M8ta - Listening Impressions??

[ThomasW]

Yep don't let a measley $8000 just for tweeters stand between good friends....:wink:

[ColoradoTom]

Glue, glue, and more glue

Glueing up panels - already through 2 gallons of Titebond.

Jon - looks like I may make some modifications to the design. I'm investigating changing the braces to intersect the front and back panels at 90 degrees. This will allow easier routing of the dados and will also increase accuracy of the fit. I've got everything marked up on my full scale drawing to make sure the opening for the RS225 and the vent are OK. Unless I'm having some sort of brain fart this should make no difference in the design or the strength of the structure. The dados combined with biscuits should give a pretty solid enclosure.

By the way.... with all the talk about the shellac I'm considering that as a final finish. If I get enough time to practice I may attemp a "French Polish".

Tom

[JonMarsh]

Monsieur, I encourage and applaud your creativity! Have you ever done a "French Polish" before? I've read about it, but haven't tried it.

[ColoradoTom]

Monsieur, I encourage and applaud your creativity! Have you ever done a "French Polish" before? I've read about it, but haven't tried it.

I actually haven't done it, but I've watched it done on a guitar - takes major time/patience and is a little difficult when you are doing edges... which is a PITA for this particular design. I should be able to practice on the test facet panel. When done well the finish looks like glass. The only major problem is that the finish can be damaged by alcohol - and I'm pretty sure this first time I have someone over to look/listen they'll prop thier margarita glass on one of them!!

Does the picture bring back fond memories??

[ThomasW]

We've never used 2"X4"s to build any of our speakers....:wink:

At some point we should discuss something frequently overlooked, that being the felt gasket material used to cover the front baffle.....

[JonMarsh]

I actually haven't done it, but I've watched it done on a guitar - takes major time/patience and is a little difficult when you are doing edges... which is a PITA for this particular design. I should be able to practice on the test facet panel. When done well the finish looks like glass. The only major problem is that the finish can be damaged by alcohol - and I'm pretty sure this first time I have someone over to look/listen they'll prop thier margarita glass on one of them!!

Does the picture bring back fond memories??

I'm not sure "fond" is the right word- maybe "familiar" would be more appropriate?

That's the thing that worries me about shellac finishes- I remember all those adomnishments when I was a little kid not to put a glass or cup on the table, especially not a cold one, becuase of what it would do to the finish. Ureathanes are nice in that regard- very durable. :T Probably the best choice for a klutz like me.

[JonMarsh]

We've never used 2"X4"s to build any of our speakers....:wink:

At some point we should discuss something frequently overlooked, that being the felt gasket material used to cover the front baffle.....

That and the embedded neodymium magnets from Parts Express to mount the grille without any physical fasteners.

Image not available


You know, we have to keep some secret sauce in all this....

I really ought to go back and do some more pics and posts with grilles and other stuff- I'll put it on my short to-do list. :rofl:

[ColoradoTom]

We've never used 2"X4"s to build any of our speakers....:wink:

At some point we should discuss something frequently overlooked, that being the felt gasket material used to cover the front baffle.....

2x4's...... if I could post a higher rez picture you'd see that those are custom made 3.5 x 3.5 cauls .

THAT picture looks interesting... have you made these already!!!

Also.... I kinda feel like and idiot here but how do you post a picture within the text??

Tom

[ThomasW]

That's a pic off the Avalon website. The only box speakers I have in the house are M8aMKIII wall-mounted in the bedroom. (the front baffles are covered with felt)

To put a picture in a post, you paste the URL of the image inside brackets [i-m-g] [/i-m-g] or you click on the postcard icon in the post a message box, and paste in the URL. The image must be hosted somewhere online it can't be one that's simply stored on your PC

[JonMarsh]

PE 2" dome mid is out. nice, compact, very flat response to almost 10K. Doesn't go super low, but plenty low enough.

Is it time to consider trying the M8ta as a three way also? 800 Hz and 2 kHz?

Suppose I'll have to order a pair sometime soon. Better see how the distortion looks before counting any chickens or planning fried chicken.

[JoshK]

Have you ever done a "French Polish" before? I've read about it, but haven't tried it.

Well there was this girl in college.... :rf

[ColoradoTom]

PE 2" dome mid is out. nice, compact, very flat response to almost 10K. Doesn't go super low, but plenty low enough.

Is it time to consider trying the M8ta as a three way also? 800 Hz and 2 kHz?

Suppose I'll have to order a pair sometime soon. Better see how the distortion looks before counting any chickens or planning fried chicken.

Jon - Please stop!! You're killing me!! I haven't even finished the two way version and you're moving on to a three way Opus-like version. And to make matters worse, every time I'm out working on my M8ta's I'm thinking about how I could modify things to look more Isis-like. I'm thinking of something more "hooded" in appearance - not so much a nun, but more like.......................THE EMPEROR!!!!! 8O

Finished my test of a French Polish and have decided that it's just too labor intensive. You are basically putting on hundreds of microscopic layers of shellac, which even in my less than professional test looked quite promising, but the time required to do a pair of M8ta's would be significant. I'm sticking to tung oil - which done right probably gets you 80% there.

