Build Thread - Baronettes Towers

[JShadzi]

I recently finished a project based on Dan Poinsett's Baronettes design, after speaking with him we discussed the option of my making a larger ported floor standing version of his original sealed bookshelf design. I designed a 1.3 cubic foot enclosure tuned to about 40hz, I also used CLD on the driver mounting baffle.

These use the Morel CAT 308 tweeter and Dynavox LW6004PMR-N 6.5" woofer (a steal at $50 each!)

Crossover components and assembled

Cont...

 

[JShadzi]

First step was to get started on the cabinets. Construction of the main enclosure was from 3/4" Aruco plywood, however the front 2-piece baffle was made from Yellow Poplar heartwood, as well as the cabinet top. The cabinet is black Duratex and the poplar left natural and Shellac'd.

Plywood cut and glued up

Internal baffles cut and finished

There is a sub baffle that helps facilitate the CLD vibration control, the lower front sub-baffle is made from 1/2" plywood and will eventually have the poplar lower baffle glued to it, however the top sub-baffle is 1/4" birch plywood and will eventually have sorbothane bonded to it, then the poplar top baffle bonded to that.

Sub baffles are recesses with a rabbet

Braces going in

and glued in

Sub baffle has oversized cutouts to allow drivers to pass through. Sub enclosure all glued up

And with 3/4" roundover on back

I also flush mounted some poplar in the back for the terminal recess

And mocked up some "flying buttress" feet

Cutting and fitting the poplar front baffles

And the top

Drivers recessed and cut out

Breathing cove cuts on back of baffle

Roundover for 3" port

Inside of port painted

And fitted

Cont...

 

[JShadzi]

Cabinets masked off and primer'd black

Then 2 coats of black Duratex

Shellac going on the poplar, 3-4 coats with light sanding between

And poplar top and lower baffle glued on

Upper baffle glued on, I tested 3 different glues and this one bonded to the sorbothane best

Crossover and drivers installed, cabinet lines with foam and lightly stuffed behind the woofer

Feet glued on

Almost done!

Cont...

 

[JShadzi]

Nearfield measurement

And the finished product!

 

[JShadzi]

Here is a few videos of them playing

And some Stevie Ray

They sound excellent especially for the cost in drivers of under $275. Bass is very clean and effortless to below 50hz, the woofer is very well composed never complaining for getting out of shape even with 200 watts going to it, no low frequency high pass and 95+db at 1 meter.

Highs sound very much like a dome tweeter but no harshness or sibilance, very neutral sounding speakers with lovely detail and authoritative bass, no subwoofer is needed below 90db and w/in reason. Dan did a really nice job on the crossover for these.

The woofer easily does more than its rates 2.4mm Xmax, in fact I find myself day dreaming of a reference tower with 4 of these in each for bass and midbass duties

The cabinets are very non resonant, the CLD prevents vibrations and resonances from the baffle to transmitting to the cabinet itself, and even the driver baffle itself is very non-resonant.

Really please with these and would recommend them for anyone looking for a budget friendly compact tower using very high quality components and that can hold its own with multi-thousand dollar commercial speakers.

Let me know if you have any questions or comments, Thanks!

Javad

 

[Lojzek]

Hi Javad,

awful lot of work invested in these. Congratulation! I know they look
even better in real. How much does a sorbothane sheet cost? Maybe I'd
take a chance with it if I could get it in Europe not too expensive.

 

[zman01]

Javad,

Congrats and thanks for sharing. Great attention to detail and results to show for it!

 

[dragonweed]

Hi!

Beautiful project, executed with great care... Only one observation though:
the small (0.3mH) coils in your crossover are placed at the worst possible location, right next to the flux path of the large iron core woofer coil.
What this means is, that the the tweeter signal will be constantly modulated by the stray flux of the woofer coil. You can test it in a simple way: replace the woofer with a suitable high power resistor, then play music on the tweeter, with the resistor connected, then try it with the resistor disconnected.
You will be surprised ..... I know, because I tried this a few times.

 

[Zodd]

Awesome work on the cabinets - they look fantastic.

Your measurements also look very nice and smooth. How do they behave impedance wise?

I'm not familiar with the Baronettes original design - are you using the original design drivers and if so, did you change anything w reg to the xo and vas matching?

Reg the drivers, I recognize them both as Dynaudio designs - do you know if they are licensed models or some type of collaboration with either Morel or Dynavox?

Highly inspirational post JShadzi, thx!

/Z

 

[JShadzi]

Hi Javad,

awful lot of work invested in these. Congratulation! I know they look
even better in real. How much does a sorbothane sheet cost? Maybe I'd
take a chance with it if I could get it in Europe not too expensive.

Hello Lojzek thank you for your kind words!

mcmaster.com has nice large sheets of this, or smaller sheets can be purchased on ebay or Amazon and could be used similarily though it would be more work IMO.

If you need help shipping to Europe don't hesitate to ask for my help, my company ships to Europe extensively so I could send you something if it would help.

Thanks!
Javad

 

[JShadzi]

Javad,

Congrats and thanks for sharing. Great attention to detail and results to show for it!

Thank you!

