Ekta Grande project/AR-1 variation

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Rear port and terminals

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Welcome to the club CTC!!!

IMHO untill you don't try them with some HiQ SS beast you will not hear what those babies really can...I'm curently using Karan KAS270 and sound (not just bass) is much better than with any other amp I tried in the past...(some PP KT88, EL34,...) Wondering what will happened if (or when) I try my Ekta's with Pass (XA.5) :)

Great work and enjoy!!!
 
Time to upgrade

I can’t believe it’s been over 5 years since these were built.

I like to build stuff and have built over 6 different speakers/subs since these. Picking up ideas and learning as I go.

Spent the summer on my car projects, Factory Five 818 and my ‘69 MB 500HP sleeper. A few more weekends to go on the MB, but plotting out my next Audio project.

I really want to build Troels “The Loudspeaker” which is based on a JBL 4345. But reality is they need a dedicated room because of their size. While digging around on what to build I noticed Troels had upgraded the crossover components since my build date.

That got me thinking about possibilities to use some of the things I’ve learned in the past few years and upgrade a little more than the crossover.

I really enjoy my Ekta’s, so getting excited to see what some upgrades can do.

I think the upgrade could be money well spent as the Ekta’s use current high end ScanSpeak Revelator drivers and I still love the look of the cabinets. The cabinets are built well and braced well. The downside is the smallerish pair of 7” mid-bass drivers. But I have already built a pair of matching subs with matching ScanSpeak Revelator 13” drivers, each with their own REL Accoustics 500 watt amps.

On the original build I made a pocket in the base of the cabinets, accessible from the bottom, for the crossover. This is one of my regrets. The space is not really large enough which puts the coils close enough to interfere with each other, based on some tests I’ve read about. So I’m going to make a removable panel in the bottom, build an entirely new crossover, and install inside the cabinet. There is some room behind the middriver and tweeter that I can open up to the mid-bass section to offset the space used. I think I could use some more dampening behind the middriver and in the bass cabinet section.

And then I went shopping. New binding posts, Cardas Rhodium on copper, DH Labs PTFE silver coated copper, 12 awg to crossover, 14 awg to mid-bass drivers, 18 awg to middriver, 20 awg to tweeter. Connecting the tweeter and middriver crossover components will be solid silver PTFE Neotech, and solid copper PTFE Neotech for the mid-bass driver components.

Following Troels updated (values did not change) crossover I ordered Jantzen Audio Silver Z-cap’s and Alumen Z-cap’s. I also upgraded the resistors, for the mid-bass drivers Jantzen Supers and then went crazy and ordered Path Audio resistors for the middriver and tweeter.

I never really got around to properly installing feet. I have played around with some spikes and stuff. But nothing to really make me happy. No carpet now so I ordered some aluminum feet with some adjusting knobs from McMaster and some steel plates to span the width for the feet.

Parts are all here, now just need the time. Should be fun and I hope provide a benefit.

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I really want to build Troels “The Loudspeaker” which is based on a JBL 4345. But reality is they need a dedicated room because of their size.

Using DSP and multiple efficient amplifiers can reduce the size of "big sound" speaker cabinets. A 5cuft cabinet(H46" xW18"x D17") with a modest 18" width will fit most rooms. Troels uses an $800 woofer. Great "big sound" 3-ways can be built with $500-$600 total driver cost/speaker. To simplify the cabinet finishing, an edge-machined flat black baffle with oiled plywood sides produces a classic look.

Consider a fun build without perfectionist efforts. :):)
=====
The BMF1 speaker custom-built by Tweek Geeks has received high praise in public shows. The use of two-sealed, near-floor, side-side, counter-force, DSP-controlled room-equalized woofers provides a BIG-BANG in a medium size cabinet. The Tweek Geeks website has several construction pictures,

HIGH-watts to two 24Hz equalized 12" woofers allows a modest total 5cuft cabinet that fits many homes.

$13 B-52 PHRN-1014 1" Horn 10" x 14" Bolt-On waveguide
Model: PHRN-1014|Part # 299-2303 Parts Express
$63 Peerless 1.75" DFM-2544R00-08 compression driver
$188 Eminence KappaLite 3012HO Midrange:
TWO $146 Dayton RSS315HF-4 12" woofer (two in series = 6.2 ohms)
==========
$560 for drivers
 

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Using DSP and multiple efficient amplifiers can reduce the size of "big sound" speaker cabinets. A 5cuft cabinet(H46" xW18"x D17") with a modest 18" width will fit most rooms. Troels uses an $800 woofer. Great "big sound" 3-ways can be built with $500-$600 total driver cost/speaker. To simplify the cabinet finishing, an edge-machined flat black baffle with oiled plywood sides produces a classic look.

Consider a fun build without perfectionist efforts. :):)
=====
The BMF1 speaker custom-built by Tweek Geeks has received high praise in public shows. The use of two-sealed, near-floor, side-side, counter-force, DSP-controlled room-equalized woofers provides a BIG-BANG in a medium size cabinet. The Tweek Geeks website has several construction pictures,

HIGH-watts to two 24Hz equalized 12" woofers allows a modest total 5cuft cabinet that fits many homes.

