Recent content by akl

measuring amplifiers you do quite strange measurements. Ever looked at the different standards ?! Ever thought about the results yourself. IT would be very nice to explain a little bit, what you are doing. Are you looking for any results to judge the performance of your gear ?! or are you...

I'm starting to use REW to measure the performance of my headphone amplifiers --- You are measuring strange values and you do not state what you are doing , quite far away from the standards. dBFS at analog systems? what is dBr refeferring to? what is the load ? There is no figure /...

Performance of the power amp ( LoudSpeaker or HeadPhone). Do you judge the noise ? I had to controll this at the worlds presumably lowest noise hp-amp (RME). You have to state the noise relative to 1 mW (this is an absolute noise level, not the max. noise ratio ! ). So you may like to use dBm...

Sorry I definitely do NOT understand why you like to use the current. It makes it very complicated and you measure usually a voltage. How do you measure the current, it is complicated to do with usefull precision and without common mode problems. It is much more important not to refer...

Measuring amplifiers, especially headphone. Important is the LOAD impedance, I use 32R _and_ 150R , sometimes also 16R and 600R. I usually make a fast test stating the max. usable level . I use the SCOPE at 1 kHz and look at the clipping point. You have to have a RMS Voltage Meter for...

... I should mention the methods to measure those distortions. REW allows such sophisticated DifferenceTone distortion measurements and ... measuring such distortions employing an external stimulus is an extra level of complications. You have to enable 3 (!) instances of REW ('multiple'...

I did a lot of measurements (also distortion tests with REW). Even a lot of balanced connections may not be really good. The quality depends on the common mode impedances of the OUT- und INputs. (The common mode impedance at single ended is ZERO ! ) The common mode impedances should be high...

You do not get a cal-file. It is NOT that the cal file is accurate, but you may judge a little the quality of the MIC , including the outliers. Behringer ... you get no quality control at all. The MIC-capsules may be almost the same ones. The second problem are the errors of the MIC-amp...

I would use periodic pink noise and (synchronised) analysis by REW . 500 - 2k (?) or 150-5k . Make several measurements and vary many parameters, If you get a steady calibration all is o.k. . (You should note the # dBFS at a certain SPL level and calculate your max. SPL level). Since even...

I use 3 minidsp UMIK 1 and the calibration file had been wrong by more than 3 dB ! IF you measure the sensitivity of a loudspeaker taht is double the power and a lot of power if you have to buy that extra power.

Just a comment concerning win XP and REW . win XP seems NOT to work with JAVA 8 (just 7-79) my win XP machines switch from beta 47 back to beta 13 or beta 8.

With the Behringer MIC ( and a MIC PreAmp and an AD ) you are just able to compare measurements, but you will not know which one is the right one ... the better one. CAL files (only individual ones of course with ser No.) are helping a little, but this still has a lot of tolerances. CAL files...

Why ? I use JAVA at 24 bit !

! This is correct . (The max SPL must be at the stated self noise, not inserting an attenuator increasing self noise). 4 db (A) (I doubt this is true) to 94 dB SPL ( == 1 Pascal ) is the SNR ( 90 dB ). The EIN seems also too good (-125.8 dBV). The dynamic range is NOT at exactly the SNR...

You mix very special Data. A selfnoise of 4 dB (A) will be to low, the EIN will be to good, the dynamic range 115 dB will be wrong and a gain in dB FS is impossible. I have never seen such an input using umik-1 and java. You state the dynamic range of a 16 bit system with rounding...