swechsler
Frog Whisperer
Look for marine woofers. Car woofers can deal with heat and moisture/humidity but aren't really designed for continued weather exposure.
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DIY Planar Ribbon Speaker Line Array
- Thread starter Tom Levno
- Start date
getdadams
New Member
Working on my own line source array with these. Will be testing once wire comes in and I get side wing built and installed. The plan is to do 200Hz to about 1.5kHz and then cross over to line of GRS Slim planar tweeters. Bottom will be filled out by 7" open baffle woofers and then crossed to subwoofer. Crossover is the minidsp 4x10.
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SleeperSupra
Super Member
I would look at these.
Aluminum / magnesium cone, spiderless design, beryllium dust cap, neodymium magnet utilizing a copper Faraday ring and t-type gap for lower distortion. Very fast and accurate.
https://www.dcgold.com/
Read the customer reviews.
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Tom Levno
New Member
Interesting. I'm curious about your plan for amplification, I've always had the best sounds when I try to keep the crossover frequencies out of the human vocal range, especially the female vocal range. That's tough to do with the resonant peak the panels have at 255 Hz. I expect you will get sweeter sounds if you cross over at 300 or 350 Hz and go up to 2.5 KHz to let the panels sing where they do their best. You will also be able to play them louder without distortion if you stay away from that peak from 200 to 250 Hz.
Looking forward to updates on this project.
getdadams
New Member
I may move up from 180Hz, just using that as a starting point. Its where Brian Cheney at VMPS crossed them over but he wasn't running them as dipoles. The minidsp will make experimenting with cossover points easy. 6 of these planar drivers can go much farther down in frequency than a single as they add output at lower frequencies where the sound doesn't beam. The large wing I'll be using will help from dipole cancellation at the lower frequencies and the dsp can always compensate as well.
Choosing as low a crossover as possible to tweeters to reduce the effects of the time delay between mid and tweeters lines as you move left to right. Output from one line will arrive with enough phase rotation, it starts cancelling the output of the other line, leaving a severe depression in the response.
The amount of cancellation per degree of off axis is due to two things. The acoustic center spacing of the 2 lines and the crossover point. The greater the distance between the acoustic centers or the higher the crossover point, the greater the problem.
Keep in mind the GRS drivers are dipole planar as well and will have all the goody magic of the Level 9 planar, just taking advantage of the narrower GRS driver and its ability to go higher in frequency and at the same time keeping it above 1kHz where it has higher noise.
I'll keep posting updates as I get farther along.
getdadams
New Member
Forgot to mention amplification. For testing purposes I'll be using a multi-channel BK amp that puts out around 100W per channel. My end goal is to puts amps right at speakers so thinking modules from Neurochrome or something similar. Shouldn't need tons of power as these lines should be reasonably efficient.
getdadams
New Member
Meant where GRS has lower noise.
Brian played around quite a bit on the Monsoon panels. Brian liked to run the panels as full range as possible, to keep the band pass crossover frequency out of the midrange. Eventually, he used approximately 270Hz, on the low end, and 6.5KHz on the high end, on his final few designs. It sounded good, but the panels beamed at the high end. The speakers needed a lot of toe in to compensate.
getdadams
New Member
Another good reason to lower the crossover frequency to the tweeters. The narrower GRS drivers should beam less. I'll play around with lower frequency but 270Hz would take almost all female vocals off the Level 9 planars except for the highest pitched.
getdadams
New Member
Those are Eminent Technology LFT-10 drivers with a BG Neo3 tweeter and Parts Express Reference 7" woofers in another design I did. I plan to redo them with wings on the open baffle and do open baffle woofers.
getdadams
New Member
FYI, I did have a driver that measured high resistance over 4ohms. Should be closer to 2.8 nominal. I ordered hardware to try the repair/upgrade on the connection. Drilled out the rivets and installed aluminum 4-40 screws, washers, solder tab and nut with nylon insert so they don't come loose. Now it reads 3ohms which is well within the other drivers I have. Also makes it much easier to connect wire for testing without having to solder them.
You can see in the first photo around the rivets, there are some dark patches that appears to be gaps in the trace which explains the higher resistance.
You can see in the first photo around the rivets, there are some dark patches that appears to be gaps in the trace which explains the higher resistance.
Well thought out. Good to see the wing on one side too. Very nice!
(Edit) - I'm curious on how well the 2 open baffle woofers keep up? An array of multiple (larger) OB woofers might work better, due to their increased efficiency and extended bass response.
(Edit) - I'm curious on how well the 2 open baffle woofers keep up? An array of multiple (larger) OB woofers might work better, due to their increased efficiency and extended bass response.
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getdadams
New Member
You might be right. I intentionally made the bottom cabinet separate so I can replace if I need to with just a stand. These 2 woofers will only cover 60 to 80Hz up to the lower frequency I end up going with on the mids. So I may end up with an array of woofers as you suggest. Either way, subs will cover lowest frequencies.
