Scan-Speak 15W/4524T-02 & D2604/8320-02 "Limited Edition" Combo

[technodanvan]

Got an email from Madisound marketing these two units:

ScanSpeak Limited Edition D2604/8320-02 1" Textile Dome Tweeter

https://www.madisoundspeakerstore.com/soft-dome-tweeters-scanspeak/scanspeak-limited-edition-d2604/832002-1-textile-dome-tweeter/

ScanSpeak 15W/4524T-02 Limited Edition 5.5" Fiberglass Cone Woofer

https://www.madisoundspeakerstore.com/approx-5-woofers/scanspeak-15w/4524t02-limited-edition-5-fiberglass-cone-woofer/

$288.60 USD for a full kit of two drivers and two tweeters. Supposedly only a few hundred sets will be available, but I don't know if that's per store or what.

I still haven't done any measurements on the desktop speakers I started for my wife three years ago, so I hadn't really been thinking about starting another project. For some reason I like the look of these. I did a little research but can't seem to find any recommended designs from Scan-Speak, which I think is weird since they are clearly meant to complement each other.

Any thoughts? I might just grab them to play around with next year, but I probably should finish my other project first! Might grab a pair or two of these as well, just because you never know what comes up...

Seas Prestige 27TFFNC/C H1482-06 1" Soft Dome Tweeter

https://www.madisoundspeakerstore.com/deal_of_the_day

[JonMarsh]

That's an interesting offer from Madisound- the tweeter is likely to be a very good value at that price, as it's rather similar to the larger much more expensive series.

The woofer is an odd duck- the extra magnet appears just to be a buck magnet for shielding purposes (as in AV applications near CRT) there is no back side field plate, and no apparent way to couple the flux differential. Also, the woofer has the classic breakpoint in response intended to make it possible to crossover over with a single large inductor for BSC and flattening out the top end rise; this design always seems to have a mechanical discontinuity that is apparent as a glitch in the impedance curve. it's not a bad deal at $90 bucks, but not a great deal.

If some one came to me and said, "build me a small desktop or stand speaker with great drivers for not too much money, I would likely go with the Aurum Cantus AC130F1 instead (about $50)




but the SS8230 tweeter would probably be just fine.

I ought to buy a couple of those and test them.... question is, is it as good as an RS28a/f, or not, or better?

[scottvalentin]

These are also on special at Solen and gosh hard to resist!

[JonMarsh]

What's curious is the difference in performance (SPL) of the 8320 versus the 8330- the latter appears to be quite peaky, the 8320 only minimally so; but the 8330 has 0.3mm Xmax, while the 8320 is 0.1. OTOH, the gap is the same length (likely the same motor) and the 8320 has a longer voice coil, so it will probably have a sort of soft overload characteristic.

Curious, but interesting. Worth testing, to see what happens as one pushes it. And the price looks good. Also, it's a face plate more like their big guys than the 8330, which is clearly a Discovery series product.

and they've got a few in stock, too.

[NyxOne]

That's an interesting offer from Madisound- the tweeter is likely to be a very good value at that price, as it's rather similar to the larger much more expensive series.

The woofer is an odd duck- the extra magnet appears just to be a buck magnet for shielding purposes (as in AV applications near CRT) there is no back side field plate, and no apparent way to couple the flux differential. Also, the woofer has the classic breakpoint in response intended to make it possible to crossover over with a single large inductor for BSC and flattening out the top end rise; this design always seems to have a mechanical discontinuity that is apparent as a glitch in the impedance curve. it's not a bad deal at $90 bucks, but not a great deal.

If some one came to me and said, "build me a small desktop or stand speaker with great drivers for not too much money, I would likely go with the Aurum Cantus AC130F1 instead (about $50)




but the SS8230 tweeter would probably be just fine.

I ought to buy a couple of those and test them.... question is, is it as good as an RS28a/f, or not, or better?

I think there is more than meets the eye! Le is incredibly low (0.2), lower than a Scanspeak Reveletor (0.25) actually. There is an Alu shorting ring and copper cap in there. Xmax is healthy 5.2mm with an xmech at 8.0mm.

