Custom built Cabinet (SDA) ??

Toolfan66

Has any one ever built a set of cabinets for their SDA's?? I'm not talking a custom SDA, I'm talking about taking a set if lets say 3.1tl's keeping the baffle to spec and the inner dimentions to spec but doing a custom outter shell..

I have thought about doing this with my 3.1tl's, WHY??? Why not?? I think it would be a fun project, and having a set that would look like no others..

I dunno just thoughts right now. I do know if I did, the cloth sides and wood caps would go away as I would want a look more modern..

Like I said just thoughts as these will be my winter project..

engtaz

Sal's work might as well be considered a cabinet build.

michaeljhsda2

Yes, I thought about doing something similar to that...building cabinets for a pair of 1.2 TL's that look like the 2.3tl's. The internal volume would be the same as the 1.2tl's and the cabinet height would be the same as the 2.3tl's, only it would be deeper. 3/4 inch MDF, sand and then another outer layer of 3/4 inch MDF. No cloth sides or wood caps. High gloss piano black finish. Mye spikes. Cardas binding posts. The crossovers (Gimpod custom boards) would be mounted inside the bottom of each speaker.

Joe08867

I have also thought about doing something similar to this with a more modest SDA2 setup.

Keeping the volume and dimensions but encasing it in something more fabulous.

As Sylvester Stallone once said: "GO FOR IT"

Face

As long as the front baffle width and height are kept the same, as long as the interior volume, you're golden. You can use thicker materials and build the cabinet deeper to keep the interior volume the same.

In those dimensions, 3/4" MDF would need a lot of bracing or would resonate badly. I would recommend at least 1.25" MDF, Baltic Birch, or Bamboo(plyboo). Anything else would be a waste of time.

heiney9

The drivers are set in the baffle with a certain precision. They are not 100% flush but angled (for lack of a better term) by certain degree's. It's minimal but I'm sure there is a reason for it.

H9

michaeljhsda2

Face wrote: »

In those dimensions, 3/4" MDF would need a lot of bracing or would resonate badly. I would recommend at least 1.25" MDF, Baltic Birch, or Bamboo(plyboo). Anything else would be a waste of time.

Good to know. thanks This might be my winter project.

woofiepaws

Now all we need is for Polk to start making passive radiators again and our speakers could live forever.

thejck

this is something that me and robert(neighbor) talk about a lot. we want to do this and use gimpod's boards to build the crossovers. maybe we will find the time to do it sometime soon. but i am really looking forward to someone trying this

Toolfan66

Face wrote: »

As long as the front baffle width and height are kept the same, as long as the interior volume, you're golden. You can use thicker materials and build the cabinet deeper to keep the interior volume the same.

In those dimensions, 3/4" MDF would need a lot of bracing or would resonate badly. I would recommend at least 1.25" MDF, Baltic Birch, or Bamboo(plyboo). Anything else would be a waste of time.

Thanks Mike,

That would be my plan with the baffle and all. I really like the look of that bamboo wood, I will look into it more when I get home.

I would also make a custom binding post plate..:cool:

cnh

More power to you Larry. We're all 'eyes', waiting on your work!

Have fun!

cnh

codyc1ark

woofiepaws wrote: »

Now all we need is for Polk to start making passive radiators again and our speakers could live forever.

I would think that you could use an aftermarket passive? Maybe one with more 'tuning' options?

dorokusai

I think its a terrible waste of time if you plan on changing anything but aesthetics.

I've had custom work done to remove the cloth panels, install solid wood endcaps on a few models and re-veneer them entirely but that's about it. I've seen some models with the front baffle veneered and it looked pretty nice on some, not on others. I like the lines on the SDA speakers and the contrast between cloth/wood and the trim strips but that's just me. These projects just hold very little fascination for me as I've owned dozens and dozens of Polk's and modded them mild to wild, cleaned them up and fixed them up so they live again and etc etc.

Toolfan66

No faith Mark?? You know if I did do this it would never be half assed..:cool:

heiney9

Larry do you have the specific dimensions for each MW cut-out in the baffle? Or are you not doing this from the ground up? The drivers don't sit flush, they are ever so slightly angled.

H9

Toolfan66

heiney9 wrote: »

Larry do you have the specific dimensions for each MW cut-out in the baffle? Or are you not doing this from the ground up? The drivers don't sit flush, they are ever so slightly angled.

H9

Ground Up if I decide to do it. I have a set of 3.1tl's to go off of for specs..

I would like to use only the drivers and tweeters from them and redo all internal wiring, binding post's / cups, use Tonys boards, and upgrade all caps/risistors/ and inductors. put in some adjustable spikes, and make a grill that snaps on with magnets.. and can't forget the rings!!!!

