I found with the HD600 that EQ'ing up the bass to Harman levels made the bass woolly, I couldn't find much detail in the bass, I put it down to distortion issues.
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Sennheiser HD650 Review (Headphone)
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Yes. This is amplitude modulation distortion and you can identify it using a two tone test signal.
Phoney
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I feel like using his measurements to EQ the FR to the harman curve usually gives the most accurate results. Ofcourse there will allways be exceptions, but generally.
Phoney
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Look at oratorys links here. This is using full harman bass boost for the HD650, +9,3db at 20hz. I believe the red line in the last graph is audibility, and the bass distortion is below the limit?
I had the same experience as Robbo9999 a couple of years ago: EQing the HD650 bass back up to Oratory's version of Harman was a total fail. The bass lost all integrity. I fiddled with a high pass filter, but my DCA planar was so much more tolerant of EQ (and less needy in the bass to begin with), that I just stopped listening to the HD650. Every few months, I get curious and give the phones a try, but they are just weak at the bottom end, once you're used to clean, low-distortion bass. (And I'm not a bass-head: I usually tune to -2 dB or so vs. Harman at the bottom end.)
Looking at Tyll's numbers, the total distortion in the bass and sub-bass seems very high whether or not EQ to Harman is applied. Trying to reconcile subjective experience with the objective numbers, an alternative explanation for my experience would be that my attempt to beef up the bass of my HD650 was roughly coincident with my acquisition of the low-distortion planar phones: perhaps listening to the planar simply sensitized me to the high level of bass distortion that was always present in the HD650, and whetted my interest in richer bass. After all, at that time my only prior experience with higher-fidelity headphones was with Ety ER4 IEM's, which are also light on the bottom end. Maybe I'll check that out next time I get an itch to swap headphones.
Do you know what sort of levels you listen at? I only ever listen to my HD6XX out of my phone which has a pathetic output of 0.3V, "almost useless" according to amir, so I know I listen very quietly and I've tested massive boosts like +12dB at 20Hz and never heard any distortion.
I don't listen to much music with bass that low though so maybe I haven't experienced what it is supposed to sound like.
I don't listen to much music with bass that low though so maybe I haven't experienced what it is supposed to sound like.
I don't listen to bass for the sake of strong bass, but I like to EQ for acoustic sources (classical, folk, etc) so that there is clean bass in reserve to create a full FR and convincing fidelity. (I listen to electronica, too, but bass is almost like a separate "instrument", not just a frequency range, with that.) The point being: dynamic range down to the sub-bass, separation, accuracy vs. distortion, realistic balance with mid's and high's.
On that score, the DCA planars were a revelation for me. Plenty of clean, undistorted bass, easy to EQ, wonderful separation. I also have a Sundara. It needs a little bass boost and accepts EQ gracefully. I hear a little more resonance in the mid-bass, but find it pleasant with bass guitar. If those sound like your values, then give the planars a try; or perhaps there are dynamic drivers that do the same thing. Whatever the reasons, I find it hard to go back to the Sennheiser HD650 bass b/c it sounds congested and underpowered to me now.
Those distortion measurements seem a bit low in the bass for what would be a 94dB measurement (accounting for the +9dB bass EQ), from what I remember from seeing other measurements of the HD600/650 then I remember higher amounts of measured distortion in the bass. I tend to think the red line of audibility in that graph is a bit high basing it loosely on my subjective experience of listening to different headphones that have different amounts of distortion susceptibility. But yeah, I put my experiences of the lack of bass detail within HD600 when EQ'd to Harman as being a result of bass distortion, but it's not like I did scientifically valid listening tests, and nor did I control for listening levels beyond saying to myself "yes this is my typical listening level". It is my current opinion of why I didn't like bass EQ on the HD600 though.
Phoney
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I agree, I use a +8db boost in the sub bass but I think the bass sounds similar to other headphones that I've tried. And I have tried a lot of different ones, lots of planars amongst them. Maybe I just don't mind a little bit distortion, but I also don't listen particularly loud either. Like oratory says, boosting the bass by 8db will give you the same rise in bass distortion as turning up the volume by 8db, and vice versa. Your hearings sensitivity to the higher frequencies matters aswell, because if you're not sensitive to those you will probably listen at a louder general volume. Lastly I do think that bass distortion post boost is often not as audible as many would think.
Phoney
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Oratory mentions that for example Tyll was using an older rig, which explains the difference in the measurements.
As another data point, and this is the HD600 rather than the HD650, my HD600 had around 1.4-2.5% THD (measured on my miniDSP EARs rig) at around 30Hz when measured at 84dB at 1kHz, which is higher distortion than the HD650 graphs you linked earlier. At the moment I still think it's distortion related why I couldn't get bass detail in the HD600 when using EQ, but I may need to correlate this with distortion measurements I've done on my other headphones where I can get good bass detail. I also wonder if IMD (Intermodulation Distortion) could be a factor, as that is different to Harmonic Distortion that we normally measure for, so praps it's IMD related rather than THD.
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Phoney
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Oh right.. Well, the HD600 does usually require a larger boost. If it has higher distortion aswell, then it could explain why the distortion is more obvious to you than what it is to me. Maybe even the higher boost in itself is enough to make it audible.
In my experience, boosting the <150Hz region, on any decent headphone is a non issue in terms of distortion perception. It's easier to get too much bass before any annoying distortion sets in. Except for, I guess, what would be more noticeable, in ear cup interactions with the outer ear, and, or, higher harmonic artifacts perceived as moodiness, woolliness transiting into the mids, etc...
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... to my ears and taste and imo and all of that applied... ;-)
Distortion in bass..undetectable when it stays under 20%..?!?
What do you guys think of this..? https://www.axiomaudio.com/blog/distortion And under 40hz, undetectable until it reaches 100%..!! So why do we chase low dist woofers and servo control etc,, if we cant hear it anyway..?!? Apologies if this has been posted before.
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How Much Distortion Can We Hear With Music?
How much distortion can we hear with music? An experimental study at Axiom.
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... to my ears and taste and imo and all of that applied... ;-)
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music_lover
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I have bought and sold many high end headphones in the span of 13 years. When I first tried the HD 650, I was not impressed. In fact I kinda was disappointed and thought my beyerdynamic DT 990 sounded superior. This was in 2010. In 2023, after having owned several planars, estats and high end dynamic cans, I only have one headphone in my collection. Yes, it is the 650. It took me years to appreciate what the 650 has to offer. The absolutely natural, full and euphonic vocals are the highlight of these headphones. I even got to try the Sony R10. No other headphone I tried produced the same midrange. The other headphones may have better technicalities, but they can't match the timbre and sheer musicality of the 650. I am fully satisfied with the HD 650 and it is my end game headphone and will be for a long time.
Rosenbloom
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Same here. Over the years I had spend much on different headphones. Now I keep only one HD6XX. I am fully served and satisfied.
Found same thing with HD6XX, bass is bit mushy by default, bumping the bass up draws more attention to this effect.
Snuffy
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I bought my HD650's in 2004. Used an Asus Xonar Essence ST at first, then later Schiit Modi+Mini. When I started using them again after a several years hiatus, I upgraded to a Geshelli J2 and Monoprice THX AAA 887. This was a big improvement over the Schiit, but I feel like they don't have the same magic they had back in the day. Tried various profiles in Equalizer APO and that helps some, but there still seems to be something lacking. This may be due to the fact that my home theater is so good, I'm now spoiled and its all in my head. My question is, could age have decreased their quality? Are the new HD650's any better? Is it worth blowing several hundred dollars purchasing the same thing I already have?
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