Sensitivity is also good. Nearly 90dB whereas the Reveletor has 87dB.

Frequency response is good, breakup is bening and the only blemish is the 1 dB dip at 1.2khz. There is also a sort of downward slope that might require a little less BSC than usual (maybe 1 dB less).

The way I see it, it's a poorman Relevetor. Discovery frame, cone, spider, etc with a sort of Reveletor motor.

Solen has announced a design contest (Quebec/Canada only) with a 35% rebate on these.

Chuck

Edit : It was also the last drivers designed by one their lead designer (Birger Jorgensen) before it's death.

[JonMarsh]

I think there is more than meets the eye! Le is incredibly low (0.2), lower than a Scanspeak Reveletor (0.25) actually. There is an Alu shorting ring and copper cap in there. Xmax is healthy 5.2mm with an xmech at 8.0mm.

Sensitivity is also good. Nearly 90dB whereas the Reveletor has 87dB.

Frequency response is good, breakup is bening and the only blemish is the 1 dB dip at 1.2khz. There is also a sort of downward slope that might require a little less BSC than usual (maybe 1 dB less).

The way I see it, it's a poorman Relevetor. Discovery frame, cone, spider, etc with a sort of Reveletor motor.

Solen has announced a design contest (Quebec/Canada only) with a 35% rebate on these.

Chuck

Edit : It was also the last drivers designed by one their lead designer (Birger Jorgensen) before it's death.

Those are all pretty interesting points... especially the design contest! Well, you've convinced me they are both worth checking out. Certainly the first step, which is checking breakup effects and coloration with pink noise. (listening) and HD plots.

Another friend reminds me I need to be careful about chasing butterflies, though. And if these are truly limited edition (Gee, Steen, we only have enough parts on hand to build a couple of hundred of these...) then that is unfortunate, for the long term usefulness.

I'm also thinking an MTM would be more useful, as regards dynamic range.

[NyxOne]

I'm also thinking an MTM would be more useful, as regards dynamic range.

My thought also! A 5 incher can only do so much! Bass extension is not terribly good either but if we're willing to loose a bit of efficiency we can use higher than usual DCR on the main coil to raise the QTS of the driver. I've modelled it with 0.5 ohm in serie and it does give us a bit more of usable extension!

Chuck

[JonMarsh]

Yeah... and those 0.75 cu ft PE cabs that are still available would take a lot of effort out of the build. i'm thinking something to put in and upgrade my man cave speakers for now...

Better find some time this evening to do some modeling... Hmm, what are all these butterflies doing around this time of year? :B

[Steve Manning]

In your case I'm starting to think that's all you can see.

[technodanvan]

I went ahead an ordered a pair of each. I'm not sure I can squeeze a full MTM into my house without my wife noticing, but I will spend some time jotting down a few excuses tonight. If any of them look like they'll work I'll grab another set of drivers.

[JonMarsh]

I went ahead an ordered a pair of each. I'm not sure I can squeeze a full MTM into my house without my wife noticing, but I will spend some time jotting down a few excuses tonight. If any of them look like they'll work I'll grab another set of drivers.

That's my man! More drivers are always good- right? :B

[JonMarsh]

In your case I'm starting to think that's all you can see.

[ATTACH=CONFIG]26682[/ATTACH]

Maybe it's just something wrong with the last pair of glasses I bought...

At least, they're not rose colored... :B

[technodanvan]

That's my man! More drivers are always good- right? :B

Well, we'll see how it works out.

By the way - it's probably going to be a few months before I can really sit down with these, so if you want to play around with them without having yourself another permanent party in the Marsh household I can send them your way.

[JonMarsh]

That's a generous offer if you're inclined to to that- I'd pay shipping both directions, and provide you with measurements and FRD and ZMA files if that would sweeten the deal. PM me if you end up being able to proceed at some date.

[technodanvan]

That's a generous offer if you're inclined to to that- I'd pay shipping both directions, and provide you with measurements and FRD and ZMA files if that would sweeten the deal. PM me if you end up being able to proceed at some date.

Sure thing, I'll shoot you a PM whenever they arrive. I'll at least pay for shipping to you, since you're doing all the legwork!

