an interesting driver.
About one and a half year ago you reviewed the Scanspeak Illuminator 12MU, which is somehow a contender for the MR13TX. How would you compare both? What are your subjective impressions if you compare them? And which one do you like more? 🙂
Best regards
Matthias
thanks a lot for this great review. This is really an interesting driver.
About one and a half year ago you reviewed the Scanspeak Illuminator 12MU, which is somehow a contender for the MR13TX. How would you compare both? What are your subjective impressions if you compare them? And which one do you like more? 🙂
Best regards
Matthias
I think this driver has quite a bit of potential in a 3 way. Because of the non half roll, surround, the off axis response is much smoother in the 3-5k region than the corresponding midwoofer version. Would be interesting to straight up compare the midwoofer version and the pure mid together and see how the distortion numbers hold up.
I've auditioned this SB Textreme mid. It has the obvious sharp breakup at 5.5 - 5.7 ish k, but what makes it more severe in behavior is the constant radius profile dished cone. Based on my experience with this driver and the shape / geometry of its cone, it should never be used in the breakup range, even when EQing most of the peak amplitude out. The CSD still shows the breakup trail being present after EQ has been applied. Judging by the CSD and the on axis linearity, the stored energy is evident when looking at how the breakup peak turns into a significant sharp off axis dip, indicating its a radial cone mode (no resonance at the center connection point at the cone/VC former junction). I was still able to detect the peak's audible presence after what appeared to be successful application of EQ based on FR sweeps on axis and up to 30 degrees off axis.
To be fair and thorough, giving it a chance, this Textreme driver does sound very good when crossed lower than 2.5 - 3 k at a 3rd order slope. It doesn't however sound much better than a decent alu/mg cone without considering the motor characteristics, which are very good on the Satori. A loose weave, visco elastic dampened carbon fiber cone driver such as the Audax HM130CO will usually equal or even outperform it based on having heard both drivers in other applications. Above the maximum useful LP point, considering beaming and off axis linearity, the MR13TX isn't better than some other less expensive composite weave cone drivers such as the 15M4624G. I'd even consider the $100 Seas MCA15RCY coated paper cone mid over the MR13TX when crossing higher despite the breakup onset of the cone material. I would definitely not use the MR13TX as a wide range or fullrange driver due to the peak behavior. It sounds much like a metal alloy cone driven in its breakup range.
Trying to stay on topic and while not apples to apples, there is a pattern in behavior which shows itself using the chosen diaphragm or cone designs. When comparing a constant radius dished cone profile with a typical dome driver such as a larger dome midrange, they use practically the same shape of emissive surface. They're however both driven from different attachment points on their diaphragms. This has a big impact on radial breakup behavior, whether it negatively and by how much impacts performance closer to the upper rolloff limit. As with metallic cone materials, other stiff materials such as Textreme and other resin bound composites will show tall, narrow FR breakup peaks which need to be avoided in the dricers chosen operating bandwidth. Their breakup needs to be at least 30 dB down in amplitude compared to the operating range amplitude. Otherwise it will be audible, making the speaker fatiquing and hard to listen to for longer periods of listening.
Considering the performance above 500 hz, a higher end 3" alu/mg dome such as the Bliesma M74A is definitely going to outperform it in a few ways and obviously do better off axis being a smaller diameter driver. The cost is similar between them as well. I've auditioned the Textreme version Bliesma M74T mid dome which was equally outstanding as the M74A and M74B. They were more resolving and accurate as the silk version M74S and even what I've recalled having used the well regarded ATC soft dome.
Because of the significant difference in behavior and sound of the Bliesma Textreme M74T above 5k compared to the Satori MR13TX, it leads me to believe the Textreme material requires tight termination and dampening at its edge to control ringing and breakup. The dished inverted cone design isn't preferred if its not being driven from the outer diameter. The smaller VC version Accuton ceramic drivers suffer from similar issues as the Satori, being they use the same type of dished inverted dome diaphragm driven by a small VC. Perhaps a different diaphragm or cone profile would have improved this behavior, but it appears the Textreme material is limited to specific shapes and profiles which can be realized with its application. I'd only choose Textreme as a diaphragm material if it's being edge terminated driven by the VC, otherwise it requires significant mechanical dampening to control its breakup and should only be operated within its pistonic range, including the majority of its overlapping rolloff range.
As a recording engineer, purely objectively I’m going to have to agree with @profiguy on this one…..that high Q break up energy is centered right where vocal sibilance and sssss is captured………vocal recordings done with average to poor conditions or de essing will have listeners cringing when that resonance gets excited…crash cymbals too…..OUCH!…2.5-3k max with a steep filter. The only advantage i see to this driver is the lower midrange capability from the larger cone area and stiff cone.
All that being said, from a listeners perspective I’m biased as I’m fully committed to true ribbon tweeters as the best high frequency device for the average size listening space and purpose where the space has mild to moderate acoustic treatment. Fans of dome tweeters with more flexibility is use cases take note, the SB midrange is an EXCELLENT driver for that purpose and would be ideal for a TMWW tower type speaker topped with a 1” dome.
All that being said, from a listeners perspective I’m biased as I’m fully committed to true ribbon tweeters as the best high frequency device for the average size listening space and purpose where the space has mild to moderate acoustic treatment. Fans of dome tweeters with more flexibility is use cases take note, the SB midrange is an EXCELLENT driver for that purpose and would be ideal for a TMWW tower type speaker topped with a 1” dome.