Seas Excel Mag vs Seas Excel Nextel

[Branwell]

Hi,

If you have heard both the Mag Excels and the Nextel Excels, was hoping you could share your opinions of the relative differences.

Branwell

[JonMarsh]

Haven't heard the Nextel's yet. Based on distortion measurements, I would prefer the Mag Excels. But you know, I'm one of those curmudgeonly objectivisits (sometimes called "engineers").

I think part of the reasoning behind the Nextels is to enable fairly high performance designs with simpler crossovers. OTOH, they have a bit of an HF peak, too. 10 dB or thereabouts.

If I was going in that direction, I'd look at the Peerless Nomex Exclusive series; not as pretty, but about half the cost, and very good performance also.

~Jon

(PS- the best "midrange" driver (frequencies, not price) I've tested so far short of an Accuton is the W22).

[capslock]

Have you found an Accuton that has lower distortion than a W22? I would be very surprised!

While the newer models with titanium former have better motors than the older versions, there is still room for improvement. Also, CSDs are excellent only for a few models.

[capslock]

OK, read your comments in some other threads. The C90 is really incredible, but also increadibly expensive.

[JonMarsh]

Yeah, definitely incredibly expensive. But it sure does look good- at least on paper!

Maybe by February when my finances will have recovered from Christmas... it would be funny to have a system where the midrange driver cost more than all the other drivers put together.

BTW, have you head of anyone testing or working with the underhung motor C13-6 tweeter?

[capslock]

No, none of the new drivers (C13, C24, C90) even appear on the Accuton homepage, but I had a look at the C90 datasheet from Madisound. The FR and distortion measurements look like they were done by Bernd Timmermanns, so I would not be surprised to see reviews in the next issue of HH (due out early February).

The CSDs are done with an ATB system. Klang & Ton used to do ATB CSDs, and they were next to worthless, no idea why. Clio CSDs have been much more revealing (BT's been publishing them since 96 or so).


Is there already a first XO version for your W22 / Millenium? Or maybe even an alternative one for one of the small Seas or the RS28?

[JonMarsh]

No crossover work this Christmas "break"- it's not been much of a break, with preparations of an APEC Professional Advancement Seminar and CES presentation dominating my "free" time.

Accuton is very strange about not posting or updating data on drivers on their own web site. But maybe they don't care much about what the world other than their larger commercial customers know, and they don't want to undercut dealers like Soniccraft who mostly have only the older drivers in stock.

[ergo]

I got a pair of W18NX001 and T29CF001 a little while ago. They sure look absolutely great I'm also guite sure the grey color of basket and front plate has a bit of marketing behind them. I have W17E002 and Millennium pair already but putting a W18NX next to Millennium - well it is not the best visual mach Tehnically would be wonderful I'm sure.

I bought them just because I got them basicly half the street price.

I have not had time to test them yet, but I'm planning to do it this month.

The current plan is to attempt an open baffle mid configuration. We'll see how WMT per side will handle things. I will use SS 8565 60L sealed (with flow resistors) bass module and cross to mid whereever the mid can still handle enough SPL.

BTW, Jon your Arvo Pärt project material seems to be your only project that has no sticky thread in this forum. I have tried to find all info on Arvos with search but it's not easy. Perhaps you can someday gather some info into one Sticky thread.

Arvo Pärt is my fellow countryman btw I saw the "ä" in the Pärt is strange letter for most of you. We also have õ, ö ,ü letters used in Estonian language So it's lucky that the name of the project is not JÄÄÄÄR like one of the bands in Estonia (means "edgeof the ice")

Ergo

PS. I wonder if all the special character joke is visible at all - different laguage PC's might not show the whole joke.....

[Jed]

No crossover work this Christmas "break"- it's not been much of a break, with preparations of an APEC Professional Advancement Seminar and CES presentation dominating my "free" time.

Jon, Are you dead set on using the W22 in a 2-way? I know you have the cabinets for them, but I'm not sure the W22 will be the ticket for bass- as was mentioned before. But of course, what better driver is there for midrange in a 2-way- not much is better I presume. For me though, the lack of slam with the W22 under 100HZ would prevent me from spending all that time developing a 2-way crossover for it- unless of course you use subs to take care of the lower octaves etc. I'm sure you gave this a lot of thought - why can't we just combine the low end of extention of the RS225 with the low midrange distortion of the W22 darnit! In my 3-way system (OW1, W15CH, and W22), I'm going to take the W22 out and use it for something else and substitute an RS225 or even an L22.

Jed

[capslock]

Hmm, I am slightly puzzled as to why the W22 would lack slam. BR or sealed? It might well be an alignment issue that is easiliy dealt with by changing the tuning or using an LT circuit.

