I must be crazy....

**ThomasW** · 17 January 2001, 02:20 Wednesday

Hi Andrew

Yes the link is to this forum

I looked at the speaker building.com article and it's certainly a good speaker and a very well written document.

As far as midwoofers are concerned, many times it's a tossup. When buying in the $125+ range, drivers by Eton, Focal, ScanSpeak, Seas, etc., all are state of their art. There will of course be sonic differences, but usually they are subtle. It's best to audition as many as possible, but frequently that's impossible.

So the options are as follows. The "safest" bet is to go with a high-end kit. You get the best drivers, a proven design, tech support, and probably higher resale value. The down side is higher cost and lack of flexibility chosing the system.

The other option is to create something from scratch. This allows picking and choosing from the best drivers available and tailoring the design to your specific needs/wants. The obvious down side of this is the potential for the system to be less than optimal.

Some things to factor in the mix are, one's first DIY system usually won't be their last. So flexibility for upgrading or use as "effects" speakers is always a nice option. This means building something like a 2-way book shelf that sits on a bass-bin, is a solid idea. Bass-bins are pretty generic and can easily be adapted to match up with a good number of top modules.

In addition there's an interesting post on the Madisound forum. A Focal Audiom dealer posted that he doesn't think that the Audiom bigger woofers, offer any advantage over the standard Focal woofers. Interesting....

So here's my sugggestion. Research all the high-end 2-way "bookshelf" kits you can find, either MT or MTM. Chose one and build it. Then make a bass-bin using 2-10" drivers, if you want a narrow cabinet. Yes you can use the Focal 11"s if you really want to spend that much money

. Anything smaller than 10"s and you'd probably end up wanting a sub. But don't go overboard getting really high-end 10-11"s. They just don't make that big a difference.

Now in a few years you will probably get the urge to upgrade. So just make new top modules and use the old ones for rears.

theAudioWorx
Klone-Audio

**AndrewM** · 17 January 2001, 13:35 Wednesday

Yea, yesterday at work was such a madhouse that I left the office with my mail program open, the mp3 player (filled the office with music all night)...ahhh the joys.

Anyways, I liked the premise of the speakerbuilding.com setup, and who knows I may still go with that setup, although it's a little big.

The Watt/puppy clones are another option that I'm seriously considering, I've managed to talk to a couple of people who have built them according to the plans and they are all very satisfied. But I think the bass just won't be there from a pair of 8's.

I'd like to find a nice high end kit, but so far other than the Orca plans I haven't found to much that really sparks my interest. Although I'm intrigued by the BESL Series 5 MTM with the Seas W18 Magnesium cone and the Seas Millenium tweeter. But I haven't seen a whole lot of comments on that particular tweeter, and when it comes to spending this kind of money I'd like to have as much info as possible.

I agree that this won't be my last DIY project, however with my work schedule the way it is right now I don't have a lot of free time to do these things, for example it took me a little over 2 months to get a pair of Adire Vented 281's up and going (although most of that was painting), and they still need a little finishing work. So it could literally be a year or so between big projects.

I started the thread over on Madisound about the Audiom woofers, and the result was pretty much what I thought, the Audiom woofer is an awesome piece, but it's not really worth the extra cash for them, but there is a small difference. Maybe I'll save those for a future project when I have a better room to put them in.

But I must say that your idea of finding a good 2-way MTM/TM system and then add a bass bin isn't a bad idea, and for some reason I wasn't even really thinking in that direction.

About the whole bass situation, I am living in an apartment/townhome type deal, so there isn't anybody over or under me, but on 3 sides there are. Now the building is constructed real well and I never hear my neighbors or vice/versa, but I also don't have any kind of sub setup, so I doubt I can make those same claims if I had some of these tempest/shiva setups that I've seen, hence the desire to get to the 30Hz range, then I can drop the sub idea and be happy.

Ok, so a few options I could look at,
The BESL system 5, don't know the tweeter at all, the mids have a great reputation if x-overed properly. BESL has a highly regarded name, so I think it's probably a well designed system

Zalytron/Orca Aria 7, this can be used as a regular floor-standing setup, then build a new cabinet (from vented to sealed) when I want some more bass.

Zalytron/Orca Aria 5, pretty much the same as above but with less bass, but no need to rebuild a cabinet.

