OK, lets design and build the best speaker possible (“No compromises?”)

[JonW]

I’d like to propose a fun design exercise and see where it might end up.
I’ve been reading some books and a lot of this web site, trying to learn about speaker design and construction. I made a sub and I’m in the middle of making the Modula MT’s. It’s all quite fun. :T And now I’m thinking about making some DIY speakers to replace my main commercial speakers. I’m wondering what might constitute a “no compromises” pair of speakers. Something to live up to my 7 foot tall sub. Maybe there are some designs already out there? Some practical constraints will come into play, like keep them under 500 pounds so they can be moved, etc. (see below). But what might we end up with if we tried to design the best speakers possible?

Here are some things I think might be good to start guiding the design:

-General: I’m thinking a 3-way design (tweeter, mids, woofers) might be best. That way it will be a full range speaker. And anything more than 3-way gets pretty complicated with regard to crossovers, integrations, etc. So maybe keeping it a 3-way will maximize the chances of it sounding good. Maybe it’ll be MTMWW or WMTMW or…?

-Crossover: Maybe passive to start. But let’s pick configurations, drivers, etc. prior to getting into any crossover design.

-Size: Let’s say it can be as big as needed to optimize the sound quality. Within reason, however. I’d think 8 feet tall and 500 pounds would be both very cumbersome to construct and move around when complete. If things are getting quite large, it might be helpful to break things into separate cabinets. Say an MTM top with a WW bass bin bottom, for example.

-Cabinet design: It’s a DIY design, so it has to be buildable by a nonprofessional woodworker. Let’s say it’s buildable by someone with strong woodworking skills. Maybe Avalon-esque faceting is the limit for complexity.

-Efficiency and amplification: Let’s say normal amps at normal prices are up to 200 W. So perhaps that’s what we should work with. If we use the THX standards as a very rough guide for desirable output, I think that’s 105 db transients. So that’s how loud we’d need to go without any distortion. Biamping would be fine. Having 4 amps around at 200 W each is reasonable, I think. Triamping only if you ask very nicely.

-Bass extension: It needs to play every note of music cleanly, before dropping off. It’s aimed at being full range for a critical music listener. But it’s OK to supplement it with a sub for movies. No need to play 10 Hz at 110 db for some movie explosions.

-Cost: Let’s say no limit for now. I’m curious where a “no compromise” design might lead to. Maybe we could come up with different flavors for different budgets later. If a good design were to emerge and it could be built for, say, $2,500 in crossover parts and drivers, I might like to do it.


So what would be the best speaker possible? What drivers to use? What configuration? What’s it going to look like? What do all you bright folks think?

OK, go! :B

[chasw98]

If Jon and Thomas are allowed to play in this, we can stop right now. Can you say quad amped, active XO, Saint-Saens?

[Dennis H]

This is one of those open-ended questions with no answer. One guy's best is another guy's suck-monster. It's impossible to say what will sound best without considering room and placement issues. Your question seems to imply a box speaker would be best but many here would say boxes suck and the ultimate speaker is a dipole crossed to a sub somewhere down low. See JonMarsh's preliminary thoughts on the Arvo Mark 3 for a no-holds-barred dipole design concept.

[Dennis H]

Can you say quad amped, active XO, Saint-Saens?

Jon doesn't like active XOs above the bass region. Also note that Thomas built a prototype BG line array for his family room and replaced it with an Arvo. The old room/placement thing I mentioned above. Line arrays have very specific room/placement requirements,

[jonathanb3478]

I love to see "no compromise" projects where the project scope states that there are 4 compromises:

Cannot be more than 3-way

Cannot be too large to move easily

Cannot be too hard to build

Has to be efficient enough to get to 105db at 200w.



I would not use "no compromise" in the thread title. I could see "cost no object", but certainly not "no compromise".

[JonW]

This is one of those open-ended questions with no answer.

