Thank you for this write up. The SB34NRXL75-8 is on my watchlist. I can mate it up with the 18 sound 6nbr430 and Wavecore W030 combo at 500hz.
@hifijim
Consider measuring closer to the woofer
eg. 50cm, 31.6cm, 10cm, or 5 cm.
This will allow +6, +10, +20, +26 dB higher signal to background noise ratio, and more accurately assess the HD of your SB34RNX.
Of course, your microphone needs to be able to manage that without much distortion itself. The Audix probably could, but some clues are when Distortion goes up 20dB, when the SPL only went up 10dB.
If this happens, then you will have to reduce the input level to the device under test.
@HiFiCompass measures at 31.6cm and I think that’s a good compromise to increase SNR by 10dB.
The rationale for my commentary is that you may find that your SB34 non L model measures better than what your current
“ 1m in-room” response currently shows, and the gap between the non-L and L may be smaller than you think. Particularly when intend to use it, at the bottom of a 3 way under 200Hz.
Consider measuring closer to the woofer
eg. 50cm, 31.6cm, 10cm, or 5 cm.
This will allow +6, +10, +20, +26 dB higher signal to background noise ratio, and more accurately assess the HD of your SB34RNX.
Of course, your microphone needs to be able to manage that without much distortion itself. The Audix probably could, but some clues are when Distortion goes up 20dB, when the SPL only went up 10dB.
If this happens, then you will have to reduce the input level to the device under test.
@HiFiCompass measures at 31.6cm and I think that’s a good compromise to increase SNR by 10dB.
The rationale for my commentary is that you may find that your SB34 non L model measures better than what your current
“ 1m in-room” response currently shows, and the gap between the non-L and L may be smaller than you think. Particularly when intend to use it, at the bottom of a 3 way under 200Hz.
Last edited:
Hi Iam, which others would you rate as gems? Any 15"s? I have no experience with SB acoustics, but there is a compression driver which I would like to try. I have checked the small coaxial drivers (5-6"), but it seems Sica has better offers (my application would not be hi-fi with the coaxes).
I found this comment specially interesting, I have 3 sealed LAB12s going below 80-90Hz and I was wondering how the SB34NRXL75 would compare. The labs sound very good and volume is small (sealed). The SB34NRXL75 seems to be a better option if crossing over higher, say at 150 Hz, but, how would you compare both below 100hz?
I don't know the SB Audience drivers. They seem good for the money but not sure if they can compete with a little more expensive B&C or 18Sound? The compression drivers are interesting for Power HiFi use - but I really like DE360 for that. Coax don't look very promising to be honest.
There is a HiFi 15" which looks very good in a closed cabinet - but had no use for that up to now.
I'm not a friend of heavy membrane hard surround long stroke drivers. But that's definitely some bias cause the LAB12 really works and measures and sounds good! The REAL strength of the SB34NRXL is the use in a 3way, up to 4-500Hz. It is still great as subwoofer of course but there are plenty of good chassis in this range. Past 200Hz ... not so much.
So when you are happy with your LABs there is no reason to change them until you want to change something in your system in a bigger scale. Just build 5 more and do a 2x4 double bass array ... 😎
There is a HiFi 15" which looks very good in a closed cabinet - but had no use for that up to now.
I'm not a friend of heavy membrane hard surround long stroke drivers. But that's definitely some bias cause the LAB12 really works and measures and sounds good! The REAL strength of the SB34NRXL is the use in a 3way, up to 4-500Hz. It is still great as subwoofer of course but there are plenty of good chassis in this range. Past 200Hz ... not so much.
So when you are happy with your LABs there is no reason to change them until you want to change something in your system in a bigger scale. Just build 5 more and do a 2x4 double bass array ... 😎
Thanks for your reply. They seem to have at least two which are well regarded, the 15" for OB and the Rosso compression driver (I cant remember the model names, but they are popular here as you might know).
This was an interesting comparison Link .
Sorry but this measurement setup ... look at the "frequency response" of the first 2 measurements, they are totally different. He measured 50% the room ...
Hello hifijim,
I would like to learn which drivers they are and what performance behaviors they may offer over Acoustic Elegance, Audio Technology (Skaaning) or pro woofers.
I don’t need a lot of power handling as my listening levels are lower. Quality is my goal.
