A nice commercial kit- North Creek Pegasus

[JonMarsh]

Frequently the topic comes up of what commerical kits are good, better, or best, or what we might recommend for someone that doesn't want to go the whole hog DIY route.

There are a lot of nice products out there with varying levels of design sophistication, but I'll admit I'm a little biased about my design preferences, and there's not too many kits from the DIY kit companies that I'm fully enthusiastic about.

One company I've purchased components from frequently (most often custom crossover coils), and for which I have a fair amount of respect for their principle designer is North Creek Music. George has introduced a new design which looks to be quite well executed; the thinking behind it is quite sound, IMO, and bears a closer look for anyone looking for high quality and acoustic performance at a fair price. :T





Pegasus System

My understanding is that a dual driver sytsem using the W18 is in development, to be titled the Prometheus, which will use a configuration and tweeter ribbon similar to the Manifest.

Now, lest everyone think I'm turning into a schill for George and abandoning my DIY projects, do note the prices which this level of quality commands. :E

In bang for the buck, I think we're doing pretty well here with the various Modula based projects.

But I understand that the level of DIY we do here isn't for everyone, and that high quality kits have a place in the audio universe. I think George's better designs will compare well to a lot of fairly high end commercial offerings- let's not forget the crossover work he's done for B&W and Apogee- those are fairly serious calling cards.

~Jon

[DearS]

he says 10 awg inductors are all the rage, I mean they really make a difference. Jon.....help. the price of crossover, testing, and matching, $600 on top of the drivers. its quite steep a rise from a similar DIY project. although I've seen similar speakers going for over twice as much "krell". So in the retail market, it fits in as a "bargain" so to speak. the "bels" are right in line also.

although he says " we are trying to produce the most accurate family of loudspeakers ever made – in both the frequency and time domains."

interesting

[JonMarsh]

Well, you know, a few folks have "complained" about the crossover cost in the Modula series - because most of them are AWG14. And I use film and foil caps in the series parts of the tweeter crossover.

The M8ta is similar- AWG12 coils in the series woofer and shunt tweeter (not zobel), film and foil caps in critical locations. Good parts do cost. But considering the enclosure effort and all, I think it's worth it if you're looking to optimize the performance as much as possible for the basic configuration.

Now, the full blown Arvo Part passive crossover uses AWG12 coils in many locations. Again, film and foil caps in critial spots.

The big key to Georges B&W replacement crossovers (which even B&W has bought and defines as a reference for the 801 and 802) is getting rid of ferrite core coils, using low DCR air core coils and high grade film caps ONLY.

Not much differencein philiosophy here, really.

[DearS]

I see

[Interious]

Interesting thing about this design...

Early spring of this year I called George to ask about his Manifest design. At one point I asked why he had not yet used Seas Excel drivers and he replied that there was just something wrong with the sound. He said he was unable to listen for more than a couple hours, and eventually not at all.

That conversation occurred much before Pegasus' introduction, which kind of imparts a sense of authenticity to his advert copy on the site.

Anyway, it looks like he solved the problem.

There are threads on Madisound.
Dave

[Feyz]

.

That conversation occurred much before Pegasus' introduction, which kind of imparts a sense of authenticity to his advert copy on the site.

I had an email conversation with him more than a year ago which he had mentioned the same thing that he had problems with long term listenibility of the Seas drivers.

[JonMarsh]

He feels like he's fixed it with the current crossover point.


Swing low, sweet chariot....

It sings sweeter crossed down low....

[Dennis H]

He feels like he's fixed it with the current crossover point.


Swing low, sweet chariot....

It sings sweeter crossed down low....

You sly dog.

It wouldn't surprise me if he even did a bit of the old Cauer thing with the notch lining up with the resonance peak. He says he hates high-Q notch filters but maybe it isn't a notch if you bury it in the lowpass. Somehow he has suppressed the peak pretty well and his "3rd order" crossover that he swore to on the Mad board looks suspiciously like 5th or 6th order acoustical for the first 30dB on the lowpass. With those asymmetrical slopes, I can see why he has to tilt the baffle back.

