I'm always willing to learn! is there any video tutorial or link that could show me how to do that the you mention with my amplifier?
probably takes more than a video to understand and do it the proper way! maybe I need equipment that I don't have in my basement right now I can tell you that, I do have a voltmeter! I just would like to finis my project with the best possible results.
thank you so much for the advise.
All you need is a voltmeter and a signal generator.
There are free apps, or you can download various sine waves.
Just follow these steps
LIMITER VOLTAGE-How to measure preset settings.
When determining what voltage limiters are set at, without a voltage number, you must measure the actual voltage output of the amplifier.
It is VERY IMPORTANT to use a voltmeter that has a flat response in the audio freq range. MANY do not.
If you are using a meter that does not have a flat response, then you should ONLY use a test freq of around 60Hz. This may mean bypassing various HP filters during the test, but be SURE to turn them back on after the test.
If you are using a flat response volt meter, then use a test freq around the middle of the response range of interest. It does not have to be exact, just somewhere in the range before rolloffs
1: DISCONNECT the loudspeakers!!!!!!!!! And hook the voltmeter to the output of the amplifier in question.
2: We are going to “assume” a 2 stage limiter. If there are more (3 is ideal), then simply add the additional steps, which are the same basic procedure.
3: Apply a sine wave to the input of the device/system and turn the level up until the voltmeter does not increase with increasing signal level. MAKE SURE that no stages prior to the amplifier or the amplifier itself are clipping. If they are, then readjust the gain structure of the system.
This voltage should be the or “heating”, or “RMS” limit of the system. Note the voltage and write down the threshold setting.
4: Now either bypass the limiter in step 3, or raise the threshold to the maximum. Now increase the drive level until the meter no longer increases in voltage. MAKE SURE there is no clipping anywhere in the system path-including the amplifier. Readjust gain structure if needed.
This voltage should be the peak voltage. Note this voltage
5: Re-engage the limiter in step 4 that was bypassed.
6: If there is a 3rd limiter, it would be the program limiter, and the step for it would be between 3 and 4 above.
7: Reconnect loudspeakers
ROUGH GUIDELINES FOR LIMITER SETTINGS
Voltage. Determine the continuous voltage rating. The formula is the square root of (continuous power rating x impedance).
Use this as a basis, the thermal or RMS limiter should be ½ of this voltage (1/4 power).
Program limiter should be the continuous voltage rating
The peak voltage should be 1.414x the continuous voltage (2x power). YES, that is 3dB down from the actual peak rating of the loudspeaker, but it has been determined that this is a safer setting to use than the “near death” rating.
ATTACK TIMES
Thermal/RMS large subs 3seconds, general woofers 1 second, midrange 0.5 seconds, HF 0.1seconds
Release time should be 1.5 to 2x attack time.
Program The attack time should be equal to the freq of the high pass filter for the xover. Ms=1130/HP filter freq. The release time should be between 10-20x attack time-15-16x is considered “ideal”.
Peak should be as fast as possible.
