[JoeDoe]

 

 

 

 
KSC 75's: Hiflight Edition
 
I'll get back to you this evening after I A/B them with the unmodified 75s.

 

[Cu Chulainn]

Looking forward to it!

Those pads are rather interesting...Are they as uncomfortable as they look?

 

[swmkdr]

Also looking forward to it, will wait for your impressions before I decide to pull the trigger (or not) on my own.

 

[JoeDoe]

Quote:

Also looking forward to it, will wait for your impressions before I decide to pull the trigger (or not) on my own.

Will get back later!
 
Quote:

Looking forward to it!

Those pads are rather interesting...Are they as uncomfortable as they look?

Because the headband is so light, they aren't uncomfortable at all. Obviously they're a cheaper foam, but they feel fine, not irritating at all.

 

[shotgunshane]

I just received a second modded pair. This one identical to the first but with an additional 47 ohms of resistance added inside the cans (same as Joe received). In a day or two I'll give a brief comparison of the two but I'm really liking what I hear.

 

[Xprime4]

I bough a pair around a month ago or so and the right driver make an aweful noise when bassline hit. They were never really driven hard and they might not have 5 hours of use. Any idea?

 

[julian67]

I bough a pair around a month ago or so and the right driver make an aweful noise when bassline hit. They were never really driven hard and they might not have 5 hours of use. Any idea?

Switch off any bass boost or other equalizer. Use a device with enough power to drive the phones properly. If that makes no difference then use the warranty and get a replacement.

 

[JoeDoe]

Alright here we go:
 
For the A/B I used the following source gear:
 
IPC 120GB (mostly ALAC and 320 mp3) -> JDS C5 -> 75s
MBP (mostly ALAC and 320 mp3) -> Audioquest Dragonfly -> 75s
 
Aesthetically Speaking:
 
You can see the pictures I took a few posts above this. The mods Ron did at Hiflight were: a headband mount, replacement center-holed pads, drilled and resin coated driver covers, and an additional 47 ohm impedance upgrade (bringing the total to roughly 107).
 
The headband seems to be from Parts Express - very minimal in design, super lightweight, and adjustable. No qualms here.
 
Replacement pads are super light and a little thicker than the stock pads. They aren't super soft but the clamp is so minimal that they aren't irritating in any way. 
 
Now for THE SOUND:
 
First impression: SPACE!!! The HF 75's are much "bigger" in every sense. I'm sure the centered pads lend themselves to this, as does the drilled covers and higher impedance. In any case, the clarity and detail that we like are still there but the sense of depth has increased noticeably. One of my favorite test tracks is Adele's "Someone Like You" Live at Royal Albert Hall. She has the audience sing in the third chorus and my HD580s have me looking left and right for the audience! The HF 75s take the decent space in the stock model and enlarge it  without any loss in quality. Another test track was James Blake's "Retrograde." Even though the sounds are electronic, he did an excellent job reproducing a cathedral-esque soundscape. The HF 75s give you the reverb/space in such a space much more easily than the stock version. 
 
The BASS: I'm not sure that the lower range is extended, but I get the sense that it has become "easier" for the HF 75. Sub-bass response is noticeably more present, yet never distorted. Once again "Retrograde" really yields some excellent sub-bass that I remembered hearing for the first time in my TF10s and I'd put the HFs right on par with those in this respect. In 311's "Daisy Cutter" I often find the bass distorted and offensive, covering up the other instruments especially during the song's chorus. However, the HFs have smoothed said bass and given it more equal weight from the top of its range to the lowest. The mid-bass to me remains very similar to the stock mod, if anything it has smoothed thanks to the impedance mod. The fullness we've come to like in the stock model certainly hasn't gone anywhere. 
 
MIDWAY: The mids are a little smoother IMO than the stock 75s. This could be a result of the bigger sense of space mentioned above (think hearing a full orchestra sound from the back of the concert hall after they've blended, rather than hearing each sound individually while listening to a string quartet from the first row). Even though this is contradictory, I do think the mids have come forward a little compared to IMO, a slightly recessed mid in the stock model. The guitars in Del Amitri's "Roll to Me" are clearer and I hear both guitar parts and the organ in the bridge much closer than before. All in all, they're still rich and pleasant, never overbearing.
 
The TREBS: IMHO the trebles are the least affected by the mods. They may be a little smoother but there's certainly not a huge change. I've never found the 75 treble offensive or sibilant to begin with and the mods certainly don't produce any negative affects. 
 
Minor DETAILS:  The detail and clarity are improved for an already detailed sound. Subtle nuances found in the tracks mentioned above come through much more easily than the stock 75s, i.e. hi-hat patterns, vocal breaths, guitar harmonics, etc. Getting to hear those sorts of things really make this hobby enjoyable and I'm glad the detail of the stock cans was able to be improved. An excellent example is the percussion and ambient sounds used in Melody Gardot's cover of "Over the Rainbow." I didn't really get a sense of different sounds coming from different sides with the stock 75s, but they showed up beautifully with the HFs. 
 
