Rabbit
Administrator
Posts: 7,087
|
Post by Rabbit on Aug 19, 2013 21:41:55 GMT
The hump looks a lot more respectable. Still retains slope down to 1kHz. Does the lowered hump make it less dark, Frans?
|
|
solderdude
Administrator
measureutternutter
Posts: 4,882
|
Post by solderdude on Aug 20, 2013 5:58:12 GMT
It makes it sound 'flat' and realistic. The gradual slope from 150Hz to 4kHz still gives it a warmish 'tone' but definitely not dark. The filter shaved off a good 5dB which is very noticeable as it is over a wide part of the FR.
I can get it really flat if I wanted but it takes away the fun.
Completely flat it doesn't sound as good as good as the filtered and modified T50RP sounds, it does come very close though in sonic signature. The differences become obvious when listening to the finer details where the EVO is slightly less 'refined'. When quite flat the EVO, like the T50, becomes very picky of recording quality. With a more 'fun' setting this is less problematic.
I feel the HD681 should be a fun headphone but as 'dark' or should I say 'muffled' sounding as the stock EVO isn't desirable. Stock the EVO has a 'similar' sound to all of those newer headphones intended for the 'younger disco crowd' (beats e.t.c.) muffled, no details and fatty bass.
For some reason only some of the headphones Superlux makes can be turned in real gems. Others just are so-so even after modification while the look similar they do differ.
|
|
proid
quite active
Posts: 113
|
Post by proid on Aug 20, 2013 6:25:00 GMT
I totally agree, Frans. The EVO should remain it's fun sound which make it very enjoyable. But i still have some concern about the 4k dip, can you lift it up more with the filter?
|
|
solderdude
Administrator
measureutternutter
Posts: 4,882
|
Post by solderdude on Aug 20, 2013 7:10:56 GMT
Alas, that dip is so sharp it cannot be dealt with with a passive filter, nor with a very sharp digital one I reckon. It seems to be something in the driver itself, as it doesn't go away with completely different pads nor with different positions on the measurement rig. I even doubt it could be lifted with a very sharp digital filter as I suspect (not know) it is a break-up artefact in the membrane itself. You cannot 'motivate' that to vibrate correctly by applying more energy. It would most likely result in higher distortion. The felt on the driver seems to 'worsen' the dip though by making it deeper, more 'nulling'. The 'jagged' behaviour above 5kHz also seems to point in driver/membrane issues.
Everything up to 3kHz (after filtering has been applied) seems to behave pretty well though which is a good thing.
Fortunately dips are not as audible as peaks and since it is narrow isn't very obvious. It's just one of those things that cannot be fixed I'm afraid.
|
|
Rabbit
Administrator
Posts: 7,087
|
Post by Rabbit on Aug 20, 2013 8:02:06 GMT
Most will probably prefer a slight bass lift Frans. I guess it retains the Superlux sound Sig slightly too. To get that bass down to flat is quite a lot of eq'ing. I guess it goes a bit lifeless? I didn't think you'd so easily get that bass off down to flat.
Do you prefer the raised bass Frans, or is it the fact that it's not as resolving as the T50 or 40?
Using GE eq from an iPod via their programme makes the Superlux sound stunning. At first, I thought it was too much but going back to stock revealed instantly how good it sounded on eq. I can't check from here what the eq'ing from GE does, but to my ears, it was excellent.
Is the sensitivity still good? Another useful thing is the headphone works well with girly amps with low power!
|
|
solderdude
Administrator
measureutternutter
Posts: 4,882
|
Post by solderdude on Aug 20, 2013 8:20:36 GMT
The GE EQ is based on the old HD681 so won't 'fit' EVO as the EVO doesn't need a substantial highs correction and does need more bass correction.
I reckon the EVO will still sound 'warm' and highs might be a bit too much subdued. Perhaps the filter design will be close to the GE correction for the lows (as it doesn't compensate for truly flat on EVO but will show a slight increase in bass as with my filter, except there will be somewhat more 'detail' in it as GE probably over compensates the highs a bit.
I use the T40/50 for reference grade reproduction (so well made recordings ONLY) and like to grab DT990/HD650/HD681 for the recordings that aren't that well recorded or are low on 'bass' levels.
I still have to compare the old modified HD681 directly to a modified EVO but not until I am ready with experimenting. Thinking of using SRH940 pads as they are very comfortable and a good fit (easy to mount).
That'l be the next step. SRH940 pads and seeing what filtering it needs.
In my final report I will most likely present 3 options: Stock pads + filter (with and without felt). T50RP pads on EVO. SRH940 pads on EVO + filter.
|
|
Rabbit
Administrator
Posts: 7,087
|
Post by Rabbit on Aug 20, 2013 9:18:57 GMT
Yes, it was warmer, but the bass was much more under control. Perhaps a bit 'flat' sounding but way better than stock.
The t50 pads seem a great option with no filtering. I'll have a look for a pair when I get home.