Cut dado's for the braces and did a dry fit of the cabinets - making the dado's run 90 degrees to the front/back made the manufacturing process much easier and the cabinets seem very dead and strong. Just received the drivers from PE and Madisound and will be working on the front baffle this week/weekend. I am a little concerned that the top of the vent is within 2 inches of an internal brace and may look into options with either moving the vent slightly or changing the cutout pattern in the brace to allow better air flow - am I making too much of this??

ThomasW- I'm trying to work on ideas on the felt/grill. I'm assuming that the felt is as important on this design as it is to Avalon. Has anyone used the "stick on" felt from PE??

Got my supply of caps & inductors this week... I remember seeing an external crossover box for the Ascent?? model and thought that perhaps it was a little bit of hype - after seeing the size of some of these, I now feel the crossover enclosure was no joke!!

[kvardas]

Being that the cabinet is already constructed, could a forstner bit be used to bore the hole to minimize headaches?

[ThomasW]

If you're good with a Forstner bit larger than 4-1/8".......:wink:

[ColoradoTom]

Being that the cabinet is already constructed, could a forstner bit be used to bore the hole to minimize headaches?

Actually, the cabinet isn't assembled. I've been doing a "dry" fit to check everything prior to final glue up. I always do a dry fit because it often catches something I've missed along the way.

It will be pretty easy to take the offending brace and punch a larger hole in it on the drill press and that's probably what I'll do........

ThomasW - looks like a beautiful end of the week and weekend here in Colorado!! Looks like I'll be getting a tan while working on the final cabinet work.

[taz13]

Jon
Try this on that Rosewood, works for me.

http://www.graftedcoatings.com/wood_clear_ktm9.asp?iid=25

http://www.doolinguitars.com/waterborne/instructions.html

[JonMarsh]

Actually, the cabinet isn't assembled. I've been doing a "dry" fit to check everything prior to final glue up. I always do a dry fit because it often catches something I've missed along the way.

Absolutely recommended step, mandatory in my opinion, especially for a woodwoorking challenged EE like myself.

ThomasW - looks like a beautiful end of the week and weekend here in Colorado!! Looks like I'll be getting a tan while working on the final cabinet work.

I'm jealous- we're soggier than a paper towel at the bottom of a lake, here, and they're forcasting more rain through Tuesday.


I almost refrained from posting about the possibility of a midrange, it may not even be very feasible crossover wise (a relatively narrow bandpass, though I've pulled it off before 800Hz to 3 kHz), but Evil Twin used force mind control and made me do it... just stirring up trouble, IMO. :P

Now you see why I have trouble finishing things in one fixed form... I'm always evaluating the possibilities.

[ColoradoTom]

Jon
Try this on that Rosewood, works for me.

http://www.graftedcoatings.com/wood_clear_ktm9.asp?iid=25

http://www.doolinguitars.com/waterbo...tructions.html

This looks really interesting as an option!! BTW - pretty nice example of a harp guitar on Mike Doolin's site.

[taz13]

For Canadians there is http://www.woodessence.com/

[taz13]

A couple of French Polishing Tutorials

http://www.milburnguitars.com/fpintro.html

http://www.am-wood.com/finishes/french.html

[Jed]

I wonder how that new Dayton RS midrange compares to a C44 or C79? I wouldn't be suprised if the Dayton compares favorably when used from 800-2 or 3K. Hmmmm M8ta RS225, RS 2", and RS28a sounds good to me!!!

[ThomasW]

ThomasW - I'm trying to work on ideas on the felt/grill. I'm assuming that the felt is as important on this design as it is to Avalon. Has anyone used the "stick on" felt from PE??

Yep it certainly makes a difference. Though we don't post much about it, we use it on all our speakers...

Don't know about the PE felt. The stuff on the Avalon's is 3/8"-1/2" thick and has a very high wool content.

McMasterCarr.com sells it = $$$.

I get it locally at a place that makes custom gaskets. They sell the roll-end leftovers from their contract jobs. Originally I bought it from the place that supplies Avalon, but they stopped selling to the public a while back.

[JonMarsh]

Secret sauce: don't use a round cutout in felt for tweeter, use a tall diamond style cutout.

[Jed]

Secret sauce: don't use a round cutout in felt for tweeter, use a tall diamond style cutout.

For Accuton tweeters, could one do this without removing the grill and get all the same benefits?

[kvardas]

4 1/2" bit

http://www.mlcswoodworking.com/orderstatus/html/smarthtml/pages/forsbit.htm

[JonMarsh]

For Accuton tweeters, could one do this without removing the grill and get all the same benefits?

Could try it, but you wind up with an air gap between the felt and the actual tweeter frame surface. A surface that has some concentric features which contribute to diffraction at discrete frequencies. But it might help quite a bit- certainly something I'm going to try on my next unmodified C23-6 applciation.