[JonMarsh]

Thanks- I appreciate that, and I'm sure it will be interesting for both of us to see what these puppies can do.

[scottvalentin]

I actually was going to pull the trigger, but Solen has gone out of stock of the tweeter.
Also, the discount from the design competition was open only to residents of Quebec.

Nonetheless, I am very interested to see the measurements and what you get cooking Danny!

[JonMarsh]

I actually was going to pull the trigger, but Solen has gone out of stock of the tweeter.

really?

In fact, searching Solen now doesn't turn up any listing for the D2604/8320-02 anymore, and search doesn't either. I wonder if someone didn't come in and sweep up a bunch of them at once, as I as pondering doing at Madisound.... and they had 32 on hand when I looked earlier this week.

Though these parts (woofer and tweeter) are showing up in the Recent products pane on the front page, neither shows up in search anymore.

Someone scooped them up, OR, there's a lot of Canadians stocking up for those long cold nights to come this winter and working on their DIY projects!

[NyxOne]

Solen's contest is not officially ON. I know a few people who have registered themselves including myself but we haven't heard back from Christian (Solen) just yet.

Either the demand is extremely high (I doubt it) or something's fishy about all this!

I just dropped them an email. Will report back if they reply!

Chuck

[NyxOne]

Just received an update from Solen and apparently they've removed the drivers from their website as they're being reserved for the contest participant. I guess they got more interest then they expected!!!

Drivers will ship next week.

Chuck

[18inch]

well, i ended up getting enough for an MTM setup! couldnt resist ! :P

actual build should be next spring

would you guys think these would work well in a sealed enclosure or should i focus more on ported ?

[fish fingers]

Anyone know why SS put such a conservative rec x/o point on those tweets? 2.5khz (12dB)seems high for an fs of 500hz

[JonMarsh]

Look at the Xmax. Only 0.2mm P-P. 0.1mm Xmax. Usually I'm looking at tweeters with 0.4mm Xmax.

Yes, it will have a sort of soft overload characteristics, as the gap is reasonably long, but so is the voice coil.

[NyxOne]

Scan-Speak 15W/4524T-02 & D2604/8320-02 "Limited Edition" Combo

Look at the Xmax. Only 0.2mm P-P. 0.1mm Xmax. Usually I'm looking at tweeters with 0.4mm Xmax.

Yes, it will have a sort of soft overload characteristics, as the gap is reasonably long, but so is the voice coil.

I'm using this tweeter LR2 acoustics @2khz without any audible strain. It also doesn't show any significant distortion and most of it is 2nd order.

LspCAD estimate that with the current crossover with 64 watt to the system only 4 watt goes to the tweeter so although technically it doesn't have much XMAX it sure performs well under the circumstances.

Chuck

[NyxOne]

Scan-Speak 15W/4524T-02 & D2604/8320-02 "Limited Edition" Combo









Solen's contest is almost over so I should be able to post a few measurements soon.


Chuck

[Zvu]

Can you post raw measurements of the drivers, with distortion plots maybe ? If it's not against the rules of contest, of course.

[NyxOne]

Can you post raw measurements of the drivers, with distortion plots maybe ? If it's not against the rules of contest, of course.

I should be able to provide in box (Dayton TWC-0.25BK Cabinet) impedance, frequency and distortion measurements for both drivers before monday. However, the diffraction signature will be present as will the diffraction loss (wihtout BSC), something to keep an eye on.

Chuck

[Zvu]

Great, thanks.

[Evil Twin]

I should be able to provide in box (Dayton TWC-0.25BK Cabinet) impedance, frequency and distortion measurements for both drivers before monday. However, the diffraction signature will be present as will the diffraction loss (wihtout BSC), something to keep an eye on.

Chuck

I would be interested to see those, too, as a cross check- I am conducting the same tests in the same enclosure!

[NyxOne]

Woofer farfield



The woofer dip at around 1.2khz - 1.3khz is real.

Woofer nearfield



I'm not sure what's up with the bump at 750hz. It might be an artifact caused by nearfield measurement OR I did not chamfer enough the inside of the driver cutout OR driver's natural response.