[Paul H]

Jon - you might just have some good advice for me for the W18 in my current project - I'll be swapping some parts in the crossover to check out a lower frequency lowpass.

Dennis,

Tilted baffle? I don't see it in the pic above?


Paul

[Dennis H]

"The approach we are incorporating for the two-way Pegasus is more straight forward – the stand mounted version requires horizontal tweeter offset to the outside of the cabinet (away from the listener) and a simple but significant angle back; the tower version is built with the woofer above the tweeter. "

[Paul H]

Guess I should have read the link ops: - Thanks Dennis.

Paul

[Dennis H]

He may be tilting the whole speaker back rather than a sloped baffle. It does look square in the pic.

[tktran]

In my eyes, George's release of the Pegasus is no much to write home about.

More than anything, the critical analysis over at Madisound and ensuing reply by George is free advertising.

There have been many well thought out designs featuring the W18E, partnered to excellent tweeters, which measure superbly and probably sound fantastic.

The BESL System 5 MT, Ellis Audio 1801, Salk Sound Veracity QW are other commercial kits, as well Troels Gravesen's free-to-DIY TJL design,

Due to the ~4.5Khz resonance I've always thought that the W18 would benefit most from a low and/or steep crossover, as long as a suitably robust tweeter was up to the task. This is the main difference that I can see in the North Creek design.

I'm sure this is a nice speaker, but can we expect some kind of revelation? Even if it is, what is the reason for such late release. Isn't this just another way of saying "It took me ages to get it to sound good?"
No doubt other guys have experimented with low/steep crossovers on the W18E? Knowing Jon, I think we already know the answer to that question. :-)

Other designers/manufacturers who nailed it years ago are curious, but after the initial hoopla, go back to their desks and drool for the next batch of new drivers to play with...

This was not intended as a poke at North Creek. If it sounds like one, then I apologise. But in a commercial market isn't the time-to-market critical?

I wonder how long it will be before we can expect a North Creek release with the Nextel Excels?

[Interious]

I have no idea how Pegasus performs; but I have the 1801b and though it does some things fantastically well (driver integration, OW1 is magic), it is a flawed design.

Regarding the prolonged time to release: I'm not sure I see the relevance?

It is unlikely that George has unlocked some hitherto unheard W18 magic.

I should note that I had no intention of providing advertising when I posted the initial thread on Madisound. I've never built or heard a North Creek product.

[DearS]

flawed design, please do tell.

sound fatigue? high crossover?

[JonMarsh]

You sly dog.

It wouldn't surprise me if he even did a bit of the old Cauer thing with the notch lining up with the resonance peak. He says he hates high-Q notch filters but maybe it isn't a notch if you bury it in the lowpass. Somehow he has suppressed the peak pretty well and his "3rd order" crossover that he swore to on the Mad board looks suspiciously like 5th or 6th order acoustical for the first 30dB on the lowpass. With those asymmetrical slopes, I can see why he has to tilt the baffle back.

Well, it IS possible to do a 3rd order all pass, not Butterworth network- this is how the Elaine Marie/Modula MT is roughly configured. It's nominally 3rd order slopes in the crossover region, but like the Pegasus has a nice anti-phase null.

Well, if nothing else, it's provoked a little discussion....


Thomas always says one of my parents must have been a troll....

~Jon

[jdybnis]

Eventually it came to me that the problem with the W18’s upper midrange is a two edged sword. The mechanical break up of the cone is a high Q mechanical resonance. The "low pass network plus trap" approach creates a second high Q resonance. The problem, then, is that there are two high Q resonances in the electrical/mechanical/acoustic system right in the middle of the range where the ear (at least mine) is most sensitive.

What is the designer saying here? Does the notch filter create a secondary peak somewhere, or is a high Q dip somehow audible beyond canceling out the peak?

[JonMarsh]

One could interpret this several ways.

