Sennheiser HD598Cs measurements and sketch impressions

Discussion in 'Measurements (unsanctioned)' started by Biodegraded, Jun 3, 2017.

  1. Biodegraded

    Biodegraded Acquaintance

    Joined:
    May 28, 2017
    Likes Received:
    43
    Trophy Points:
    18
    Location:
    Calgary AB, Canada
    Sennheiser HD598Cs, http://en-ca.sennheiser.com/headphone-around-ear-home-mobile-hd-598-cs; SBAF discussion thread here. Introduced late 2016, These are closed-back versions of the open HD598/HD598SE. RRP $CAD 299.95, but currently on Amazon.ca for $CAD 183 and Amazon.com for $US 124. Can often be found cheaper; mine were $CAD 110 last Black Friday.

    Claimed specs: distortion @ 1 kHz < 0.2% @ 100 dB, sensitivity 115 dB/V @ 1 kHz, impedance 23 Ohms (presumably also @ 1 kHz but this is not stated). So they’re easy to drive but if impedance vs frequency (I’m not set up to measure this) has the common big peak in the bass, source output impedance of more than 3 Ohms could lead to overemphasis there.

    Construction seems fairly sturdy but the (nicely padded) headband is not as solid as the 598SE. Velour pads, fake leather headband cover. Light and comfortable on my size 6-7/8 to 7 head, with a fairly firm but not killing clamping force. Likely not great for big heads though: see this thread. They come with two detachable cables, a 1.2 m version with a universal one-button mic/remote and 3.5 mm plug and a thicker 3 m version with a 6 mm plug. These plug into the left earpiece with a 2.5 mm bayonet-locking plug which I think is Sennheiser-proprietary. The shorter one in particular has an annoying springiness which resists coiling or draping.

    Here they are modeled by the lovely Pseudodegraded, whose head is slightly smaller than mine, 6-3/4.

    [​IMG]

    My measurement setup and its shortcomings are described here. The short version is that I think my FR results are a bit rolled-off in the bass, take too deep a plunge at 3-3.5 kHz, and are low from c. 7 to beyond 10 kHz; and distortion, particularly in the bass, shouldn’t be trusted too far (or maybe at all – see this discussion).


    Frequency response

    [​IMG]

    [​IMG]

    For my rig: strong through the bass, strongly rolled down through the upper midrange and lower treble (below the 3-3.5 hole), and low through the mid and upper treble. The channel imbalances through the treble vary as the phones are repositioned for different measurements, but persist. In the second graph above I’ve included curves from the HD280Pro (also circumaural) and Momentum On-Ear for reference if you’ve heard those and for comparison to published curves (Innerfidelity HD280, Innerfidelity MOE, HeadRoom build-a-graph page) to illustrate the characteristics of my measurement system vs more familiar ones.

    I think the perception of a v-shaped response that’s been mentioned is due to the drop in the upper midrange combined with the strong bass. The treble itself is down compared to the other phones. Listening (Magni 2U), the bass on these is certainly there in quantity, but seems a bit boomy; the 280s’ bass is more recessed but more precise. Further up the range the Cses come across as smoother, although the midrange might be a bit over-influenced by the bass; but upper piano notes seem lacking. Treble seems fairly well balanced with upper midrange and has no unpleasant piercing notes. I’d agree these sound v-shaped, but maybe too much at the bass end and this pollutes the lower midrange somewhat. Bear in mind though that these comments come from someone who likes his modded K702s o_O


    CSD right & left

    The plots below go down to 45 dB to show what happens around 35 below the 80-85 dB treble region, where they look pretty good: ridges coming down from the peaks at 8, 11, and 15.75 k are gone well before 2 ms, which should translate into treble that shouldn’t be harsh. Even if my system does underrepresent amplitudes in the mid-treble, this is still a nice result.

    [​IMG]

    [​IMG]


    Distortion right & left, %

    Not sure how significant these plots are, but here they are for completeness.

    [​IMG]

    [​IMG]

    Overall, I quite like these phones but find the thick bass and its effect on the lower mids a bit annoying. I did some quick listening comparisons with a friend’s NAD HP50s and AKG K550s and concluded I liked the tonal balance of the NADs best. We also compared his open-backed 598SEs: these of course sounded very different, having a nice open and detailed midrange. I must be just about the only one here who hasn’t heard the HD600 or 650 so I can’t comment on the comparisons that have been made to those.
     
    LSW, Thad E Ginathom, Lurker and 3 others like this.

  2. a44100Hz

    a44100Hz Friend

    Friend
    Joined:
    Jan 1, 2016
    Likes Received:
    900
    Trophy Points:
    93
    Location:
    US East
    They don't compare to a modded HD650 for clarity and presence, but they don't have to. They're fun EDM / electronica cans. I've started using them at work straight from my phone and I prefer them to the Noble X's for that purpose. There's another thread with some impressions here (link).
     
    Cspirou and Biodegraded like this.
  3. Lurker

    Lurker Acquaintance

    Joined:
    Oct 10, 2015
    Likes Received:
    52
    Trophy Points:
    18
    This site also has some measurements although their compensation curve for the frequency response has a 4dB bass boost below 200Hz, so keep that in mind when looking at the plots. Distortion on your setup does seem boosted. On Rtings dummy head they barely hit 0,1% @1kHz @100dB.
     
  4. Biodegraded

    Biodegraded Acquaintance

    Joined:
    May 28, 2017
    Likes Received:
    43
    Trophy Points:
    18
    Location:
    Calgary AB, Canada
    Nice. Shame no impedance though.

    Yes!
     
  5. Biodegraded

    Biodegraded Acquaintance

    Joined:
    May 28, 2017
    Likes Received:
    43
    Trophy Points:
    18
    Location:
    Calgary AB, Canada
    Update: impedance curve

    The necessary technology has been acquired. North Korea and Iran will have to search farther afield for the final components for their own pet projects...

    Impedance measurement was checked using HD280Pro and Momentum On-Ear against the measurements at Innerfidelity. Differences are under 5% across the range, so the curve below ought to be pretty close to reality too. Which is interesting, because the impedance claimed on the box is 23 Ohms but they measure higher than that everywhere (minimum 27, 29 at 1 kHz).

    [​IMG]
    [​IMG]
    Slight bump in the bass. Higher output-impedance sources (more than about 4 Ohms) would start to reinforce this area, which is already pretty strong.

    Similar curve to the HD569 recently reviewed by Tyll; not surprising given the similar design. Different drivers though I think.

    I now have better distortion measurements than the dog's dinners posted above - but the noise in my system is still too high for them to be meaningful, so I won't post them.
     

Share This Page