Northcreek doesn't offer any kind of smaller setup, and they use the Scan Speak tweeters.

Zalytron's other kits, they have a ton of bookshelf/stand mounted setups in all ranges using all kinds of drivers from Seas to Focal to Cabasse.

E-speakers, Andre is a joy to work with, and he likes the PHL stuff a lot, and I've heard some other good things about PHL from some other people, could also have Andre come up with a design.

What would I be losing out on by going with say an Aria 5/7 using the Focal mid instead of using something like an Eton/Seas mid range? Am I going to be missing a lot?

What else is out there?

Thanks again.
Andrew

**ThomasW** · 17 January 2001, 15:08 Wednesday

Hi

Just a quick note to address some items.

There's certainly nothing wrong with the big Seas or ScanSpeak tweeters. My personal preference is the Focal metal domes, I think they are more revealing of the source. However, if the playback electronics aren't first-class, a better option might be the soft domes.

Regarding Watt/puppy clones, my preference is an MTM configuration. I like the way they load into the room/image, compared to a TM config.

Regarding who's kit to get, I really can't say.

Andre should be good to work with he certainly charges premium prices. I know nothing about the PHL drivers, but I think there are better cone materials from other mgfrs.

Zalytron is frequently a pain to deal with, but their pricing is good. I don't think you'd be making much of a trade-off with the Focal mids.

North Creek gets lot's of good press (remember you can put a "tower" MTM config in a much smaller box. Only the low bass is lost). They used to publish their XO designs and they were good. I think they go a bit overboard with the designer XO components. But then again most of the high-end kit makers do the same.

BESL I don't have a clue about. They certainly aren't very forth coming regarding their XO designs.

None of these companies make "bad" speakers. I'd say go with something from Zalytron. They have been in business a long time. Their pricing is good. And they probably aren't going to drop off the face of the earth anytime soon.

The ScanSpeak and Seas kits from Madisound should also be quite good. I've been a customer since they started in business. They've have always offered great customer service.

theAudioWorx
Klone-Audio

**AndrewM** · 17 January 2001, 16:45 Wednesday

Well, I have to say that my preference falls in the same line as yours in that I prefer a Focal metal dome over the soft domes. I just don't get excited with the sound of a soft dome tweeter, now I haven't heard a lot of them (like the Seas unit and the high Scan Speak), but out of all the ones I've heard nothing does it for me, they sound good...but just not great..to me anyways.

It's funny that I was almost going to get the Aria 7 kit a number of months ago, but instead I opted for the Adire kit for the lower cost, plus I'm a skeptic at heart and just didn't think a DIY kit like that could sound as good as it did.

So me being the skeptic, do you think it's possible to achieve JM Labs Utopia like sound from one of these kits? For instance, the Aria 7 Monster has always captured my eyes (although I would throw out that ugly cabinet), but a sealed Aria 7 system sitting over dual 13" Focal's (non-Audiom) should sound good, but will it sound that good?

Here's a highly opinionated question

Between Seas and Focal (in general) for midranges do you have a preference? I think I'll stick to another kit again instead of trying to do something custom, or using the Madisoun LEAP service, or at least use the kit as a starting point and then add to it if needed. And Zalytron (they offer the most kits that interest me, Northcreek, BESL, etc only have maybe a couple higher end kits) offers both Seas and Focal and Cabasse (although limited selection) based kits.

This is the part I hate, not being able to easily hear any of these I have to rely on what other people say, now usually if you get 5, 10, 15+ people commenting on a certain driver you can get a good idea on sound.

Andrew

**ThomasW** · 17 January 2001, 17:21 Wednesday

There's no reason a kit can't/won't sound as good as an assembled speaker. Sometimes they are better if the mfgr has cut corners. This won't be the case with something like JM Labs though.

