Sennheiser HD650 Love (Appreciation Thread)

Feels strange referencing this post from a while back, but I have been studying the data and it has provoked some thoughts.

If you look at the Frequency Response graph you will see little change in the overall plot. However, if you compare the impulse response, you can see a dramatic shift in signal decay. The result of the mods is a much cleaner impulse response that looks much more like it should. Too me, this would indicate more dampening.

This is where things get weird. The measured power efficiency has gone up by almost 100%! That's pretty crazy... Logically, one would assume that this would be the case with less damping since the driver has to work less hard to produce sound.

How can this possibly be? Could it be that the removal of the driver foam decreases damping, and leads to higher efficiency, while the adjusted damping on the pad side has worked to control the impulse by adding damping? Recalling an interview with Paul Barton, both sides of the driver are vital for effect tuning.

Just pointing these observations out so we can more effectively understand what the mods are doing.

 

The sensitivity rating on the pdfs can be inaccurate sometimes. The mods won't change the sensitivity. Also the frequency response will change its sensitivity rating since the volume is calibrated against a 500Hz tone. The volume calibration seems off sometimes, for example the Utopia plots seem higher than they should, causing better SNR for the distortion measurements = lower distortion. Also the sensitivity in that case seems a little high. I doubt it's more sensitive than the Elear (Focal even specs the same sensitivity. But it does have a slightly lower moving mass (135mg vs 150mg) = higher sensitivity and the magnet is stronger.). Might have something to do with phones that have a lot of level variation at the 500Hz tone with the different headphone positions on the dummy head (where the rig doesn't readjust the volume for every new trial).

However what's interesting is that Hands' HD650 has a different impedance. The change of Q at the 100Hz bass resonance (can be seen clearly in the electrical phase and frequency response) is caused by the back foam removal, but the change in DC (or 1kHz) resistance points to slight driver changes. What's also interesting is that Tyll's plots indicate that the HD6X0 is more sensitive than the HD800 which just doesn't match my experience. My HD600 is 2db (or maybe more) less sensitive than my HD800.

 

Reflects my experience. My 650 with dynamat is 2-3dB less sensitive than 800 SBAF+SDR. However, my measurement instruments are phone decibel app and my ears.

 

Just remeasured. My modded HD800 is about 2.7db more sensitive at 500Hz than my HD600, but the mods do push 500Hz up. The HD600 is slightly higher from 1-4kHz (relative to 500Hz), while the HD800 is almost perfectly flat on my rig. Subjectively the HD800 is almost exactly 2 steps more sensitive with the Ragnarok (2.5db).
Also measured the DC resistance (with the stock cables). I didn't expect such a big mismatch in both cases, but the HD800 drivers are more closely matched than the HD600 ones.
HD800: 310L 307R
HD600: 295L 307R

 

Having just spent the best part of the past day digesting this thread, all I can say is, God damn you all to hell.



My Utopia savings fund is now £233 lighter. Planning on invalidating the warranty pretty quickly. Thanks for all the info in this thread, chaps .

 

Oh, fun! I sort of love the unmodded 650 with it, it is a little dark and growly, but very non-fatiguing to listen to with decent detail- especially when balanced. There's a bit of me tempted to try modding, but I think I'd have to get a second pair for that, as the unmodded sound really is floating my boat.

I go through phases of enjoying the warm, growly 650s, and sometimes the slightly too clinical planars right now, it's a happy place to be in. Very little upgradeitis here beyond possibly a slightly sharper planar and maybe eventually some HD800S- and even then, I think I'd want to keep the 650s.

(..though I am going to have to google, and find out how big a quarter is, and see what local coin matches best...)

 

USA quarter is pretty much the same diameter as a UK 10 pence (the modern type)

 

Lazy person's google, the interface is far nicer. Thanks!

 

Wait. What?
*checks Amazon UK*
*realises it's cheaper to buy a brand new 650 from Amazon UK than to get one secondhand in Singapore*
*ORDERS*

Oh, and I hate you all too.

 

Yeah pretty bonkers price at the moment, cheaper than an HD600. Btw, Amazon UK out of stock at the moment so I ordered from Gear4Music for the same price (plus £5 next day delivery).

 

Amazon's probably out of stock because you foreign devils have noticed that we're actually getting a decent price on something, and have cleaned them out

(Enjoy!)

 

Have you thought about doing just the damping mod on your current pair? It makes things sound better without really changing the character of the sound. To my ears, FR is pretty much unchanged, but midrange is clearer and better delineated from the bass, some slightly plasticky resonances are removed, and everything feels a bit calmer. Plus it's trivially reversible in the unlikely event you prefer it without.

 

I have considered it, yes. I'm occasionally pretty clumsy, though -impressively so- so I'd rather mess around inside a spare pair.

 

You just have to have confidence in yourself. I am quite clumsy myself but I managed to do it ( albeit kinda shitty) and it turned out fine. The dynamat can be pulled off rather easy in case you do mess up. So stay optimistic and you can do anything you set your mind to!

 

I bought a pair thanks to @PoochZag throwing out the cheap alert on the Deals thread. They came in today and I have less than 1/2 hr. with them so far but already I really like these with a Yggdrasil and MicroZOTL 2. I'm pretty impressed given they haven't broken in yet and no mods done. I heard a pair of HD800s earlier this year for a brief time, and don't remember them to have been a significant improvement, at least with my musical tastes.

I think that with these, my TH-X00, and ancient Etymotic ER-4s, I pretty much have the bases covered. I might even get rid of my Koss ESP-950s.

 

Hey @crazychile !

I sold my ESP-950's not long ago. I have had the 650's for a while but revisited them recently and decided that even though the Koss does macro-detail very well, the Senn's are better overall. Planning to pick up a Joti sometime soon...

 

Hah, confidence in myself is something I'll never have; I've met me.

Still nice to hear that you managed to do it- I'll probably give it a go at some point, on a second pair. It'd be pretty cool to be able to compare modded and stock directly, anyway.

 

I've only been listening to my 650s for about 2 weeks, but I already love them. It's so nice to have spent money wisely and not fallen for Head-Fi hyped flavors of the month.

 

The first step is to admit that you have a problem!

 

While I really like the Koss', They give me the itch to go full gonzo into an upper Stax model with a KGwhatever amp, and that's a whole lotta coin. More than my toys budget for the next couple of years. So that's not going to happen. I've had more fun the last couple of months enjoying the gems among the real world stuff. I'm really just enjoying what I have without obsessing about the next upgrade. So the Koss' and a few other items may be in the For Sale section in the near future.

However, I've also been considering the Joti....to be used at work.