[Dynky]

Hi folks
I'm currently enjoying my setup consisting of a double 12" W-frame accompanied by a Mark Audio FR driver on each side.

 

These have been built however by yours truly and since my woodworking skills are ok at best but far from perfect, I'd like to get new units built by someone who can actually do a decent (ie professional looking) job.
To make things a little more difficult I live in Belgium, so shipping imho is only economically viable as long as these can be sent over as flatpacks.

There are a few great builders here on AC which will probably be willing to have a look at my specific question and who are definitely be more than capable to build things matching the quality level I have in mind, but after using the search function for any of them making "W-frames" I only came across flatpacks being offered/built for double H-frames.
Unfortunately those do not suit for my specific listening situation, as with the current design the FR is exactly at the right (ear)height...which it wouldn't be when stacked on top of an H-frame, as this is easily 12-15cm higher.

So...starting this topic might just trigger someone to chime in with a solution, or redirecting me to a builder that has effectively such W-frame flatpacks on offer, who knows?   
any help you can provide will be greatly appreciated

[Danny Richie]

Those really don't look too bad to me.

You could roller coat them with Duratex then paint them the same gloss white and they'd match your uppers and look great. The Duratex will hide any seam lines too.

Nice job on the open baffle design too. I bet that worked out pretty well.

I have measured a few sets of those drivers and they all need a corrective filter to handle some of the break up in the top end. I wish you were near by. I'd whip one up for you that will smooth out the response. And then you'd like those drivers a lot more. There may be a little bit of step loss to compensate for too. Easy fixes.

[Captainhemo]

Man, shipping is going to  be pretty costly. I looked at sending one of our  Ottica MTM flat packs  over to England and  it was crazy... those   packs weigh about  50 lbs...  or dual  H-frames are  just over 70 lbs (30" x 24"  x 12" )  per box and there  is 2 of them .  W-frames would be similar although  we don't currently offer them, just not enough demand.
 
Probably doing something like Danny mentioned above would be your best bet unless you can find someone local to help  you out ...

jay

[bdp24]

Here are a couple of thoughts:

1- The cost to ship to you a pair of W-frames built of MDF, even if sent as a flat pack (unassembled, to minimize the carton size), will be considerable. MDF is heavy! Danny has posted diagrams of both a W-frame and an H-frame in the woofer listings on his website. They are very clear and include exact dimensions---you can have a cabinet maker build you W-frames locally, using that diagram. That might be the cheapest way to go, overall.

2- I have a pair of W-frame flat packs that were made by a subwoofer company that went out of business a few years back. They are made of 3/4" MDF from Danny's diagram, and have not been assembled (the MDF panels glued together), nor of course painted or veneered. I'm willing to let them go, if you're able to wait a month or so. I recently moved 1100 miles, and a bunch of my stuff is still in storage at my old location. I'll be driving down and bringing a load back up in about a month or so. PM me if you want to discuss it---Eric.

But I agree with Danny---your W-frames look good! And I see you doubled up on the side panels, an excellent idea. Are the frames made of birch ply, as they appear to be?

[Dynky]

Thanks for the responses so far, these surely give me something to think about 

My frames are effectively made according to those very diagrams/drawings listed on the GR website, so I know of the plans' existence and have used them to get to this result.
Never actually thought of taking those over to a professional woodworker and have them build their version of them, but that might just be the best and certainly most cost efficient idea, now I think of it.

The current cabinets are indeed made out of birch plywood, as I never planned to use veneer on the front and back edges, as can be seen...they're only veneered on all the bigger surfaces, as this was my very first attempt on doing so and I don't mind those edges being visible like this.

Another idea I'm toying with is doubling up on these per side, so using 4 x 12" per side, in fact sort of building 2 separate W-frames/side which would be positioned right next to each other...or maybe even go as far as to redesign those plans a bit to end up with one solid "squarish" double W-frame that holds 4 drivers all together.
The only thing I can't estimate is whether this would technically work, to be precise, whether the output/headroom would effectively gain from that, or are there also obvious drawbacks in such an idea...apart from the cost obviously? 

The reason I wonder is because there seem to be quite a bit of (previously) double driver frame owners who have upgraded to a triple driver frame with very (only?) positive results...but as I can't go up in height for the reason mentioned in my OP, doubling up these W-frames on each side seems the next best (and only?) option to me?

btw; I know the FR driver needs some correction, but as I'm running the whole rig actively filtered via DSP, that's easily taken care of

[Danny Richie]

btw; I know the FR driver needs some correction, but as I'm running the whole rig actively filtered via DSP, that's easily taken care of

If you can figure out a way to handle it passively and replace the DSP with a high quality DAC then your performance will go up considerably across the board. Something to think about....