Regarding midbass cone materials, I do prefer the kevlar sandwich, (Eton or Focal)to anyother. Carbon fiber is good as too. There are more issues with metal domes other than just the cone breakup modes. They dent easily, and once dented there's no getting the cone straight again. Any of the "plastic" cone drivers will take some abuse, and be no worse for the wear

The Aria 7 sitting on a dual Focal 13" bass-bin, would be a pretty awesome system. It would certainly give most $5,000+ systems, a serious run for their money

theAudioWorx
Klone-Audio

**AndrewM** · 18 January 2001, 14:58 Thursday

Ok, so here is a preliminary sketch if you will of this project. The drivers in question are the Focal TC120tdx/2, 7k4411, 11v7511...I picked the 11's over the 13's as they will go in a smaller box and play lower (by about 3db). The woofer volume works out to be 6.05cu/ft and tuned to 31Hz with a slot port, but that's with no bracing and I need 6 cu/ft per Focal's recommended enclosure size. I figure some stuffing will bring that back in order once some bracing is in. The mid/hi enclosure is about 1.3 or so cu/ft (the tweeter will be sealed off from the mids), that gets me a Qtc around .54, the mid/hi cabinet is basically a duplicat of the Aria 7 Monster design, in fact the whole thing is except for making adjustments for the woofer substitution.

Cabinet's internal width is 12".
The angles are on the front face are only about 3 degrees, any ideas if this is going to cause any kind of problems? Basically it's only 2" back at 48" in height, so it's not a very big angle, but definatly breaks up that "flat" panel, crate/coffin look.

Andrew

**ThomasW** · 18 January 2001, 17:33 Thursday

Nice drawing

Do you really want a 200+lb cabinet? Might be a whole lot easier to build the speaker as 2 separate enclosures. Just a thought anyway....

theAudioWorx
Klone-Audio

**AndrewM** · 18 January 2001, 18:18 Thursday

Thanks, it's amazing all the things you can do with Visio...it's not a CAD program though, so it won't do 3-d...but it's a bit easier to use also.

As far as 200+ lbs of cabinet, I figure with 1"-1.5" cabinet walls, .5"-.75" bracing, plus drivers plus maybe some type of deadening to the cabinet walls I figure it could easily be somewhere in the 200-250lb range. Basically I'm thinking of doing it this way as I need that extra 1.5 cu/ft behind the mid/hi cabinet to make the whole setup semi sizable for my room, at least footprint wise.

The other part is that with a 6cu/ft bass bin well built/braced is going to weigh in around 175-200lbs itself, the mid/hi cabinet in the 50-70lb range. Basically with either setup they can't be just picked up and moved upstairs, they'll have to be strapped down to a dolly and lugged...but once they are there and setup, I never have to move them again, let the movers worry about it next time and give them a big tip.

Of course another idea would be to try and engineer some type of a modular system for it, so it comes apart in smaller pieces. That would be a nightmare to design well, but not impossible.. hhmmmm maybe design the MTM cabinet to slide into the rest of the cabinet...would have the best of both worlds then.

How about the angle issue, is this going to cause any kind of wierd sonic problems? The engineer/math wiz in me doesn't have me convinced that time aligned drivers are all that necessary (maybe gives you that extra 1-2%), but I did this for asethetic reasons (obvious since they aren't close to being truly time aligned).

Andrew

**ThomasW** · 18 January 2001, 19:30 Thursday

If you'd like, I can get the speaker angles Jon used for the SLAMM clones. They aren't any big secret. But they do "focus" the sound at a specific distance. I don't remember if he chose 8' or 10'.

Now the real Wilson X1 Grand SLAMMS don't have the angles. They have individual boxes for each of the three MTM drivers. When the speakers are "installed" the boxes are aligned to focus the sound at a sweet spot. They also have 2 rear firing "ambient" tweeters, this makes them sound less like a "box" speaker. The ambient tweeters aren't Focal TC120dx2. They are relatively inexpensive Audax metal domes.

Not Found

http://www.wilsonaudio.com/products/x1/index.html

Click on the middle picture in the "additional photo's" to see how they are made.

If you build them as 2 modular units, you can upgrade the top modules without messing with the bass-bins.

theAudioWorx
Klone-Audio

**AndrewM** · 19 January 2001, 00:22 Friday

Yea, I'd be interested in those angles, although my sitting position is a little further away (12-13 ft), it would be interesting to see the corolations.

You know it's funny that I never hear that many good things about Wilson's stuff, the magazine's rave about them, but other than that it's a real mixed bag. I wonder if thats just because of the price or if they just aren't all that as they say. I was impressed by the Watt/Puppies that I heard, but I wasn't thinking of buying something in that price range, so maybe I wasn't as critical in my listening. Also doesn't David Wilson set most of those high end systems up personally (or with a tech), I thought I had read something along those lines at sometime. I wonder if the setup is included in the $100k+ price tag.