Yeah, I know. But there are many design elements that most people can agree on. After reading "Loudspeaker Design Cookbook" I came to udnerstand (a little) why all the speakers out there sound so different. There are many design choices along the way. Perhaps a collection of reasonably bright people can iterate down to a single design or a small group of designs. Not that I'm calling anyone here bright. :P

[Dennis H]

Good point Jonathan. ALL speakers are compromises. You define your goals and choose the compromises that come closest to meeting them.

[JonW]

I would not use "no compromise" in the thread title.

Perhaps you missed the "?" at the end of the "no compromise" in the title. I put it there for a reason. I also put it in quotes, to imply it's a thought. But not the absolute focus here. Speaker design, as I understand it, is always a set of compromises between many, many factors. What if we eliminate factors such as price, size contraints to fit a certain room, WAF, the need to use a particular driver... Where does that take us? I certainly don't know.

And if saying the speaker should be less than 8 feet tall and 500 pounds... that it needs to play loudly without distorion... If those things are compromises, well, then yeah, I'm all about compromise. And should never use the term "no compromise."

[jonathanb3478]

And if saying the speaker should be less than 8 feet tall and 500 pounds...

Well, the 500 pound figure rules out some combinations of construction techniques that I am a fan of. Say I wanted to combine one-piece, 4"+ thick cement front baffles (like the old Hales Design Group "Concept" series back in the 90s), with a marble slab base. I am out of luck, because you "compromised" with a 500lb limit.

that it needs to play loudly without distorion...

I never questioned a commitment to low distortion at high volume. You should avoid straw man arguments, they do not help your point. Quite the opposite, in fact.

What I pointed out, was that you said 105db @ 200w. "No compromise" would be "however many watts are needed to get to 105db, so be it".

If those things are compromises, well, then yeah, I'm all about compromise.

If you are happy with your size compromise, that is fine. I am just pointing out that it is a compromise.

I already touched on the whole "straw man" thing. You certainly have no need to defend your love of high volume at low distortion to me. I never attacked it, nor would I ever do such a thing.

If you want to set a minimum efficiency for this project, that is cool with me.

And should never use the term "no compromise."

Agreed!

:T

[Hank]

As Chasw98 alluded to, it's coming in the form of Jon's Saint-Saens, which might be his finest work (until the next one). Anyway, interesting exercise. I cut the cabinet parts for a local guy's dipoles that Greg of Selah Audio designed. Two Accuton mids per side - I hear you can't get better mids from a cone driver that the Accutons. You might consider them for your fantasy speaker.

[Paul H]

If I was going for something like you've described in the first post here - see my avatar for one interpretation - a 4-way active dipole - it's not perfect, but it's very good, in my biased opinion

[Jed]

I think you need to set some more design constraints because some ultimate dipoles are already in the works. For example, maybe this should become the Isis clone thread. C24, C90, and dual Aura 12" woofers. That should do it. Wish I had space for something that enormous.

Jed

[seattle_ice]

I think I get what the OP is going for. Many of the designs we see are 'compromised' by budgetary, space, WAF and construction complexity concerns. I would be interested in what would come up if most, if not all, of these concerns were, if not eliminated, then mitigated to a minimum.

If I put a 'Speaker Wish List' this would be it:

1. An excellent sounding speaker, not too bright, not too boomy, but chrystal clear, with a wide soundstage and lots of 'presence' from ~30hz - 20khz.
2.Would suit at least a large percentage of the Audiophiles that would build it.
3.Is somewhat forgiving about room placement.
4. Not extremely demanding for amplification ie: I wouldn't have to run 500 wpc to enjoy reference listening levels. Would sound good from the typical HT Receiver with maybe 100 wpc and even better through high end gear.

Just my .02 worth.

[cjd]

Well, I've built the mini version (see RS 3-way thread in Mission Accomplished)

If i have to keep it 3-way, I guess I'd have to really stretch things and go high quality 15" sub drivers, 8" mid-woofers, and a tweeter that can handle that low crossover.

It isn't full range for me unless it'll do pedal from organ, which is 16Hz.

