New Driver Tests: SB Acoustics, Scans, Seas, and others

[Jed]

Look for some new driver tests of the SB Acoustics 5", Scan Speak W15 non coated woofer, SS6600, and Seas L26 in this space this week. I have the drivers in house and will run some tests soon.

[Silversmoky]

Some nice driver choices Jed. Look forward to seeing the results.

[HareBrained]

Good. I've been wondering if the SB15 is worthy of its published specs.

[oldbar]

....

[Jed]

SB Acoustics 5" driver in a Madisound 20L box measured on the ground plane (about 1watt/meter):

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SB Acoustics 5" Harmonic Distortion:

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Scan Speak 15W Non coated FR (same conditions as SB driver):

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Scan Speak 15W Non coated Harmonic Distortion:

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Note: there are some box artifacts in these measurements (especially below 80hz). Use for quick reference only and compare only this set of measurements to each other and not other drivers from a different batch. All the settings would have to be exact for a real comparison to be drawn. In this case, the 2 drivers above are from a batch with the same settings and same box.

[cotdt]

Looks great! Almost as good as the Scanspeak except more distortion at the low end and less efficient.

Jed, is your Scanspeak 15W the small magnet or large magnet or double magnet version?

[Jed]

Jed, is your Scanspeak 15W the small magnet or large magnet or double magnet version?

Yeah, I'm pretty impressed with the SB driver for the money- it sure has a nice motor.

The SS is this one:
ScanSpeak 15W/4531G Revelator 5.5"

[jkrutke]

Look at the beautiful top end roll off on the scan speak. They sure know how to make a well damped cone. The uncoated one I tested was the 15W8531K01. The K is the former material (kapton) and other than 8 ohms impedance, they should be the same. Maybe there some strategic top end damping in the former that allows for a smooth upper rolloff.

[Jed]

John, yeah the Scan just sounded so clean during the testing. I've done enough distortion testing now that I know the results will be good/before I see the graph. The Scan was no exception.

[Hdale85]

How much does the SB acoustics run? It sure is boring looking though

[JonW]

Thanks for the measurements, Jed. Good to see. :T

Did the SB sound different than the Scanspeak?

Yeah, the top end roll off of the Scanspeak is kind of soothing to look at. Even the SB looks better up there than the metal cone drivers I’ve been looking at, lately. For distortion above ~100 Hz, the SB looks a little bit better. Below ~100 Hz, well… maybe use them as mids in a 3-way.

[Jed]

Thanks for the measurements, Jed. Good to see. :T

Did the SB sound different than the Scanspeak?

Yeah, the top end roll off of the Scanspeak is kind of soothing to look at. Even the SB looks better up there than the metal cone drivers I’ve been looking at, lately. For distortion above ~100 Hz, the SB looks a little bit better. Below ~100 Hz, well… maybe use them as mids in a 3-way.

The SB low end had noticeable "harmonics" below 100hz, but it wasn't annoying or anything like that, in fact some might prefer the added "warmth."

The SB will find a home in a 2 way MTM + XT25, and a 3 way speaker I have planned with an XT25 and either an RS270 or L26.

The Scan is going in a no compromise 3 way with SEASL26 and SS6600 with LR2 slopes.

Needless to say I'm glad they both tested so well. Don't have to go back to the drawing board on the design choices.

[JonW]

Sounds like an excellent no-compromise 3-way. I've been thinking about something along pretty similar lines- 6600, Scanspseak mid, etc. But I may design a couple other projects first, to get some more experience. How did you pick the L26? For my 3-way, I'm not sure which woofers to use, what size, how many, etc.

[TacoD]

The Scan is going in a no compromise 3 way with SEASL26 and SS6600 with LR2 slopes.

Why don't you use the Scanspeak 26W or an Aurasound? SPL will be limited by the L26, so in my view it is not a "no compromise" .

[Jed]

Why don't you use the Scanspeak 26W or an Aurasound? SPL will be limited by the L26, so in my view it is not a "no compromise" .

L26 is well documented on Mark K's page. It's an excellent performer in a sealed box with deep bass extention. SS 26W might be a tad better but seems to like a ported box.

The Aurasound also needs a ported box and I don't think they are as good as some give them credit for. More of a sub than a woofer. Plus, last time I used a single Aura NS10 the impedance dipped pretty low with a crossover Fc around 200-250hz. I'd like to shy away from 2.5ohm minimum impedance curve and steep phase angles. Enter Seas L26.

[Mark K]

The SS 26W is really only a candidate 4LR or steeper. And pricey.
The Aura is an interesting choice as it too could be used second order. Sensitivity and impedance are lower. But, it's not a bad choice. However, it's on sale which makes me wonder if it's going to be discontinued. The L26 is a proven performer and has been around for quite some time now.

I too have been fiddling with an L26 based 3 way. Though I'm inclined to make any future 3 way at least active for the W-M transition. Jed is just way more productive than I am...