What I tend to agree with George about is that the approach of the Thor, where you use a relatively conventional crossover point, and a high Q notch filter to "de-tune" the break up peak so that it falls back down into the normal moderately low order roll off (and the combination is at a relatively near level to the nominal pass band response, say, -12 to -18 dB) is probalby less than optimal and leaves an audible signature. There still will be time domain issues (smear); it's not all about amplitude response.

Now, how to solve that problem, we take somewhat different approaches.

~Jon

[TacoD]

I did a cauer ~1300Hz x-over to a Seas millinium, so I stayed well under the K3 harmonic. And it sounds wonderfull. I must thank Jon for inspiration for these crazy x-overs.

[JonMarsh]

You're very welcome, Taco, and thanks for the kind words!

~jon

[Jonasz]

Speaking of cauer crossovers, what's the lowest x-overpoint you can use between a Neo3 and a W18EX? It's supposed to be a low output system for smaller rooms. I'd sure would like to test that combo when I already have them. :P

Jonas

[JonMarsh]

B&G says the standard configuration is good down to 2 kHz, or in a dipole or larger tuned reary chamber, down to 1200 Hz, with the caveat that nominal sensitivity is reduced by ~3 dB. If you've really got your heart set on a Neo3, I'd suggest experimenting with baffle (will need a largish one to support lower cutoff frequencies) and rear loading, before finalizing the configuration and developing a crossover.

MOST of the leaf type tweeter's we've seen measured don't fare so well compared with the good domes... so if it was my money, aside from the Gee Whiz factor, I'd think long and hard about using this over an H1212. I'd do some linear and non-linear distortion comparisons, and also some waterfall plots against potential competitors. In the USA, from PE, the Neo3 PDR is ~$40, depending on quantity.

Have fun with your project, Jonas!

~jon

[jdybnis]

Won't the time domain problems sort themselves out too when you correct for the amplitude peak? Time and frequncy are fully determined by each other since the driver is a minimum phase system.

[JonMarsh]

Well, you might think that, and PERHAPS if you had an anti-response complement in the electrical network which exactly mirrored the driver, this could be the case...

BUT, in real life, some ugly factors rear their head.

The driver in no way resembles a "simple" single peaking function as regards the mechanical issues- there are radial and bending modes in vibration which can manifest in various ways in the cone response. Even expressing simple dynamics of cone vibration requires third and fourth degree differential equations.

So, let's look at Geroge's analysis of the W18 modes, which is a lot more subtle and thoughtful than I usually encounter in print (I think some folks think I'm looking every where for speaker modes and blow things out of proportion because of my insistence on examining the impedance curve, nearfield plots, and shaped sine burst response).



While the main breakup mode near 5 kHz is the one "everyone" pays attention to, just like many other drivers I've tested, there are other issues which occur lower and higher in frequency and are measurable with the right techniques. In principle, to fully correct these in the amplitude and time domain will work IF the driver is truly minimum phase by itself, and IF we compensate each one of these issues individually. How many tuned notch circuits are you willing to implement in your passive or active crossover?

Now, all that aside, we also all know that the dispersion of a driver is quite related to the radiating cone diameter, and this also imposes (IMO) a useful upper limit beyond which we go only at peril to the power response profile.

The lowest frequency issues George identified with the W18 are at ~2.4 kHz. So, while the Excel cone shape helps push the main peak up higher, there are still problems down lower that must be considered, lest we get the "signature" which has plagued Taco, George, and others working with the W18 using more conventional approaches (like Joe D'Apollito's Thor design).

Considering the inherent bandwidth/dispersion limitations as well as cone modes, I'll stick by my persnickity recommendation of a 1400Hz crossover point for a high grade 7" two way using this driver (or the RS180), and no higher than 1800 Hz for a "bang for the buck" approach. IMO, a 2400 Hz crossover, as many have used for the W18, is decidedly suboptimal.

But you know, this IS a free country, so we can all build what we want to our hearts content. Our only goal here (since we're not selling anything to anyone) is to share info about how to build the best speakers we can conceive of for playing back music in our homes- the best at at specific cost and complexity level, of course.

