FR vs True Peak

C

camplo

Registered
Thread Starter
Joined
Oct 12, 2018
Posts
11
I have reason to believe that the FR measurement isn't showing true peak spl.. anyone know the exact details?
According to my research, a sine waves true peak is 3db over rms, and from my experiments, I believe that the FR that REW records is rms spl, not true peak.

edit: Answered my own question
1730734148312.png
 
Last edited:
C

camplo

Registered
Thread Starter
Joined
Oct 12, 2018
Posts
11
I guess the real question is how to get the measurement to read True Peak, in order to properly judge THD...
 
C

camplo

Registered
Thread Starter
Joined
Oct 12, 2018
Posts
11
Can you explain please? THD has RMS and True Peak, no different than the fundamental. THD can be viewed as RMS or True Peak no different then the Fundamental signal. So it would make sense to Display THD as true peak if displaying the Fundamental as true peak, is what I am saying. I don't even know if this is possible since I have not come across any program that will show FR measurements as True Peak anyway. If you can't create fundamental signal measurements from True Peak then you can't create THD measurements following True Peak. If you can create FR measurements from true peak, you can create THD measurements from true peak.
 
Last edited:
C

camplo

Registered
Thread Starter
Joined
Oct 12, 2018
Posts
11
John Mulcahy said:
THD is a metric, not a signal.
Click to expand...
Hi, this is a quote from the link you shared " THD is a measure of that additional signal content not present in the input signal."

Once again, True Peak - "A true peak, in the context of audio signals, represents the absolute maximum value attained by the signal waveform, irrespective of its duration." The Fundamental signal the additional signals that are known as THD have RMS values and True Peak peak values.
It would be so great to be able to access to True Peak measurements of both, signal types, available. Yes REW calculates its THD from RMS values, but I do not see why True Peak values cannot be an option. Also, I know of no software recording such data but as a loudspeaker designer it would very useful.
 
Last edited:
John Mulcahy

John Mulcahy

REW Author
Joined
Apr 3, 2017
Posts
8,052
That quote: "THD is a measure of that additional signal content not present in the input signal." Check the definition of a metric.

The peak value of a signal over a duration is a single number that captures the signal level at one instant within that duration (interpolated from oversampled data in the case of digital true peak monitoring). Your comments about "True Peak" are nonsensical. There is "no software recording such data" because it conveys so little information as to be pointless.
 
J

JLM1948

Member
Joined
Jan 12, 2019
Posts
130
camplo said:
Hi, this is a quote from the link you shared " THD is a measure of that additional signal content not present in the input signal."

Once again, True Peak - "A true peak, in the context of audio signals, represents the absolute maximum value attained by the signal waveform, irrespective of its duration." The Fundamental signal the additional signals that are known as THD have RMS values and True Peak peak values.
It would be so great to be able to access to True Peak measurements of both, signal types, available. Yes REW calculates its THD from RMS values, but I do not see why True Peak values cannot be an option. Also, I know of no software recording such data but as a loudspeaker designer it would very useful.
Click to expand...
Can I ask you a definition of THD True Peak? What do you expect from it? As a loudspeaker designer, I fail to understand what additional knowledge it would benefit you.
 
You must log in or register to reply here.

Popular tags

20th century fox 4k blu-ray 4k uhd 4k ultrahd action adventure animated animation bass blu-ray calibration comedy comics denon dirac dirac live disney dolby atmos drama fantasy hdmi 2.1 home theater horror kaleidescape klipsch lionsgate marantz movies onkyo paramount pioneer rew romance sci-fi scream factory shout factory sony stormaudio subwoofer svs terror thriller uhd ultrahd ultrahd 4k universal value electronics warner warner brothers well go usa
Top Bottom