As for the 2units vs. 1unit, I agree it would be better for moving and for future designs, however I need to get it approved by the spouce (and she's very patient with my audio/video hobby), I like the single box idea better for the looks reason (something this big has got to look good), but me being a male, I'll sacrifice some looks for other things....she probably won't. But we'll see, either way I don't look forward to moving them around during the building and setup period, but the end result should still be worth it.

Andrew

**ThomasW** · 19 January 2001, 00:56 Friday

I've heard the real SLAMMs, they sound stunning. Of course they were being driver with $30,000+ of Mark Levinson electronics.

Yes custom installation by Wilson Audio is included in the price.

I'll get a copy of the angles and send them to you. I'll ask Jon how much they would change for the 12' distance

theAudioWorx
Klone-Audio

**AndrewM** · 19 January 2001, 10:34 Friday

I've heard the real SLAMMs, they sound stunning. Of course they were being driver with $30,000+ of Mark Levinson electronics.

I have no doubts about that, this is the problem with building very high end speaker systems, we can build them for literally pennies on the dollar, but most of us probably don't have that ultra-high end equipment to drive them with. I don't think Mr. Levinson would be willing to send over a parts list and a few schematics, and hey while he's at it some assembly notes.

Andrew

**ThomasW** · 19 January 2001, 15:52 Friday

Well the SLAMM clones sound pretty good too. And they are being driven by more modest electronics

Jon is going to drop by this thread in a day or so. He'll give you particulars about the driver layout. BTW if you want to copy the top module of the SLAMMS with the Eton drivers, I'm sure we can get him to assist with XO design.

theAudioWorx
Klone-Audio

**AndrewM** · 19 January 2001, 16:20 Friday

That would be great, I'm interested in maybe trying it out with the Eton mids...and from there it's only a 12" and a 15" to making an X1 clone...errr that's bad thinking, I don't think that thing would fit in my room very well. So how much do the clones weigh in at, a bit less than the originals I would hope? Which drivers did you choose for the bottom cabinet, did you stick with the Focals (the originals use Focals I believe) or make a substitution (since Focal doesn't make a 12" or 15" driver anymore). Do they share the same volume in the cabinet, or is one say sealed and the other ported? Ever try those with a passive x-over between the mid/hi's and the bass bin?

I don't think the Girlfriend would ever go for anything that big...hehehe

Andrew
(wondering how to justify such a huge speaker)

**JonMarsh** · 22 January 2001, 11:34 Monday

I must be crazy.....

I thought that a few times while planning my X1 "clones". But there's quite a bit of satisfaction involved from taking something from a notebook full of ideas and sketches and calculations, to 375 lb. of speaker system sitting in each front corner of your living room.

Various notes and comments in no particular order:

1. The facet angles for the 7" midwoofers is 15 degrees. The Wilson X1's are angled also, but differ in having seperate sub enclosures for the two 7" midwoofers, and mounting them and the tweeter modules in a aluminum frame which allows adjusting the front to back alignment. The Wilson X1 uses a 2nd order all pass crossover from the midwoofers to the tweeter; coincident voice coil mounting is essential to getting flat on axis response through the passband in an all pass crossover. The advantage of this crossover configuration is the relatively lower power handing at the crossover knee, the disadvantage is the reatlively poor vertical dispersion at the crossover frequency - narrow polar pattern. This results in a dip in the room power response.
The "clones" use a modified third order B3 network, which is less senstive to time alignment, requires more components, has higher power handling reuquirements at the crossover knee, but attenuates faster out of band. It also has a wider polar response in the crossover region, and flatter overall power response into the room, plus it doesn't require wiring the drivers out of phase, as the 2nd order all pass does. It also allows having the tweeter a little further forward, which reduces the early reflections from the tweeter in the original X1 design which cause irregularities in the response due to comb filtering of the direct and early reflections. The angled mounting plates provides for the on axis mid response to be focussed about six feet out and create a wider vertical dispersion pattern without as much off axis cancellation between the drivers. IMO, the best that you can do with two mid soruces. spaced this far apart. BTW, xover frequency is 2.5 kHz.