C

[ThomasW]

Also note that Thomas built a prototype BG line array for his family room and replaced it with an Arvo

The only conclusion to be drawn from this, is that living with one massive line array in the house is enough. That's also why the Arvo Ultra's had a short life in the family room...:wink:

Speaking of the Arvo ultra's that was a pretty kick-*ss system that certainly fits into the topic of this thread. For those not familar with that project, HERE's a link....

[seattle_ice]

Thomas:

Are those Arvo Ultra's 'done' done? I may have misunderstood, but it seemed like you were still finalizing the Xovers.

A seperate thread in the Missions Accomplished with the specs, BOM, etc. would probably garner some interest and help with the readability (read 'Find information amongst 5 zillion posts) factor.

What was the approximate cost of building those behemoths? Amazing. I can see people (ok - me) building something like that just for the wow factor.

I am in the planning stages of my new Music studio/Theater/Listening room. It is a large room (600 + ft.^2) and there is lots of room.....

[ThomasW]

Are those Arvo Ultra's 'done' done? I may have misunderstood, but it seemed like you were still finalizing the Xovers.

They were simply the standard (original) Arvo design (as posted in the Mission Accomplished section) with another woofer section grafted on top.

I used a generic active XO for the woofer section, as I do with my standard Arvo's.

They were operational for several weeks then disassembled since they were visually too large for the room. This was just a test to see what they'd sound like, and they sounded very good.

[seattle_ice]

Oh, ok, now I remember.

Sometimes the sheer amount of information on here can be a little overwhelming. I sometimes have trouble keeping it all straight, though I have read all the posts, many more than once.

[JonW]

OK, the conversation is getting more on track. I apologize if my initial list of considerations were taken to be requirements. Nope, just a place to start. Fell free to change things around.

I think I get what the OP is going for. Many of the designs we see are 'compromised' by budgetary, space, WAF and construction complexity concerns. I would be interested in what would come up if most, if not all, of these concerns were, if not eliminated, then mitigated to a minimum.

Exactly! :T

If I was going for something like you've described in the first post here - see my avatar for one interpretation - a 4-way active dipole - it's not perfect, but it's very good, in my biased opinion

Very nice looking. I thought a 4-way might be too complex to begin with. And we might have a higher chance of getting something to sound good if we stick with a 3-way. But maybe not. What’s good about them and what don’t you like?

As Chasw98 alluded to, it's coming in the form of Jon's Saint-Saens, which might be his finest work (until the next one).

I’m not familiar with this one. Are there details available?

Anyway, interesting exercise. I cut the cabinet parts for a local guy's dipoles that Greg of Selah Audio designed. Two Accuton mids per side - I hear you can't get better mids from a cone driver that the Accutons. You might consider them for your fantasy speaker.

Any particular model? In picking drivers, we’ll have to get someone here with actual measurements.

I think you need to set some more design constraints because some ultimate dipoles are already in the works. For example, maybe this should become the Isis clone thread. C24, C90, and dual Aura 12" woofers. That should do it. Wish I had space for something that enormous.

Interesting. I’ve not had a chance to hear those. We don’t necessarily need to clone another design, although that would be fine, too.

Well, I've built the mini version (see RS 3-way thread in Mission Accomplished)

If i have to keep it 3-way, I guess I'd have to really stretch things and go high quality 15" sub drivers, 8" mid-woofers, and a tweeter that can handle that low crossover.

It isn't full range for me unless it'll do pedal from organ, which is 16Hz.

C

Chris-
I hope your hand is healing well.
Yes, I’ve read through your RS 3-way thread. And I’m thinking about trying to build a pair. It looks very nice. (Maybe I could take a drive to Chicago to have a listen some time?) But I’m thinking maybe we could come up with something a little better.
No need to keep it 3-way. I just thought that might up the odds of it sounding good the first time around. And OK on the 16 Hz. Good point.



ThomasW-
So what is the nicest sounding DIY speaker you’ve heard? That might help focus things a bit.

Thanks fellas. This is interesting.

