# Purely for discussion - WMTMWW



## Owen Bartley (Oct 18, 2006)

I was doodling at work today, and found that my little sketch came back to the gigantic crush I have on the Dynaudio Evidence line (Master/Temptation/Center - they are all gorgeous).

I still like big speakers, and want to be proud of those big speakers, especially when they are built and finished beautifully. I do want to have a large front stage someday for my home theatre, and would also like to incorporate some DIY, both to save some money, and to do the build itself.

Now, I have no misconceptions about designing a crossover myself. I can build cabinets, I can ASSEMBLE crossovers, but I wouldn't attempt to design my own network, especially of this complexity. In all likelihood, if I do get to build my dream big speakers, I'll use one of the many proven designs or kits. But for the sake of argument, here's today's lofty audio dream sketch. A WMTMWW based (with no actual research or compatibility checks) loosely around a ribbon tweeter, some unidentified mids, and the Extremis 6.8/Subduction 6.5 woofers for some good displacement.










I had a few ideas like the angled rear and bottom ports, and I would brace them within an inch of their lives, and I have some great ideas for finishing. I didn't have any REAL reason for posting, except that I'm sure there are more than a few nuts out there like me who just love this hobby so much that it occupies your brain at all times, and there might be a few who have had similar ideas.

So... let this be a short thread and tell me all the reasons why something like this would never work. Maybe tell me why it would be brilliant. Or post your random scribblings and show me I'm not alone. Maybe this will become the "sketchy idea" thread, and maybe someday something from here will even get built.


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## JCD (Apr 20, 2006)

You are not alone..










I'm a CPA, so my thoughts run to the cost part.. but there is a pic someplace that I can't find that has what I envisioned the speaker would actually look like rather than the generic version shown here.


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## dyohn (Apr 17, 2008)

Your tower design reminds me of the Adire Apex...


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## Lucky7! (Jan 7, 2008)

Owen Bartley said:


> I was doodling at work today, and found that my little sketch came back to the gigantic crush I have on the Dynaudio Evidence line (Master/Temptation/Center - they are all gorgeous).


I tend to prefer large symmetric array speakers, since I first saw the Dunlavy's. If I were buying today, rather than building, and was a lot richer than I am, I'd be trying to audition something like the PBN Master Reference



Owen Bartley said:


> I still like big speakers, and want to be proud of those big speakers, especially when they are built and finished beautifully. I do want to have a large front stage someday for my home theatre, and would also like to incorporate some DIY, both to save some money, and to do the build itself.


DIY is fun, gives a sense of accomplishment, adds a level of experience to an otherwise passive hobby (listening), and can sometimes be cheaper. However it is really more about getting tha best performance you can for the $. The only real equivalent designs in terms of performance from what I am building, would cost me upwards of $30k in Australia. There will be under a 7th of that invested in the mains when completed.

If you are trying to get a budget design by DIYing for less $ than you can buy retail, then you might be disappointed because o/seas manufacturing can be very cheap, and that has lowered the prices of second hand speakers to some extent too. I am *not* trying to put you off, but would like to be realistic in terms of expectations and cost.



Owen Bartley said:


> Now, I have no misconceptions about designing a crossover myself. I can build cabinets, I can ASSEMBLE crossovers, but I wouldn't attempt to design my own network, especially of this complexity. In all likelihood, if I do get to build my dream big speakers, I'll use one of the many proven designs or kits. But for the sake of argument, here's today's lofty audio dream sketch. A WMTMWW based (with no actual research or compatibility checks) loosely around a ribbon tweeter, some unidentified mids, and the Extremis 6.8/Subduction 6.5 woofers for some good displacement.


My first thought was that 3 of the same drivers do not lend themselves to matching as easily in impedance as two or 4, so add another to the top and make it a WWMTMWW. You'll also get a bit more displacement, SPL capability and a bit lower distortion as each will have to excurse less for a given displacement. The Exodus Anarchy's are the later replacement for the Adires, and would suit if you wanted smaller drivers and a narrow profile cab.

