AudioNervosa
Self Medicating => General DIY => Topic started by: richidoo on July 16, 2015, 07:23:23 AM
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I'm building a new speaker, Brines Acoustics TT-2000, aka M18-T772.
(http://brinesacoustics.com/Pages/TT-2000/TT-2000_VGA.jpg)
http://brinesacoustics.com/Pages/TT-2000/Main.html
http://brinesacoustics.com/Pages/M18-T772/Main.html
Solid pine boards.
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I made the box taller than Brine's design in order to raise the wizzer to 44", up from 30" in stock box. I like HF to come from above my ears, not below and I'm too stiff (and proud) to sit on the floor. So I stretched the box by 7" and put the box on a larger footprint and 7" tall pedestal box to which I can add weight. The innards remain the same so the MLTL works as designed.
Being a resonant box with a port, I can't use current source amp here, but if I like the sound of it, I'll build Neurochrome 300B amp.
My first DIY box was also for FR driver, built of solid pine. It sounded great, even witrhout stuffing or bracing, so I'm trying it again here. Removable bottom panel allows access to the interior.
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I'm watching with interest :rofl: :rofl:
Keep the pics coming
Bill
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Very cool Rich. I can't even draw a straight line, so all of you DIY guys amaze me! I'll be watching too! :D
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Thanks Bills :)
Gluing the front baffles on.
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(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRK_UYApoE4-FSvTAeFPngVGQAfE22sN9CDBbpWog4S9c11xp7I)
Well, they're standing upright, playing music! Needs some fine tuning, but it's a good start. Music really gushes from it. The pine really sounds good. Easy to listen all night. Unbraced box ringing a little too much, but that was expected and the ringing is sweet, just blooming on a couple frequencies. Some bracing and stuffing as per Brines' design and it will be pretty nice, methinks. I'm glad I did it in pine.
I was a little worried at first, it was pretty rough with the brand new drivers... but after an hour of playing some pop music the bass started to come. It has no crossover, of course, because only one driver, but it has a contour filter to roll off the rising high frequencies and it has a zobel network to flatten the rising impedance, so that tube amps will not have rising FR in the treble.
I am looking forward to getting them dialed in so I can get on to the wood finishing. Corners will get rounded over, wood sanded and sealed. There is still the pedestal box to build to add another 7" to the height.
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Looking good Professor. SET amp next ???
charles
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Yes, I plan to build the "Damn Good 300B" PCBs from Neurochrome.com, with Electroprint stranded silver plated copper winding transformers and Black Treasure 300Bs.
One thing I'm concerned about is the beaming highs. I have them ponting almost straight at me to get full extension. I can tweak the zobel filter to increase the highs, then toe it out a little, but it's still tweaky and then anyone sitting on beam would be uncromfortable. So I might add a dome tweeter at 5k with 1st order crossovers to broaden the HF dispersion. If I put a tweeter above the FR driver, then I wouldn't need a pedestal to lift the FR driver higher. I'd probably go for the SB Acoustics SB29RDNC. 94dB sensitivity, 4 ohm, neodymium, dimple dome, like on my Satori tweeters which I love.
The bass is suprisingly good now that they are mostly broken in. Bracing is up next. I have an elaborate bracing scheme, but braces take up box volume, and they may shift LF vibes up into more audible HF range. I also don't want to over do it and stop all the lovely woody sound, so I will start with just a few cross braces wedged in tight and see how that goes. Then add some loose pink 2" FG.
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Looking good Rich :thumb:
Glad to hear your not disappointed with the sound.
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Can't wait to hear them, and the Trairos!
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Only concern is the HF beaming. Sounds nice in the sweet spot, but gets muffled past 10 degrees off axis. they need to cover a larger area to serve in this role. I have a week left to decide but leaning toward returning them. Sorry! :(
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After listening to them for a couple hours I'm leaning toward keeping them. YAY! They do some things really nice.
Won't work for downstair speakers though.