Rabbit
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Post by Rabbit on Oct 19, 2015 19:09:24 GMT
It's a bit of a wrestling match to get them on but once on, the fit is really good. I do like the pads.
Not so good with V6 though.
Are the velour hm5's the ones with velour on skin connection but pleather on the sides? Also, the angled ones?
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Post by Deleted on Oct 19, 2015 21:00:52 GMT
Hi Ian,
The velour pads Frans has are entirely velour and non-angled. I think the ones you are describing are what Brainwavz refer to as their hybrid pads. Believe they are also non-angled but they do also make an angled pleather pad.
Just to avoid confusion the pleather pads Frans measured are the original HM5 pads (non-memory foam) rather than the newer memory foam variant. This pad has now been discontinued I believe.
I think that makes about 5 types of HM5 in total so plenty of options to experiment with!
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Rabbit
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Post by Rabbit on Oct 19, 2015 21:16:35 GMT
Ok. Thanks Mark. There are quite a few variations.
The ones that I have are pleather and angled. I've also seen flat in both pleather and velour. I think I've also seen a velour surface with pleather sides.
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Rabbit
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Post by Rabbit on Nov 1, 2015 9:09:28 GMT
Now a Mk III is out, it looks as though new mods might be necessary. The new one has the same drivers but the frequency response looks a bit flatter in the middle than mk II. Still rolled away in the bass which is a shame for a planar. You'd think it would be a little more linear down there.
By all accounts it's a bit better than Mk II. Slightly less sensitive. A little more bass weight. Square wave response looks a fraction tidier. Most measurements look kind of similar to mk II though.
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solderdude
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Post by solderdude on Nov 1, 2015 9:40:31 GMT
Yes, new mods will be needed. There are already some 'alternative' measurements out there but most of them I do not trust.
The squarewave response of Tyll's pages can NOT be taken as real. Have studied a bit on them and when you do you will find that the ringing you see there is not there in reality. It's the ear cavity in the measurement head that you see. This means that when you find a really nice squarewave in his plots that headphone has a substantial 'dip' around 3kHz that 'compensates' for the gain in the artificial ear canal. My measurements have shown that the T50RP driver is incapable of reproducing above 20kHz (with a filter !). I think this is due to the relatively high mass of the membrane.
From what I can see on Tyll's plots is: Rolled off in the bass and treble (probably partly fixable with a filter) Relatively high amounts of distortion compared to 'better' ortho's/dynamics The 3kHz dip has been removed (compared to the older version which all have the dip) There is a substantial treble peak at 10kHz which may be audible as increased detail at a first glance but needs to be removed. The enhanced 100Hz bass (where most bass notes are) will give the appearance of good (tight and present) bass but when you love bass extension this headphone will likely disappoint.
In my experience, bass extension is just as important as treble extension to me. It doesn't have to extend beyond my audible limits though. Sure, a headphone that lacks extension can still sound quite good and totally believable BUT on direct comparison you start to miss that extension. As with everything in life .... it's only when you have 'tasted' something and youy are deprived of it again you start missing it. Fortunately ... also as everything in life ... when you have settled again the missed part isn't as dearly missed again and can get by without it. However, when you DO have access to something that does everything you want going backwards isn't a real option.
Not going to buy one though... BUT if someone did and wants it measured/compensated/modified just send one over and it will give me yet another purpose in life.
I DO like the colour scheme... it would go really nice with my X3.
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Post by Rabbit on Nov 2, 2015 16:00:40 GMT
I did use Tyll's graph but just to compare old with new to see what differences his gear brought up. The mid area looks a bit flatter, but it's surprising that they haven't managed to get proper deep bass when they are capable of it.
For me though, the stock tr50 just lacks air and extension in the treble. Seems they've tried to improve it but not enough to warrant buying another's one.
I know exactly what you mean about deep bass. It's an area overlooked because many makers put a mid bass hump in which gives the impression of deep bass, when in fa t some headphones really roll away quite rapidly down there.
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solderdude
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Post by solderdude on Nov 2, 2015 20:35:31 GMT
The pads appear to differ and they may well have been changed so the dip in the upper mids is removed. Perhaps at the cost of low freq extension. Differences between the T20RP and T40RP are not that big except for the bass boost (open T20) The T40 (closed) appears to have much less bass but when you overlay the red and green trace they match except between 300Hz and 1kHz. That could well have been caused by the sealed enclosure. Tyll's plots are interesting. Especially because when you open the new T50 and the old T50 both in new tabs on your browser you can easily 'switch' between the tabs and see the differences quite clearly. Just made an animated gif ... not exactly alligned but the idea is there... Picture was made from 2 screenshots of innerfidelity plots using an online gifmakerWhat's obvious is that for both headphones the drop off in the low frequencies is actually the same. Also the behaviour above 3kHz is pretty much the same. What's different is the part between 100Hz and 3kHz which seems to have been 'scooped out' in the newer version. This also explains the lower efficiency while the same driver is used (membrane and magnets, not damping). I suspect Fostex did this 'scooping' by means of the foam around the driver and the pads. Probably the pads absorb (or more likely leak out) the freq range between 100Hz and 3kHz. I think leaking out is most likely the case because when you look at the isolation plot next to the FR you will see the new one has less isolation from outside noises right between 300Hz and 3kHz. Surely that can't be by accident. Another interesting thing is the impedance plot. Nice and flat with the old one (well damped) and a slight bump around 100Hz so less damped there. Giving it the slight bump around 100Hz. It is also clearly visible on pictures that the front damping paper is absent and the rear paper has an extra hole in it in a specific location. Funnily enough in my mods I actually increase the damping in front (with added felt) and the rear of the driver (in the cups) which lowers that peak around 8kHz. For me (with mods and filter) the T50RP is very well extended to both sides of the spectrum and well controled. The new T50RPmkIII would probably be modified and filtered towards the same (flat-ish) response and thus will not sound better. It would look better though, nicer headband and orange accents. On the other hand the cable on that thing might be the first one to be replaced unless it isn't as stiff and microphonic and prone to loose contact as the original one.