-Jon

[cjd]

Jon: as long as I'm expecting you, swing by. In fact, my wife might really like you (or, maybe not... who knows what's next!) if you wanted them so bad you just went home with the ones in my living room. Add a sub, cross ~50Hz, and they're full range - being sealed rolls off the bottom end some.

Hand is doing really well - I often forget it was inujured, but then it itches or twinges or something. 98% of my range of motion back, strength returning... good stuff. Takes 6mo+ for the swelling in the knuckles to go away which is what's hindering range of motion.

I think "ultimate system" is really a difficult concept, because there are sooo many variables.

Next time I have room, I'll be doing more open baffle work. I could just build the Arvo's but what is the fun in that? (note that they're an open baffle variant of what I described, almost - 12 instead of 15"...)

If big boxes doesn't work for you, clearly that's not an ultimate system.

So, as already mentioned, what compromises must you choose today?

C

[Landroval]

I wonder what's the situation with Jon's Isiris project...

[JonW]

Chris-
Great that your hand is coming along. The first 98% can go quickly, but that last 2% may take a while. Be patient. But I’ll say, I’ve got a healthy fear of my table saw.

Sorry to disappoint your wife, but I won’t be taking your speakers off your hands. I want to build some myself. Not sure I can ever even buy speakers again, at this point.

Yup, lots and lots of variables for an “ultimate system.” That’s why I asked the original question.

I’ve shied away from the Arvo project only because I have the impression it’s not a completed design, and has the potential to be better.

If we tried to design the speakers based upon committee, the experiences, the brains of everyone here, I’m curious to see what we might end up with. And heck, maybe I would build them. No size restrictions (big boxes are AOK by me), no bias toward a box vs. open baffle, etc.

[SteveCallas]

For those with open baffle systems, any truth to the "driver self noise" notion, even at low volumes?

[soho54]

That would probably depend on the drivers used. I'm working on a set of Arvo and they could be listened to from the rear. You would have to bump the treble a little though, monopole tweeter and what not, and imaging takes a hit. Zero "self noise" at low volumes. At loud volumes (+90db) the wiring was a problem, just had to add a few more cable clamps.

[AJINFLA]

This may be possible if you can eliminate one critical factor. People.
Not the room, or the drivers, or the cabinet type, or anything else.
If you could get (most) everyone to have roughly the same opinion, then "Best speaker possible" would certainly be attainable.

cheers,

AJ

[JonW]

This may be possible if you can eliminate one critical factor. People.

That's why I moved to Indiana. :P

I'd think there are _some_ things we could agree on. So I'd like to see what they are. And then maybe make some choices from there on a system. To come up with one I'd like to have as well as a few other people might enjoy.

-=-=

Related to what Steve asked, regarding open baffle systems:

What kind of amplification do these systems typically require in order to sound good? If they're less efficient than box speakers, are they still OK with 200 W (or 400 W biamped) or do they need 600 W of pure class A or what?

[Dennis H]

If we tried to design the speakers based upon committee

Well, you know what they say...... a camel is a horse designed by committee.

[SteveCallas]

Lost of resistance in this thread.....

How about phrasing it this way - and Jon, let me know if I'm off base. The MTM's are generally regarded around here as the best speakers you could build in the neighborhood of $800.

What if the neighborhood was more like $2500-$3000?
What if you could make them several feet tall and have them weigh a few hundred pounds?
What if WAF wasn't given much (if any) priority?
What if you want to achieve a huge soundstage, pinpoint imaging, amazing clarity, and scary dynamics?
What if you can use enough drivers to get the sensitivity up to the 92db+ range so you don't have to run hundreds and hundreds of watts through your speakers to reach 105db peaks?
What if you want to reach 105db peaks cleanly?
What if you want to have reasonably flat and clean extension to the mid 20s?

Taking all that into account, while there probably still won't be a unanimous design choice, there should be a pretty good idea of what he's shooting for. Certain designs probably won't be given much consideration anymore.

Honestly, after typing that, I'm thinking line array is the answer. Anything else though?

