#1994 by third harmonic
January 15th, 2016, 8:02 pm
Hi,

Understanding the limiter section of m50q...
What ist the Hold time?
I need limiter settings for the rcf LF18N401 woofer, required frequency band 20-60hz
Program: 2400w
AES: 1200w
Voice Coil Diameter: 4 inch, 8 ohms

My suggestion:

Rms limiter section
TrueP: 400w
AttackT: 6s
Hold Time: ?
RelT: 10s

Peak section
ThresholdV: 138v
(V2400*8)
Hold Time: 0,016s?
RelT: 0,256s

the maximum possible value attack time und release time in the rms-section is 4,5s!?
What is the Hold Time?

Hardware: m50qh
Soft: v. 2.6.1

greetz th
#1995 by AzzimontiMichele
January 18th, 2016, 11:35 am
HI th,

the hold time is the time the limiter takes before releasing the reduction. Thus, once the signal drops below the thresh, the limiter will keep the reduction during the hold time and than it releases.
Peak Limiter doesn't have an attack time because it is a "zero-attack" time limiter, so it start limiting as soon as the signal is higher than the thresh. Hold time is the same as for the RMS limiter.
I suggest you the following value:

RMS:

thresh: 720 w ([Paes x 0.6]*R/8)
attack 3,5 s
hold: 1.5 - 2 s
rls: 4.5

Peak: 167 V (unfurtunately the max thresh for M50 is 135 V) (sqrt[Paes*R]*1.7)
Hold: 0.0008-0.016 s
Rls: 0.256 s


Time values are fix, and no more than 4.5 s for the RMS and 2 s for the peak are available.
You wrote in your suggestion the TrueP thresh, but this kind of limiter (the TruePower limiter) is not available in M series amp.


Regards

Michele
Powersoft Staff
#2192 by third harmonic
September 24th, 2016, 6:42 pm
How calculate m50q hdspeth for 4 ohms per chanell, formula?
for sample 2x lf18n401/8ohms <60Hz
1200aes per unit

Kind regards
#2904 by Mark Oakley
April 9th, 2018, 10:36 pm
I'm setting up the limiters on my (2) M50QDSP+ETH amps for my monitor wedges, which are rated for 460w. @ 8 ohms. I calculated the corresponding voltage to be 60.66v, so I want to have the limiters engage at 59v. I set the Peak Limiters in Armonia for 59v, stored the Preset, and went to do a gig

The monitors at the gig weren't a loud as usual, and at one point when I bypassed the Limiter the level was substantially louder.

Today I measured the output voltages with my volt-ohm meter. When the M50's limiters are set to 59v, the maximum voltage the amp will produce is around 42v. To have the Limiter engage at 59v (as measured on my meter) I need to set the Limiter to 80v in Armonia. Why the discrepancy?

-thanks, Mark
#2905 by luigichelli
April 9th, 2018, 11:39 pm
Hi Mark, you're right...
M Series tends to limit more than calculated on the power limiter. Unfortunately we can't simply fix it because so many people already did presets, and we can't change the limiter behaviour on their settings.
We will think about a possible workaround for this and keep you updated.
Thanks for noting this!
#2907 by Mark Oakley
April 10th, 2018, 3:44 pm
Hi Luigi:

Thanks for the info. On a related note, the M50Q is rated at 135v maximum output, but I measured around 80v actual output when the clip indicator first begins to light up (one channel driven). That's still 1600w @ 4ohms-no complaints!

-Mark