What I recommend to anyone unsure of which path to take, is try several approaches. Build and investigate many different approaches yourself, then use your instruments and ears to figure out what works best for you.

There's no need to take my word for it- the lessons we really believe in are the ones we learn for ourselves, aren't they?

~Jon

[Jonasz]

Thanks Jon, sure I will have fun when this is not my main system but my learning/have fun/bedroomsystem! :P

Your last post is very interesting and made me decide to use the lowest possible x-overpoint. If it's something I hate it's harsh sounding speakers. :evil: The tweeters I have on hand is SS9900, Neo3 and XT25. I consider the XT25 a little "boring" and I don't wanna use them. That leaves 9900 and the Neos. If I go for an active approach around 1400hz I guess I can easily test them both. The actual baffle is 12.5" wide, I hope that can help the Neo's low end a little.

Jonas

[AndrewM]

Considering the inherent bandwidth/dispersion limitations as well as cone modes, I'll stick by my persnickity recommendation of a 1400Hz crossover point for a high grade 7" two way using this driver (or the RS180), and no higher than 1800 Hz for a "bang for the buck" approach. IMO, a 2400 Hz crossover, as many have used for the W18, is decidely suboptimal.

-- sigh --

Andrew
Stuck with expensive tweeters that need a 2-2.5Khz x-over

:P

[Davey]

All of these two-way 7 inch box systems are compromised to begin with since most likely they'll be using passive (lowish slope) crossovers and be expected to function as "full-range" systems. It's a tough job for a 7 inch mid-bass driver to....excel....in this type of system. If there were a 7 inch driver that could cover this range perfectly with no downside everything other driver would be obsolete, but as it stands now the W18 is one of the best options.

Anyway, it doesn't matter if you're George Short, or Dennis Murphy, or Jon Marsh....these are JUST a two-way box systems and they're all pretty much the same thing...conceptually.

I still think it's a better idea to force the mid-bass driver a bit higher than to force the tweeter to go lower.

Cheers,

Davey.

[AndrewM]

I still think it's a better idea to force the mid-bass driver a bit higher than to force the tweeter to go lower.

The question is "how" then, if you go to a smaller driver (which in theory should move break-up modes higher, certainly not an "absolute" truth though) then you compromise the bottom end, perhaps to the point of needing to build a 3-way. Or you can filter all your sound through a hundred x-over components

Anyway, it doesn't matter if you're George Short, or Dennis Murphy, or Jon Marsh....these are JUST a two-way box systems and they're all pretty much the same thing...conceptually.

Perhaps, but I see a distinct difference as well, I see one group who does as you suggest above and try and push the x-over higher and another who push it lower. I see different theories on what is important in the design, all the way to people essentially saying that break-up modes on a woofer are less of a problem than others think, or that off-axis response is way down the list of what is important, etc, etc. I don't think there is a "right" or "wrong" at least in broad design strokes.

[Dennis H]

Andrew, if you need to cross at 2K, the new version of the Seas L18 (H1224) might be a candidate. Its major breakup at 7K is quite a bit higher than the W18's at 4.5K. Zaph did a design with it and couldn't hear the sibilance that he hears with the W18 using "conventional" crossovers.

http://www.zaphaudio.com/audio-speaker17.html

Distortion

Nothing too surprising about the CSD. The cone rings like the liberty bell at 7Khz but is well behaved in the midrange. This driver's THD is what makes it special. Other drivers like the old L18 and the current Excel W18 have the breakup node in the 4-5kHz range. Observe the W18 distortion plot in the lower right corner of this spec sheet. A breakup node of 4.2kHz directly correlates to a peak in 3rd harmonic distortion 1.6kHz. Sharp peaks at a particular frequency will always cause a peak in the 3rd harmonic distortion plot roughly 2 octaves below. Notching out the breakup node is not enough to get rid of its effects. The only way to avoid it completely is to cross over below the frequency where the peak is not excited as a harmonic. With the L18 and W18, that means crossing over at 1.5kHz or lower. Many designs don't do this, and the sound is artificially colored as a result. It's most obvious with a solo piano. For a nifty test of this, set up a W18 system with a crossover frequency of 3kHz, and a perfect LR4 response. Play a recording that runs up the notes. When you get in the range of F6, F6# and G6, the piano will suddenly become completely unnatural sounding. In most recordings however, something like this is somewhat masked, and rather than sound unnatural, the music just changes character a bit. It's still noticeable however.