I like the idea of an all metal 3 way second order. Unconventional...that's me. 1.3k crossovers, mmtmm dipoles. What better to round out the series than a shallowly crossed set of metal cones? Oh, it can be done... :E

[norcad]

The L26 gives a tight and dry bass with little distortion, thats for sure. But deep bass in a sealed enclosure? No, not IMO.
And like TacoD says, they dont handle to much power, and the sensitivity isnt to high, so limited SPL/headroom is infact an issue.

I love Seas drivers, and I do have L26 at home, but I dont use them for the moment, mostly because I like to play load. I ended up with CA26 in 65L BR in my Seas 3 way.

If you use L26 in a BR it works better, with a Vb of about 80L.

[Jed]

The L26 gives a tight and dry bass with little distortion, thats for sure. But deep bass in a sealed enclosure? No, not IMO.

Point taken, although some consider sealed bass below 40hz "deep." Relatively speaking of course. I get plenty of power from my Seas W26s in the Tombstones so unless 110-115db peaks are your cup of tea, the L26 will hold its own just fine below that. I may try it ported as well, but in 60L. Unibox says it can be done with the correct port tuning.

Mark K- your projects are always great and I look forward to seeing what you come up the the L26.

[tktran]

Hi Jed,

The SB looks like good value.

However, I'm a little surprised about the SS. From 200Hz to 2Khz, The 3rd and 5th order are higher than the 2nd and 4th respectively.

This is unlike John's findings (albeit a different model)

Most SS drivers I've seen with the SD/SD-1 motor have lower 3rd than 2nd, 5th than 4th etc.

What do you think?

regards,
Thanh.

[cotdt]

Why does it matter that odd order distortion is higher than even order? Low even order distortion tends to mean a good cone while low odd order signifies a good motor, though there is a lot of overlap of course. At one point I thought that only odd order distortion mattered and used the AA Poly 6.5" midwoofer, but found that its high 2nd order harmonics are clearly audible despite extremely low 3rd order harmonics, and there was this thickness in the lower mids. Now I only pay attention to total harmonic distortion.

[Jed]

Hi Jed,

The SB looks like good value.

However, I'm a little surprised about the SS. From 200Hz to 2Khz, The 3rd and 5th order are higher than the 2nd and 4th respectively.

This is unlike John's findings (albeit a different model)

Most SS drivers I've seen with the SD/SD-1 motor have lower 3rd than 2nd, 5th than 4th etc.

What do you think?

regards,
Thanh.

I bet if I tested the Scan at a higher level, the 2nd and 4th order would be more than the odd order harmonic distortion. Either way the Scan is very very good. Maybe if I have time I'll turn up the wattage and see what happens. I noticed this trend after I tested the Seas ER18 driver. Lower levels the 2nd order was lower than 3rd, but when pushed a bit harder the reverse was true. So I'll leave it at that for now.

[tktran]

Hi Jed,

I see. I shouldn't really compare with John's findings because the conditions were different.

I think he tested at a higher level (~96dB @ 1/2m= 90dB/1m for starters)

[Jonasz]

I wonder if the mids in the Wilson Maxx could be a variation of the SB 6,5"? They kind of look similar (apart from the number of screws) and this is what the homepage says about them:

With this new driver, Dave and the Wilson design team, have, in strategic partnership with a new driver manufacturer, raised the performance bar in the critical midrange. To meet the design challenge of a highly rigid but low moving mass cone, we co-engineered a special blend of carbon fiber and paper pulp.

[dlneubec]

Jed,

You really should take a look at the Lambda TD12H. I'm using it in my BaSSlines project and it is probably the best sounding and most extended 12" woofer I have heard. Take a look at the FR below. Plus is looks great, is very sensitive, can go in a small box, has a sizeable xmax, though it doesn't go real low. I have mine in about a 52L slot ported box, tuned to about 34hz for an F3 of around 35hz or so. It will go to 110db with 100 watts and not even come close to its xmax.

[Dennis H]

I don't think odd or even is the big deal. Rather, it's that the higher orders are more audible than lower orders. Here's Olson's study from back in the day plotted as % distortion for equal audibility. Olson's original graphs were plotted in dB. These graphs are right but I had to cross out and replace the author's % distortion scale because he thought -3dB was half the distortion when it's really -6dB.

[Jed]

Jed,

You really should take a look at the Lambda TD12H. ]

Yeah that driver looks most excellent and the new 6.5" driver looks great too. I want to try them all but you know how that goes.

[tktran]

Hi Dennis,

Yep I think I've seen that graph somewhere before. I am well aware of the arguments into the audibility of distortion, odd vs even, higher order versus lower order, THD versus spectrum.

I just made a comment that the SS results are not the same as John Krutke's.

Well of course they wouldn't be the same the conditions are not the same. The driver's not even the same.

My mistake, I'll leave it at that. I don't want to turn this thread into a debate about distortion.

regards,
Thanh.

[tktran]

The ETA for SB Acoustics in Australia is December. Good DIY-times ahead...

[cotdt]

I'm still a bit dissapointed that the SB Acoustics didn't surpass the Revelators, seeing as it was the same team that designed the Revelators you would expect an improvement.

[Jed]

I'm still a bit dissapointed that the SB Acoustics didn't surpass the Revelators, seeing as it was the same team that designed the Revelators you would expect an improvement.