Regards
Suppose we speak only about a subwoofer driver under 100 Hz - the SB34NRXL75-8 looks marvelous with 0.05 THD, but it might be a bit stretchy for some of us (umm, myself) with $315 price.
SB29NRX75-6 is a nicely priced at $191 but THD is 0.1 and goes to 0.5 if you add just a bit of volume.
Is there anything else that is 8"-12", has THD under 0.1 under 100 Hz (strictly sub application) and is priced like under $220?
SB29NRX75-6 is a nicely priced at $191 but THD is 0.1 and goes to 0.5 if you add just a bit of volume.
Is there anything else that is 8"-12", has THD under 0.1 under 100 Hz (strictly sub application) and is priced like under $220?
Don't forget ou ears are very less sensible in the low and that is flooded into the room noise and signals marmelade. There is a great chance the SB34 non L suffice at 100 Hz.
I would not use THD as a metric to judge driver distortion. There is a big difference in how we perceive 2nd order HD compared to 3rd order HD. A value of HD2 of 1% at 100 Hz is much less perceptible than HD3 of 1% at 100 Hz. The THD calculation just merges all HD together without distinction.
I am very happy with the SB34NRX75-6 when used up to 200 Hz.
SB23MFCL45-8 is very good. I have a prototype with 2 of them here and it shows less THD <100Hz as SB34NRXL75-8. Don't forget level at the cross over Frequency is already some dB down, so you get less THD at 100Hz compared to 60Hz.
Exactly out of that reason I showed H2 and H3 from the 10" driver! And H3 is dominating, H2 would behave as it should. That's the reason for the relative high THD at low levels - it's H3.
BUT - don't overestimate THD for subwoofers! We are not very sensitive in this frequency area and SOME H3 even sounds "tight". (transformer THD, many like that for recording and mixing)
It is a sign for linearity of a speaker and if there are any problems or strange behaviour. But the psychoacoustic effekt of THD is something totally different.
Hi all,
Thanks for all this hard work and discussion, it's really great to see. This is my first post and despite being into hifi for years and years I am only just starting to build something. Aiming for a three way speaker.
My question is this; the midrange unit I want to use only goes down to 500hz (volt vm527), can I cross the SB34NRXL75-8 at 550 or 600hz in a three way speaker or am i pushing it too far? Are there other alternatives? One of the 18 Sound maybe?
I was thinking to use a 2nd order link slope but perhaps it would be better to use a 3rd order if I cross at 550 or 600?
Thanks very much,
Josh
Thanks for all this hard work and discussion, it's really great to see. This is my first post and despite being into hifi for years and years I am only just starting to build something. Aiming for a three way speaker.
My question is this; the midrange unit I want to use only goes down to 500hz (volt vm527), can I cross the SB34NRXL75-8 at 550 or 600hz in a three way speaker or am i pushing it too far? Are there other alternatives? One of the 18 Sound maybe?
I was thinking to use a 2nd order link slope but perhaps it would be better to use a 3rd order if I cross at 550 or 600?
Thanks very much,
Josh
The SB34NRXL75-8 reportedly good for 500-600 Hz crossing.
With the VM527 as a mid, you probably want a minimum of 18 dB/octave acoustical crossover slope but a 24dB/octave would be better because this driver already have an acoustical 12 dB/octave slope down in its raw state which is in the midrange, have low Xmax and low Sd.
In my opinion, depending on the intended listening volume, the VM752 would be a better choice for this woofer.
Thanks.
Ah yes, I can see why steeper slopes with the VM527 would be beneficial. Why would the 752 be better do you think? You would have to cross in the 3k-4k hz region which I am less keen on and it has a higher sensitivity than the other drivers which would mean attenuating the crossover i think? I am pretty new to all this by the way! Your help is much appreciated, thank you.
It have higher Sd (more membrane area) so probably lower distortion around 500 Hz. But this depends on the goal max SPL.
Of course the crossing to tweeter needs to be lower than with the VM527.
Attenuating a midrange driver is typically not a big problem.
I have a question about the SB Acoustics SB34NRX2-00 12" Passive Bass Radiator; it says the mms is easily adjustable and I can see you can buy 50g weights. The spec sheet shows mms @ 294g. Clearly you can add weight, but can you remove it also? Could you go down to 50g only?