Now, with the L18 H1224's new higher breakup node, you can see in the distortion chart above that the 3rd order harmonic is pushed up to 2.5kHz. This is much more useful in a 2-way design. With the crossover placed at 2kHz, even the harmonic is several dB down, enough to not be noticed anymore. Now you can see why I've been so excited about this woofer.

[AndrewM]

Interesting, but I have a few thoughts on it (I had looked at the L18 before).

1. I'm a bit of a snob Or maybe I should say that I follow the "you get what you pay for" line of thinking, what am I going to give up by using a relatively inexpensive driver over something else. Now I realize that the 'ol adage is not always 100% correct and there are many examples of drivers that break that mold. There are other drivers as well that offer "easy" solutions (Vifa for instance), but I hear varying opinions on them. On the other hand I don't have much of a leg to stand on either, the 7" Focal units I'm using now are pretty old and don't make use of any of the "newer" technology in the motors and such (except perhaps the cone design).

2. I still see a wobble in the impedence graph at 300'ish Hz, and a dropping response after 1500Hz, which leads me to;

3. They aren't very "effecient", the tweeter is rated for 95db, and is pretty flat at 94db across the board (well down to 2Khz where it drops off), and I'd hate to shove a bunch of resistors in front of it to pad it down.

So I'm basically searching for the holy grail of speakers, high effeciency, good response in an enclosure (say down to the 60Hz range, lower is better obviously), low distortion, etc, etc. I'm not overly concerned about price, but I'm not going to pay Skaaning or Accuton type prices either.

I'm pretty much at the point with them that I'm ready to pack them back into their boxes and save it for a day when I have the time, space and equipment to do something special with them and go for something like the M8ta.

Andrew

[Dennis H]

Ah yes the old engineering conundrum -- I want a car that accelerates like a AA fueler, corners like a Formula 1 car, can climb a sand dune, will haul a dozen sheets of MDF, and gets 50 mpg.

[ThomasW]

Anyway, it doesn't matter if you're George Short, or Dennis Murphy, or Jon Marsh....these are JUST a two-way box systems and they're all pretty much the same thing...conceptually.

I get it, a Ferrari Enzo is 'conceptually' the same as a Geo Metro, since they both have a body, a motor, 2 doors and 4 wheels ..... :roflmao:

I still think it's a better idea to force the mid-bass driver a bit higher than to force the tweeter to go lower.

Having heard a statistically significant sampling of Jon's 'pre-Cauer' and 'post-Cauer' designs, we'll agree to disagree on this .... :wink:

[Davey]

I get it, a Ferrari Enzo is 'conceptually' the same as a Geo Metro, since they both have a body, a motor, 2 doors and 4 wheels ..... :roflmao:

Oh, c'mon. You know perfectly well what I'm talking about.
There are about 3000 of these type of 6-7 inch two-way systems out there. Sure, there are some that are terrible and some that are terrific, but they certainly don't fit into the category of other, more.....(I'm looking for the right word here)....evolved systems like the Arvo, Orion, NaO, etc.

Cheers,

Davey.

[AndrewM]

Ah yes the old engineering conundrum -- I want a car that accelerates like a AA fueler, corners like a Formula 1 car, can climb a sand dune, will haul a dozen sheets of MDF, and gets 50 mpg.

Don't forget it has to cost $20k

[ThomasW]

Oh, c'mon. You know perfectly well what I'm talking about.