I think those impressions cover everything I've heard. If I need to mention the most obvious changes, they're certainly a bigger sense of space and the improved and smoothed bass response. My findings in those respects certainly are consistent with the mods Ron did. 
 
I certainly would like to thank Ron at Hiflight for his excellent work and professionalism. I certainly recommend these mods to anyone with a pair of KSC75s to spare. They take an already impressive sound and make it even better in very noticeable ways, still for much less than competitive sounding cans.

 

[Cu Chulainn]

Really nice review, thanks

 

[FieldingMellish]

Thanks for taking the time to write about your experience with it. Do you feel that the bang for the buck was worth doing rather than selecting a set of cans elsewhere; one that fulfills your desired sound requirements without modification?

 

[JoeDoe]

Thanks for taking the time to write about your experience with it. Do you feel that the bang for the buck was worth doing rather than selecting a set of cans elsewhere; one that fulfills your desired sound requirements without modification?

Well the mods cost $60 so all in all I'd be surprised if I could find this kind of sound and a $75 package. In addition, for me the whole process was enlightening. Are these mods I could've done myself? Probably. However I enjoyed learning and experiencing what could come out of $5 spent at Office Depot!

Id still recommend the mods to anybody. Ron did a great job and was very helpful throughout the process in making recommendations and keeping me updated

 

[julian67]

I'm a bit less ready to be excited about the HighFlight modded KSC75.

My biggest reservation is the impedance increase. Surely this is only useful when using a receiver or hi-fi amplifier? It's about the last thing I would want to do to any headphone to be used with a portable. I already know from personal experience that my Clip+ can't adequately drive phones with 60 ohm impedance and that my substantially more powerful (about 30%) iRiver H140 and H340 are about the minumum required. I would consider using a resistor with my Yamaha HT receiver but not with my domestic portables and 100% absolutely definitely never with my personal players.

I also know that one can buy for between $10 and $15 an inline resistor that can be used when necessary and disconnected when undesireable. i.e. resistor adapter This looks to be a much more sensible solution for anyone who uses a mix of portable players, amps, receivers etc.

As for the headband, grilles, pads and so on this is the work of a few moments at the tiniest expense. I'm not criticising HighFlight's price because everyone deserves a fair reward for the benefits of their labour, knowledge and expertise and $60 including some materials looks very reasonable in those terms .

But I am really doubtful that there is anything these changes can achieve beyond a slightly different frequency response and a small perceptual change due to the thicker pads moving the driver a little further away from the ear. How any difference can be made to the hardware's ability to resolve detail is surely a mystery.

If you look at the frequency response and distortion measurements Koss KSC75 Frequency Response and CSD Waterfall Plots of the stock KSC75 you can see that what needs improvement is stuff you can't greatly change: the bass response rolls off very obviously below 60 Hz and there is bass distortion so if you try to boost the bass towards a flat response you will run into problems very quickly. You can make some small but noticeable improvements with Equalization and by drilling holes in the cover but ultimately you cannot escape the physical limitations of the driver.

My expectation is these HighFlight modded KSC75s sound different than the stock but not necessarily better, and that the higher resistance alone pretty much guarantees that if there is a real improvement it will only show itself when paired with a receiver or other amp with relatively high output impedance.

The kind of assessment that would actually be useful and credible would be by someone without any financial or personal stake in the products or the transactions, and would involve at minimum volume matched comparison between stock and modded phones, and ideally done blind either with the drivers mounted in clips or in a headband.

 

[shotgunshane]

An iPhone drives the 75's with +47 ohms just fine. No AV, stereo receiver or even portable amp is necessary.

I'm not going to bother DBT over $50. Sorry if this is not credible enough. The headband, resin coated housings and pads make the majority of the difference. Impedance gives different flavors, its not a necessity but the deep bass does sound better to my ears, real or imagined, that's all that matters but with sweeps and tones I've heard 40hz at decent volume compared to 60 and above. I'm also sure there is variance in a product so cheap.

Here is an easy way to add custom amounts of impedance: http://item.mobileweb.ebay.com/viewitem?itemId=290372905689

 

[JoeDoe]

Well to each his own I suppose. I enjoy the mods and stand by my assessments. I have no background in electrical engineering or digital sound but I think my ears may have benefitted from several years of classical music training.

Whether my observations are quantifiable through any sort of assessment device I don't know, but ultimately everything I posted comes down to my ears

 

[FieldingMellish]

I learn tons from you gentlemen and for that I am appreciative.