HD660 and HE400 headphone mod project updates

I have been insanely busy over the past few months and not had time to finish off all the projects I started, so, I thought I would do a quick update so show how things are getting along
customcans.co....

[@Had__Music]

The reason why this channel is attractive is that it starts from simple design mod to internal-parts mod. In addition, by attaching the measurement data together, it is possible to check how the frequency response changes/or does not change. So, the pleasure of watching the interesting process of modding and the usefulness of checking the measurement data coexist. Great job!

[@CustomCans]

Thanks. We will hopefully build a fancier test rig soon to get better data

[@kennethlilley4296]

Great work on the HE400SE's 👍 I look forward to seeing a combined insert and magnet modification😉 The amplifier sounds interesting especially at the target price, so I hope you sell loads of cables and can put them into production👍 As an added bonus it will also help you personally as it will stop you playing with your knob for twenty hours at a time! 🤣

[@CustomCans]

Lol... good point

[@H-4-D3423]

With how good you have the HE400 sounding now Jason, it would be really interesting to see if you can almost completely close these off...!! A closed-back, bang for the buck audio killer... :)

[@sambryant2283]

Loving the R&D.

[@CustomCans]

Thanks - it is expensive but fun and may pay off in the future ;)

[@adrianmuza3374]

Nice grippy knobs do pay off for sure.:)

[@kyleirelandtech]

It was interesting seeing you mod the Sennheiser HD 660 S and Hifiman HE400SE as these are the only headphones I really have. I daily drive the Sennheiser HD 660 S and have had them a while. The HE400SE I bought a little while back to try out. The stock silver cable sucks but Hifiman sent over the new black one. I use Grado SR60x while in bed but the cable is horrible.

[@CustomCans]

It is surprising how bad some headphone cables are ;)

[@Tripokaridos22]

Amazing Work, in my opinion 660s are ready to go no mods needed. Years ago i use a hd650 driver inside the HD599 angled plastic frame and i got way better soundstage (like u said) ànd also it needed more power and i had more distortion. To me HD6 series are all about the sound signature this soundstage and the only need is the mod that u had on hd600 and 650 giving a small low end without braking something else .

[@CustomCans]

Thanks ;) it is the " not breaking something else " which is always the hard part

[@PinePizza]

installed the copper mod, got tubes, it's great

[@Tripokaridos22]

@@CustomCans exactly the problem with mods and pads is this , unfix something u brake something. Your copper mod is something very clever , u should have it on black colour for people like me that want something elegant .

[@ariam6168]

@@Tripokaridos22 My 660s could definitely use a bit more sub bass, but I think the best “fix” is a bit less lower midrange bloat in the 150-250hz range. It just slightly masks over the rest of the midrange details to my ear and eq confirmed it for me

[@shreddherring]

The hd700 are already angled like this. So, the 660, which was an attempt to take the 700 and turn it into a 650, with the added angled mount, would be trying to take it part of the way back to being a 700. I think it could be worth picking up a pair of 700's, it might help to give you a more complete picture

[@CustomCans]

I don't think I will be able to afford some HD700 for quite some time but maybe one day ;)

[@DonutsReview]

Looking forward to the modded HE400SE stealth reviews.

[@CustomCans]

Yes - I got destracted and forgot to send them off to the reviewer - they are now on their way to "Reviews By WaveTheory" to have a play with

[@robr1533]

Regarding the Mod for the He400se and i did the stl file happen for just the grills ?where you popped the grill off and replaced with 3d printed grill and wave form. Thank you once again

[@alwe8019]

Aww man, the HD660S could definitely use more subbass . Awesome work still!

[@CustomCans]

I am not beaten quite yet, may still be able to squeeze a little more out

[@alwe8019]

@@CustomCans I am praying to the lord lol. The 660S sounds awesome but there’s also something missing in the highs. They‘re sometimes crystal clear and sometimes drums sound like a wet noodle…

[@Synthematix]

The thing is what i have discovered with open backed headphones is they will sound like crap unless you have very good amplification, all headphone amps sound different, and guess which one is the best to my ears, the one in my Sony JB930 minidisc recorder, its bassy and punchy as hell with sizzling highs

[@CustomCans]

Oh.. Man, I used to have one of those and regret getting rid of it - I used to love the keyboard input to add track titles and stuff

[@Synthematix]

@@CustomCans Best format ever mate, ive got discs here i recorded 20 years ago still play 100% perfect, yet most of my cd-r's have rotted and fell apart, as they have no protection, i use minidis to record music i make myself, theyre brill machines the sony jb QS series

[@zerranox9801]

Hey, are you going to make the STL's public, or is there anyway to buy them? Would love to try to mod both of these myself. Anyways, great mod!

[@CustomCans]

Yes, I will try to get them uploaded this weekend and add a link on the video description

[@zerranox9801]

@@CustomCans Thanks!

