From two posters on the forum who'll remain anonymous...
Quote:
Not to build up a dust cloud, but I just did an A/B with my AD700 (1 kHz SENSITIVITY: 98 dB/mW at , IMPEDANCE: 32 ohms) by listening at comfortable music levels to Radiohead's Nude voice stem (volume for singing parts, listened carefully for noise during quiet passages) straight from my computer headphone jack (MacBP) and switched quickly (>15 seconds) to the headphone jack in my speakers (which serves as my amp, lol). Surprised with the results, I repeated them 4 times, and then did them with my Etymotic ER*6i (noticeably noisy headphones, 1 kHz SENSITIVITY: 108 dB @ 0.1V, IMPEDANCE: 16 Ohms) 3 times.
My sony has a built in 7 watt amp, and I can turn down the volume to equal listening volume while my MBP output is at full, so I believe this is a valid piece of equipment for your assertion.
My results: I could not detect a noise difference with the AD700. When I tried the ER*6i, which are more sensitive with less impedance AND have a noticeably higher noise floor, I could not detect a difference in the volume or grain of the noise. I did, however, notice that I can hear Thom York's monitors singing his lyrics before actually performing them on the track . If Melos' theory had applied, I would have heard a reduction in noise. If my amplifier was of poor quality, I would have heard an increase in noise or noise volume, or other artifacts. I heard neither, despite being able to induce a low gain. I'd conclude, then, that impedance and sensitivity have a greater impact on the noise floor than a max SNR coupled with inducing a low gain.
Isn't the decreased gain in an amp achieved through attenuating resistance? By raising impedance? IF this last bit is true (which I can't test with materials at hand, just different headphone models), I'd say sensitivity has the largest impact on the noise floor level.
Quote:
| >If it was source noise, the amplifier would have to either drop detail of >everything including noise while amplifying whatever left which would >make it a bad amp indeed or either magical. Its the higher impedance of >the headphones dropping the noise floor you hear I bet. Err. Here is how you control the noise: turn up volume on the source to the max, thus achieving highest SNR possible from it. This is too loud for most portable equipment. So now you plug an amp with gain 1 in and turn things down. SNR is maintained but now you have comfortable volume. Impedance of the headphones was irrelevant. |
Not to build up a dust cloud, but I just did an A/B with my AD700 (1 kHz SENSITIVITY: 98 dB/mW at , IMPEDANCE: 32 ohms) by listening at comfortable music levels to Radiohead's Nude voice stem (volume for singing parts, listened carefully for noise during quiet passages) straight from my computer headphone jack (MacBP) and switched quickly (>15 seconds) to the headphone jack in my speakers (which serves as my amp, lol). Surprised with the results, I repeated them 4 times, and then did them with my Etymotic ER*6i (noticeably noisy headphones, 1 kHz SENSITIVITY: 108 dB @ 0.1V, IMPEDANCE: 16 Ohms) 3 times.
My sony has a built in 7 watt amp, and I can turn down the volume to equal listening volume while my MBP output is at full, so I believe this is a valid piece of equipment for your assertion.
My results: I could not detect a noise difference with the AD700. When I tried the ER*6i, which are more sensitive with less impedance AND have a noticeably higher noise floor, I could not detect a difference in the volume or grain of the noise. I did, however, notice that I can hear Thom York's monitors singing his lyrics before actually performing them on the track . If Melos' theory had applied, I would have heard a reduction in noise. If my amplifier was of poor quality, I would have heard an increase in noise or noise volume, or other artifacts. I heard neither, despite being able to induce a low gain. I'd conclude, then, that impedance and sensitivity have a greater impact on the noise floor than a max SNR coupled with inducing a low gain.
Isn't the decreased gain in an amp achieved through attenuating resistance? By raising impedance? IF this last bit is true (which I can't test with materials at hand, just different headphone models), I'd say sensitivity has the largest impact on the noise floor level.
