That driver is on sale right now for $219 at Madisound for Black Friday.
Its definitely not a 95 dB/W driver looking at the graphs and the basic efficiency rating of 1.05%, which is essentially 92 dB. It also doesn't have any impedance control measures. The double suspension is great, as is the 4.5" VC no question, but for higher end hifi use, those are just more parasitic drag. The high 5.25 kg/S Rms shows the suspension imposes alot of resistance to low level details. The weird frame size and design is also an issue if you want to experiment swapping in other drivers. This woofer is unquestionably a decent bargain on sale, but I wouldn't say this is comparable to a TAD driver in any means.
Interesting observations, @profiguy
I didn't say it was like the TAD. Joseph Crowe did. https://josephcrowe.com/blogs/news/sb-acoustics-nero-15sw800-with-cabinet-no-1798
Even for use <100Hz?
I didn't say it was like the TAD. Joseph Crowe did. https://josephcrowe.com/blogs/news/sb-acoustics-nero-15sw800-with-cabinet-no-1798
Even for use <100Hz?
@mikessi Yes, I was referring to JCs remark about the TAD comparison.
Higher Rms and Kms will affect mainly low frequencies. The lower these numbers are, the better. Double spiders are a good thing from a cone control standpoint, as they keep the cone perpendicular to the magnet gap. The drawback is potentially more resonances, which commonly occur in stiffer spiders if they're undampened.
Many lower mid resonances will originate from the rear suspension, which can be seen in the impedance graph. The issue here is SB usually greatly smooths these graphs, so they don't show up.
Not all wiggles in the impedance plot are a potential issue, but chances are any obvious peak will be audible and may elevate HD. If the peaks are audible, there's usually not much you can do, especially if its stored energy, even with DSP.
Higher Rms and Kms will affect mainly low frequencies. The lower these numbers are, the better. Double spiders are a good thing from a cone control standpoint, as they keep the cone perpendicular to the magnet gap. The drawback is potentially more resonances, which commonly occur in stiffer spiders if they're undampened.
Many lower mid resonances will originate from the rear suspension, which can be seen in the impedance graph. The issue here is SB usually greatly smooths these graphs, so they don't show up.
Not all wiggles in the impedance plot are a potential issue, but chances are any obvious peak will be audible and may elevate HD. If the peaks are audible, there's usually not much you can do, especially if its stored energy, even with DSP.
Thanks for the further clarifications. 👍
If the issues show up as lower mid resonances, they are not particularly relevant for my application as the drivers are being used only as subs, with the highest possible crossover point at 120Hz LR4.
J.Crowe mentions a peak at 290Hz but nothing else significant. By that point, with a more typical 70 or 80Hz LR4 in my application, output will be down some -40dB.
If the issues show up as lower mid resonances, they are not particularly relevant for my application as the drivers are being used only as subs, with the highest possible crossover point at 120Hz LR4.
J.Crowe mentions a peak at 290Hz but nothing else significant. By that point, with a more typical 70 or 80Hz LR4 in my application, output will be down some -40dB.
Had some time today to work on PEQ of the subs.
I decided to try positioning the mic 9' from the midpoint between the speakers which are 8' apart. Front baffle of 521 clones are 5' from wall behind. The sub baffle is 4' from wall,1' behind the 521 baffles, in between the 2.
Signal to the sub is L+R
Sub EQ (in miniDSP 4x10HD):
1. 35Hz peak, 2.2Q, +15 dB
2. 58Hz peak, 3Q, -7 dB
3. X-over: 60Hz LR4
4. Level: -4 dB
The graph below shows sub and sub w/ 60Hz LR4 (green)
As mentioned before, using the single sub as true sub with the LX521 clones (LR4 low pass to sub, LR4 high pass to main) is not beneficial. Instead, LR4 low pass was applied to the sub & run concurrently with the LX521 with its level reduced by -4 dB.
The curves below shows LX521 and LX521+sub. The latter ends up with the bass level too high. I need to reduce the LX521 bass level below 60-70Hz by 4-5 dB to get a better total balance so it better shares the bass load with the sub to reduce distortion.
I decided to try positioning the mic 9' from the midpoint between the speakers which are 8' apart. Front baffle of 521 clones are 5' from wall behind. The sub baffle is 4' from wall,1' behind the 521 baffles, in between the 2.
Signal to the sub is L+R
Sub EQ (in miniDSP 4x10HD):
1. 35Hz peak, 2.2Q, +15 dB
2. 58Hz peak, 3Q, -7 dB
3. X-over: 60Hz LR4
4. Level: -4 dB
The graph below shows sub and sub w/ 60Hz LR4 (green)
As mentioned before, using the single sub as true sub with the LX521 clones (LR4 low pass to sub, LR4 high pass to main) is not beneficial. Instead, LR4 low pass was applied to the sub & run concurrently with the LX521 with its level reduced by -4 dB.
The curves below shows LX521 and LX521+sub. The latter ends up with the bass level too high. I need to reduce the LX521 bass level below 60-70Hz by 4-5 dB to get a better total balance so it better shares the bass load with the sub to reduce distortion.
Only thing he litterally said there, is that the SW800 has a IMD distortion profile a little worse then the TAD 1601B he tested.
Also be aware he purchased new 1601B's the motor is not identical to the original, as was measured/compared in the JBL tech sheets vs some of they're drivers with less then stellar results, the original is a fairly simple construction with 7 of the Alnico cylinders, identical to the ones sitting in some of the PT-R's (just 2 ofc).
It also was tested in his 1798 cabinet, which is the same for both drivers.
They do not share much similarity.
One is a modern PA sub driver.
The other is made to much tighter tolerances, with a hand doped surround. SW800 cone is pulp, the TAD has a highly treated pulp cone, about half of it's thickness is the coating to suppress resonances and breakup modes.
He also noted the sw800, 290hz resonance.
But the SW800 has a nice combination of parameters, and it will be happy with more power then the TAD in the long run.
Alnico motors does not have a love for high temperatures over extended periods of time in general, although the 1500AL family has som interesting design features in that regard.
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