ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: UPA-1 “sliding xover point”: myth or something else  (Read 2065 times)

Doug Fowler

  • Member since May 1995, 2nd poster on original LAB, moderator on and off since 1997, now running TurboMOD v1.826
  • Administrator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2331
  • Saint Louis, MO USA
UPA-1 “sliding xover point”: myth or something else
« on: August 02, 2022, 12:49:23 PM »

Would someone with access to a UPA controller and a measurement rig please confirm/deny?

It’s time to put this one to bed, either outcome. 

Thanks.
Logged
Brawndo, the Thirst Mutilator. 
It's got electrolytes. 
It's got what plants crave.

Matt Fowler

  • Newbie
  • *
  • Offline Offline
  • Posts: 1
Re: UPA-1 “sliding xover point”: myth or something else
« Reply #1 on: January 15, 2024, 10:38:32 AM »

Would someone with access to a UPA controller and a measurement rig please confirm/deny?

It’s time to put this one to bed, either outcome. 

Thanks.

Hey Doug

I run some UPA-1a’s with a couple of M1A controllers. Have also spent many hours reading all the various forums trying to figure this one out as it would be awesome to be able to use some of the extra cabs I’ve got as delays and fold back without having to fork out the small fortune the controllers go for these days. In the end I gave up and went with the conclusion at least half of the info I could find said and accepted that they just don’t work properly without their magic Meyer voodoo controllers and my 6 spare upas are essentially useless except for spare parts without getting more of them 😂

As far as figuring out the voodoo goes I’m more than happy to do the testing if I can with the equipment I have (ecm8000, 6in/6out interface, REW, Open Sound Meter, XTA DC1048) but not exactly sure how I would go about it. I was thinking maybe I could run the link outs from the HF and LF amps direct to my interface and grab traces at various levels to at least see if the crossover moves. Not sure how I’d reverse engineer what specific filtering/limiting goes on though. If you have any suggestions or ideas or specific info you want let me know. 
Logged

Riley Casey

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2129
  • Wash DC
Re: UPA-1 “sliding xover point”: myth or something else
« Reply #2 on: January 15, 2024, 11:21:21 AM »

Been a while since I had any Meyer gear in inventory but the lowest hanging fruit would likely be to connect the processor to an amp that will easily exceed the protection voltage trigger at the sense inputs. Feed pink noise to the input of the processor and feed the processor outputs to the input of your analyzer set up in RTA mode.  Store the crossover curve measured at a low level below the protection threshold then increase the level in to the processor until the protection LEDs light up. At that point monitor the crossover curve on the display as you increase the level. If the sliding crossover is implemented you should see the result on the display as the curve moves to the right when monitoring the high pass output. The processor also includes limiting as part of the protection so the increase in output level should not be linear. All of this should be doable without speakers connected but if you want to test with a load a couple of high power capacity 8 ohm subwoofers should suffice without damage but still make the fairly simple analog circuitry think there is a UPA at the end of the wires.


... but not exactly sure how I would go about it...

ProSoundWeb Community

Re: UPA-1 “sliding xover point”: myth or something else
« Reply #2 on: January 15, 2024, 11:21:21 AM »


Pages: [1]   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.027 seconds with 20 queries.