2. The bass bins use Audax 13" and 15" drivers, because I already had some, and this was part of the motivating scenario, "Gee, I already have some very good 13" and 15" drivers, how much more would I need to invest? BTW, Focal does still make 12" and 15" woofers. The Audax drivers are optimized for high BL product; I've used them in some subwoofer designs with slot loading from the late 70's. They're not optimized for high Xmax. What they do work well is QB3 alignment bass reflex with active EQ to flatten the room response; in the alignment I chose, the drivers are overdamped, with a gradual roll off from 150 Hz on down to the system tuning of 27 Hz. A simple pasive or active shelving EQ adjusts the bass to "flat" in the living room, after using a combination of RPG Acoustics program and Wilson's technique for inverse voicing location to determine the optimum positioning. Because an active crossover is used, about 35-50 lb. of passive crossover weight is saved in the speaker cabinets, (10AWG low loss coils are HEAVY!), and the LF transient response and damping isn't compromised by the coil impedance. It just costs more, including designing and building a custom active crossover.

3. Tweeters- room power response about 9-10 kHz is filled in by Audax DTI01, same as Wilson X1; these are flat and smooth up to 40 kHz. Main tweeter is the Focal Td120tx2 (may not be remembering that number correctly!)- it's the closest in design and construction to the wilson custom tweeter- both are double magnet, both are ferrofluid cooled, efficiency the same, same diffusor, the Wilson reportedly use a different magnetic iron, and some other refinements. I think this is one of the finest sounding tweeters in the world because of the self damping characteristic of the tioxid dome- it doesn't "ring" in the same way (like a bell) because of the self damping characteristics of the tioxid coating. Yes, there is an upper end break up peak, around 38 kHz, but it's relatively tame, again, I think, because of the tioxid material.

4. Midwoofers- Wilson uses a custom Dynaudio in the X1, uses Scanspeak carbon fiber drivers in the Wilson "Max" (a mini X1). I prefer the Eton drivers, because their sandwich Kevlar/nomex cones resist breakup until very high frequencies, and are also quite light (Eton 370 cone mass is 1/2 of scanspeak 7" drivers). They are the only cone drivers I've heard that compare in midrange clarity with a planar system, with good crossover design and cabinets. The 370 is not a good driver for a full range system, but it's excellent from 125 on up. For a "mini monitor", I'd use the 360, with a 2 kHz fourth order all pass. This might be an interesting way to do a Watt Puppy, but I'd use dual 11" Eton's or dual Focal 12's for the bass. Eight inch drivers just don't move air.

One key to the overall performance of the X1 approach is the large vertical source size in the important "power" region, from 100 Hz to 250 Hz; this makes the speaker much less susceptible to the nulls and dips in response in this region which plagues box speakers (because of room placement issues) compared with planars like maggies, and gives it more accurate timber and dynamics in this all important part of the musical spectrum. I'm finally fairly satisfied with my main speaker system; now I'm just trying to figure out what I'll build for rears- probably a Watt/Puppy clone along the lines I've described.

Regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**AndrewM** · 22 January 2001, 21:18 Monday

Wow! Thanks for all the info Jon, that's a lot of info to digest. Well, I think the X1 idea has been vetoed out, so I'll stick with the original plan for the MTM with a dual smaller woofer solution.

So here's what I've basically settled on;
Focal 120tdx/2 tweeter, basically the best metal dome tweeter.

Woofers, I'm about 98% set on going with dual Focal 11V7511 woofers, in Focal's recommended box size and tuning I'll end up with an F3 around 31Hz, they are on sale at SpeakerCity (always a bonus), and I like the sound of these as well.

Mids, I'm just undecided on this one. On one hand I can go with the Focal 7" Kevlars, I even have the benefit of the Orca designed x-over for them, but I've heard people mention better drivers (not a whole lot better, but better none the less), the Eton drivers interest me, especially between what you and Thomas have said about them I'd be interested in giving them a shot.

However, I have a few questions, Madisound carries the Eton 350, 360 and 372 with Heat Pipe in the 7" line, so the drivers you used are no longer available. So I don't know if your x-over design (if you would be willing to share

) would work by making the substitution, so does the kevlar breakup happen high enough up that a "textbook" 2.5Khz 3rd order x-over get rid of the problem, or do I have to add some extra filtering in the mix to get rid of it? I'm seriously lacking in the measuring department as to x-overs go. I wouldn't mind investing in some if I had more time to invest in the hobby.