I was just teasing Davey .... :B

Ah yes the old engineering conundrum -- I want a car that accelerates like a AA fueler, corners like a Formula 1 car, can climb a sand dune, will haul a dozen sheets of MDF, and gets 50 mpg.

It should run on sea water as long as we're fantasizing.....:wink:

[JonMarsh]

Yeah, but with those performance specs, it'll take a "Mr. Fusion" to get that kind of performance out of seawater....

:rofl:

Originally Posted by ThomasW
I get it, a Ferrari Enzo is 'conceptually' the same as a Geo Metro, since they both have a body, a motor, 2 doors and 4 wheels .....

Oh, c'mon. You know perfectly well what I'm talking about.
There are about 3000 of these type of 6-7 inch two-way systems out there. Sure, there are some that are terrible and some that are terrific, but they certainly don't fit into the category of other, more.....(I'm looking for the right word here)....evolved systems like the Arvo, Orion, NaO, etc.

Cheers,

Davey.

Nah, Thomas, it's "An NSX is conceptually the same as a Fiero, since they both have four wheels, two doors, a rear drive mid engine, and two seats for passengers". That's closer to what Davey was saying...


Now Davey, there you go, sounding just like Hank... what, another 7" two way?!?!?!?

But as Evil Twin said to me one time, that Yoda was always telling him in the old days, "The Force flows from mastery of the simple designs, it does- in unnecessary complexity lies the dark side..."

I love unnecessary complexity, I guess.... :B ... or find it "necessary".

But I do think mastering the design of "simple speakers" is a real aid to concentrating on the right things in bigger projects- one reason I've gone up and down that path before- for example, the Modulas are better small speakers than the X1 SLAMM klones, yet the X1's were developed as an outgrowth of some smaller designs I did which in turn were much better than my previous "large" design...

The circle is a wheel.... it's a Buddhist kind of thing, but seems how life works at times.

~Jon

[Davey]

Oh, I love these speaker/car analogies. I need to figure out if my setup is like a Porsche 993 or a Cadillac Escalade.

Davey.

[DearS]

I would say Dodge SRT-4, lots of bang for the buck. almost as fast as a porsche 993, but much cheaper. plus its has a cheapish interior.

[Paul H]

... But I do think mastering the design of "simple speakers" is a real aid to concentrating on the right things in bigger projects ....
~Jon

Heyyy - what are we saying here - some of us like to jump in at the very deep end ..


Paul

[JonMarsh]

Heyyy - what are we saying here - some of us like to jump in at the very deep end ..


Paul

We've noticed that. And commend you for your audacity and courage. :T

Me, I'm a slow learner, and it's taken a lot of mistakes to learn as little as I know now... no "stinkernet" most of the time I've been doing this....

[Interious]

Sheesh. What an OT nightmare this once great thread has become.

Dave

[Paul H]

Sheesh. What an OT nightmare this once great thread has become.

Dave

You are correct - I believe you were about to explain your 'flawed design' quote when we interupted ...

I have no idea how Pegasus performs; but I have the 1801b and though it does some things fantastically well (driver integration, OW1 is magic), it is a flawed design.

... please continue.

Paul

[Interious]

I've had some problems with my self-built 1801b samples that apparently no one else has had. Dave Ellis bent over backwards to help me and frankly I promised him that I wouldn't really discuss the problems in public forums. It was probably a mistake to make such a promise. I've broken it already by suggesting that it's flawed.

I should be precise and state that my particular samples are flawed. Mainly, lumpy bottom--lower midrange to upper bass, roughly. I've been able to EQ some of this out with a DCX. Endless porting/stuffing variations yielded mixed results.
The problem is most noticeable with male voices--a hollow thickening. Excessive bass energy overall, almost like there is too much BCS. My room aggrevates this, but I've heard it in other rooms. Cabinet or xover mistakes? I don't think so. It is a mystery.

The imaging is quite satisfying but not as vivid as my set of B&W 303s ($250/pair). The 1801b is reported to have holgraphic imaging, but I've never observed it.