For hitting a $55 price point versus a $220 price point and to have the performance come even close is pretty dang respectable. In that case the 5" and 6" woofers look very good.

The larger woofers are another matter. In voice coil magazine they didn't fair too well.

[dlneubec]

I'm still a bit dissapointed that the SB Acoustics didn't surpass the Revelators, seeing as it was the same team that designed the Revelators you would expect an improvement.

My recollection is that when they announced this line, it was to be their first line, the "budget" line. They said they had plans for a higher end line, but it may have even been under a different company name. I'm not sure what happened to that, but maybe they only sell those to OEM's if they have even created that high end line yet.

[Jed]

My recollection is that when they announced this line, it was to be their first line, the "budget" line. They said they had plans for a higher end line, but it may have even been under a different company name. I'm not sure what happened to that, but maybe they only sell those to OEM's if they have even created that high end line yet.

I talked to Madisound a month or so ago and they mentioned there will be a 4" and 8" in the budget line, as well as an all new ultra high end line. That will likely be more expensive than the Revelators.

Jed

[TacoD]

Was the high-end line not called SCAR?

[Mazeroth]

Thanks for the measurements, Jed. That little 5" SB looks very tempting.

Has anyone measured or used the 6" version?

[Jed]

Has anyone measured or used the 6" version?

Zaph measured it and it is also excellent. Same trends in the bass and midrange performance.

[Paul Ebert]

So, how high do you think the 5" could be crossed over? I'm looking for a midwoofer for a MT with the D26NC55. The 5 dB dip at 1.5k concerns me.

[cotdt]

So, how high do you think the 5" could be crossed over? I'm looking for a midwoofer for a MT with the D26NC55. The 5 dB dip at 1.5k concerns me.

Looks more like 1.7kHz to me, but the 5dB dip probably just comes from poor surround termination. It won't sound bad though it might be a little less detailed sounding.

[Jed]

So, how high do you think the 5" could be crossed over? I'm looking for a midwoofer for a MT with the D26NC55. The 5 dB dip at 1.5k concerns me.

Well, with the D26 you can cross around 2.2k and that should work fine with the SB 5". The dip at 1.7kish won't really be that audible since it is so narrow and dips are harder to hear than peaks. I'm planning on using a XT25 with them so I'll likely cross around 2k- even better because by 2k the response of the SB 5" will need to be down around 6db anyway for it to sum properly with the tweeter at a Fc at 2k. I'll just use the acoustic dip to my advantage instead of doing everything electrically. Well that's the plan anyway.

Jed

[oldbar]

My SB 5" which I measured tonight also has the the 5.4db dip around 1600 which should not be noticeable at all .
I will be crossing mine around 2100.

[cotdt]

You can try getting rid of the 5 dB dip by coating the cone edge/surround interface.

[Jed]

I decided to run a few more tests of the SS W15 at a higher level. Now it is closer to 92-93db per meter.

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Here's the Seas L26 at around 85db per meter. Ignore the spike at 4k (the large peak in the response caused the input to clip at that frequency)

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And the SS6600. The best tweeter I've tested.

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Here's the SS6600 in the cabinet I'm using it in.

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[Silversmoky]

Thanks for doing the measurements Jed. That 6600 is impressive.

[Jed]

Thanks for doing the measurements Jed. That 6600 is impressive.

You're very welcome. I'm pretty impressed with all 3 drivers actually. The W15 would be better if it didn't have the energy storage around 900hz, but it's not bad at all (almost a complete lack of high order harmonics). It should be smooth a sounding 3-way. I managed 2nd order slopes very easily.

[Mark K]

You're very welcome. I'm pretty impressed with all 3 drivers actually. The W15 would be better if it didn't have the energy storage around 900hz, but it's not bad at all (almost a complete lack of high order harmonics). It should be smooth a sounding 3-way. I managed 2nd order slopes very easily.

Hi Jed,

I'm curious about your impression that there is any energy storage at 900 Hz with the W15. How do you see this? My tests show that the W15 has very low linear and nonlinear distortion around this frequency.

[Jed]

Hi Jed,

I'm curious about your impression that there is any energy storage at 900 Hz with the W15. How do you see this? My tests show that the W15 has very low linear and nonlinear distortion around this frequency.

Mark, are we comparing the same driver? All the ScanSpeakW15 drivers I've seen have something going on with an impedance wiggle at around 800hz-1k.

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And the FR has a slight bump before a slight dip at 1k. My FR measurements earlier in this thread are no exception. Nearfield it seems a bit less pronounced, but as I went and took measurements in the farfield it became more pronounced. I ended up using a narrow notch filter to flatten this frequency non linearity, but could do little about the small dip at 1k.

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Perhaps you are talking about the Seas W15CY? Which is perfectly linear until its main breakup peak. That said, I'm looking forward to working with the SS W15 for it's very low high order harmonic distortion and very usable and extended FR to hit the target LR2 slopes. I've heard a few Scan Speak 15cm drivers and they all were very musical and detailed to my ears. I can't wait to hear this system. The crossovers will be ordered Monday, so I can begin the listening and tweaking- which this is all about.