$13 B-52 PHRN-1014 1" Horn 10" x 14" Bolt-On waveguide
Model: PHRN-1014|Part # 299-2303 Parts Express
$63 Peerless 1.75" DFM-2544R00-08 compression driver
$188 Eminence KappaLite 3012HO Midrange:
TWO $146 Dayton RSS315HF-4 12" woofer (two in series = 6.2 ohms)
==========
$560 for drivers

Thanks for your comments and taking the time to post.

I never really thought about multiple amps. Reading about Daniel Hertz 4 channel amp and the M1 speakers gives me something to think about.

Where can I find out more about the Basic Maximus 18?

Thanks
 
Where can I find out more about the Basic Maximus 18?Thanks

Short-story: TODAY to build a Maximus-18 you would email diysoundgroup.com and discuss purchase of their HTM-12 two way Econowave with passive crossover, and also ask for the CNC file to cut the Maximus-18 cabinet panels. You would add an 18" woofer of your choice and add+tune Bi-Amping.
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The Maximus-18 speaker kit was developed at diysoundgroup.com by adding a passive-crossover 1,500Watt subwoofer under the well tested HTM-12 2-way EconoWave into one modest size cabinet. The Forum thread states subwoofer power demands were so high that expensive woofer inductors sometimes over heated and failed. Customers also wanted more woofer room equalization control than a passive crossover. Recommending a separate HTM-12 kit and a separate subwoofer kit has now evolved into the normal alternative to the Maximus-18. An example Xover is attached for the Eminence Delta Pro 12A midwoofer and high value Peavey LoRider18 woofer.

diysoundgroup also designed the $900 65" tall WMTMW "model 1899" kit which uses two modest power 18" woofers in a larger volume. Scary-big home theater speakers.
 

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Finally have some time to get back to my Ekta rebuild.

After stripping out the drivers and the crossover I realized how many mistakes I made the first time around. This was my first real speaker project so to be expected I guess. Anxious to see if any of the mistakes hurt the performance.

Not sure how I calculated the cabinet volume before. The cabinet sides are on a radius, so a little hard to get the volume perfect. But the way I measure now it looks like I only had 48 L for the woofers instead of the 60 L needed per Troels design.

I had 15 L blocked off behind the tweeter/mid range driver area. So first up today was opening up that area for the woofers.

My original crossover coil layout was too close together. I’ve read that this can cause issues. So this time I followed Troels layout exactly.

I previously used 2 layers of heavy felt for cabinet dampening, along with the required Acoustilux. This time around I pulled out all the felt and installing a layer of Ultra Touch Denim Insulation. I will reinstall the Acoustilux as per Troels recommended locations. I did line the cabinets previously with 2 layers of bitumen pads.

I bought these 2 1/4” round aluminum feet from eBay to go on the spacer bar under the speakers. I had to drill and tap the existing holes to a larger 1/4” x 20 thread to match the bar and threaded knobs from McMaster. Really turned out nice.

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Then of course is the upgraded crossover and wire. Should finish tomorrow (Sunday) to give them a listen and see if any improvements.

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If all goes well I will be pulling out the drivers to refinished/repaint the cabinets. A couple dings and some defects in the underlying wood starting to show through.
 
After another full day of working on the upgrades I finished the pair.

The crossovers tucked in their new home

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I tried to apply everything I’ve learned in the past few years in this rebuild.

Wire size appropriate for each driver, 20 ga for the tweeter, 18 ga for the mid range, 14 ga for the woofers, 12 ga between the binding posts and the woofer crossover, 14 ga between the binding posts and the mid/tweeter crossover.

All premium products.

All the wires twisted, tweeter/mid run up one side of the drivers, woofers run up the other. Everything tie-wrapped to keep from making noise.

Besides covering the entire inside with 2 layers of bitumen pads and one layer of 1 1/2” denim insulation, I placed two layers of Acoustilux behind the woofers and over the crossovers at the bottom.

I know the crossovers will need some time to settle in, but after two hours of play time I can’t belive the difference.

The overall presentation has really filled out. Still same basic sound, but deeper bass and clearer top end. I’m assuming the correct/increased cabinet volume is the reason for the fuller bass and the crossover for the clearer highs.

Over the two hours I played everything from classic piano to rap. Increasing the volume along the way. Using the decibel app on my iPhone I was hitting 100 db at 80% available from my preamp. (My room is 25’ deep x 30’, listening position about 12’ back from speakers) no subs connected.

One album I use to measure my system by is Wild Garden by Josefine Cronholm. On really good systems her voice draws you in, you can hear her breath and can imagine her forming the words. If everything isn’t up to par it goes from uninspiring to unlistenable. This upgrade has got me to inspiring, almost there I think!

Off work again tomorrow, so I’ll let these run all day and see how things progress. Hopefully the Hypex FA501 amps arrive early and I can move on to getting the subs going again.
 
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