Tweeter farfield



Most of the non flatness is caused by diffraction. Eg : The large dip between 2.5khz and 4khz and the bump 4.5khz and 6khz (most of it goest away if you measure it off axis)

Tweeter vs Woofer relative level



A few notes about the measurements :
- No smoothing (that I can remember of...)
- 60dB scale
- 300hz - 20khz for farfield measurement
- Something like a 4-5ms gate + blended
- 1m distance
- Drive level are obviously not accurate.

Sorry for being sloppy with the measurement but I was in a hurry!

Although I've the distortion measurements, the graphs are super stretch for a reason I don't understand yet. This might be a bug of Omnimic latest version... OR it's my fault!

Chuck

[NyxOne]

I've been able to resize the images to make them less stretched.

I don't think the drive level was high enough but still you can have a good idea what they're all about.

- Measurement done at 32 cm
- Around 103-105db (> 91dB @1m if i'm not mistaken).
- 1/48 octave smoothing
- Red (2nd), Purple (3rd), Green (4th), Cyan (5th)

Woofer



Tweeter

[scottvalentin]

Thanks for sharing your data Chuck looking forward to seeing the completed project.

[Zvu]

Thanks for the measurements.

Frequency response looks like without serious issues for both drivers. Midbass breakup is well damped and benign. Distortion profile for midbass is a bit surprising. I'd cross it with tweeter at about 1.5KHz LR4 to avoid that HD2 rise as much as possible. Maybe slightly higher because of tweeter Xmax. It could work as nearfield monitors or desktop speakers.

Other than highish HD2 in midbass, both drivers look ok but that's about it.

Thanks again for measurements.

[NyxOne]

Glad you liked the measurements. I wish I could take better measurement but I'm not as devoted and knowledgeable as some other members.

Concerning the drivers distortion, take them lightly and let's wait for John's measurement!

Also, unless I'm wrong, i believe 2nd order distortion is relatively harmless and usually forgiven when higher order harmonics distortion is kept low.

That being said I'm using both in the same system LR2 @ 2khz and they sound really clean.

Chuck


Chuck

[technodanvan]

Thanks for the measurements Chuck! Jon has mine at the moment so it'll be interesting to see what he comes up with. Hopefully they have good QA/QC. Your setup looks really sharp! I've never used the Dayton boxes but have only ever seen very good things...maybe I'll need to go that route this time.

[NyxOne]

Thanks for the measurements Chuck! Jon has mine at the moment so it'll be interesting to see what he comes up with. Hopefully they have good QA/QC. Your setup looks really sharp! I've never used the Dayton boxes but have only ever seen very good things...maybe I'll need to go that route this time.

I can vouch for Dayton's cabinet! If you're lazy or lack finishing skills like I do it's a good way to get near professionnal result! There's always a small defect here and there but most people won't be able to notice if you're a feet or two away!

Chuck

[JonMarsh]

Yah, a realistic criteria is whether you can spot problems from horseback- if not, then you could consider it more than good enough, unless you like to pay Wilson Audio prices or make comparable fabrication efforts (*they have a variety of interesting video's documenting their manufacturing and finishing processes.... )

[TEK]

Probably not this, but it was interesting anyway...

https://www.wilsonaudio.com/videos/video=a-brief-history-of-cabinet-materials-at-wilson-audio

[5th element]

Yeah they measure quite nicely. Certainly a 'higher 2nd order' type design but all the other harmonics are nice and low.

[Zvu]

Yah, a realistic criteria is whether you can spot problems from horseback- if not, then you could consider it more than good enough, unless you like to pay Wilson Audio prices or make comparable fabrication efforts (*they have a variety of interesting video's documenting their manufacturing and finishing processes.... )

