The Darbari: new speaker project

[tcpip]

I have the board+components for the Marchand Electronics XO. George had it with him before giving up and I too seem to be going the same way. Will be glad to send across the same if needed. I don't recall if it is mono or stereo.

Sir, after seeing Goorooh Angshooh meticulously building his active analog line-level crossovers, and after seeing digital programmable crossovers, I have sworn that I will only touch the old-style analog active crossovers, if ever, after I have finished the full implementation and fine-tuning using DSP. What would take me a year using analog can be done in a month using DSP. And unlike some of you, I'm seriously growing old.

 

[tcpip]

My project has come back to life.

• I found a polishing chap to do excellent glossy PU polish.
• I found a carpenter to make some simple baseboards out of ply. These baseboards will be fitted below the large woofer enclosures.
• I got the help of Sound Foundations to make metal baseplates. These will go below the plywood baseboards. These baseplates have been fabricated out of 8mm brushed 304-grade stainless steel, and have been pre-drilled and threaded for Sound Foundations spikes. I intend to use three spikes per speaker. (Each SS baseplate weighs about 14kg!)

Now to fix the drivers, wire up everything, measure their SPL and phase, and then get to work with the MiniDSP. Miles to go before I sleep.

 

[tcpip]

Got the speaker enclosures home. Set them up in the living room just to see what they do to the livability of the room. They are big, so I have begun to wish I had built them shorter. But that's just DIYer's remorse, I guess. However, I have almost decided that I will make a wedge-shaped isolation layer between the upper and lower enclosures so that the midrange and tweeter point downwards a bit (5-10 degrees) so that I get on-axis tweeter output at the listening position.

I built a kind of slip-on plastic 'cases' or 'covers' for the speakers out of some sort of plastic-foam sheet, 1.5in thick. Helps me keep the speakers covered and safe when kids play in the living room. (They shoot plastic arrows at each other! Gasp! Choke!)

I am using a piece of the same plastic-foam sheet as an isolation layer between the upper enclosures and woofer enclosures. I may replace it with something better (or better looking) later.

 

[ghatgepatil]

That is indeed too huge for comfort! No backlash from the home-dwellers as yet or did they resign to their fate a long time ago? Whatever be, the wood-cuts and curves are looking very classy, yes, all except for the overall height! Maybe, they would have been fit for an auditorium!

 

[mpw]

tcpip,

the enclosures are so big.. a couple of kids could play hide and seek..:lol:

indeed a few more could be safely hidden..:lol: ( pure pun only sir !! )

but they look good and if they sound good.. then maybe your folks will let you keep them

i have been seeing this thread off and on and though i dont understand much of the technical details as yet.. i one day hope to listen to these.

I have heard Kapvins active rig at his place and this will be good to hear and file in the memory bank.

good luck !!

regards
mpw

 

[GeorgeO]

Looks good Tarunbhai, albeit "economy pack".

 

[tcpip]

i have been seeing this thread off and on and though i dont understand much of the technical details as yet.. i one day hope to listen to these.

I intend to call all forum members to my place for an evening once the speakers start singing. Let's see whether it is before Dussehra or after. (Some may ask, "Which year's Dussehra???" )

I am told there are half a dozen forum members in New Bombay itself, and Hemant Waghe stays quite close to my place. Should be fun to meet.

 

[somakmaitra]

I intend to call all forum members to my place for an evening once the speakers start singing. Let's see whether it is before Dussehra or after. (Some may ask, "Which year's Dussehra???" )

I am told there are half a dozen forum members in New Bombay itself, and Hemant Waghe stays quite close to my place. Should be fun to meet.

Tarunda Darun hoache :clapping:
Tobe Boudi ki bolche

 

[olly42]

Wow Looking Good

 

[tcpip]

Tarunda Darun hoache :clapping:
Tobe Boudi ki bolche

Actually she is holding her breath and waiting to see how it sounds. She still thinks the old Wharfedales sound better than the Asawaris, so I am not exactly going to judge the Darbari from her reactions. We will cross that bridge when we come to it.

 

[tcpip]

Drivers are being fitted

Driver fitting has started.

A tragedy occurred. In spite of having built a few speakers, and having spoilt a few drivers, I spoilt one of the tweeters today. it's the same old problem -- tweeters are unable to withstand the heat of the soldering. One of the leads of one of the tweeters came clean off. I have ordered a replacement from the US, through Borderlinx. I will waste Rs.8-10K now.