[sandbagger]

for shipping out of the country look at USPS, I have used them a few times on heavy stuff and its much cheaper than UPS/FedEx if you can get the package size under the max

[Dynky]

If you can figure out a way to handle it passively and replace the DSP with a high quality DAC then your performance will go up considerably across the board. Something to think about....

I guess you're not a big fan of DSP and/or active filtering, but as there's more then some minor adjustments to be made in my room to get it sounding as I like, that's not going to change anytime soon.

Any thoughts on the "quadruple" W-frames?

[Danny Richie]

I guess you're not a big fan of DSP and/or active filtering, but as there's more then some minor adjustments to be made in my room to get it sounding as I like, that's not going to change anytime soon.

Any thoughts on the "quadruple" W-frames?

It tends to suck the life out of the music and cause a more two dimensional sound stage. A lot of it has to do with the quality of the D/A conversion and output stages on those devises. In most regards they are pretty cheesy.

It also can't really correct room related issues. While a bright area can be turned down to compensate for the reflection, the reflection is still there and adversely effects the sound stage. Real room treatment is the only way to effectively control it.

Plus the controls on the servo sub can adjust most of the areas where room loading occurs or where a peak or a dip is created.

On the quadruple.

It really depends on how hard you are working the two that you have. If they are barely having to move to match the Mark Audio driver then the benefit will be pretty small if any. Equal distribution of the bass in the room is more of a benefit.

But if they are being worked out pretty hard at times, then adding two more will cut the work load in half and the settling time as well. So you have more speed, better detail, better resolution, better definition, etc.

[Dynky]

Well,...when listening to stereo they really aren't pushed to their limits, even though I do frequently play some bass-heavy music, but when I look & listen to movies (and I use these same OB fronts in a 4.0 setup), the power LED on my HX300 amps sometimes do blink, indicating that they're pushed to the max, at least the amps are.

I'm with you 100% on treating the room acoustically first and foremost btw, which has already been done here quite a bit and will be even augmented in the very near future, as I'm currently finalizing my plans to build some "custom framed" absorption & diffusion onto both main side walls of the room...but even then I still run a digitally controlled rig in the sense that 90% of my source material is either streamed music or video incl HD surround sound (vinyl plays only a small part in my listening habits), so as long as the source end is of high enough quality including the processing/preamp/crossover/correction with it's D/A stages, I'm convinced that DSP shouldn't pose a problem in the way of loosing "life" or musical flow as some call it, as long as it's used in the correct  and minimal fashion (ie only when all other means have been exhausted)

[bdp24]

Dynky, if going double, stacking two W-frames would be better than side by side, I believe. I may be doing that myself, with H-frames. Two of Jay's (Captainhemo) frames stacked are 5' tall, exactly the same as my Eminent Technology LFT-8b's, with which I use the OB/Dipole subs (in place of the ET's built in woofer.

[Dynky]

I think sound-wise it will surely be better when stacked, but as explained in my OP, this isn't an option in my situation, as I can't put the FR driver any higher up then it is now...and frankly I also wouldn't want such a high tower (of 3 or even 4 drivers) in my room from a purely visual perspective

[Danny Richie]

...but even then I still run a digitally controlled rig in the sense that 90% of my source material is either streamed music or video incl HD surround sound (vinyl plays only a small part in my listening habits), so as long as the source end is of high enough quality including the processing/preamp/crossover/correction with it's D/A stages, I'm convinced that DSP shouldn't pose a problem in the way of loosing "life" or musical flow as some call it, as long as it's used in the correct  and minimal fashion (ie only when all other means have been exhausted)

Oh it won't hurt to add correction or not add correction. If you are using a DSP processor then it is already in the signal path. And it won't matter too much about the source material. It's the D/A conversion and output stages on those devices that are a bottle neck.

Rich Hollis makes a Digital crossover that will do all of that and it uses a pretty high end DAC and output stages. It is the only high end unit of its kind that I know of. I recommend it for those that want to go that route.

The DEQX is about a mid-fi level piece of gear at best. And it is pretty pricey. Rich's unit is less than half that price, and beats up on it pretty easily.

All others that I have seen, tried, and heard, fall under the budget level of performance. And most of them do really suck the life out of the music. Typically getting all of that out of the signal path and going with a good DAC is a big step up in performance. So keep that in mind for future upgrades.

[Oscillate]

Danny

What about using an active crossover such as the First Watt B4?
Any thoughts on the sound quality or practicality from doing so?
http://www.firstwatt.com/b4.html


...for those of us who can't afford to ship a 2-way line source to
GR Research for a proper passive crossover design

[Danny Richie]

Danny

What about using an active crossover such as the First Watt B4?
Any thoughts on the sound quality or practicality from doing so?
http://www.firstwatt.com/b4.html


...for those of us who can't afford to ship a 2-way line source to
GR Research for a proper passive crossover design

Text book style slopes used in such devices don't work for line sources. The filters for line sources have to control the coupling effect of multiple drivers. So the crossover filters are very different.