Current CLIO Pocket software shows THD as numbers instead of curves. This is less useful than that of REW and ARTA. CLIO Pocket also uses logchirp to measure frequency response. Distortion information is indeed available in the processed signal. I wonder why they don't show it. They may don't want the software to be too "powerful" in order not to adversely affect the full-featured CLIO market.
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You may need a mic amp for QA401. Can it be EMU0404?
I wish Audiomatica will enhance (add more features) the CLIO Pocket software. Signal is captured already. It is just a matter of software processing.
Nope. I got me emu0404 burnt after a modification of the ADC circuit.
The calibrated mic is a superlux ecm999 which is connected to REW with Shure X2U.
Just a few AP-S1 measurements of my CLIO Pocket.
AP-S1 sampling frequency was 48 kHz. AUX input was connected to CLIO Pocket output.
The bar shows THD+N of 1 kHz, 1 V output.
Right most figure shows background noise level measured by using bandpass filter of AP.
AP-S1 sampling frequency was 48 kHz. AUX input was connected to CLIO Pocket output.
The bar shows THD+N of 1 kHz, 1 V output.
Right most figure shows background noise level measured by using bandpass filter of AP.
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Very good result. Few sound card in the normal value has such a solid parameters
Hi,Panson
Thanks for your kind response!Today I find out that something interesting in REW and Arta.
First of all,all kinds of functions that I test between them indeed the same outcome and get the identical result.
Whilst I feel that REW outperforms Arta at some extent including data interchange,fast SPL calibration,data curves comparisons and the unique wavelet transformation.However,I realize that one display parameter should be been pointed out,that’s the RMS input level in the RTA spetrum.In REW it seems that 3dBFs higher than Arta if you feed the same signal level into them and make comparisons(I use an additional signal generator rather than the one into them providing the identical source entirely,take a measurement of the 6” monitor box with the nearfield method and keep all the conditions equivalent ) .Furthermore I also perform an another experimentation with the soundcard loopback testing.The results list below,please take notice of the RMS level displayed
Something weird?Disregard the RMS value ,THD and THD+N make no difference nearly.Maybe several checkouts can make it come out. Whereas it’s still a very good and excellent measurement tool.
Thanks for reading!
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This is probably due to the REW and ARTA defining the dBFS in different ways.
See here
a) RMS value of a full-scale square wave is designated 0 dBFS, all possible dBFS measurements are negative numbers. A sine wave could not exist at a larger RMS value than −3 dBFS without clipping,
b) RMS value of a full-scale sine wave is designated 0 dBFS, a full-scale square wave would have an RMS of +3 dBFS
This is usually what explains the 3dB difference between measurement systems.
Meaning that you can test this out if you feed in a signal that is just below clipping and see what value each system gives you...
See here
a) RMS value of a full-scale square wave is designated 0 dBFS, all possible dBFS measurements are negative numbers. A sine wave could not exist at a larger RMS value than −3 dBFS without clipping,
b) RMS value of a full-scale sine wave is designated 0 dBFS, a full-scale square wave would have an RMS of +3 dBFS
This is usually what explains the 3dB difference between measurement systems.
Meaning that you can test this out if you feed in a signal that is just below clipping and see what value each system gives you...
Good job,one should pay attention to the 3dB difference to the signal feeding into the system！Note also test the voltage before making measurement.As long as the same amplitude the signal is，the same result regardless of what the RMS value shows.
Thanks for your reply！
Thanks for sharing your interesting data. I remember there is some differences in octave smoothing implementation as well.
A few months ago,I had asked for help about this question from its software programmer Ivo.He said that arta utilized the same algorithm with MLSSA in contrast to REW which employed the similar processing algorithm most plateforms do.REW always fits the common visual requirement.
Best
Do you mean how to measure a bass reflex-enclosure? I do near-field and far-field SPL. You can find a useful app note (http://www.audiomatica.com/wp/wp-co...Loudspeakers-at-low-Frequencies-with-CLIO.pdf) for near-field approach at Audiomatica (CLIO vendor). Near-filed is used to measure low-freq. in typical living environments. Time-gated far-field is used to measure mid-high freq. We splice both measured data to form a full bandwidth freq. response.
I don't think it is a different level into the system, it is referenced differently to 0dBFs. No?
Jan
Both the levels are the same in dB which can be tested with SPL meter for confirmation,just REW looks upon the clipping level as -3dB around as some soundcards may cause clipping!