I’d be really keen to see the Hifiman HE1K models added to the ratings too.
I pulled the trigger and bought a pair of HE1000 v2 yesterday. The V2 profile excites me more than the new Stealth and the SE versions. Since the V2 is officially discontinued, I also didn’t want to miss the chance of grabbing a new pair from Hifiman before they’ve sold out. At $3.5-$4k AUD I struggled to justify it, but at $2k AUD it was hard to resist!
The only fundamental challenge with Resolve’s list is the source equipment.
Some of these headphones respond quite differently to a quality tube amp verses solid-state as an example.
This is true - the amplifier impedance can literally change the frequency response. This is not something I’d want happening when comparing headphones directly, as it’s not the tuning the manufacturer intended. If Resolve doesn’t use a tube amp when doing critical analysis and ranking a headphone, that could be why. In my opinion, it’s the right move.
This isn’t necessarily the case. For example, ZMF sells tube amps recommended to use with their headphones, so you can’t assume that the way something sounds on tubes isn’t the way the manufacturer prefers.
That said all ranking lists are subjective and weird, so I wouldn’t stress that much about what equipment he uses for testing; it’s whatever he thinks he wants to listen to it with and his subjective impressions of them.
I know at least that Resolve has tried tube amps, since he said he liked the Forge.
As you noted, yes I do have reference tube amps to test with as well. But out of curiosity, do you think it matters that something sound the way the manufacturer prefers? I actually think there is an argument for this in the case of high output impedance and non-linear impedances for headphones, because bass level could be significantly different. But, as a default I have a hard time imagining this should be required for every headphone.
I think synergy is important regardless. Could be a certain tube topology/amp or specific solid state amp. People really just need to get ears on things and try with different sources. I’ve had a few high end tubes amps and they all had different synergies with my headphones. Same with some solid states. Some were a hit and some a miss, and some of it is a preference.
It’s nearly impossible for a reviewer to have everything in house, so take a little from the review and figure out your moves. Talk with others in the hobby who have or had similar gear as you for other perspectives.
This is good advice IMO. You can’t get perfect insight as to what the qualitative experience is going to be like without trying stuff. One of the benefits of going to shows and meet ups.
I’ve messed around with using the “wrong” amps for a given set of headphones, but some headphones simply cannot generate much bass so the concern is merely theoretical. Speakers capable generating a lot of bass may differ.
I do avoid using low impedance headphones on OTL amps because they often sound thin, scratchy, and awful.
Well I think you have to contend with two things, one is nonlinear impedance vs output impedance, but the other is also excursion limits and distortion. As you say, some headphones can’t really take the bass lift, whether with a higher output impedance pairing or with EQ.
The Focals for example… pairing with higher output impedance or EQing up the bass is generally a bad idea, because that will run into the excursion limit in low frequency (it hits around 8-10hz first, so even though its outside the range of human hearing, it’ll still tzzzzzt when it hits that frequency at a certain SPL). So if you add a bass shelf, the excursion limit hits at lower volumes.
Just to point this out, because perhaps it’s not obvious, but this works both ways.
While headphones do differ in there response to an amplifiers output impedance, the reverse is also true.
Amplifier FR and Phase response change in response to load, notable lower impedances tend to result in earlier bass roll off. It’s less of an issue for amplifiers with a lot of feedback, but it impacts SS amplifiers as well as just tube based ones.
So when you have something like an HD600 that has elevated impedance at low and high frequencies, your not getting the FR from the amplifier into a fixed load. Though it’ll be less dramatic going from 300-600 than it will going from 32 to 64.
This would be interesting to test and plot the effects of.
You can demonstrate it fairly easily for simple amplifier circuits in simulations.
If the output is capacitively coupled, it also acts as a CR High pass filter in line with the load which obviously changes it’s response as the load changes, and in some designs because of the reluctance to use electrolytics as coupling devices, and the expense of large value none electrolytic capacitors, it can edge into the audible realm for lower loads.
The only attempt I’ve seen to capture real world amplifier behavior for active loads was at SBAF, there were so fairly interesting results, but I’m not sure you could draw general conclusions from them.
While, trivially, this is true, the actual degree of change here is a function of the relationship of Zout and Zload. When Zout is very small vs. Zload, the voltage drop is very small, and the maximum frequency response change is, correspondingly, very small - e.g. a 1ohm output impedance will produce less than .03dB of total voltage drop with the HD600, so the most change in response you could possibly have is <.03dB.
In general, this is kind of a distinction without a difference, to use a @Resolve ism - when we consider amplifier FR with headphones, we are looking at the same changes in the output voltage which produce the changes in headphone FR with amplifiers, it’s just a matter of whether we look at the voltage node between the amplifier output and headphone input, or the sound pressure.
I wouldn’t really go this far - there is a rich tradition of testing the impact of phase angle on amplifier performance - e.g. you can find articles using AudioGraph’s PowerCube from decades ago - and the SBAF results were basically reading the tea leaves in noise from back-EMF.
You might have missed the EQ’d list.
Where the limits of a transducer are explored beyond what a source may be able to affect.
@Resolve Is this list maybe due an update to include the Modhouse Tungsten? I’m very curious where you’d put it.
Yeah I do need to update stuff. Sorry I’ve been away on vacation and pretty busy otherwise with various projects so it’s been tough to maintain. At some point I’ll do a big update - but the Tungsten would rank highly.