[@kyleandryscik150]

How is the progress on the HD660 mod coming? I just finished modding my DT 990 pros and am shocked how much better they are. Now i'm hoping there is still a mod coming for the 660s.

[@marcp.1752]

Way cool, hopefully some 3D printing service can print them out, when you make the STL's avialable. I have no clue about 3D Printers, never had one. ;-) About the HE-400, i'd love to hear my HE-400se with your latest mod. Because i am totally not happy with the SQ from this Headphone, it sounds naturally like rubbish compared to my HD 650, sad but true...is there *any* possiblity to get that huge mid to high frequency curve more flat? It's crazy.... Regarding a headset amp, it should being always Class A...these sound really great, i've bought some back into the late 80's, early 90's, it was a hobby...long ago...well, quality neutrik connectors, same for chinch connectors, quality PCB & layout, Toroidal transformer, selected transistors, 1% metal film resistors, and nice, small alu case for it.

[@CustomCans]

This one won't be class A but I know what you mean - they are special.

[@gabsriel]

A PowerDac V2.1 with hardware volume control would be a breeze ;-) ;-) ;-)

[@CustomCans]

I am looking to play with a DAC in the future - I will check it out

[@jstevo1349]

have you tried the magnet on the 400se as well? and have you tried multiple magnets across the driver?

[@CustomCans]

The magnets on the Stealth magnet version are thinner and more fragile so i have not tried that as I was scared of breaking them in the process.

[@DVolF]

How do other magnet positions affect? What are the exact dimensions of the magnet? What happens if you take a stronger magnet?

[@DVolF]

@NateSF may be use magnetic coil instead of iron magnets

[@deadlycrispy8545]

bit late to the game did you finish the HD660s mod with an STL file at all

[@BL4CKSMITH1234]

Hello everyone, any news about mod for HD 660s ? Thanks

[@CustomCans]

No, sorry I kind of gave up on them as I could not seem to get the results I was looking for, I have been designing parts for other headphones and learnt some now things so may take another look at them next

[@DAZZLINRAINBOW]

Any updates on the hd660s?

[@wrighty338]

keen to send my 660s in at some point

[@CustomCans]

If you want them customised, we could certainly do that - still not 100% on the mods for the 660 yet though

[@chefsteve8381]

Would your mod work on the HE 4XX ? Also nothing really wrong with the HD660 just the price...keep up the interesting work...

[@CustomCans]

Yes the mod would work on the 4xx as well

[@Dinobaburas.]

Hi, Have you tried any of the Focal line, I'm interested in the Stellia, I own a pair of the beyerdynamic t5 3rd generation at the moment.kind regards Jim.

[@CustomCans]

I had a quick look at the Clear MG at canjam in London, they looked beautifully made but well outside my price range at the moment

[@Dinobaburas.]

Yes, the price frightens me too. Maybe some day, I like closed back.

[@willie9537]

Will the magnet mod on the Hifiman he-400 work on the he-400i?

[@CustomCans]

Yes but i am not recommending it any more as a few people dropped the magnet into the diaphragm and killed them. we have new updated 3D printed inserts that do a better safer job

[@willie9537]

@@CustomCans Thanks I appreciate you get back to me. Enjoy your day.

[@llHaziell]

DIY hd700 with 660s drivers?

[@CustomCans]

Maybe.... I have not herd the HD700 yet so can't compare

[@frederf69]

is the magnet idea just for the HM HE400, or would this work for any planar's?

[@CustomCans]

It is very difficult to say - the HE400 are a basic model so have a lot of room for improvement - most planars have had a lot more refinement already done and adding magnets may make things worse. They are also quite easy to damage so I don't reccomend trying it on anything you care about too much ;)

[@ready5991]

Have you had a look at the drop / Hifiman HE-R7DX? Would be interesting to hear your thoughts on stock sound / modding at that price bracket Would also like to check if I’m entered for the closed sundara giveaway? (I left some comments but I don’t think I asked specifically)

[@CustomCans]

The Drop stuff is quite expensive to get in here in the UK due to postage and taxes so I doubt we will get any in.

[@CustomCans]

I think we had over 500 comments when I last checked - My team will be in charge of going through them and deciding on their favourites. If you left a comment - you are in with a chance ;)

[@Tripokaridos22]

By the way now that u have them and spend time on them , Was i correct? Are they technically better than 600 and 650 on speed and imaging.... Did u hear that ? Are still 600 your favourite;

[@CustomCans]

Yes I am learning to appreciate the 660 more, I have not had a listen side by side with the 600 for a while as I don't have any in at the moment. I should have some more 600s next month so will try them and see if the angled driver adapters work on those as well

[@Tripokaridos22]

@@CustomCans I cant wait to hear what u think. Angled drivers put some measurements with them .