[Ric Schultz]

Brain,
Good job!!!

Here I go again.....he he.   You would be the perfect person to try a serious brace up the back and report back.  Make it out pieces of three quarter inch birch plywood that are glued together so they are as thick as the magnet on the Alpha.  Attach the brace at your base, epoxy it to your Alpha magnet then have it attach to the baffle above the alpha and then have it run up further and epoxy it to the Tang bands magnet and then attach it to the baffle above the tang band.  This super brace would take your speaker into never never land.  Also, putting EAR SD 40AL on the Alpha basket will help the sound mucho.  Look at the speaker in the enclosed link and imagine that he also would have the brace right up against the magnets and epoxied.  Also, your brace would be considerably thicker than his.  Please try it and report back to educate others.

http://www.iol.ie/~waltonaudio/ob.html

[brian t]

cheers ric ok will investigate that, first prototype wasnt successful i made it out of steel bars but it was no where near rigid enough still think utilising the bass driver basket as a support is the way to go but realise its probably going to need support at top of baffle just trying to do something that looks nice heres a pic to stop anyone going down the same route 

[brian t]

just wondering ric having that brace bang up against the bass driver it has a vent so presumably i would have to drill out the brace to allow for this?

[mcgsxr]

I would route out a hole for the VC vent for sure - don't want to starve that engine of cooling air!

[Ric Schultz]

Yes, of course, you would want a hole/vent for the woof.

Please try using the binding posts as a clamp only....bring the wire underneath the speaker and wrap the bare wire around the outside of the binding post.....then remove the crappy spades on your speaker wire and form the bare wire into a loop and tin it.....put it also on the binding posts and clamp the wires together......much more pure and real info by getting rid of your binding posts and spades.

Run your wires directly to the drivers and not through the speaker (I know, won't look as good).  Also attach the wires to your drivers directly at the point the voice coil wire goes through the eyelet.  All this gives better sound.

Please felt around the tweeter and midrange.  This will give less brightness and more focus.

I'm so dang pushy.....he he.

[Bob in St. Louis]

Most impressive Brian. Well done Sir.
I've got several builds under my belt, and I find your work inspirational.

Rock on Brother.

Thanks for the tips on the wood hardener. At the top of page one, I was going to ask how you planned on dealing with the edge seams of MDF. But I'll just sit over here in the corner and watch you perform some more magic.
Seems you "got it covered". 

The circle jig is amazing. Looks MOST versitile, very impressive.

Bob

[brian t]

bob, thats one of the reasons for applying the wood hardner it stops the mdf expanding ,we call it joint creep when you have got 3 layers of mdf that can be a problem but this does reduce the chance of this happening i am not saying its 100% effective but its the best i have found.

[brian t]

Lowtech, hi i was waiting for this, one of the reasons i dont post very often there is allways someone waiting to put a spanner in the works ! people like pictures, i do, i have only just started this thread happy to answer any questions if i can,i am no expert. these sound great to me, yes me, for all i know they may be a pile of crap as you seem to think the xover is all wrong i bow to your superior knowledge. details you ask for 4.7mh inductor to bass driver/ tangband full range/ 3uf cap to tweeter as i find most fullrange drivers lack a bit of sparkle. you may be an expert in paint spraying but a lot of people are not including me! thats why i enclosed pictures.i dont worry too much about the science behind all this as the numbers dont always add up ,example is why does my cheap 845 valve amp sound far better than than my krell fbp200 amp i  use, according to technical spec its full of distortion.   you may be right in your assumption that these wont work with the xover i have, i accept that. but i only have to satisfy MY ears, RELAX THIS IS SUPPOSED TO BE FUN

[opnly bafld]

Lowtech, hi i was waiting for this, one of the reasons i dont post very often there is allways someone waiting to put a spanner in the works ! people like pictures, i do, i have only just started this thread happy to answer any questions if i can,i am no expert. these sound great to me, yes me, for all i know they may be a pile of crap as you seem to think the xover is all wrong i bow to your superior knowledge. details you ask for 4.7mh inductor to bass driver/ tangband full range/ 3uf cap to tweeter as i find most fullrange drivers lack a bit of sparkle. you may be an expert in paint spraying but a lot of people are not including me! you may be right in your assumption that these wont work with the xover i have, i accept that. but i only have to satisfy MY ears, RELAX THIS IS SUPPOSED TO BE FUN

Nice post and nice speakers!
lowtech's body of work here leaves a lot to be desired. 