[JonW]

How about phrasing it this way - and Jon, let me know if I'm off base.

You got it. :T
I might take a couple things off your list so we don't make it _too_ restrictive at the beginning. Maybe forget about the 92 db efficiency and the mid 20's extension. It'd be great to keep them, of course. Although I wonder if that would limit us too much. But hey, this is all flexble. So far, we're only talking about starting points.

[Dennis H]

The trouble with line arrays is they need to be designed for a specific listening distance. If you look at the graph in Jim Griffin's white paper, you can see that you will be in the nearfield at some frequencies and the farfield at others. That means some frequencies change 6dB when you double the distance and some only change 3dB. If we can get everyone to agree on a listening distance, LA's may be a good option.

Personally, I think the Arvo/Orion concept crossed to an IB sub is a better option.

Edit: I found a copy of Jim's graph that I marked up with grid lines to make it easier to read. For example, a 5' array, 10' away, will have a nearfield-farfield transition at about 1kHz --- not good if you want to keep an even frequency response as you move around the room or to have a single design work in different sized rooms.

[JonW]

See Dennis, now you’re contributing. :T :P

I didn’t know that about line arrays. Good point. Makes sense, though, given the size of a tall LA.

Personally, I think the Arvo/Orion concept crossed to an IB sub is a better option.

OK, so what do you like -and dislike- about the Arvo?

My understanding of the Arvo is that A) it’s not yet a complete design and B) (for open baffles in general) it needs massive amounts of power to run well. Correct or not?

[JonMarsh]

Ooh, you guys have been having a party talking speakers and I didnt' even know....


Sorry I haven't been around much, but between work and a bum knee that required surgery last week, things have not been at all normal around Casa de Juan.


Dennis H's reprint of Jim Griffin's chart is very appropro regarding the issues around line sources, and is one reason I'm still hanging back a little from the Saint-Saens, though also wanting to complete some other stuff well underway is part of it.

I really do agree that we have a good example of this kind of effort with Paul H's dipoles with the Seas drivers- a lot of craftsmanship and effort went into that project, and I wish there was some way I could hear them sometime.


The Arvo/Isiris diople is an effort to put a lot of the best ideas that have been kicked around here the last few years into practice, in a very "methodical" kind of way, including full baffle simulation, driver selection through a lot (for me) of measurements, and yet still wanting to keep something that's semi-practical (?).

My notion of semi-practical being that they don't weigh more than 200 lb. per side, and much less if possible (remember, I've done the 375 lb. monster loud speaker thing- X1 SLAM Klone (which is going to be retrofitted with some new drivers and a new woofers setup sometime in the next year or two). So, the "Isiris" project with C90, either C13 with waveguide or C24, and Aurasound 12's is the design I'd submit for Jonathan B's consideration for a three way. Realistic low end extension won't meet Chris's requirements, because without sub I'm only shooting for 35 Hz. There's an alternative design with lower cost drivers roughed out, too, destined in principle for a magazine article (I have a commitment, now I just need time).

For those that haven't read ideas scattered through other threads, the Saint-Saens is a quasi-line array dipole design, using B&G RD50's, Fountek JP2 (8 per side), and not yet determined or purchased midwoofers, though Aurasound is the most likely vendor. (think 4-12's or 6 10's per side) . Could be a lot iffier design technically, and some possibly questionable choices- more "romance" than "science", which is why they're named after one of the foremost French romantic composers of the 19th century.

[JonMarsh]

See Dennis, now you’re contributing. :T :P

I didn’t know that about line arrays. Good point. Makes sense, though, given the size of a tall LA.



OK, so what do you like -and dislike- about the Arvo?

My understanding of the Arvo is that A) it’s not yet a complete design and B) (for open baffles in general) it needs massive amounts of power to run well. Correct or not?

Yes, it's still in evolution. Wait.

