tuyen Posted April 29, 2013 Posted April 29, 2013 yeah mate, that's one of those usb minidsp mics. haven't got it working well though.. the input signal is too low, so then there is heaps of noise and not an accurate capture compared to the dbx mic i had before. need to play around with it a bit more, maybe it is just a settings issue. anyone else out there with one of the minidsp usb mics and got it successfully working with REW 5 or RealRTA?
Owen Y Posted April 29, 2013 Posted April 29, 2013 REW 5 is supposed to have all the calibs for the MiniDSP I believe? I am starting up REW 5 right now, but my onboard sound is crap, so will install a PCI soundcard soon. I was thinking of getting one of those MiniDSPs, but may start up with the RadioShack SPL meter and/or a DIY Panasonic capsule mic (Mitey Mic) I knocked up. Keep us updated, same this end. PS. You could just about ditch one of those tweets & have a 3-way + sub maybe?
tuyen Posted April 30, 2013 Posted April 30, 2013 (edited) Hi Owen, yeah I have applied the calibration file to REW 5, but it still not picking up a strong enough signal to give a clear reading. I've never used REW before though, so could be a setting related issue. I've only used TrueRTA and dbx mic in the past which was quite easy to use. curious to know if anyone out there with one of the minidsp mics have it setup and reading correctly. I'll try checking the minidsp forums to see if there are any other users out there.. re only using 1 tweeter, have experimented at length in the past. The beyma has slight rolloff at the top end, so without eq, it lacks even treble response and the sound is too directional (think treble from a panel!). As for just running just the goto tweeter, it doesn't play low enough to blend with the goto midlow horn. I do regret selling the goto sg-370 midhigh driver and goto 600hz horn One thing I haven't tried is using the BMS 4540ND 1" cd tweeter with the 600hz autotech elliptical jmlc horns for mid-high duty instead of the beyma. It definitely will have a more wider dispersion pattern. I did use it as a tweeter run in 3-way setup (>3000hz) and the sound was too hot in the mid highs but still lacks top end response. Also needed eq to sound balanced. If it works well as mid-high, will sell off the beymas response of the 4540nd: Edited April 30, 2013 by tuyen
Owen Y Posted April 30, 2013 Posted April 30, 2013 I see.... tricky business, these high sensitivity tweets. As I am finding too. That BMS 4540 is super sensitive. But not too uniform. Am interested in any info about the MiniDSP mic with REW, as they look good value mics to get.
Owen Y Posted April 30, 2013 Posted April 30, 2013 tuyen, Do you think that the signal level problem is not due to the USB input, but more likely something other?
tuyen Posted April 30, 2013 Posted April 30, 2013 hi Owen, nah, not USB port. quick check on minidsp forums and seems like few are experiencing same issue. I have to check which batch my unit is from but I have feeling it is first batch. minidsp will offer full refund! woohoo! http://www.minidsp.com/forum/18-umik-questions/8868-umik-1-update
tuyen Posted April 30, 2013 Posted April 30, 2013 think i'll just eventually fork out and get another calibrated dbx mic again. need one of these too: http://bluemic.com/icicle/ $$$$$$
Owen Y Posted April 30, 2013 Posted April 30, 2013 Or maybe one of these (recomm by TrueRTA)... http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-801 Plus one of these... http://www.amazon.com/MXL-MICMATEC-Preamp-Condenser-Microphones/dp/B000VZ8WC2/trueaudio
aertex Posted April 30, 2013 Posted April 30, 2013 (edited) Hey Tuyen, I have just noticed these new horn set up posts of yours-dont know how I missed them?? You have made awesome progress now has some real potential for excellentness..I would love to have a listen at some time. Could even bring up a few odd drivers/horns and amps to play with if you want. GTG at yours?.......when and where. I'm booked in right? Edited April 30, 2013 by aertex
Owen Y Posted April 30, 2013 Posted April 30, 2013 TrueRTA recomms on their home page: http://www.trueaudio.com/index.htm Shame about the MiniDSP.
tuyen Posted April 30, 2013 Posted April 30, 2013 Hey Alan, Yeah, I ended up taking over Jack's thread ages ago. Not that he really cares.. or knows even! Welcome to come listen some weekend soon. Let me tweak my system a bit more though.. currently not totally happy with active sub integration or the beyma as midhigh. Really need some measurements to know what is happening and where to go. Bev with his gear, helped me last time with setting up the sub when I had the 15" woofers in the ported cabs. But he is back in Denmark now for couple of years, so I'm stuck at the moment! the room is actually quite small and is also used as a storage room (not used as my primary music system anymore), so not really suitable for any serious SNA GTGs unfortunately.. still doing the whole horn thing just for a bit of fun really! any progress on your horn setup? decided on a bass cab design yet?
