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95Honda
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« on: July 18, 2007, 04:32:00 pm » |
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Well, I wanted to build a pair of higher efficiency mains for a system I had designed a while back for a guy I worked with. His sub to match these mains is pretty healthy, an Earthquake Magma 15 in a large vented box with a 500W BASH plate amp.... Anyway, I could get the Eminence Beta 12CX coax from Parts Express for $49 each and the APT 50 super tweeter for $19 each. I still haven't decided on a crossover yet, I may just try and find a schematic for the HE12 crossover and use that, I'm just not sure if the APT 50 is what Dan used with the HE12, I also think that whatever tweeter he did use, was modified to take a lower crossover point, I'll figure something out eventually... Anyway, since these won't be needed to supply alot of bass, I built a set of 1ft3 sealed enclosures (The Beta 12CX has a fairly high Q), I will fully stuff them and have a 100Hz 6db/octave HP filter installed to flaten the response out a little and prevent over excursion and distortion, it only has about 3mm of one-way throw... Anyway, on axis, I think these will be a great little set of monitors and should get plenty loud with 100 watts or so. Pics soon to follow...
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« Last Edit: December 15, 2007, 01:38:15 am by 95Honda »
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Forceaudio
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« on: July 18, 2007, 04:32:00 pm » |
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MikeS
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« Reply #1 on: August 31, 2007, 04:51:32 pm » |
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Sounds interesting......Did you ever finish this project?
This is the first time I've been online for a month and a half. My PC busted......
Had to pony up for a new one.....
Mike
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95Honda
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« Reply #2 on: September 01, 2007, 03:20:25 pm » |
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I have them all done. They sound reall good... I can really see why the commercial offering uses a vented alignment.... The make great little monitors, but have no real output below about 60Hz in that small sealed box. Box isn't overly punchy like I thought it would be, but I put a pound of AcoustaStuff in each cab..... Coaxial really sounds good, I was surprised.....
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Forceaudio
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« Reply #2 on: September 01, 2007, 03:20:25 pm » |
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95Honda
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« Reply #3 on: September 01, 2007, 04:32:45 pm » |
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Here are some pictures of the cabinets in my garage and then finished and listening tests sitting on top of my mains. I don't have a picture of the sub with me, but it looks really good and sounds good also...
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MikeS
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« Reply #4 on: September 02, 2007, 12:12:00 am » |
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A good coaxial is quite a stereo experience.
I'm still using the same cabinets at 3.5 feet internal volume tuned to around 30-32 Hertz, and jammed packed with polyfil.
With the breadboard networks parked right on top of the cabs.
The bass grinds right on down. They image real well, like headphones.
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95Honda
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« Reply #5 on: December 15, 2007, 01:37:13 am » |
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I dug up a few more pictures of the cabinet construction...
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MikeS
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« Reply #6 on: December 15, 2007, 09:55:02 am » |
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I notice some sort of aftermarket printed circuit board type of crossover networks.
Are those a offering from Parts Express?
I always ponder buying one of those fancy pro-sound active crossovers with time delay correction/EQ.
But they are spendy, and over my head.....
Use the active crossover to feed a pair of similiar amplifiers, one for the B&C 12CXT's compression tweeter, and the other for the woofer.
I have two of the same type of Magnavox SEP 6BQ5 amplifiers.
The balanced/unbalanced input/outputs could be a issue, but it would be fun to play with.
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Forceaudio
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« Reply #6 on: December 15, 2007, 09:55:02 am » |
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95Honda
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« Reply #7 on: December 15, 2007, 12:24:55 pm » |
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Those were a pair of the Eminence crossovers, I added a zobel and some tweeter attenuation, I think I paid $15 each for them, and with the time crunch (those were done 1 week before I left Spokane) it was money well spent...
I remember reading all about the Behringer FDP on Hometheater Shack, they even had a forum section on it, full crossover with all kinds of filtering....
I was banned from there though, honestly, a bunch of pussies run that site, LOL!
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black00
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« Reply #8 on: December 17, 2007, 11:34:07 am » |
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Those were a pair of the Eminence crossovers, I added a zobel and some tweeter attenuation, I think I paid $15 each for them, and with the time crunch (those were done 1 week before I left Spokane) it was money well spent...
I remember reading all about the Behringer FDP on Hometheater Shack, they even had a forum section on it, full crossover with all kinds of filtering....
I was banned from there though, honestly, a bunch of pussies run that site, LOL! hahaha...you were banned....  |
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95Honda
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« Reply #9 on: December 17, 2007, 11:44:52 am » |
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hahaha...you were banned.... You know it.... |
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todd.brust
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« Reply #10 on: December 17, 2007, 02:36:21 pm » |
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banned? how did you manage that? and a quick question...does the coax work kind of like a duplex set up where the high frequency driver mounts on the back and the sound is directed through the pole piece and out where the cone is? i am on my break at work right now and don't have the time(or ambition) to look at this point...i'll have to check into it later  |
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95Honda
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« Reply #11 on: December 17, 2007, 11:10:32 pm » |
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I was banned because I didn't play well there...
A coax is a coax, it means that the the drivers are coaxialy mounted (same center point) There are a lot of ways to go about it. Sometimes they mount the tweeter driver behind the woofer and the first section of the horn throat is inside the pole piece, like on the Eminence. Sometimes both voice coils use the same motor, sometimes the same voicecoil drives both the high and low frequency radiating element. Sometimes the high frequency driver is mounted in front of the low (like most car audio coax drivers)... Either way they are all coaxial, because their acoustic centers are on the same axis... You'll here words like "duplex" and "compound" and "coincident", these are really all the same thing, they are just different ways manufacturers descride thier way of tackling a coax. It is like when one manufacturer calls thier sub amp Class D output stage and another calls the same amp Digital Switching output stage.....
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todd.brust
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« Reply #12 on: December 18, 2007, 11:17:40 am » |
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i understand the concept of a coax speaker...i just wasn't sure how these eminence speakers went about it though...i've seen 15" coax speakers set up like a car audio coas, but then again i've seen the duplex style coax....the duplex style really interest me...like the old altec with the multi-cell horn
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Forceaudio
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« Reply #12 on: December 18, 2007, 11:17:40 am » |
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95Honda
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« Reply #13 on: December 18, 2007, 11:33:47 am » |
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These Eminences are set up like your "duplex"
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todd.brust
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« Reply #14 on: December 18, 2007, 02:44:26 pm » |
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cool stuff...but now for the real question...how did or do they sound assuming you still have them?
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Forceaudio
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