I'm not to concerned about how low they will go as the Focal woofers will play up more than high enough (150-200Hz I would think the x-over could be). As far as going active for the bottom, I would love to but between building it (not a big problem) and buying an extra amp (the bigger problem) and designing something custom (not gonna happen) I think going passive for now is a good idea. If I have to, I can EQ the system a little, just need to go rent a good RTA and Mic and tune it a little.

Andrew

**ThomasW** · 23 January 2001, 00:22 Tuesday

Andrew

I spoke with Jon regarding the Eton part numbers as he was posting his reply. His suggestion was to use the 372 with the "heatpipe". My guess is that you could use Jon's XO with minimal modifications.

BTW, contrary to what was posted on HTF, there aren't significant break up issues with these drivers. Nor is there as big a spike in FR as the Excel has. The Eton 372 plots are below.

These are the Excel plots

theAudioWorx
Klone-Audio

**JonMarsh** · 23 January 2001, 11:25 Tuesday

The 372 is extremely similar to the 370 in basic cone construction; it has higher compliance, and in the version with the heatpipe, it doesn't have the standard dome, but does have higher power handling. You pretty much could drop in 372's in a midwoofer application for the 370's; I've built some MTM bookshelf speakers which were originally designed around the midrange crossover developed for the 370, and the 372 worked fine.
A point to consider in choosing your woofer's is the upper end response, it should be smooth and extended, and without any wrinkles in the impedance plot (which indicate breakup modes, even if you don't see them clearly in the amplitude response), because if you're going to go with a passive crossover system, the most elegant way to get good conversion efficiency and a simple crossover for the mids is to use a 6 dB per octave roll off on the woofer system, up to about 600-700, so that it fills in for the baffle step response of the dual 7's, and kill it faster above that. Then the seven's should be rolled off with an acoustic transfer function (high pass) of 18 dB /octave, which will be some combination of their own LF roll off and the actual cross over. This is how the Watt/Puppy's and Wilson X1 do it, also; it allows you to avoid killing some of the dual 7 efficiency in order to compensate for baffle step. With my own system, I do all the EQ and compensation in the custom electronic crossover, both for the LF section and the mids, so there's a bit more flexibility, particularly for tweaking.

Regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**AndrewM** · 24 January 2001, 12:47 Wednesday

Well, that is one of the reasons I decided to go with Focal's for the woofers, the non-kevlar woofer (11V7511) looks to be fairly flat (except a 1-2db bump in the 100-200Hz range) up until the 600-700Hz region, then it looks like it starts to have some breakup in the 1Khz+ region. The impedence plot looks very smooth as well except for a couple of minor bumps

Are the graphs for the 11V7511. The 11K7511 actually looks a little smoother as it doesn't breakup till 2Khz, and the impedence plot is even smoother than the 11V.

So I may want to go with the 11K, it goes almost as low (31Hz vs 33Hz for an F3), and needs a smaller cabinet by 20 litres. But it costs a little more money (About $25 ea, or about $100 more for the whole project).

So I think I'm just about there in terms of planning, I need to finish the drawings for the cabinets and get those finalyzed. So we have a Focal tweeter, 2 Eton 372's and 2 Focal 11V woofers per side, is there anything I'm missing or any other recommendations that anybody wants to throw into the mix?

Andrew

**JonMarsh** · 24 January 2001, 16:49 Wednesday

Hi Andrew,

The second set of plots look better to me, because they don't have the wrinkle at 1 kHz in the impedance plot that the first does; you can see this in the amplitude plot of the first, also,with the rise before 1 kHz and the dip afterwards. Either could be made to work, of course, just a matter of cost and preference. It sounds like your plans are set, though I'd consider a power response fill tweeter also. You always have to decide just where to draw the line, though!

-Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**AndrewM** · 24 January 2001, 17:44 Wednesday

Hmmm, well the difference in cost is around $40 a speaker, so it's more like $160 difference for the whole project, which is not to bad (I never expected this to be a cheap project). But between the 2 materials of Polykevlar and Polyglass which one would you say sounds better in a woofer role? Or if it would be to close to call how much extra work in the x-over is it?

