Obtaining my White Whale (25 Driver IDS-25 Line Array Build)

I've been sitting on the desire to build a pair of nearfield line arrays for the last 6 years after reading the work of Roger Russell and his column systems. 5 years ago I started building a prototype pair with cheap $1 Aurasound 3" with the end goal of building a separate, finished pair with Peerless TC9's. I never finished those after moving from NY to Florida for work.

To make a long story short... I finished them! Below are photos of the build. It has taken me several months to get them done and that was with having a cabinet maker build the cabinets. I never realised how many technical design decisions went into making these.

My goal was to have the best performance in a $3,000 budget (most of that went into the cabinets).
 
(Once I figure out how to upload photos) Here is the prototype my cabinet maker made for approval before building the final cabinets. The construction quality was fantastic but I ended up making a lot of asthetic/performance changes. As you can see, we experimented with a full length grill option that would have been a full length sheet of perforated metal.
 
Thank you!
 

Attachments

  • 20190309_112522.jpg
    20190309_112522.jpg
    336.6 KB · Views: 899
  • 20190309_112531.jpg
    20190309_112531.jpg
    367.6 KB · Views: 887
  • 20190309_112536.jpg
    20190309_112536.jpg
    333.7 KB · Views: 866
  • 20190309_112541.jpg
    20190309_112541.jpg
    276.3 KB · Views: 853
Here is the flush mount test as well as two styles of routing for the back of the drivers. I settled on the simpler of the two as it saved time and wasn't sure the extra meat for the screws was worth the extra complication.
 

Attachments

  • 20190319_190934.jpg
    20190319_190934.jpg
    274.1 KB · Views: 783
  • 20190319_190942.jpg
    20190319_190942.jpg
    346.7 KB · Views: 270
  • 20190319_191007.jpg
    20190319_191007.jpg
    245.9 KB · Views: 260
  • 20190319_191044.jpg
    20190319_191044.jpg
    282.8 KB · Views: 303
I had gaskets made on a water jet at a local rubber and gasket company to seal the drivers to the cabinet. I made the template in Photoshop. They cost $1.35 per x 50. Way better than cutting them individually by hand!

The flush mount in the cabinets were measured and tested the for these gaskets and remain flush.
 

Attachments

  • 20190313_172804.jpg
    20190313_172804.jpg
    480.6 KB · Views: 311
How to find the sweet spot

Question for you line array guys before I return to posting build photos. How do position them to get a good sweet spot in the listening position? They have such a large sweet spot that it's like not having a sweet spot at all. I have no problem positioning point source speakers.

Is ironic, I built them to hear this huge sweet spot. Now I can't seem to find it because it's so huge.
 
Question for you line array guys before I return to posting build photos. How do position them to get a good sweet spot in the listening position? They have such a large sweet spot that it's like not having a sweet spot at all. I have no problem positioning point source speakers.

Is ironic, I built them to hear this huge sweet spot. Now I can't seem to find it because it's so huge.

Flashlights or floodlights, we choose our poison ;)
 
Nice! Did your guy do those cabinets by hand, or are the baffles and such done on a CNC router? Also, where did you find drivers for $1 each??? I’m about to start designing some for myself, and the pain of $10 x 50 ea has got me a little bummed. $50 for 50 drivers would be super.
 
Nice! Did your guy do those cabinets by hand, or are the baffles and such done on a CNC router? Also, where did you find drivers for $1 each??? I’m about to start designing some for myself, and the pain of $10 x 50 ea has got me a little bummed. $50 for 50 drivers would be super.

The cabinets were done on a CNC machine. He has done very fine work for a long time and said that this was the most precision demanding work he has done. I don't think he could have flush mount the drivers without the CNC machine.

The TC9's were a little under $8 with bulk pricing of over 50 drivers. The Aurasound drivers were bought several years ago to build a prototype and I still haven't used them.

This photo shows both drivers side by side.
 

Attachments

  • 20190408_215305.jpg
    20190408_215305.jpg
    361.7 KB · Views: 253
  • 20190408_214147.jpg
    20190408_214147.jpg
    285.4 KB · Views: 187