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Post by c61746961 on Nov 12, 2015 21:49:11 GMT
Friends, I have finally built myself a measurement rig not unlike Frans' solid plate rig (calibrated mic flush mounted plus high quality foamie and a bit of felt). In this post I shared the results of my ear-tuned T50RP mod using a version of the 'stratopads', and a tweak I made after being able to obtain graphs. Thanks for your efforts BMF and Frans, you have been an inspiration To make the HM5 velour pads work you have to reduce the driver damping compared to the Shure pads and introduce specific materials to reduce the ringing at 1 KHz, in my case (I removed the damping paper long ago), a combination of open-cell foam, make-up 'wedge' foam (seems latex) and a PVC foam mesh (from a shelf liner) did the trick. There's also some ear-side baffle damping to keep some of the bass energy from leaking out, I believe stratocaster achieved this using a ring of felt, it didn't work as good for me. Here's my measurement of the PortaPro for reference (clamping card against the plate): Cheers and happy modding!
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solderdude
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Post by solderdude on Nov 12, 2015 22:04:56 GMT
Here's my PortaPro (actually Rabbit's portaPro) It isn't clamped against the plate but has a small rubber part between it mimic'ing the air volume shape of an outer ear. Without it the peak at 5kHz would measure lower in amplitude. The PortaPro is a well documented headphone though on-ear is a bit tricky to measure correctly above 1kHz. Tyll's measurementsGoldenears: Russian measurements (flatbed = SF, HDM1 is real dummy head) You can use the measurements below 1kHz to compensate for your own measurements and get more accurate results.
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Post by c61746961 on Nov 12, 2015 22:09:23 GMT
Haha, we're talking about the same stuff in two threads, I posted another graph, this time with a lighter clamp: It seems I will have to compensate for bass gain from 0-100 Hz approximately, do you have any clues for me?
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solderdude
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Post by solderdude on Nov 12, 2015 22:14:33 GMT
see my post while you were typing the one above.
That should give clues how to compensate below 1kHz.
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Post by c61746961 on Nov 14, 2015 1:34:36 GMT
Thanks, Frans, I derived a compensation curve based on the Porta Pro and K7XX measurements here and elsewhere. Here's the last iteration of the mod, compensated this time: The channel imbalances in the bass and low treble have proved to be difficult to fix.
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solderdude
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Post by solderdude on Nov 14, 2015 6:41:59 GMT
That is mighty impressive. It only needs the EQ to add the part above 10kHz.
Would you care to show what mods you did ?
IME all T50RP drivers I measured differed in the lower frequencies.
I can measure the Philips before shipping it to you and then it is easy to compare the actual plots.
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Post by c61746961 on Nov 14, 2015 8:40:17 GMT
Thanks Frans. This was successful in great measure because of stratocaster's experiments.
I think I'd still like to reduce the 2-6 KHz range a few dB, as it is it's kinda shrill with some music.
Surely I can do a rundown of the mods tomorrow, mind that I removed the damping paper long ago when I was starting with modding so they will not transfer 100% to stock pairs, however, I played around with many materials and two elements have constantly shown their effectiveness:
1) HM5 velour pads. 2) Latex foam makeup wedges directly behind the driver.
I'm not saying you cannot achieve flatness with other pads, but it was quite easier this way. It seems you have to leak a lot of bass to bring out the 3-5 KHz range, the mk3 variants do this via vents on the baffle lips. I had to undo a lot of damping when I first got the velour pads too, I was using the 840 pads before.
So you still have a pair of Downtowns you are willing to part with?, cool! Please quote me in a PM, hopefully the shipping costs aren't prohibitive. My father owns the DT250 that you measured, he uses it for studio work. I'll measure it when I go visit.
BTW: When deriving the compensation curve I arrived at two that differed by almost 5 dB in the low bass, one based on the PortaPro measurements here and elsewhere and the other on Tyll's K7XX measurements. In the end I picked the one that looked smoother and more of a rising gain towards the lower frequencies (K7XX). Maybe I should average a bunch of them and be done with it.
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solderdude
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Post by solderdude on Nov 14, 2015 15:10:51 GMT
Feast your eyes on this T50RP I guess you want it like this Oh wait, that's mine on a Kameleon Slight 'dip' between 2kHz and 6kHz, great extension well below 10Hz, and in the top to 20kHz. Don't mind the 70Hz dip... its a coupler 'thingy' Below (in the same scale/format) a modified T50RP with HM5 pleather pads and below the same with HM5 velours pads. It seems you definitely need other mods than my 'standard' ones. In this case the 1kHz would need to be reduced for it to sound good though (as well as the high frequency part)
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