Hello,
Just bought the DX9 AKM (mostly for the looks, yes
) and, on single ended, it seemed a bit quiet for my taste on low volume masters like Steely Dan and after applying some negative pre-amp for EQ. I didn't have this issue with L30 II, my old amp.
This made me curious and did a fairly unscientific experiment which confirmed what I was hearing. Basically, I plugged the L30 II in DX9 RCA outs, set high gain max volume for both. Then I measured average SPL with a phone db meter over a few one minute fragments from some songs. During measuring the phone was unmoved and right next to a headphone cup (which was also not moved, just plugged in alternatively in the L30 II and DX9 6.35 outs. Yes, I am aware the absolute SPL measured this way is worth nothing but what I was interested in was the average SPL difference between L30 II and DX9. And this one turned out to be remarkably similar across all headphones used. L30 was always 3.8 to 4 db louder.
The difference is perfectly logical for Sennheiser HD800: more than double the watts at 300ohms in L30 II favor, the math is almost perfect at 3.8 dbs.
Where it made less sense was for Focal Clear and Hifiman HE1000, which are 55 and 32ohms impedance, respectively. The difference should have been 1db or around that, not 4.
And even less sense for Audeze LCD X and Dan Clark Aeon X Closed. 3500 vs 3300 watts at 16ohms would mean the SPL should have been nearly identical. But no, still 3.8 to 4 db difference.
As I said, I am aware it's not entirely but the result was always in the range 3.8-4 db averaged, always in favor of L30 II across couple dozens experimental pairs using the headphones mentioned above. Also, I measured the DX9 balanced output the same way and it was 5.9 to 6 db louder than SE output so the difference checks, as it should be 6 db over single end. Only have Focal and Hifiman balanced cable though so these were the only ones measured on balanced,
Audio theory is not my strongest suit so it's perfectly possible I am missing something but does someone have an explanation from seeing the same db difference for LCD X and HE1000 compared to HD800? For the first 2, if the specs are correct, the difference should be minimal to none.
Thanks in advance!
Edit: now I see the correct thread for this would have been Amplifiers, Phono preamp, and Analog Audio Review, if someone can move the post there (or wherever this kind of post belong, I would be grateful)
Just bought the DX9 AKM (mostly for the looks, yes
) and, on single ended, it seemed a bit quiet for my taste on low volume masters like Steely Dan and after applying some negative pre-amp for EQ. I didn't have this issue with L30 II, my old amp.This made me curious and did a fairly unscientific experiment which confirmed what I was hearing. Basically, I plugged the L30 II in DX9 RCA outs, set high gain max volume for both. Then I measured average SPL with a phone db meter over a few one minute fragments from some songs. During measuring the phone was unmoved and right next to a headphone cup (which was also not moved, just plugged in alternatively in the L30 II and DX9 6.35 outs. Yes, I am aware the absolute SPL measured this way is worth nothing but what I was interested in was the average SPL difference between L30 II and DX9. And this one turned out to be remarkably similar across all headphones used. L30 was always 3.8 to 4 db louder.
The difference is perfectly logical for Sennheiser HD800: more than double the watts at 300ohms in L30 II favor, the math is almost perfect at 3.8 dbs.
Where it made less sense was for Focal Clear and Hifiman HE1000, which are 55 and 32ohms impedance, respectively. The difference should have been 1db or around that, not 4.
And even less sense for Audeze LCD X and Dan Clark Aeon X Closed. 3500 vs 3300 watts at 16ohms would mean the SPL should have been nearly identical. But no, still 3.8 to 4 db difference.
As I said, I am aware it's not entirely but the result was always in the range 3.8-4 db averaged, always in favor of L30 II across couple dozens experimental pairs using the headphones mentioned above. Also, I measured the DX9 balanced output the same way and it was 5.9 to 6 db louder than SE output so the difference checks, as it should be 6 db over single end. Only have Focal and Hifiman balanced cable though so these were the only ones measured on balanced,
Audio theory is not my strongest suit so it's perfectly possible I am missing something but does someone have an explanation from seeing the same db difference for LCD X and HE1000 compared to HD800? For the first 2, if the specs are correct, the difference should be minimal to none.
Thanks in advance!
Edit: now I see the correct thread for this would have been Amplifiers, Phono preamp, and Analog Audio Review, if someone can move the post there (or wherever this kind of post belong, I would be grateful)
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