WRT xovers, passive requires quite a lot of measurement, simulation and experience to get right. Active would be far easier, and something like a DCX2496 simplifies the process in many regards, and adds EQ for no extra expense. Amps can be second hand, say a recent AVR with 7.1 inputs giving you 8 channels in one package, with remote for reasonable money, especially if people have upgraded to get HDMI or HD codecs, neither of which are needed in this application. I have other options if you're interested too.

Zaph has lots of driver tests on his site for modest size mids and the Tand Band W3-1337SD looks like a very good driver and many like it in builds like the Statements. Personally, I would wait for the soon to be here Acoustic Elegance TD6.5M

Far ahead on my build list is a bedroom speaker a bit similar in design to yours, using the Ariel mids and tweets and passive xover (already own them) in a small sealed box and a 10" (undecided yet) above and below.


Owen Bartley said:


> I had a few ideas like the angled rear and bottom ports, and I would brace them within an inch of their lives, and I have some great ideas for finishing. I didn't have any REAL reason for posting, except that I'm sure there are more than a few nuts out there like me who just love this hobby so much that it occupies your brain at all times, and there might be a few who have had similar ideas.


Lots of bracing is worthwhile. I use a copy of the B&W matrix system in all my builds.

I also like bottom ports. Flaring is good and can reduce audible chuffing, but far better is to design so the ports don't make noise except at extreme levels.



Owen Bartley said:


> So... let this be a short thread and tell me all the reasons why something like this would never work. Maybe tell me why it would be brilliant. Or post your random scribblings and show me I'm not alone. Maybe this will become the "sketchy idea" thread, and maybe someday something from here will even get built.


It can work, and possibly brilliantly, but there is still a lot of design work needed on your part to make it more than an idea. Plenty of us have some knowledge and experience to help, but you'll still need to do most of it. It will be a steep learning curve, but you sound like yo have the woodcraft, so if you have the willingness to learn the electronic and design aspects, you can make a ripper speaker.

One thing to note is you will need to buy or borrow some measuring gear; a calibrated mic, a preamp and software, the latter of which I can find for you free. The hardware will be maybe $100-120.

FWIW, my builds started in the design stages a couple of years back, and whilst they have diverged, they were inspired by these two threads.
Stig Eriks Ultimate Speaker and 
Jack Bouska's Stoplights. There is actually a wealth of innovative design in this thread.


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## dyohn (Apr 17, 2008)

By the way, if anyone is interested in the plans for the Adire Apex, including his linear phase passive crossover design, I have permission from the designer Dan Wiggins to share the plans. It was designed using his Extremis 6.5" mid-woofer which is no longer available, but the Anarchy woofer from Exodus Audio should drop right into the design without modification.


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## Lucky7! (Jan 7, 2008)

I'd be curious in seeing that too - I'll shoot you a PM with email addy.
I like the Exodus drivers and have been curious about doing something with the Anarchy since it was released.


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## mdrake (Jan 31, 2008)

Gr research has a diy kit similar to your drawing. http://www.gr-research.com/index.asp?PageAction=VIEWPROD&ProdID=121 It could make for a good study. : )
I would second the use of active crossovers if you build from scratch.
_Posted via Mobile Device_


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## Owen Bartley (Oct 18, 2006)

Hey, that's a lot more feedback than I thought I 'd get, thanks guys.

The Adire Apex is a really nice looking speaker, as is the GR OB-7 Plus. Very interesting hybrid open baffle design, and it comes in kit form for a very reasonable price.

A9X, thank you for all the tips. My main drive to DIY things like this is like you said, to maximize performance dollars, and to have a personal attachment to the project, to have something I could really be proud of. Plus I love having projects to work on. Maybe there will be a time when I can have a proper workshop, and can make a speaker design area to learn how to properly measure drivers and really build my own stuff. For the foreseeable future, it will remain a bit of a pipe dream though, and I'll have to stick to building what others have perfected. I do like to dream still, and live vicariously through you and others who can do this kind of work and have it make sense to them. 