Lin

[studiotech]

Lowtech, hi i was waiting for this, one of the reasons i dont post very often there is allways someone waiting to put a spanner in the works ! people like pictures, i do, i have only just started this thread happy to answer any questions if i can,i am no expert. these sound great to me, yes me, for all i know they may be a pile of crap as you seem to think the xover is all wrong i bow to your superior knowledge. details you ask for 4.7mh inductor to bass driver/ tangband full range/ 3uf cap to tweeter as i find most fullrange drivers lack a bit of sparkle. you may be an expert in paint spraying but a lot of people are not including me! thats why i enclosed pictures.i dont worry too much about the science behind all this as the numbers dont always add up ,example is why does my cheap 845 valve amp sound far better than tha krell fbp200 amp i  use according to technical spec its full of distortion.   you may be right in your assumption that these wont work with the xover i have, i accept that. but i only have to satisfy MY ears, RELAX THIS IS SUPPOSED TO BE FUN

Yes to each his own, BUT you did say that they were a little bright sounding and if you are running the TB full range with its rather larger peaking in response, PLUS running the Neo3 on top, you will definately have a hot, bright response.  Nothing wrong with a few more pieces to get it right, right?  I hate to see people got to all the effort to make a killer baffle/box/enclosure, whatever and then not take the necessary steps to get the best performance.  Your system, looks great, was well built, why settle for inferior sound?

greg

[brian t]

cheers lin, happy to receive any comments good or bad as long as they are constructive. we are all here here to learn from each other. going to have a serious rethink on the baffle support it is going to need scaleing up a bit but needs to be stylish to get past the all seeing eye of my girlfriend.

[Bob in St. Louis]

..........these sound great to me, yes me
..........but i only have to satisfy MY ears,
..........RELAX THIS IS SUPPOSED TO BE FUN

Nothing else matters.

[brian t]

greg, point taken am open to any advice on the xover i have, but i will leave it as it is untill the drivers have run in then see how it pans out.cheers

[ebag4]

cheers lin, happy to receive any comments good or bad as long as they are constructive. we are all here here to learn from each other. going to have a serious rethink on the baffle support it is going to need scaleing up a bit but needs to be stylish to get past the all seeing eye of my girlfriend.

Brian, beautiful finish, really outstanding.  With regard to the brace, I built a speaker similar in shape to yours a few years ago and I too needed a brace.  I decided to build mine from two pieces of MDF laminated together, with mine I used this brace as a wire chase to the MTM section I was using, you obviously already have that covered.  Anyway, I liked the look of the curved brace and in your case you could also modify it to support the woofer magnet if you chose to do so, I used a separate magnet mount on mine which supported a Hawthorne Augie.  If you are interested here is a lnk to the pics:

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1296

Best,
Ed

[studiotech]

greg, point taken am open to any advice on the xover i have, but i will leave it as it is untill the drivers have run in then see how it pans out.cheers

Just one more bit of advice that is not a tweak.....

Break-in happens MORE to ones ears than it does to the drivers.  A tipped up response may at first sound like too much, then the brain gets used to it and thinks that it is just hearing extra detail or that the driver has mellowed out(not so to any significant extent).  After a while though, you may find yourself feeling tense rather than relaxed after a listening session.  The best systems have correct detail, but can still sound relaxed and pleasing at the same time.  I experimented quite a bit with that same TB driver as a possible mid in my system, so I'm not just "spouting off" hearsay.  I have first hand knowledge of that driver and what it does well and where it needs help.

Have fun, experiment and learn.

Greg

[studiotech]

Brain,
Good job!!!

Here I go again.....he he.   You would be the perfect person to try a serious brace up the back and report back.  Make it out pieces of three quarter inch birch plywood that are glued together so they are as thick as the magnet on the Alpha.  Attach the brace at your base, epoxy it to your Alpha magnet then have it attach to the baffle above the alpha and then have it run up further and epoxy it to the Tang bands magnet and then attach it to the baffle above the tang band.  This super brace would take your speaker into never never land.  Also, putting EAR SD 40AL on the Alpha basket will help the sound mucho.  Look at the speaker in the enclosed link and imagine that he also would have the brace right up against the magnets and epoxied.  Also, your brace would be considerably thicker than his.  Please try it and report back to educate others.

http://www.iol.ie/~waltonaudio/ob.html

Wow, I love the look of that wide baffle with the glossy red and black spine.  Nice.  Reminds me of the studio mains I built.

[brian t]

Ed, lovely implementation of the brace in your design, i like the curved sides as well top class.i see you have used a separate brace for the bass driver thanks for sharing,food for thought.

[brian t]

greg, in its current state you may well be right the speaker being a bit hot ,just enjoying the transparancy of them at the moment will interesting to see if i still feel the same after a few weeks with them, i think its worth pointing out the type of sound i like wont be everyones cup of tea,i focus on getting realistic dynamics,detail retrival,and the ability of the system to start and stop and as such this may lead to a sound that is unbalanced, i have heared too many "accurate" speakers in the past and the result tends to be boring.just my thoughts no critisismn of anyone elses efforts , just think its good to know where i am comming from.
 

[JohnR]

Nice build, Brian 

There are clearly different "schools of thought" in how one might approach building an OB speaker. If only they had invented the teleport already and we could all just pop around to each others' place for an hour or two to share in the experience.

[brian t]

cheers john yes that would be handy thats the only trouble with working on a project like this on your own you cant always see the wood for the trees! so i am grateful for anyone pointing out any errors i may be making from fellow audiophiles here who have a grasp of the technical aspects of speaker design which i do not have, i am a nuts and bolts type of guy. am going to construct a full length brace to stabilise the baffle as my initial design was obviously flawed