Hello, I just joined, primarily for the audiophile products. Looking at purchasing the NHT C3 speakers for our new living room. Space is about 15 feet wide by 33 long and they will fire long ways. Space is just for general listening, music room with all equipment is downstairs, so hoping they will fill it with sound nicely. Cheers.
Mar 18, 2024
Full article here: http://nwavguy.blogspot.com/2011/06/sennheiser-hd-650.html?m=1
His calcs are not wrong, but they refer to power required to accommodate 115 dB peak levels. That is really f'ing loud.
In my experience, the HD6xx get plenty loud from only 2 Vrms or about 12 mW.
To reach a loud, safe level of 105 dB peak volume (90 dB avg volume), only about 5 mW is needed.
A great resource is here - https://diyaudioheaven.wordpress.com/tutorials/power-impedance-etc/ Tabulated data is here - http://www.mediafire.com/view/dzwe1g73q6pbhnx/headphone%20power%20table.pdf
Using specs from here - http://fiio.net/en/products/71/parameters - in single ended mode the X7 mk2 has 6Vpp or 2.1 Vrms. In balanced mode you have 10Vpp or 3.4Vrms. Both specs are less than is available for the NX4 DSD (2.9Vrms low gain, 5.8 Vrms high gain).
I'm not saying one is better or worse, but they should drive the hd6xx equally well (and loud!). However, your understanding of what the specs mean is a little off. Happy listening, at any rate!