Hi!
Beautiful project, executed with great care... Only one observation though:
the small (0.3mH) coils in your crossover are placed at the worst possible location, right next to the flux path of the large iron core woofer coil.
What this means is, that the the tweeter signal will be constantly modulated by the stray flux of the woofer coil. You can test it in a simple way: replace the woofer with a suitable high power resistor, then play music on the tweeter, with the resistor connected, then try it with the resistor disconnected.
You will be surprised ..... I know, because I tried this a few times.

Thanks for the feedback, I will look into this more, I did struggle to fit all the components onto that board, what would you suggest doing with the inductor? I rotated it 90 degrees in hopes to minimize the effect.

Awesome work on the cabinets - they look fantastic.

Your measurements also look very nice and smooth. How do they behave impedance wise?

I'll have to upload an impedance sweep, I'll do a post below showing the port tuning work I did.

I'm not familiar with the Baronettes original design - are you using the original design drivers and if so, did you change anything w reg to the xo and vas matching?

Yes the original design used the same Morel tweeter, it actually used a different part # woofer but Dynavox has updated the basked, but the voice coil and cone are identical and the new version measures identically to the older version.

Reg the drivers, I recognize them both as Dynaudio designs - do you know if they are licensed models or some type of collaboration with either Morel or Dynavox?

I know Morel and Dynaudio share DNA in their history, I can only imagine Dynavox has copied some of their design cues but I'm not certain of what connection there is if any. However the DV appears to be a suitable quality replacement to either Morel or DA for approx 1/3 the price or less, very impressed with this driver.

Highly inspirational post JShadzi, thx!

/Z

Thank you, so glad you enjoyed it!
Javad

 

[JShadzi]

I fined tuned the port tuning by changing the port length until it was exactly where I wanted it

Thanks,
Javad

 

[LewinskiH01]

Have you had a chance to listen to these? What's your assessment of the impact of Sorbothane CLD on sound quality?

 

[JShadzi]

Have you had a chance to listen to these? What's your assessment of the impact of Sorbothane CLD on sound quality?

Hello yes see post #5 above, they sound excellent. The CLD baffle is acoustically dead, at 90+db I can put my ear directly on the baffle and hear minimal sound, vibration or resonance. The rest of the cabinet is equally dead due to lack of mechanically transferred vibration from the drivers. The acoustic back wave is controlled with internal egg crate foam lining and poly stuffing behind the woofer, further isolating/absorbing vibrations.

The result is a very acoustically dead cabinet, with reasonable wall thickness and bracing construction (all walls 3/4" except for front lower baffle at 1.25" thick, cabinets finished weigh less than 40lbs.

Second project I've used CLD on and really like the result. Sorbothane is by definition viscoelastic and the ideal material to use for CLD, and this glue and process I used in this build attach the baffle securely and with no mechanical coupling.

Thanks!
Javad

 

[LewinskiH01]

Thank you.
Your drivers are screwed to the outer plate only, right? The screws don't pass thru the sorbothane and onto the MDF. Right? So vibrations generated by the drivers excite the outer plate and that energy is dissipated by shear on the sorbothane. So some energy goes from one driver to the next, but it doesn't get to the cabinet. Am I understanding it right?

 

[JShadzi]

Thank you.
Your drivers are screwed to the outer plate only, right? The screws don't pass thru the sorbothane and onto the MDF. Right? So vibrations generated by the drivers excite the outer plate and that energy is dissipated by shear on the sorbothane. So some energy goes from one driver to the next, but it doesn't get to the cabinet. Am I understanding it right?

Exactly correct! And yes a next step further would be to out each driver in its own CLD baffle, to prevent any interactions between those two, and wouldn't be terribly difficult to do.

 

[LewinskiH01]

Exactly correct! And yes a next step further would be to out each driver in its own CLD baffle, to prevent any interactions between those two, and wouldn't be terribly difficult to do.

Thank you.

Since you are trying so many techniques and materials, have you looked into Micarta for the front baffle? Micarta is actually a brand, I think DuPont's. I know it has very good tensile properties while damping vibrations a lot. It's used for many applications, including when you need to make external gears and want to minimize noise. A steel gear is a lot noisier. Micarta gear is silent (relatively speaking).

I have access to 40mm Micarta sheets I plan to use for front baffle on a sealed midbass enclosure. CLD is another approach that intrigues me, but sourcing Sorbothane sheets would be complicated for me. So maybe you want to try Micarta Haha

Very good craftmanship, BTW!

 

[JShadzi]

I have access to 40mm Micarta sheets I plan to use for front baffle on a sealed midbass enclosure. CLD is another approach that intrigues me, but sourcing Sorbothane sheets would be complicated for me. So maybe you want to try Micarta Haha

Very good craftmanship, BTW!

Thanks for the kind words!

I'll look into that, It sound like a phenolic material, would be interesting to use.

If you need I'm happy to ship you Sorbothane from the US, my company ships many packages every day to international destinations, happy to help.

Thanks!
Javad

 

[LewinskiH01]

Thanks for the kind words!

I'll look into that, It sound like a phenolic material, would be interesting to use.

If you need I'm happy to ship you Sorbothane from the US, my company ships many packages every day to international destinations, happy to help.

Thanks!
Javad

Thanks for the kind offer Javad. I'll keep it in mind. The big hurdle is clearing customs here. And I still need to decide on the final design.

Nevertheless, thank you!

 

[Bill poster]

Any issues with the xmax? Guessing some extra travel above quoted spec