MarkK's testing revealed that the W22 has poorer LF distortion behavior than an RS225 or an 21W8555, but I doubt that this would show up as lack of slam, especially at moderate volume. It might even be perceived as more slam, due to transient harmonics on high volume attacks.

The Excel W series (along with their more humble L cousins) have a well designed pole piece geometry, resulting in the best BxL linearity I have simulated from any driver I have taken apart. The Peerless HDS drivers use a nearly cylindrical pole piece that gives much worse BxL linearity. While I have yet to sacrifice an RS driver, from pictures at diymobile.com I suspect that they use a relatively primitive extended cylindrical geometry.

What I suspect why the Peerless, Scan and RS do better is the use of heavier short circuit rings which are more effective in cutting LF flux modulation. The cure for the W22 would be to suplement the inside lower ring by an outside lower ring, or to use a compensation winding on the pole.

But again, if the flux modulation issue makes any difference at moderate levels, it will most likely be to increase detail and slam on the W22.

All drivers mentioned, with the probable exception of the Peerless Sandwich and Nomex cones, will be pistonic to at least 500 Hz, so I wouldn't expect significant sound differences there. The suspension is also beyond doubt, except maybe for a light question mark in the case of the RS225.

So this observation really bests me.

[Jed]

Hmm, I am slightly puzzled as to why the W22 would lack slam. BR or sealed? It might well be an alignment issue that is easiliy dealt with by changing the tuning or using an LT circuit.


So this observation really bests me.

As fa

I'm using the W22 in a 50L ported box tuned to around 30HZ. Dual flared ports with the port firing to the rear. The tuning is for a flat response- no boost in the low end.

I've heard the RS225 in the same size box (optimized like the W22) with identical X-over points each optimized for the specified design- around 300HZ LR2. The RS225 plays lower and with greater authority. Maybe I should shorten the ports in my speaker to create a higher tuning frequency? That would result in a slight bump in the low end response with slightly less extention, but maybe it would sound better?

Jed

[JonMarsh]

Jon, Are you dead set on using the W22 in a 2-way? I know you have the cabinets for them, but I'm not sure the W22 will be the ticket for bass- as was mentioned before. But of course, what better driver is there for midrange in a 2-way- not much is better I presume. For me though, the lack of slam with the W22 under 100HZ would prevent me from spending all that time developing a 2-way crossover for it- unless of course you use subs to take care of the lower octaves etc. I'm sure you gave this a lot of thought - why can't we just combine the low end of extention of the RS225 with the low midrange distortion of the W22 darnit! In my 3-way system (OW1, W15CH, and W22), I'm going to take the W22 out and use it for something else and substitute an RS225 or even an L22.

Jed

No, I have them mainly for testing in my Arvo diopole configuration; a shoot out with the 8" Peerless Nomex Exclusive.

I have heard the W22 in a similar type system, a modified set of Avalon Eclipse owned by Ayre. I've toyed with trying them in the M8ta cabinet, but since that design was intended to be fairly wide range "standalone" and was tuned/optimizeds for the RS225, I don't think I'll change it at this point, unless I can't get the mids to my liking. But never say never, isn't it "assume" that makes an ass out of u and me?

I suppose the only way to really know would be to try both configurations. I just have to question whether it's important enough to spend that much time on!

The M8ta project has gone unfinalized way too long; it's still a matter of finding a little more free time. I have some more tweeter measurements to do before making the final choice (Hales Transcendence, RS28a, Millenium Excel, H1212).

[capslock]

One thing I have been pondering is to use a W22 or W18 as a coax. I have a couple of those tiny Audax car tweeters with a 25 mm Titanium dome. The could sit right on the copper shorting tube that the phase plug usually rests on. The cone, being relatively shallow, would also form a nice waveguide. Still, they might be somewhat excursion challenged. However, now that I have a little lathe waiting to be put to use, making a new long gap motor is not out of the question. But I don't know how much of a problem both modulation of the tweeter's sound by the movement of the waveguide and the influence of the woofer's pressure on the tweeter membrane are.

The other thing I have been pondering is to use a larger tweeter such as the Audax TW025A20 (the one with the heavy Nd ring magnet that never really made it to the market but is still available through e44.com) or the XT25SC. It could either sit on an extended phase plug, about 3 cm in front of the neck of the woofer's VC. In this case, I might surround its faceplate with a ring of heavy felt. There was a German system that used a 13 cm woofer and a tiny Nd tweeter with a felt ring, and this ring was surprisingly effective in surpressing cavity resonances between tweeter and the woofer cone.

Alternatively, I might run a 2-3 in. wide "baffle" across the basket of the woofer. This approach is used by ME Gaithain in their studio monitors. It can be extended to three way, the new Dayton RS large dome coming to mind as a midrange.