Maybe part of it is that I see good speakers as art, and the idea of creating a mix of artistic, engineering, and architectural disciplines into a functional end product is really appealing to me.

Oh, and JCD, I bet my recycle bin at work has sketches like that in it 2 or 3 days a week, from system plans or very rough doodles while on the phone.


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## Owen Bartley (Oct 18, 2006)

Well, I did some more looking around, and apparently I'm not the first one to lust after the Dynaudios enough to consider cloning them. This thread was started in 2005 at HTGuide. (JCD, any relation to cjd?) I even posted in it before it seemingly dried up... who knows, maybe that's where my obsession began!?


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## lsiberian (Mar 24, 2009)

The craziest speaker I've seen is a bipolar one. I had a JL Audio 8w7 for the bottom. Infinity MRS drivers for the midrange and Unfaced HiFi RTI tweeters. 

I personally would love to see an WMTMW You don't want adjacent drivers or you get those nasty nulls. 

Use a pair of JL Audio 8w7, and Infinity MRS drivers for the midrange. 

You could make people deaf with it.


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## Owen Bartley (Oct 18, 2006)

lsiberian said:


> The craziest speaker I've seen is a bipolar one. I had a JL Audio 8w7 for the bottom. Infinity MRS drivers for the midrange and Unfaced HiFi RTI tweeters.
> 
> I personally would love to see an WMTMW You don't want adjacent drivers or you get those nasty nulls.
> 
> ...


Atta boy! now let's see a sketch!


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## erwinbel (Mar 23, 2010)

lsiberian said:


> I personally would love to see an WMTMW You don't want adjacent drivers or you get those nasty nulls.


Can you please explain this to me?


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## schmutziger (Jan 5, 2010)

I was planning something similar. 
A modular design to grow with!
It was supposed to be a topsystem with 6.5" mids and a high sensitivity tweeter
so really a MT, MMT, MMTMM system.
* with a -3dB point at 80Hz.
* the mids farthest away from the tweeter was to be shunted in below the bafflestep frequency 
*Near backwall placement for increased sensitivity -> lower distortion

i don't know how to choose a good tweeter så thats where i am right now.
Was thinging about BR for even higher output....
http://i40.tinypic.com/16knxc3.jpg


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## Owen Bartley (Oct 18, 2006)

I like where that's going, Harry! Are you looking at the Exodus Anarchy for your 6.5? SDX-7 maybe? Any tweeter preferences yet?


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## buzzardmountain (Oct 6, 2009)

dyohn said:


> By the way, if anyone is interested in the plans for the Adire Apex, including his linear phase passive crossover design, I have permission from the designer Dan Wiggins to share the plans. It was designed using his Extremis 6.5" mid-woofer which is no longer available, but the Anarchy woofer from Exodus Audio should drop right into the design without modification.


PM sent with email address.....very interested in possibly building from those plans.
_Posted via Mobile Device_


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## schmutziger (Jan 5, 2010)

Owen Bartley said:


> I like where that's going, Harry! Are you looking at the Exodus Anarchy for your 6.5? SDX-7 maybe? Any tweeter preferences yet?


I was planning to use:
Seas PX17-LTS

Qms = 1,1
Qes = 0,23
Qt = 0,19
Bl = 7,9 Tm
Re = 5,7
Vas = 0,042 m³
Fs = 35 Hz
Sd = 130 cm²
Mm = 11,8 gram 

in 7,5l i think it was.

but the tweeter is the big problem...
sensitivity at about 100db/2.83V is wanted
but this project is on hold


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## Lucky7! (Jan 7, 2008)

Based upon the T/S posted, I get 98dB/2.83V for a pair in //.
First thought for tweeter would be 18Sound ND1020 + XT120 or Fountek NeoPro5i


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