Open Baffle Epiphany!
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Poultrygeist
Lunatic Member
In my only conversation with David Dicks of Common Sense Audio he was really high on his 8" classic AN. Going with anything over 8" may call for a tweeter but an 8" with a whizzer cone can handle the highs. Wild Burro Audio sold some cheap whizzer-less Betsy's a couple of years ago and I wish I had bought a pair to play with. I picked up two 8" Realistic full rangers on the bay which I think may do well in OB. Plan to use them in an open back console radio from the 40's and drive them with a TPA3116.
Bonkers60
Super Member
I'm considering adding Minidsp to my open baffles. Currently using Emminence Alpha 15's on the bottom, with Fostex Fe126En's on the top. Right now I have no crossover, other than a low pass frequency adjustment for the lower frequencies.
I'd appreciate hearing from anyone using Minidsp and how it's working out for them. Thanks!
I'd appreciate hearing from anyone using Minidsp and how it's working out for them. Thanks!
i've had good luck w/ minidsp. you need to get a microphone and a laptop running the REW software. you use the mic to establish the room corrections you need. the minidsp software can input the room corrections into your crossover. the minidsp software lets you set crossover point and slopes. it took me a while to figure all this out; i didn't find the minidsp documentation super detailed.
downsides: 1. can't just tweak a knob or 2 as you can w/ an analog crossover. 2. you are essentially adding 2 DACs to your system, which may not be as good as your fancy DAC: minidsp converts analog to digital and back to analog so it has 2 DACs, unless i'm missing something. i haven't noticed a sound quality deficit in that systemn (in fact, it is probably my best sounding rig), but i don't know how the minidsp does its conversions.
downsides: 1. can't just tweak a knob or 2 as you can w/ an analog crossover. 2. you are essentially adding 2 DACs to your system, which may not be as good as your fancy DAC: minidsp converts analog to digital and back to analog so it has 2 DACs, unless i'm missing something. i haven't noticed a sound quality deficit in that systemn (in fact, it is probably my best sounding rig), but i don't know how the minidsp does its conversions.
Bonkers60
Super Member
Thanks Roger, does the Minidsp come with different software than the REW? Can either software operate theMinidsp? I'm planning on getting a microphone, just not quite sure how everything works.
Did you originally run your system without a crossover? Do you feel you got a decent improvement with the addition of the Minidsp? Thanks again!
Did you originally run your system without a crossover? Do you feel you got a decent improvement with the addition of the Minidsp? Thanks again!
minidsp has its own software; you have to buy it from them. the minidsp software can accept room corrections from REW.
i used a rane analog x-over 1st. problem is my set up is 2-way and i wanted to cross at 100hz and rane was 3 way and was hard to use it for a 2-way rig. had to cross higher, 150 or so, i forget just where. minidsp didn't sound worse; as i recall, it sounded better.
i used a rane analog x-over 1st. problem is my set up is 2-way and i wanted to cross at 100hz and rane was 3 way and was hard to use it for a 2-way rig. had to cross higher, 150 or so, i forget just where. minidsp didn't sound worse; as i recall, it sounded better.
Tucker99
Super Member
Some photos of my Isophon open baffles.
I allowed an anticipated small roon small footprint to drive my build.
I drove them with a Marantz 2325 and the sound was surprising good.
However there was a predictable absence of base response with the tone controls flat but I was able to compensate using the tone controls... the base needed to go way up and the kids a goodly way also.
I allowed an anticipated small roon small footprint to drive my build.
I drove them with a Marantz 2325 and the sound was surprising good.
However there was a predictable absence of base response with the tone controls flat but I was able to compensate using the tone controls... the base needed to go way up and the kids a goodly way also.
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PastTechFan
Super Member
Those look very nice! I DO like those period Isophons!
Since you posted earlier, I've picked up some Isophons from someone who gutted a Telefunken console. I have the tweets used in your setup, but haven't yet located a pair of the large LF drivers. (I have 2 pair of smaller ellipticals.)
While you would loose the "point source" benefits, I'd be very tempted to remove the tweets from their brackets, invert your baffles to get some floor effects for the bass, and mount the tweets (at ear level) in free air above the baffles (or in cardboard extensions) . Just to see how much free bass you could achieve without EQ.
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Tucker99
Super Member
I just examined the Isophons and the tweeters are attached to the frames by nuts so removal appears possible. Maybe I will try that.
I also wondered if rear side wings would increase the base?
Projects for another day...!
Bonkers60
Super Member
Glad you mentioned the software. I didn't realize that it was a separate item. Looks like 2 x 4 advanced is the way to go?
2 x 4 if you are doing a 2 way OB. software may come with the order. check the website. i bought mine 2nd-hand so had to buy separately.
Poultrygeist
Lunatic Member
For increased bass you might add/squeeze a Dayton PA255-8 woofer into each baffle near the bottom. Their cut out is 9.1" and they'll require a plate amp or something like F-Mods to low pass with a conventional amp.
Poultrygeist
Lunatic Member
If the 10" woofers won't fit on the baffle you could add wings and locate them there.
I experimented with a pair of 15" Alphas added to Wild Burro Betsy folding wings and while it worked well they were very difficult to move around the room.
I think pro woofers are a key component for open baffle speakers.
I experimented with a pair of 15" Alphas added to Wild Burro Betsy folding wings and while it worked well they were very difficult to move around the room.
I think pro woofers are a key component for open baffle speakers.
The MiniDSP has limited processing power so they have put together bundles of functions within its limitations. The modules are very user-friendly graphic apps, certainly MUCH each to use than the underlying DSP manufacturer's utility (Sigma Studio), guiding you through the general design process. With the 2x4 Advanced Crossover module you follow though: input gain, then 6-band parametric EQ, then crossovers, at which point the two channels now become four, then a further 6-band parametric on each channel, then independent output gain and delay. All of the settings are real-time, that is with the unit connected and music playing, you can hear the effect of changes as you make them.
In addition they offer as a free download the REW program, which takes response curve measurements from a calibrated mic (like IMM-6 for example) and calculates biquads required to correct to some desired level. You need an SPL meter too to calibrate the general levels. These can be automatically sent to the MiniDSP (it says) but I find typing in the settings is just as easy since you might want to apply settings to the individual output channel EQs first then re-run with the full system and apply further tuning to the general filter along with personal preferences (like bass boost).
Hope that helps.
Poultrygeist
Lunatic Member
Hope the MiniDSP works for you. My two analog actives ( Ashly and Behringer ) sit idle in a storage closet. They were not the best match for a SET amp.