Doesn't need massive amounts of power necessarily, unless you try to do all the LF EQ in the crossover. Even then, it's just voltage. The base design is similar efficiency to a conventional box speaker with baffle step compensation. Below 70 Hz I use a passive inline equalizer to pick things up another 6-9 dB; or in Thomas's case we only use a passive crossover for the upper drivers, and active down low. You don't really need much power to drive the LF drivers - it's usually the diople cancellation that limits power handling and output. Keep in mind a system with even dual 12's per side has somewhat limited LF output volume capability- but not as limited as you might think. If a monpole sub is used below 50 Hz, say an IB or good sealed box, some pretty nice stuff happens overall. ;^)

I just love what a dipole does between 70 Hz and 1 kHz. IMO, it's the only way to go if you can afford the space. Check out reviews of the Orion at Sensible Sound and the Audio Critic, and you'll get an idea of the worth of the conept. Of course, Linkwitz has done a very good job executing it. Frankly, if I didn't do DIY myelf, I'd own Orions, I expect. There are other speakers I admire from a design perspective that are more conventional, like the Avalon Isis, but setting them up to get the best sonics requires a huge room and a lot of commitment. IMO a dipole can work pretty dang good with a much simpler approach; you can get 85% of the way there with much less effort.

~Jon

[TacoD]

Hmm every one talks about big loudspeakers, does everyone across the ocean have big rooms? I would go for a big 4-way if I had the room. Ripole for <200 Hz (2x 15" or 18") dipole 200 Hz (10") - 1 kHz and monopole for the rest (7", good dome, did I already said the new 6600 sounds wonderfull).

[Dennis H]

Frankly, if I didn't do DIY myelf, I'd own Orions

Yup, a friend built Orions crossed to stereo subs at 50 Hz. With all the usual caveats -- short audio memory, different rooms, etc. -- they just sound more "real" than other speakers I've heard. I used to be a dipole skeptic because of the well-known problems with the big electrostatics and planars but live and learn. The Orion (and I'm sure the Arvo) seems to capture the strengths of both panel and box speakers and minimizes the shortcomings of both.

I really do agree that we have a good example of this kind of effort with Paul H's dipoles with the Seas drivers- a lot of craftsmanship and effort went into that project, and I wish there was some way I could hear them sometime.

Ditto that. Wish I could hear them!

[JonW]

Hmm every one talks about big loudspeakers, does everyone across the ocean have big rooms?

Some of us not living in cities do. I’d be perfectly happy with a teeny tiny speaker if it provided the best sound possible. But that’s because I’m not from Texas.

I would go for a big 4-way if I had the room. Ripole for <200 Hz (2x 15" or 18") dipole 200 Hz (10") - 1 kHz and monopole for the rest (7", good dome, did I already said the new 6600 sounds wonderfull).

Do you have any drivers in mind? Do you think trying to get a 4-way to play well together gets to be too complex? I know a 4-way can be good, in theory, if it’s pulled off well. But it might be tough to do. Then again, I’ve got no experience in design.

[JonW]

Jon-

Thanks for chiming in. If you need advice on recovering from knee surgery… well heck, I’ve got nearly as much experience with that as you do with speakers.

The Arvo/Isiris diople is an effort to put a lot of the best ideas that have been kicked around here the last few years into practice, in a very "methodical" kind of way, including full baffle simulation, driver selection through a lot (for me) of measurements, and yet still wanting to keep something that's semi-practical (?).

OK, so the Arvo project is still in progress. Good to know. And this explanation of your approach is something like what I’m after- take all of what’s been learned and distill it down to a design. I’ve read through that thread, but I didn’t know if it just kind of fell asleep or what. I’ll read that through again, in finer detail to better follow the thought process.

Yes, it's still in evolution. Wait.

Roughly what kind of time frame are you thinking about- 3 months or 3 years? I don’t see myself able to start a new project until maybe Xmas. But there’s no harm in thinking about it ahead of time and planning things out a lot. That’s served me well so far. OK, except for the knee.

And thanks for the explanation of dipole power handling. I’ve never heard a dipole in person, so it’s something I’ll have to do when I get to a city. (San Francisco in September, so look out. ) And the Orions sound like something worth trying to grab a listen as well.

