The nominal impedance of the headphone also does not determine this interaction - their reactivity (or lack thereof) does the HE-6 above are a low-ish impedance load (~50 ohms), but they're also essentially resisitive. But "high output impedance" does not equate to "unpredictable changes to bass response" - that's far too generalized of a statement. If the amplifier has atypical frequency response, is current/voltage limited, or is doing something else, that can also have an impact on the sound. So as output impedance increases, treble rolls off. Examples:īose In-Ear headphones, and the impedance rolls off as frequency goes up, as here: A lot of IEMs or multi-driver systems have much different looking impedance curves, and their FR will respond accordingly to higher source Z. Many single-driver systems have a resonance in their mid-bass and that's why "it affects the bass" is such a common explanation. And it isn't explicitly tied to "the bass" either - it is simply the inter-relationship of load impedance and source impedance. As you approach ideal power transfer you will see "boosts" (so points with higher load impedance + higher source impedance will lead to "boosts" of the frequency response). You can know pretty clearly how it will go, if you know the impedance curve of the headphone and the output impedance of the amplifier.
Oh, and you don't need to say "higher ohm" or "lower ohm" or "ohm rating" - you can just say "impedance." My guess is that if the amplifier has enough current delivery and the headphones are sensitive enough, it can probably get by well enough, but I'd be nervous about asking too much current from the amplifier depending on the cans (without more information about the 336SE's output specifications this really can be written off as idle speculation, and that's really what it is: I don't own the 336SE, and I'm speaking in generalities - maybe it works great, and at least one response to this thread seems to indicate that is the case). To your original question: I don't actually have an answer, and its something I've wondered about myself as well. "Damping factor" really should have no place in this discussion (or any discussion if I'm being entirely honest) - its a marketing spec borne out of a bygone era that's been appropriated to push a specific agenda. How you feel about it or whether or not you like it or desire it is something else entirely. The problem is that argument is a slippery slope: who gets to arbitrate what the "truth" should be here? It's an observable change, but that's where objectivity stops - the event can be seen and described, and has been. ** For the peanut gallery: I know I'm using the word "efficiency" wrong here, and it should be "power transfer" instead, but "efficiency" probably makes more sense for most people.Ī couple of years ago now, some very vocal folks latched onto this idea that "output impedance needs to be 0 because anything else represents error" based specifically on how the Sennheiser headphones (as reactive loads) respond to changes in output impedance, and that idea seems to have taken root on a large scale. Here's an example of a non-reactive load, a planar magnetic If the load is not reactive, however, the frequency response largely doesn't care and all higher output impedance will do is diminish efficiency (its basically "getting in the way"). This doesn't matter if the output impedance is the result of being an OTL, or just high value resistors on the end of a solid state amplifier. I wish the scale was a little finer, but they're showing around a 2 dB rise with the 300 ohm output. So if there is a very reactive load (Sennheiser HD 600 has been mentioned, and is a good example) its frequency response will be impacted by changes in output impedance (this is measurable and modelable), here's an example, from : Output impedance will interact with the reactivity of the load.