[JonMarsh]

I got a pair of W18NX001 and T29CF001 a little while ago. They sure look absolutely great I'm also guite sure the grey color of basket and front plate has a bit of marketing behind them. I have W17E002 and Millennium pair already but putting a W18NX next to Millennium - well it is not the best visual mach Tehnically would be wonderful I'm sure.

I bought them just because I got them basicly half the street price.

I have not had time to test them yet, but I'm planning to do it this month.

The current plan is to attempt an open baffle mid configuration. We'll see how WMT per side will handle things. I will use SS 8565 60L sealed (with flow resistors) bass module and cross to mid whereever the mid can still handle enough SPL.

BTW, Jon your Arvo Pärt project material seems to be your only project that has no sticky thread in this forum. I have tried to find all info on Arvos with search but it's not easy. Perhaps you can someday gather some info into one Sticky thread.

Arvo Pärt is my fellow countryman btw I saw the "ä" in the Pärt is strange letter for most of you. We also have õ, ö ,ü letters used in Estonian language So it's lucky that the name of the project is not JÄÄÄÄR like one of the bands in Estonia (means "edgeof the ice")

Ergo

PS. I wonder if all the special character joke is visible at all - different laguage PC's might not show the whole joke.....

Well, our US PCs and Macs will show the characters just fine- it's just a bit difficult to type them, especially on the lap which doesn't facilitate using the embedded keyboard function while typing with the alt key to type in the character code. Usually I'm too lazy, though with the special characters window available to text edit and most other Mac text programs, it's not that hard to write Arvo Pärt, is it?

Yes, I've been thinking about a sticky, but I want to have a reference design or two completed first. Also, we may lobby for a separate thread section for the "Mission Gallery".

~Jon

[AJINFLA]

Capslock,

we're thinking a lot alike! I didn't know you were a coaxial fan. I have though about doing much of what you said, since I'm going to have a pair of W22's laying around once I finish my summer project - which will be coaxial based - of course . My first question would be, how do you remove the phase plug?
The problem with this approach is twofold. As I found with using a static waveguide, the critical areas are not so much the perfect curvature of the guide, but rather the mating of the tweeter diaphram to the mouth and also the edge (outer) transition of the horn. A small tweeter that can fit into the throat would still need a relatively low Fs, since the W22 is best used to about 1.4k. The acoustic loading would be significant, making this feasible. Finding a neo tweeter robust enough to cross at 1.4k (even with the acoustic loading) and yet still be small enough to fit, is something I have yet to see. Are you sure that little Audax would work? The W18 with its higher allowable XO might be better suited for this.
You can look at what SEAS (KEF technology) did with the H1333, a small "horn" around the tweeter leading into the (cone)guide. Note also the inverted surround. If you were feeling brave after removing the phase plug, perhaps removing the rubber surround, inverting it, then gluing it to the back edge of the cone - may not seem too irresponsible :W . Then using a thin layered ring (felt?) to gradualy transition the cone (edge) out onto the frame/baffle to reduce reflection/diffraction.
Also, as you noted the modulation of the guide itself.
That issue can be reduced by shifting the range of use upwards above 300hz,
minimizing xmax requirements for high SPL. It would almost be a must IMHO if you were to take this approach. Note that KEF themselves (and Andrew Jones, now at TAD) have done so with the Ref 207.
The other option of placing the tweeter on an extended pole would lead to concerns of matching directivity. It would again force a lowish XO IMHO. The lower you go, the less the cone "sees" the obstruction. Especially if you opt for a bridge like the ME. Of course the bridge with a mid allows this.
My thoughts were to use something like the Aura NSW2, shaved down to its 47mm dia. to fit the 37mm pole extension. http://www.madisound.com/pdf/aurasound/NSW2-326-8A.pdf
hey, SL uses it! Can't be that bad. Looks crossable down to 700hz or so.
Please, please let me know if you do anything like this with your drivers. I have a boatload of coaxials from different manufacturers laying around from the years. Always best to use the research $ of others IMHO :T .
Maybe SEAS will save us both some trouble and combine a WXX with their Lotus tweeter in an "Excel coaxial" so that we don't have to do anything too drastic. But then again, we wouldn't DIY if we were not will to try huh?

Cheers,

AJ

http://www.kef.com/technology/new_uniq/newuniq.asp

http://stereophile.com/floorloudspeakers/775/

[Dennis H]

AJ, have you played with the Seas 1333? If so, what did you think? The nice thing about a coax is there is no lobing penalty for higher XO frequencies, as long as the woofer stays well-behaved.

[AJINFLA]

Hi Dennis,

sorry, don't have the SEAS. I have an old KEF uniQ 8, which is similar, but does not have the inverted surround.

The nice thing about a coax is there is no lobing penalty for higher XO frequencies, as long as the woofer stays well-behaved.