On the power responce tweeter, where is that mounted, besides on the back? Is there any special angles to be used or anything of that nature, ie, can it be mount on the back side and have the sound bounce off the back wall, or should it be angled up? Does it really add that much to the speaker sound? It sounds like it could be an interesting addition without adding to much to the cost.

Thanks again for all the help.
Andrew

**JonMarsh** · 25 January 2001, 14:00 Thursday

Well, Andrew, I have my prejudices, and a favoritism to kevlar is one of them, but the construction methods matter just as much as the material. But I would personally opt for the kevlar version; in a project like this, the amount of work and effort involved tends to really swamp out things like a $160 difference in materials cost!

Regarding the power response tweeter, some companies just use a rear firing tweeter (1), but of course, the X1's use two, one straight back, one angled up. You know, if some's good, more is better. (followed by "too much is just enough").
In the grand scheme of things, I think its desirable to balance the direct sound and the reverberant power response fairly closely in character and response- and this is one way to do this, because above 8-9 kHz, dome tweeters fall off in power response. Line arrays behave differently, and have a different "throw" and power response characteristic. Ideally, if you're building four of these, build one rough acoustic prototype, and play with it until you're happy with everything. Then freeze the design and build the final versions. If you hang oriental rugs on your back wall, or you plan on backing the speaker up to the wall, power response tweeters are probably a waste of time. In a more conventional room, with moderately live, preferrably diffuse rear walls, I like what they do. But then I built AR LST clones in the early seventies, too, so I have a history of preferring near flat room power response, but *not* with hot axial response.
You're going to have a lot of fun building these puppies, I hope you keep us posted on all the gory details.

Regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**JonMarsh** · 25 January 2001, 16:20 Thursday

This is more addressed to ThomasW; commenting on some of his responses to you. He has heard the SLAMM clones in a very early stage of development, with modified Marchand crossovers, no EQ for baffle step response, and the EQ for bass was something in a passive box designed for another system, and first generation passive crossovers. Though they had some audible frequency response colorations, the dynamics and effortless playback were pretty awesome, even with just one speaker running. That phase of development work was done with an Aragon ST, a fine sounding stereo amp, with high current output capbility.
The "current" version is pending one more HF crossover upgrade that's been modelled on the computer but not yet built, has the full custom electronic crossover with balanced transformer outputs, and is driven with Aragon Palladium Class A monoblocks- which dollar for dollar, I'd put up against anything Krell or Mark Levinson makes below $10K. The room size is not what I'd call optimum for these speakers, but still they do some pretty spooky things at times. It's the first speaker I've built that I haven't had it's successor on the drawing board before I finished them. In fact, I haven't even thought about a successor- other than doing something really weird, like a set of Maggie 3.6 with Tempest based subs. And I'm not convinced I'd be as happy- these have a coherency and "rightness" about them from the mid thirties up to the highest midrange harmonics on bass instruments (like five string bass guitar, a variety of drums & percussion instruments) that I just haven't experienced in a home system. (Most home systems *don't* do a good job reproducing bass guitar- it doesn't sound like a guitar, but like a synth instead). Some of that is due to SACD playback, and how well the 777ES handles CD, but the rest is the speakers. Ability to move air, and very smooth power response throughout the room are probably key to that. They're not as room immune as a dipole, like the Whispers, for example, but when you get them "right" (RPG Acoustics software is a big help for staring positions), it's pretty sweet.

Regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**JonMarsh** · 01 February 2001, 14:38 Thursday

Andrew,

I've been getting home late from work this week, haven't had time to get the schematic PDF'd for you, but I will this weekend, and send it out. It will be the newest version, but keep in mind it's "tweaked" for my system- your mileage may vary!

Regards,

Jon

Earth First!
_______________________________
We'll screw up the other planets later....

**AndrewM** · 02 February 2001, 12:08 Friday

No problem Jon, I'm not ready to do anything with this just yet anyways, maybe more towards the end of the month I'll actually start getting this project under way, I just wanted to get everything together and organized so when I do start I can keep going till it's done.

Also, I know it's tweaked for your system and it may or may not work for mine, but it will most likely be a good place to start from and then tweak from there. Or maybe it won't, one can never tell. I do plan on getting some type of a measuring system to at least give me an idea what is going on, and what I'll need to tweak on.

Thanks again for all the help.

Andrew

I must be crazy....

I must be crazy....

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment