post #181 of 1668
11/1/09 at 1:32am
A word about impedance and Planars:
The impedance (resistance/reactance) is steady in most Planar designs and is a constant, independent of frequency.
Dynamic drivers have a stated impedance value but it's nominal (averaged). The actual impedance can very wildly form 3 to 3000 ohms for instant peaks as an example, (measured in time increments of nano or pico ex.) and are a more complex load for an amp.
An Ipod will see the HE-5 and say "I can do it" and does. BUT the crux of the matter is SENSITIVITY!
Sensitivity, is more the ability of how efficiently the (current in this case) is turned into loudness level. Planars are, across the board, not the most sensitive of creatures.
The Sennheiser 6XX family is Voltage friendly and loves a good Voltage source. The HD800 requires a bit of both. The era of the Planar is upon us and it is now the "current" generation.
As electrostatic drivers are also planar, and with modern headphones, more common than orthodynamic headphones, it isn't correct to say that they have a nearly resistive impedance. Orthos do, but 'stats have a capacitive impedance, so it varies greatly. Also, the impedance peaks in dynamic headphones are in the frequency domain, not time.
That said, this is a thread about the HE-5, so I should talk about that. Fang kindly loaned me a pair of these headphones a few weeks ago, and I have been enjoying them since that time. These are excellent sounding headphones, some of the best I have ever heard. They have a nice, smooth response, are quite fast, no serious peaks like it seems most dynamics have in the treble, and when well amped, have great bass. I found the bass a bit rolled off on my Millett Max, possibly due to the 470uf output caps and 25ohm impedance of the headphones. It is much better though with the l'espressivo I recently finished building. Basically, I am perfectly happy with the sound, and the only headphones I have heard which I prefer are some of the top Stax, namely my SR007mk1. Koss ESP950 is up there too, though I havnt heard mine recently as it developed noise in one channel as they seem so prone to doing.
The frame for the HE-5 looks nice and feels very solid. Maybe a little too solid, as it does weigh a bit heavily on the cranium, though I suspect much of this is due to the lack of clamp and the headband not being overly padded. Still, it isnt bad at all, and I have worn far worse. The pads are circumaural, and tall enough so that my ears do not hit anything, which is great. They are covered in a velor material which is nice, but I find them a bit more stiff than I would like. The cable is a 4 conductor braided unit, covered completely in heatshrink and terminated to a Neutrik NP3x-bag (my favorite 1/4" TRS connector) and a pair of rf connectors on the headphone side. I really like the connectors used, though I am not quite sure what they are (not standard SMA, maybe OS-50). The cable is a bit stiff, but doesnt lead to audible microphonics, so OK on that front. I really like everything else about the frame though, and find it comfortable enough to wear all day. Just minor tweaks I would make really.
The Head-Direct HE-5 is a very nice headphone, and I can honestly say I prefer it over any dynamic or vintage ortho I have owned or had on long term loan. Of the dynamics I have heard, only the HD800 may be competitive with it, though the only experience I have had with that was an hour alone in Tylls room at canjam the night before the meet started. I prefer it over the Fostex T50v1 and the dbel84 modded Audeze LCD1, which I have here as loaners right now, Yamaha YH-100 and HP1/2/3, NAD RP18, Fostex T20v2, Realistic Pro30, as well as a very wide range of dynamic headphones. I do prefer my Stax SR007mk1 in every respect, but that cost me double on the used market what the HE-5 goes for new, and requires more amplification to boot. While I dont own these HE-5, I am seriously considering it if I can scrounge the needed money together (likely from the pending sale of my ESP950).
The very bottom octave (20-40Hz) of these is definitely lower in level than the 40-80 Hz range, but the bass is still definitely ample without being bloated at all.