"Open Alpha" DIY project from MrSpeakers

I still am going to write (eventually) a comparison between Open Alpha VS HE500 VS HD650. I believe T50RP lags behind in sense of macrodynamics and really only feels like Thunderpants when its accompanied with loads of bass bloom which is fatiguing ime. Still need to a/b compare with notes to confidently comment so grain of salt.

 

Need to hook T_0RP to speaker amp..

 

Could you explicitly include Tx0RP in the comparison too, especially Mk3 vs the Open Alpha & OA hybrid (Mk3 baffle)? I've gained the impression from your posts in this thread you've preferred the RPMk3 or OA hybrid over the OA but your statement above tells me I might have gotten confused.

 

Ya sorry, my post wasnt written clearly.

What I meant to say is that Tx0RP has great bass except for possibly weak macrodynamics (relative to HE500). Otherwise Tx0RP is generally very good (relative to HE500). The wonk frequency response is acceptable to me… Im reading this book currently and its providing some insight as to possibly why (thanks @yotacowboy for recommending).

Over the course of the thread Ive discovered I dislike non-vented front-side (Open Alpha) due to bass bloom fatigue (my interpretation). I then learned that Open Alpha cups and T20RP cups are overall largely the same in terms of subjectives and frequency response. And with that I cant recommend the Open Alpha.

As for CSD, I am no longer confident in their relevance or accuracy. Ive read too many discrepancies about their validity, or more specifically the validity* of my measurements and whether they have any bearing on what Im hearing. Im going to try reading this book to try educating myself. Until then Ill refrain from posting CSDs. (thanks @Vtory for recommending)

*For example, (@20Hz) how is it possible that amplitude was gained over time? Could it be cup resonance or room mode? @purr1n

Spoiler

 

Tx0RP has plenty of bass, what I worry is it might not have the same sense of weight and impact of a drum kit versus some other headphones (e.g. HE6se padrolled), need to a/b compare with notes to be sure but that is my "first impression". Its not weak in any case and if it were I wouldnt use Tx0RP. Its still the case that I prefer Tx0RP to HE6se. Right now I have HE6se out on loan but Ill a/b compare to HE500 and HD650 for my next update to this thread. Later Ill compare to Nectar Bee when its my turn on loaner tour.

^ My post from a couple pages ago. Ive just been tweaking Tx0RP since then hoping to improve bit by bit. If you're someone who isn't particularly sensitive to bass bloom then you might have an easier time. I have an easy time in that I find the wonk frequency response as-is pretty satisfying. However, there is a tad much upper bass but Im sure padrolling can fix (like @spoony demonstrated) - I just dont want to spend much more money on pads at this time and its already good enough especially for a closed headphone.

^ This is what I noticed. Going to shallower pads but with wider ear holes will result in sibilance (measured as only a few db in 7-8kHz range but that's all it takes to become insufferable). Stock pads are very shallow and narrow but they kill too much highs for me in general. The Dekoni leather pads do a decent job but I think slightly shallower would help tone down that little much upper bass. Ill probably get ZMF and DCA angled pads for T50RP to try later.

@purr1n probably busy or the tag notification gets lost in the piles of notification Im sure he gets. Ill send him a dm. Might be better posted in the CSD thread.

 

Regarding bass frequencies in CSDs: CSDs are the wrong tool for looking at bass & lower mids. On purr1n's behalf, from the CSD thread:

Edit: Your troubles with the bass are why I like the Mk3s. True, I've never tried modding a Mk2, but the Mk3 baffle having a number of front bass vents that can be variably open or closed/baffled gives an extra way to try to even out the response through the bass, in addition to the rear vent, which affects the mid- more than the low-bass; and pads.

 

T20RP(mod) VS HD650


Summary: These two headphones are so far apart on frequency response that small technical differences are difficult to discern and secondary to tone. T20RP(mod) best recommended as a guilty pleasure or as an option for noise isolation.