The 1801b is fantastically detailed, and frequently surprises. The driver combo has a cleanliness that is unlike anything I've had in my room. I think the OW1 is beguiling, but Mark K conjectures that some of that magic may come from higher 2nd(?) order distortion. If so, give me that distortion.

The design screams for t-line loading--or some other environment for the W18, and an OW1 that can be crossed lower than the sacred 1400 hz, instead of 2600 hz. All of this said--a speaker that is still well worth the $650.00 kit price.

I jest about the thread becoming an OT nightmare.
I like quality digression.
Dave

[Al Garay]

What electronics are you using with your 1801b? I found 1801s to be very revealing and ruthless with wrong combination and darn close to Orions with the right combo. Then again, some people think the SL Orions are a flawed design as well. They both sound very good to me.

Perhaps you meant that your current setup is flawed. You can always post in Madisond or in AudioCircle to find others opinion.

Jackman, are you around?

[JonMarsh]

I've had some problems with my self-built 1801b samples that apparently no one else has had. Dave Ellis bent over backwards to help me and frankly I promised him that I wouldn't really discuss the problems in public forums. It was probably a mistake to make such a promise. I've broken it already by suggesting that it's flawed.

I should be precise and state that my particular samples are flawed. Mainly, lumpy bottom--lower midrange to upper bass, roughly. I've been able to EQ some of this out with a DCX. Endless porting/stuffing variations yielded mixed results.
The problem is most noticeable with male voices--a hollow thickening. Excessive bass energy overall, almost like there is too much BCS. My room aggrevates this, but I've heard it in other rooms. Cabinet or xover mistakes? I don't think so. It is a mystery.

The imaging is quite satisfying but not as vivid as my set of B&W 303s ($250/pair). The 1801b is reported to have holographic imaging, but I've never observed it.

The 1801b is fantastically detailed, and frequently surprises. The driver combo has a cleanliness that is unlike anything I've had in my room. I think the OW1 is beguiling, but Mark K conjectures that some of that magic may come from higher 2nd(?) order distortion. If so, give me that distortion.

The design screams for t-line loading--or some other environment for the W18, and an OW1 that can be crossed lower than the sacred 1400 hz, instead of 2600 hz. All of this said--a speaker that is still well worth the $650.00 kit price.

I jest about the thread becoming an OT nightmare.
I like quality digression.
Dave

There could be a number of factors at work- height from the floor, distance to walls- note that the closes three surfaces should be spaced at golden mean ratios to get the smoothest midbass to lower mids, and at the right overall distance so that the boundary lift kicks in as the speaker is starting to roll off...

How NOT to do it... (one example- there are many variations)



How to do it...



(Calculated in a MathCAD worksheet I put together years ago- can be evaluated in SE and LspCAD, too).


I'm kind of with MarkK about the OW1, but then you know, depending on who you talk to, I'm either too much of an objectivist (like to measure stuff, and use the results), or too much of a subjectivist (hear differences in amplifiers, cables, source components, and (oh my!) loudspeaker drivers that influence my choices.

I'm a lousy moderator at keeping things "On Topic", but then some rather interesting discussions can occur which are at least peripherally related to the topic at hand. Sort of like real world conversations.

The 1801 is a fine design - some folks have asked what would I do for something similar- I think we already have PLENTY of 7" two way systems around, and I've certainly contributed my share to the noise floor. I don't know of a finer 7" midrange driver (IMO) than the W18, but I also think it should be crossed over no higher than 1400 Hz, so I think there's a little room for further improvement.

Going way off topic, into the "What were they thinking category?", I wonder why on earth Seas brought out that new T29AF-001 29 mm metal dome tweeter for $160... OK, it looks sort of average, the efficiency is higher, but the FR plots look like a dog, especially off axis. No, scratch that, that comparison put's dogs in a bad light.

The whole "Crescendo" series has me scratching my head... am I alone in this? Does the emperor have any clothes on?

~Jon