[ColoradoTom]

Could try it, but you wind up with an air gap between the felt and the actual tweeter frame surface. A surface that has some concentric features which contribute to diffraction at discrete frequencies. But it might help quite a bit- certainly something I'm going to try on my next unmodified C23-6 applciation.

Jon:

BTW - I'm running a parellel DIY project and I'm moving my Adire DPL12 subs out of their temporary enclosures into final finished versions. With all the work I'm doing with the M8ta design I decided to model an enclosure with similar "features". Since I have four drivers I had already decided to put two drivers per box. The final version I was working on last night looked suprisingly similar to the base unit of the Isis!!

[ColoradoTom]

4 1/2" bit

http://www.mlcswoodworking.com/order...es/forsbit.htm

Kvardas

That is a monster bit!!! It would make quick work of the holes in the internal brace design!!

All I can say is you damn well better clamp that sucker down tight and run your drill at low rpm or you could be running around with part of your DIY project jutting out from your chest!!

Tom

[ThomasW]

Kvardas

That is a monster bit!!! It would make quick work of the holes in the internal brace design!!

All I can say is you damn well better clamp that sucker down tight and run your drill at low rpm or you could be running around with part of your DIY project jutting out from your chest!!

Tom

My thoughts as well..... 8O

[ColoradoTom]

Pictures From Today

Here are some pictures from today's work..... these are all dry fit work making sure everything is fitting properly. One of the pictures shows the dados for the braces and the back panel - this is slightly different than Jon's design as the dados are made at right angles to the front and back.

[ThomasW]

Looking good Mr Tom.....:wink:

Oh, are they heavy yet? :B

[ColoradoTom]

Looking good Mr Tom.....:wink:

Oh, are they heavy yet? :B

Heavy???? Nah..... light as a feather......really! :crush:

These things are going to be a joy to lift up on my bench an veneer!!

Tom

[JonMarsh]

Looking very nice! :T

You have been doing your work outs and bench reps, haven't you? :yeah:

[ColoradoTom]

Subwoofer Idea

Idea #1............

There is a joke within this picture........ :rofl:

Tom

[TacoD]

Wow, you have time to make an extra small bedroom set? Or is it for the laptop.

[ColoradoTom]

Looking very nice! :T

You have been doing your work outs and bench reps, haven't you? :yeah:

Jon:

How long before you can have the crossovers designed for these???? :roflmao:

[JonMarsh]

Idea #1............

There is a joke within this picture........ :rofl:

Tom

Mini-M8ta's for Tang Band full range drivers....

[JonMarsh]

Jon:

How long before you can have the crossovers designed for these???? :roflmao:

uh, what kind of 2" woofer is that, and what about the 1/8" tweeters you must be using?

As soon as you can get me measurement files of the drivers in those "enclosures", I'm good to go....

Sort of a Bonsai speaker, huh?

[ThomasW]

High end cabinets for his AcoustiMass modules....:wink:

[ColoradoTom]

Sorry!!

I was bored waiting on glue-ups..........

Gee, I thought the cabinets would give me a hernia... these front baffles aren't far behind in the mass department!!

BTW - These are the only small tweeters in my house - and they keep me plenty busy!!

[JonMarsh]

Sorry!!

I was bored waiting on glue-ups..........

Gee, I thought the cabinets would give me a hernia... these front baffles aren't far behind in the mass department!!

BTW - These are the only small tweeters in my house - and they keep me plenty busy!!

I can well imagine....

Mine is more of a "midrange".....


Just wait till your tweeters are this old...

[ColoradoTom]

I can well imagine....

Mine is more of a "midrange".....


Just wait till your tweeters are this old...

Cute kid!!

Mine are growing up too fast.... I kinda wish I could skip right through the puberty/teen stuff though. My oldest is already in the hormonal stage - one minute she's an angel the next she's......... her EVIL TWIN!!!

Tom

[ColoradoTom]

Weekend Work

I Didn't get as much done as I had hoped - all kinds of family and work commitments. Pictures show some closeups of the dados. Other pictures show the dry fit of the front to the cabinet - I was able to cutout the driver holes this weekend!! The fronts are getting ready to have the facets cuts, hopefully this weekend!

Jon - I also included my test of a French Polish, the picture doesn't really show it but it did turn out nice!! Way too much work for a project this size for me though.

Tom

[alexnick]

Hope I don't go too much offtopic but I saw that finish and I was wonder what do you guys say about this one?
The first picture looks better than the sample!
They say it's called Myrtle Cluster Burl! How much do you think it costs?

Thanks!

[JonMarsh]

I Didn't get as much done as I had hoped - all kinds of family and work commitments. Pictures show some closeups of the dados. Other pictures show the dry fit of the front to the cabinet - I was able to cutout the driver holes this weekend!! The fronts are getting ready to have the facets cuts, hopefully this weekend!

Jon - I also included my test of a French Polish, the picture doesn't really show it but it did turn out nice!! Way too much work for a project this size for me though.

Tom

For this kind of project, you're roaring along at a pretty good clip! And looking good doing it!

I understand about the weekend- work ended up eating most of it, even the two days vacation I took. Gotta put an end to that...

~Jon