Toolfan66

This is just an idea at the moment..

gimpod

What your not going to make them out of steel. :biggrin:

All kidding aside I could and would be willing to design a set of one off boards using whatever components you wanted to use. As far as inductors go the big one yes, The board level one's I wouldn't, DK tried it and couldn't get the stock one's back in fast enough.

nooshinjohn

I wouid love to build a set in a more visually pleasing cabinet as well. I was thinking along the lines of the RTiA look with the tapered sides. Again , same front baffle and same height, but shaped differently.

dorokusai

gimpod wrote: »

All kidding aside I could and would be willing to design a set of one off boards using whatever components you wanted to use. As far as inductors go the big one yes, The board level one's I wouldn't, DK tried it and couldn't get the stock one's back in fast enough.

That's one person's opinion. I wouldn't hesitate to continue using new inductors depending on the application and loudspeaker.

SDA1C

heiney9 wrote: »

Larry do you have the specific dimensions for each MW cut-out in the baffle? Or are you not doing this from the ground up? The drivers don't sit flush, they are ever so slightly angled.

H9

Ever so slightly angled? Any way you could show this in a sketch or maybe explain it a little more technically?

Are they angled as a set or individually or in stereo/sd pairs?

Thanks,1C

heiney9

SDA1C wrote: »

Ever so slightly angled? Any way you could show this in a sketch or maybe explain it a little more technically?

Are they angled as a set or individually or in stereo/sd pairs?

Thanks,1C

Just as it says......one could assume the driver sits in the baffle cut-out perfectly perpendicular. The drivers in the baffle don't sit 100% perpendicular against the baffle cut-out they are slightly angled (IIRC, inward) it's a very small amount perhaps 3-4% and I'm not sure what models or which sets or individual drivers. I do remember reading it somewhere.

H9

Roy Munson

IIRC it's why SDAs aren't supposed to be toed in.

Toolfan66

I would like to see more on this as I'm having a hard time swallowing it. not saying your wrong H9 as I don't know. But why such an angle? when most are not going to use a laser level to set the SDA's up, if not then the speakers can be off 3 to 4 degrees. also wood shrinks and swells depending on the climate.

I would also think that if there is an angle then the right baffle would be mirrored of the left baffle, I don't see Polk going to that extent in machining such a baffle. The MDF it's self can be off a few thousands from one sheet to the next..

Like I said I don't know but I will pull out my tools and do some critical measurements..

Larry.

heiney9

heiney9 wrote: »

Just as it says......one could assume the driver sits in the baffle cut-out perfectly perpendicular. The drivers in the baffle don't sit 100% perpendicular against the baffle cut-out they are slightly angled (IIRC, inward) it's a very small amount perhaps 3-4% and I'm not sure what models or which sets or individual drivers. I do remember reading it somewhere.

H9

Or rather the baffle cut-out is slightly angled. Didn't mean to imply the the speaker itself was angled. The cut-outs are slightly angled.

Toolfan66

heiney9 wrote: »

Or rather the baffle cut-out is slightly angled. Didn't mean to imply the the speaker itself was angled. The cut-outs are slightly angled.

I understand what your saying but like I said Polk would have had a right and left baffle machined and that is what I have a hard time putting my teeth into..

FTGV

heiney9 wrote: »

Or rather the baffle cut-out is slightly angled. Didn't mean to imply the the speaker itself was angled. The cut-outs are slightly angled.

But would'nt that then mean the driver frames would not be sitting completly flush with the front of the baffle on one side?ie. as in the the driver recess being deeper on one side than the other.

dorokusai

I've never read that and my SDA CRS+ and 1C are flush. That's pretty expensive to boot in regards to a left and right model.

heiney9

I've been trying to find where I read it. It may have been in the original SDA white paper. Of course I still haven't found my compendium from the move. That has a reprint of the article in it. It wasn't much, IIRC probably less than 5*, probably the least of one's concerns.

Also remember the phase compensation, the bass/midrange drivers are recessed relative to the tweeters so their common acoustic plane, and thus the effective axis of radiation, is shifted by an angle of 20* toward the listener. As a result the distances between each set of stereo array drivers to the listeners appropriate ear are equal, allowing the bass/midrange and tweeter signals to arrive at the same time and in correct phase for accurate reproduction of the original waveform

The above is more important I would think.

H9

SDA1C

OK Heiney not to argue either but if one sda has a specific pitch if you will then it seems logical that they all will. Also the left mirroring the right makes the most sense.

I did take out a tool (starrett rule)the drivers are all on different planes if you want to get precise about it. If there is a purposeful planar difference I certainly don't measure it.

Not to say it isn't there on other SDA models but my 1C don't seem to have it.

1C

heiney9

SDA1C wrote: »

OK Heiney not to argue either but if one sda has a specific pitch if you will then it seems logical that they all will. Also the left mirroring the right makes the most sense.

I did take out a tool (starrett rule)the drivers are all on different planes if you want to get precise about it. If there is a purposeful planar difference I certainly don't measure it.

Not to say it isn't there on other SDA models but my 1C don't seem to have it.

1C

Well your assumption would be incorrect about it being the same for all SDA's. They vary widely and were a work in progress right through to the end. There is a HUGE difference between the original SDA1 and SDA 1C, not even the same speaker. Same can be said of the original SDA2 and SDA 2B

The concepts and theory are the same for all SDA's but the execution is different, with the later generation of SDA's trumping the earlier generation by a good margin.

H9