Steve M Posted April 30, 2013 Posted April 30, 2013 think i'll just eventually fork out and get another calibrated dbx mic again. need one of these too: http://bluemic.com/icicle/'>http://bluemic.com/icicle/ $$$$$$ Hey Tuyen, I've got a DBX mic + 10m cord here doing nothin', so come and grab it. Not sure what model it is, but it goes with the Driveracks, I bought it from Kosmic Sounds for $199 if that helps. Steve. 1
tuyen Posted April 30, 2013 Posted April 30, 2013 Hi Steve, Thanks mate. Very generous of you! PS. Thanks again for lending me those chip amps too. I like the audiosector lm3875 one better.. no startup/shutdown thumps! the higher powered lm4780 does controls the woofers bit better though.
aertex Posted April 30, 2013 Posted April 30, 2013 Take some time to get to the next stage. Let me know when you are comfortable and yeh, lets have a listen. Cheers for now Alan
tuyen Posted April 30, 2013 Posted April 30, 2013 (edited) No probs Alan! Progressing relatively rapidly due to some free time lately! Below is photo with the BMS 4540ND 1" cd tweets running on 600hz autotech e-jmlc horns, replacing the Beyma tpl-150h amt drivers. As the BMS' are about the same sensitivity as the GOTO mid-low horn, was able to remove the attenuator resistors on the mid low driver. Resulted in slight increase in clarity. Did have to turn down the volume on the chip amp which is powering the midlow/midhigh and tweet channels, to match the volume of the bass horn (which is now powered by the ME75C amp. The ME drives the woofers very very well, much better clarity and control in the bass notes compared to using low powered chip amps! Pity there is a bit of transformer hum ) Anyway, BMS/e-jmlc horn combo has much wider/even dispersion pattern, which makes it blend better with the upper and lower channels. But the BMS doesn't seem to have the ultra clear, low distortion sound like the GOTOs or the Beyma. Not sure which is better.. both have problems! Edited April 30, 2013 by tuyen 1
Zaphod Beeblebrox Posted April 30, 2013 Posted April 30, 2013 tuyen wrote: Did have to turn down the volume on the chip amp which is powering the midlow/midhigh and tweet channels, to match the volume of the bass horn (which is now powered by the ME75C amp. The ME drives the woofers very very well, much better clarity and control in the bass notes compared to using low powered chip amps! Pity there is a bit of transformer hum ) You should do several things: 1) You MUST elevate the ME75C to allow proper cooling. Placing it close to the floor is not suitable. Provide a minimum of 100mm elevation. DO IT NOW! 2) Try the ME75C on your mids and HF drivers. You will be pleasantly surprised. The ME75C was known for transformer noise, if transported roughly. It can be fixed by a talented transformer guy, who works with double 'C' core transformers. You have discovered the reason why I suggest that the ME75B is an overall better buy. It uses an 'EI' transformer, which can be transported to Mars and back, without suffering transformer problems. The ME750 was produced to deal with all the above issues, including poor location.
georgehifi Posted April 30, 2013 Posted April 30, 2013 DO IT NOW! True Tuyen, the 75 needs vertical air convection, it won't get it sitting on the carpet, you will cook it. And as Zaph said give it a whirl on the mids and highs I think you may be ***** ****** **** *********** ****** ** ********** ** ** *****. Cheers George
tuyen Posted April 30, 2013 Posted April 30, 2013 (edited) All good guys. Only had it on for an hour max. I personally can't stand the hum (even from 3m away), so will see if I can get it fixed or else will sell it off. The amp has original shipping crate etc. Edited April 30, 2013 by tuyen
Zaphod Beeblebrox Posted April 30, 2013 Posted April 30, 2013 All good guys. Only had it on for an hour max. I personally can't stand the hum (even from 3m away), so will see if I can get it fixed or else will sell it off. The amp has original shipping crate etc. Talk to a good transformer guy. Make certain they know about double 'C' core transformers. The ME75C transformer has steel straps, which can be adjusted. It is possible that adjustment of the straps can solve the problem. Worst case scenario is that the transformer will need to be dismantled and the faces of the core may be re-machined. I should also add that the ME75 does not reach optimum operating temperature for almost an hour. This is very important when using for mids and highs. Not so critical for bass.
tuyen Posted April 30, 2013 Posted April 30, 2013 Thanks for advice ZB. Do you know if it is possible that after adjustment/re-machined, the transformer will be totally silent? Or at least to the point where it is not audible at all from half a meter away in a 'normal' quiet room? Noticed the vibrations is being amplified by the lid which is in contact with the transformer. If I put my hand on the lid just above where the transformer is, the hum is reduced quite a bit. Still audible though. don't know any good transformer guys in Perth. But I can imagine if there was, will be a couple hundred $ just for labor for them to take a look.
Peter_F Posted May 1, 2013 Posted May 1, 2013 Hi Tuyen I'm not sure but maybe Pat at WAR Audio could help? His other company WA Rewind (WAR) may do that sort of thing? Pete
Zaphod Beeblebrox Posted May 1, 2013 Posted May 1, 2013 Thanks for advice ZB. Do you know if it is possible that after adjustment/re-machined, the transformer will be totally silent? Or at least to the point where it is not audible at all from half a meter away in a 'normal' quiet room? A new ME75C that has not been mistreated will be virtually silent. So, yes, if the transformer is correctly repaired, it will be silent. Noticed the vibrations is being amplified by the lid which is in contact with the transformer. If I put my hand on the lid just above where the transformer is, the hum is reduced quite a bit. Still audible though. It might be worth placing some compliant material between the transformer and the cover. There is very little clearance. This is the major reason ME developed the ME750 - to solve transformer issues. don't know any good transformer guys in Perth. But I can imagine if there was, will be a couple hundred $ just for labor for them to take a look. Indeed. Make certain they have experience with double 'C' core trannies. Not all transformer guys know them.
tuyen Posted May 1, 2013 Posted May 1, 2013 sato horn! next horn to build http://www.homebuilthifi.com/project/3959 5
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