Yes, that and so much more. They are not perfect of course, but I believe of all the possibilities, it is the best approach. Tannoy may have been right all these years. KEF, Thiel and even Audio Physic (under Joachim Gerhard) seem to have concluded this also.
Why we get only TPX cone/fabric dome instead of lovely metals and ceramics from SEAS, I do not know . Were I to use the 1333, I would use it above 300hz ala TAD and the KEF ref. Flank it with 2 Dayton Alu woofers and you have a pretty sweet LCR. Coherence across your front stage like there's no tommorow.

Cheers,

AJ

[Dennis H]

TPX may not be that bad. I can't recall where but I saw some distortion measurements where the TPX cones acted more like hard cones than the typical soft poly guys.

[AJINFLA]

I swore I saw somewhere that Klang&Ton had tested it (H1333). It's fuzzy, but I recall seeing that it tested well. Perhaps better than the Thiel coax. Perhaps one of our European members can shed some light on this.
Still would prefer metal/ceramic however . The version SEAS makes for Gradient in Fiberglass woofer/Alu tweeter.

Cheers,

AJ

http://www.gradient.fi/products/prelude/index.html

[Landroval]

I swore I saw somewhere that Klang&Ton had tested it (H1333). It's fuzzy, but I recall seeing that it tested well. Perhaps better than the Thiel coax. Perhaps one of our European members can shed some light on this.

I haven't read the the test, nor even seen the H1333, but I'm currently using a Seas coax with TPX cone and metal-dome tweeter. It's a custom made model for another Finnish speaker brand Chorus ( http://www.chorus.fi/ ). It's used in the Mondo series and also sold as a DIY kit. I've always liked coax-speakers, and this one is one of the nicest in addition to the Gradient models, and some Tannoys.

[capslock]

starting a new thread on home-grown coaxes to prevent further creep of this one:

http://www.htguide.com/forum/showthread.php4?p=220593#post220593

[JonMarsh]

Good move, Eric. :T

[Patrick Bateman]

Capslock,

we're thinking a lot alike! I didn't know you were a coaxial fan. I have though about doing much of what you said, since I'm going to have a pair of W22's laying around once I finish my summer project - which will be coaxial based - of course . My first question would be, how do you remove the phase plug?
The problem with this approach is twofold. As I found with using a static waveguide, the critical areas are not so much the perfect curvature of the guide, but rather the mating of the tweeter diaphram to the mouth and also the edge (outer) transition of the horn. A small tweeter that can fit into the throat would still need a relatively low Fs, since the W22 is best used to about 1.4k. The acoustic loading would be significant, making this feasible. Finding a neo tweeter robust enough to cross at 1.4k (even with the acoustic loading) and yet still be small enough to fit, is something I have yet to see. Are you sure that little Audax would work? The W18 with its higher allowable XO might be better suited for this.
You can look at what SEAS (KEF technology) did with the H1333, a small "horn" around the tweeter leading into the (cone)guide. Note also the inverted surround. If you were feeling brave after removing the phase plug, perhaps removing the rubber surround, inverting it, then gluing it to the back edge of the cone - may not seem too irresponsible :W . Then using a thin layered ring (felt?) to gradualy transition the cone (edge) out onto the frame/baffle to reduce reflection/diffraction.
Also, as you noted the modulation of the guide itself.
That issue can be reduced by shifting the range of use upwards above 300hz,
minimizing xmax requirements for high SPL. It would almost be a must IMHO if you were to take this approach. Note that KEF themselves (and Andrew Jones, now at TAD) have done so with the Ref 207.
The other option of placing the tweeter on an extended pole would lead to concerns of matching directivity. It would again force a lowish XO IMHO. The lower you go, the less the cone "sees" the obstruction. Especially if you opt for a bridge like the ME. Of course the bridge with a mid allows this.
My thoughts were to use something like the Aura NSW2, shaved down to its 47mm dia. to fit the 37mm pole extension. http://www.madisound.com/pdf/aurasound/NSW2-326-8A.pdf
hey, SL uses it! Can't be that bad. Looks crossable down to 700hz or so.
Please, please let me know if you do anything like this with your drivers. I have a boatload of coaxials from different manufacturers laying around from the years. Always best to use the research $ of others IMHO :T .
Maybe SEAS will save us both some trouble and combine a WXX with their Lotus tweeter in an "Excel coaxial" so that we don't have to do anything too drastic. But then again, we wouldn't DIY if we were not will to try huh?

Cheers,

AJ

http://www.kef.com/technology/new_uniq/newuniq.asp

http://stereophile.com/floorloudspeakers/775/

Bravo, it's this kind of thinking that's going to create the next great class of speakers. I'm building Unity waveguides, and I've spent a lot of time thinking about these very issues that you're considering.

I'm using Aurasound NSW2 for my mids, also.

:: PB ::