I've taken the paper out of the pair I brought with me and I do prefer it. The bass is flabby without eq though.
I have another stock pair at home so I'll compare next week. Especially if I still have some stock t50 pads.
|
|
solderdude
Administrator
measureutternutter
Posts: 4,882
|
Post by solderdude on Aug 20, 2013 10:05:05 GMT
|
|
Rabbit
Administrator
Posts: 7,087
|
Post by Rabbit on Aug 20, 2013 11:53:17 GMT
I'm not certain which filter I'm using on the HD681 Frans. Probably 'mk 1'.
The original 681 is less prone to marks too. Since it's cheaper and is less likely to mark, perhaps a better buy then - especially since it doesn't have the sharp dip.
The stock Evo seems 'richer' sounding to me than the hd 681. Maybe it's just a piece of paper difference really?
Have you ever tried t50 pads on original 681?
|
|
solderdude
Administrator
measureutternutter
Posts: 4,882
|
Post by solderdude on Aug 20, 2013 12:50:26 GMT
Never tried them on the original one but prefer velours pads myself. This is why I use 940 pads instead of 840 pads on the T50, HD25 velour pads on the DT1350 and K240 velours on the HD681.
Also never tried 940 pads on the HD681 either as the 940 didn't exist yet back then (okt 2009). May be an idea to give that a try as well, see how it works on that one.
|
|
Rabbit
Administrator
Posts: 7,087
|
Post by Rabbit on Aug 20, 2013 13:13:27 GMT
So many options with the 681's it's hard to settle with just one.
|
|
solderdude
Administrator
measureutternutter
Posts: 4,882
|
Post by solderdude on Aug 20, 2013 16:48:30 GMT
Padtime... to be more complete here some plots that show the influence of pads (or lack of in some cases) All plots have with the same headphone being EVO WITHOUT the felt on the driver. Blue trace = EVO, red traces is with another pad slapped on it. First the AKG K240 pads that I use on my 'old' HD681. Perfect mechanical fit. As you can see they are closely the same, except the highs aren't as 'jagged', more silky, also 1-2 dB more mids but overall little change in FR. next the SRH-840 pads that you can just fit on it although they are a bit on the small size: Notice a tad more (3dB) upper mids around 2kHz, and highs around 10kHz. SRH-940 pads, comfortable velour pads that you can just barely fit on there. A tad less bass, a tad more upper mids, less 4kHz dip (finally) less jagged highs. With a filter designed for it this may be a good alternative to the K240 pads. For those interested in the differences between 840 and 940 pads (on this headphone but the difference will aplly to other headphones as well) green = 940 pad, red = 840 pad Beyerdynamic DT990 pads: Consider how much bass the DT990 has it stands to reason the DT990 only sounds O.K. with original pads. DT770 pads have more bass, they were not tested as they are glued to my T40RP. Beyerdynamic pads are too small in diameter and can NOT be fitted. For this test they were taped onto the baffle. The test was just to see what these pads would do. T50RP pads: Hello mids... where have you been. These have been discussed earlier. It is also possible to combine these pads with a mild filter but don't think that is needed. The bass is not over powering or annoying.
|
|
Rabbit
Administrator
Posts: 7,087
|
Post by Rabbit on Aug 20, 2013 18:57:17 GMT
DT990 looks good until 4 khz and t50 also looks nice with those miss coming in. Interesting that there is less of a dip with the 940 pads too.
Really interesting. So now it's a question of which pad and filter!!
|
|
solderdude
Administrator
measureutternutter
Posts: 4,882
|
Post by solderdude on Aug 24, 2013 13:30:07 GMT
Playing with filter settings a bit. Used stock pads (K240 pads will give very similar results so only comfort is different) and the felt removed. The filter allows the lows and highs to be adjusted independently sortof like the old fashioned tone control except tailored and passive. The effect of the 'lows' filter option is given below. In all of these meaurements the highs have been filtered with 1.5mH so the highs are quite 'flat'. Of course similar plots with highs filter section but this time with the lows set to 'flat' (100 Ohm) Highs don't need that much correction so the 'steps' are smaller. When we combine those filters we can create very flat reproduction and a more 'fun' headphone. Listening impressions: flat sounds 'flat' and thus is only suited voor WELL MADE high quality recordings where lesser recordings sound dull and lifeless. On good recordings a very good and DEEP bass and good mids. Highs are good to excellent though slightly coarser than top tier headphones. For the money this 'flat' filtered headphone sounds amazing despite of the sharp 4kHz dip and slightly coarse highs. These highs improve somewhat with velour pads though. The other 'option' is to use the 'fun' version which is warmer sounding with more bass and leaning towards very detailed. It sounds LOTS better than the stock version and a bit 'too much' on high quality recordings but better on lesser recordings. Ahhh... the choices we have to make.
|
|
proid
quite active
Posts: 113
|
Post by proid on Aug 24, 2013 14:53:26 GMT
That's great work Frans, the Evo must sound very well
|
|