I’m up for a project that would really pull together a lot of the nice design aspects of the past. This sounds like lots o’ fun. :T

[Eton]

Here's the best speaker in the world No compromise @ only 250,000.00 and he will fly to your house and set them up.

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

[Paul H]

Ditto that. Wish I could hear them!

Me too - I just moved halfway cross the country, and they're dismantled and sitting in our unfinished basement. :cry:

[SteveCallas]

Jon Marsh, what sensitivity would you estimate for a finsihed Arvo?

[ThomasW]

Here's the best speaker in the world No compromise @ only 250,000.00 and he will fly to your house and set them up.

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

Wilson Audio makes no speakers that sell for $250K. The Wilson Maxx2 (in your link) sells for ~$50,000. Perhaps you have the Maxx2 confused with the Alexandria X-2 and it's $125K retail price.

Note that David Wilson himself no longer installs speakers.

FWIW the Alexandria X-2 is the newest version of what started life as the X1-SLAMM. Jon and I kloned those a few years back...here's the info article

http://www.mclink.it/com/audiomatica/img/gpphoto/Hancock/slamm.htm

[TacoD]

Some of us not living in cities do. I’d be perfectly happy with a teeny tiny speaker if it provided the best sound possible. But that’s because I’m not from Texas.



Do you have any drivers in mind? Do you think trying to get a 4-way to play well together gets to be too complex? I know a 4-way can be good, in theory, if it’s pulled off well. But it might be tough to do. Then again, I’ve got no experience in design.

It's tough to get it right, but a ripole construction will give more extension than a dipole. Using a double ripole with shared front chamber gives enough output. You can use some PA drivers here with stiff suspension and high sensitivity (you loose a lot SPL using dipoles). If you have the money you can use Precision Devices. But others like PHL, Beyma also have suited drivers. PD is a bit overkill .

As filler (10") you can go the PA route with for example PHL, or use HiFi drivers . Dayton looks as a strong candidate or more expensive stuff as Seas W22, Accuton c² 220NT6/ Audiotechnology 23I (or custom Flexunit).

As mid I would go for the more expensive stuff like Excell/ Accuton C² 90-T6/ Audiotechnology 18H, this really pays off imho.

For the tweeter the Scanspeak 6600 or one of the best ribbons Stage Accompany SA8535.

It's very expensive, but if you go the PA route you save some money and have low compression on high spl's. This just one of the type of designs which I think is coming close to very very good.

I you want a commercial top of the line loudspeakers, you can try the Dutch company Kharma

[JonMarsh]

Me too - I just moved halfway cross the country, and they're dismantled and sitting in our unfinished basement. :cry:

What a drag, Paul! How long till you get them setup?

[JonMarsh]

Wilson Audio makes no speakers that sell for $250K. The Wilson Maxx2 (in your link) sells for ~$50,000. Perhaps you have the Maxx2 confused with the Alexandria X-2 and it's $125K retail price.

Note that David Wilson himself no longer installs speakers.

FWIW the Alexandria X-2 is the newest version of what started life as the X1-SLAMM. Jon and I kloned those a few years back...here's the info article
http://www.mclink.it/com/audiomatica...cock/slamm.htm

If I was going to go that way, I'd go with the Avalon Isis. Same sort of idea, but better drivers... and possibly a better value proposition, conisderint the tweeters, driver cost, etc.

Problem is, any of these direct radiator box towers need a pretty big room setup for optimum sound.

[JonMarsh]

Jon Marsh, what sensitivity would you estimate for a finsihed Arvo?

My normal target through most of the range is effective sensitivity of 82-83 dB, plus some inline LF EQ using a passive network (which requires that the preamp put out a little more voltage- say 2V RMS, instead of the 1-1.25 normally required to drive a power amp to full output).


Re JonW's question, I hope to get back to seriously working on them in mid fall, after my hardware projects and work and extensive upcoming travel in July, August, and September are done with. May just block off the last two weeks in October for starters. I've got about 480 hours of accumulated vacation time.