Equipment: Macbook Pro > Schitt Eitr > ModiMBv2 > Jot2 > HD650 (1/4", I don't have a balanced cable yet), - T20RP (XLR)

Spoiler: T20RP(mod)

- remove driver damping paper
- Dekoni leather pads for T50RP
- some felt in cups
- added balanced connections

Large subjective differences:
- tonal

- HD650, closer to neutral but with a little too forward vocals
- T20RP, bassy, warm, and dark​

- macrodynamics

- HD650, Its not bad but not enough as your single headphone. Totally fine for lots of music but if the music is reliant on bass then the less 650 is reliable.
- T20RP, hits much harder, some is obviously the bass amplitude, possibly some is reverb from cup and deep solid pads​

- soundstage

- HD650, forward vocals which makes rest of instruments behind and so they sound like they are emanating in front of you
- T20RP, da bass is enveloping, the vocals are middle loudness relative to rest = bass > vocals > highs.

- HD650 is 2-channel speakers, T20RP is 5.1 surround sound (relative)​

- other

- both are flawed, both fill niches:

- HD650 is the reference and the bar for value, a larger niche
- T20RP works nicely as a closed headphone, the bassiness helps overcome noisy environments, not a lot of great cheap closed headphones to choose from so choose your poison​

- comfort:

- both very comfortable but:

- HD650 clamp has to be broken-in
- T20RP headband needs an aftermarket headband support (such as ZMF)​

Small subjective differences:
- microdetail

- HD650, more even frequency response helps with harmonics but I think it is also a little more resolving
- T20RP, not very far behind, obviously where frequencies are boosted (bass) the T20RP is going to sound more filled-in​

- imaging

- HD650, good
- T20RP, a little more diffuse in general but not not good​

- clarity / blackground

- HD650, good
- T20RP, better but closed cup noise isolation allows for a sense of lower noise floor (blackground), my environment is definitely not the quietest.​

- microdynamics

- HD650, good
- T20RP, not not good but the wonky frequency response makes it difficult to compare.​

Conclusion: I can get adjusted to each flavor, HD650 is extra vanilla, T20RP is extra double chocolate. Whenever putting on T20RP you can tell right away its very colored, then by end of song you’re very much tapping your feet and not too worried about what youre missing. Afterwards you put on HD650 and wonder where’s the bass, so you turn it up and notice vocals are too loud, so you turn it down again and eventually decide bass levels are adequate enough and just enjoy. Both I find flawed. Both can be great with the right music. If I could have only one headphone forever then Im not sure which Id pick if I had to pick between these two… Id very like a third option.

More notes:
The disparate and wonky (ahem T20RP) frequency responses made some technical comparisons more challenging than expected. I am iffy on the microdynamics, micro detail, imaging, and clarity comparison.

6XX with Vali2 I did not care for. 6XX with Vali2+ I liked. 650 with JOT2 I like even more. fwiw. Lots of other reasons too for change in opinion (e.g. Senn official stock pad updates, age and equal loudness contour curve possibly).

Spoiler: frequency response measure overlay, FPC

Yep. T20RPmod is not pretty. See earlier posts and mk3 thread for how to mod for neutral tone.

I tried sealing majority of cup vents to flatten frequency response but I found that in return it totally blunted decay and macrodynamics as trade-off which I did not prefer. Perhaps rear driver damping works better (but I havent tried).

Open Alpha not for me. I need front-side venting for ear fatigue reasons (see bass bloom post). OA-hybrid requires modifications to stock 3DP cups for optimization but I lost interest in pursuing.

 

@purr1n responded and created a thread. Im not qualified to judge and can only apply my very limited anecdotal evidence and based on that I find CSD and fatigue to have a correlation. But again, could be a host of other reasons like peaks in the frequency response that Im sensitive to personally but aren't captured in frequency response graphs. Human anatomy and neurology very different than measurement rig. Like purr1n, Ill continue collecting data.

fyi Please read entire reddit thread links as good points are brought on both sides but neither conclusive. Certainly purr1n has more data and experience with headphones.