I have moved to using QC jacks (female QC interconnects) to push-fit the cable onto the driver terminals. I have crimp-type silver-plated female QC jacks of all three sizes, so I can fit cables to any driver this way. This minimises the soldering needed. (I adopted this practice after having lost 1-2 tweeters.) Even after using QC jacks, you still need to solder a little bit to ensure a solid and reliable connection between the QC jack and the terminal "tongue" (the male QC jack) of the driver.

Even a three-second touch with the soldering iron softens this tweeter's plastic base for the lead. With the first tweeter, I had to struggle a bit longer, and the base clean melted and broke off. Really pissing-off and irritating, and makes me feel like such a ham-handed amateur.

In future, I will coat the plastic base block of each lead in a blob of Araldite, so that the block becomes strong and does not soften with heat. Am sick of losing lovely, expensive drivers.

The mounting screws are lovely, aren't they? They are these items from TheAudioCrafts. I am so thrilled with their looks that I intend to use them for all future projects. Unfortunately, they are not available in longer lengths, e.g. 45mm or longer, which would have been required for large heavy woofers. The photos are quite sharp; view them in full size to see the screws.

The rear view shows the binding posts. These are Dayton Audio binding posts from Parts Express with their matching mounting plates also from Dayton Audio.

 

[tcpip]

Finished fitting the woofers into their enclosures. And finally, finally, finished fitting the steel plates and spikes at the bottom.

The steel plate is 8mm thick 304-grade stainless steel, cut, drilled, tapped (for the spikes' threading) and finished in brushed finished by Ali of Sound Foundations. The spikes are also from him; they look amazingly good. He also makes small floor-saver discs to go below the spikes, and I'm using them here. DIYers in India are fortunate to have this quality of hardware accessories available at very reasonable (I would say low) prices.

Worked for about four hours yesterday, mostly moving the enclosures around, drilling, and tightening screws, with a bit of soldering for the speaker leads. Had a workout which would put gym sessions to shame. We build good enclosures with all the bracing and padding and lining needed, but they are real beasts to move around.

Each steel plate weighs 14kg. How do you fit such plates to the bottoms of speakers? Answer: you up-end the speakers first, stand them on their heads. Then you place the steel plate on the box, drill and screw. Then you fit the spikes. Then, very gingerly, you lay them on their sides and lift their heads up and straighten them. Then place the spike-saver discs below them. Then breathe, and wipe the sweat.

My dad (he is a sprightly 80-year-old) helped right through the process. He does not have the strength to even tighten the screws, they go so tight, but I couldn't have done all this alone. My palms are aching from all the screwdriver wielding. But the outcome looks good.

 

[mpw]

tcpip,

those pics look wonderful..

a lot of hard work has gone into it.

congratulations !!

I am hopeful they will sound to your expectations so that all those hours are worth it.

regards
mpw

 

[jmascreen]

What are the spikes used in

 

[magma]

looks
super
the rear of the plate looks really nice ( good design)


you have the place for the check nut i see

next time you meet me
pick them up

 

[GeorgeO]

Looking very nice Dada

 

[aks07]

Looking very nice Dada

Koto taka khoroch korle ?

And hats off to getting those beveled edges and corners exactly right. Very difficult to achieve in a manual one-off build.

 

[tcpip]

a lot of hard work has gone into it.

congratulations !!

I am hopeful they will sound to your expectations so that all those hours are worth it.

Thanks for the good wishes, but yes, it's true that a hell of a lot of work seems to be necessary to build acoustically sound (no pun intended) and good looking enclosures. And that's only the first part of the job -- the actual transducers and their tuning (the xo) comes afterwards. Wish it were simpler and cheaper -- I would have been able to build speakers more often.

 

[tcpip]

What are the spikes used in

Sorry, sir, am confused. What do you mean by "spikes used in" something?:sad:

 

[tcpip]

looks
super
the rear of the plate looks really nice ( good design)

Not to mention excellent execution.

you have the place for the check nut i see

next time you meet me
pick them up

To my eyes, they look aesthetically perfect. The small space between the steel plate and the top cap looks really elegant. I won't want to add any more steel at that place now.

Hats off to excellent hardware, sir.