It's quite interesting what Wilson Audio does with their cabinets

"The enclosure itself is a truncated pyramid; as a result the panels are nonrectangular and the internal surfaces are substantially anti-parallel. The latter minimizes internal standing-waves while the former helps to disperse and moderate the usual plate resonances present in conventional enclosure panels. In addition the interior is lined with anechoic grade foam supplemented by a volume filling of polyester fibre. The enclosure panels are cut from a dense, naturally inert composite—an acrylic, heavily loaded with ceramic and a mineral powder—which may be machined like marble. High- frequency panel modes are controlled by a highly resistive bituminous laminate on the inner surface while the remaining fundamental resonances are handled by heavy, 20 mm thick lead slabs bolted into position on elastic mountings to provide tuned, seismic damping. Furthermore, the side panels are extended at the rear to form small triangular ‘wings’. A massive alloy bar is bolted up between these wings, horizontally disposed and providing a stressed reinforcement for these largest radiating surfaces. Finally, the finished mass of approximately 25 kg provides a heavy inert foundation for the two-way driver lineup to perform at its best. The high performance attained in this enclosure design is an object lesson in the continuing importance of enclosure colouration in box speaker design. Both mechanical impulse tests and listening have shown that this quality of enclosure has a dramatic effect in improving sound quality, particularly with transients, subjective dynamics, stereo focus and depth; as such it shows that despite considerable improvements, we still have a long way to go in the field of commercial enclosure design. However, this performance is achieved at high cost, approximately 15 times that of a normal enclosure of this size."

Martin Colloms - High performance loudspeakers

[JonMarsh]

Well, I'm a lot later getting back to this than I expected, but between issues and problems in the personal life and at work, audio has been a distant 3rd.

First, I have done some driver analysis and modeling. The 15W/4524 is a quirky little guy, but I think I have some useful suggestions. Due to 4 ohm and general build, the sensitivity is fairly high, and the Qes and Qts fairly low, along with a reasonable Fs. But it doesn't model well in larger enclosures (say, 15L), will get pretty peaky with a reflex port. What does work fairly well is about 8L net, tuned to about 45 Hz. Two inch ID is fine as regards peak port velocity. But, with that sizer enclosure, you still need a port about 30 cm long to get that tuning- that's bit over 10"!! Going to probably need something creative like a bottom slot load port.

If you use crossover parts that keeps the net resistance on the woofer circuit around 1 ohm or below, you'll wind up with a curve similar to this:






Not bad, pretty near about as good as I think you get get with this driver.


OTOH, this is a small speaker, and sometimes some psychoacoustic engineering is desired, or maybe,, just plain psycho. :B

In this case, I would engineer the crossover for a net DCR of 2 ohms; it will drop the sensitivity a bit more, but it will also give you a BBC LS3/5A lift, and subjectively a more satisfying bottom end. All smoke and mirrors, but what you do in the privacy of your own home is quite up to you...






Particularly if you listen to pop and rock and roll, I think one will prefer this alignment from a small speaker.


I'm preparing to make test baffles today- hope to finish that soon.

[Wayman]

Would this driver combo work for the lower cost Ardent currently being discussed?

Cheers, Wayne

[Carl V]

I doubt it. apples and oranges. But I'll defer to the HTG cognoscenti

[JonMarsh]

Well, there are two questions here, really- could it be made to work? Yes.

Is is the right choice for the money versus performance for a midrange and tweeter? I don't think so.


The 15W/4523 is likely overall a better mid woofer for a small two way system- easier to tune for extended low end in a small box, considering the size of the driver.

But, the ZA14 is a better pure midrange IMO. Look at the factory Scanspeak impedance and SPL curves, and the 3rd party curves- this driver has a bit of a linear distortion/resonance issue at around 1.2 kHz, which shows up in the SPL response and more tellingly in the impedance curve.

Now look at the ZA14... nothing like that. For a midrange driver, we want well controlled and smooth response from say, 400 Hz to 2500 Hz. And low distortion. For the ZA14, HD2 and HD3 are equally low, at about -60 dB.




More copper in the gap, and possibly a more symmetric motor, so the big bump in HD, which is where the cone motion should be low in the upper midrange, which occurs with the 15W/4524, isn't there.

Besides, I sort of like the basket on the ZA14, as its the same as similar sized Accutons... :W

And the ZA14's are only $39.95 each. Not $89.90.

[Wayman]

Yes, hard to top the ZA14! The tweeter, while lacking the full .2mm xmax of the original 6600, does look very close?

Cheers, Wayne