[Syliano]

Hey guys,

I would like to get your opinions on this one:

My rig for producing music is: A Sennheiser HD600 with the E7/E9 combo as dac + amp and a pair of Yamaha Msp5 studio monitors.

The HD600 is for late night mixing and bass checks. I've noticed that the mixes I did with the E7 and the Hd600, before I had the E9 sounded miles better on my MSP5's then the mixes made with the E7/E9 combo. I recently tested this and again mixes made with the E7 translated better then mixes made with the E7/E9. Why is this? Shouldn't it be the other way around? The E9 gives the HD600 more power, the E7 drives them fine to though I listen to them with my volume at 39 and it can go up to 60.

My theory:

The input impedance of the E9 is coloring the sound/altering the sound to much. The 3.5mm input has 40ohm impedance and 6.3mm 10ohm. So lets say the 3.5mm jack input is to high. And to put the hd600 in the 6.3mm input I'd need a plug which also colors the sound?. The e7 has an output impedance close to zero, meaning it will not color the sound.

**Note, this is entirely my own theory I might be wrong.
 
Thanks in advance!
 
 

 

[mikeaj]

You mean to say output impedance, not input impedance (which is much higher).  A typical adapter plug would make next to no difference (certainly not something human hearing would pick up), so long as the jack connection is not poor, so you may as well use that.
 
Yes the output impedance can make some difference, but HD 600 has very high impedance compared to the output of the E9, so effects should be very small.  It should be very subtle at most.  HD 600 is like 500 ohms at 90 Hz, 300 ohms at 1 kHz and most elsewhere.
 
With like 43 ohms output impedance and 1V input, @90 Hz you get like 1 * 500 / (500 + 43) = 0.921V, @1000 Hz you get like 1 * 300 / (300 + 43) = 0.875V.  That's < 0.5 dB change in FR because of the output impedance.  I don't think this kind of shift would influence your mixes.
 
 
I'd suspect a small sample size of mixes over that.  Or maybe you're listening at different volumes with the E9 compared to just the E7, which will change the perception of the sound by a lot more than this kind of thing.

 

[kingoftown1]

the 1/4" input has low enough impedance that it shouldn't color the sound, and the HD600 comes with an adapter and all...
 
Mikeaj also brings up a good point with listening volume.

 

[Syliano]

Quote:

 
I'd suspect a small sample size of mixes over that.  Or maybe you're listening at different volumes with the E9 compared to just the E7, which will change the perception of the sound by a lot more than this kind of thing.

This might be it, I usually put the E7 on max volume (isn't that loud on the HD600 when mixing) whilst on the E9 I put it much louder, maybe to loud. This might be the problem. Thanks guys, I'm going to try mixing on lower levels with the E9 and see if that changes something.