So far the impression in one word... "Meh".

They may need time to burn-in, but so far they sound quite shallow. None of the excitement and power of the AH-D1000.

Efficiency is 103 dB (probably /1 mW), so they're somewhat quiet straight out of the soundcard at maximum loudness. Nominal impedance is 28 ohm, which can be somewhat risky for Mac owners (the Powerbook here damaged a set of cheap Sony earbuds @ 16 ohms, killed a couple cheap Technics supra-aural headphone sets with 24-ohm impedance, and damaged a set of Panasonic circumaural headphones with a 22-ohm impedance), though they'll probably be fine.

The CMoy amp couldn't drive them to decent loudness or power before the noise floor became noticeable. They are much less CMoy-friendly than the AH-D1000.

Size-wise they're a bit larger than the AH-D1000, even though the diaphragms are smaller - 35mm against AH-D1000's 40mm. Isolation is way better than with the AH-D1000 (probably 6 dB difference or more), but as the AH-D501 played quieter with the PCDP, the AH-D1000 isolated from street noise better. Even when not playing, AH-D501 are in the "what did you say?" class, whereas with the AH-D1000 on the outside world and voices are discernable.

AH-D501 have the "AKG-style" self-adjusting headband (and plastic rails), which is a bit of a problem as the fit is somewhat loose. They really need more grip - the seal isn't that good on a medium-sized head. Fine over a cap though.

So, in summary, for someone looking for a cheap companion to the Denon AH-D1000 or AH-D2000, the AH-D1000 (or AH-D1001?) might be a better alternative (or just lugging around the AH-D1000 - they're not an electrostatic set either). The price difference isn't as large as the difference in liveliness.

AKG K-240 Studio and Denon AH-D501.


Denon AH-D501 and AH-D1000 (AH-D1000 are the smaller set on the right).

Denon quote the same efficiency (103 dB/mW) for both the AH-D1000 and AH-D501, but the AH-D1000 are noticeably more powerful on any output. They're obviously different electrically, the AH-D501's lower impedance makes them somewhat more difficult to drive. AH-D1000's better dynamics could also make them psychoacoustically louder: wider dynamic range sounds louder even if the SPL is the same.

So well, they've been running for a few hours now, and it's quite obvious the impact is quite far from AH-D1000. They don't have the same quickness and energy as the AH-D1000. They still sound rather shallow and a bit apathetic next to the AH-D1000. Basically they're not a "cheap version of AH-D1000", they're something different, out there in the same class as other $50 headphones (the "501" in model index refers to suggested retail price in Japan - ~5000 yen). They're more veiled and shallow than the AH-D1000, but detail's decent. Probably better than any $50 headphones out there (PX100 et al falling into the same category). But - those are somewhat too small drivers somewhat too far away from ears mounted in a somewhat too loose frame. With a somewhat too short cable.

After the burn-in they do sound decent (probably in the same class with the likes of HD215, HD280, maybe even Grado SR60), but nowhere as exciting and full as the AH-D1000. Detail is still very good - the breath of musicians in Ketil Bjornstad trio's recordings can be heard. They can kick too - never distorted any, even the heaviest bassline. They did have some foldover distortion when overdriven to very loud volume, but the bass was mostly preserved, and everything was relatively clear - no gurgle, just dropping some of the frequency ranges. The AH-D1000 extension cable made them sound livelier... Maybe as an added resistance path they increased impedance a bit. 28 ohms impedance is probably the slight troubling issue these headphones have.

After some more time...

The extension cable helps, as it adds a bit of impedance. Brings them closer to AH-D1000, makes the sound a tiny bit more solid, makes the AH-D501 a bit more amp-friendly. They should improve with a serial resistor.

Otherwise they have a bit better-defined lower midrange and bass than the AH-D1000, but are more anemic. Probably more of a "junior" set - would do fine as a gift to a teenager or a kid, especially for the kind of pop/rock they're likely to be listening to, but there's some serious uneven-ness in treble and super-treble. The AH-D501 make the upper frequency range part of hi-hats and brass instruments sound "broken", mangling the high harmonics. Hi-hats' sparkle is muffled and mangled. There's a veil of darkness supplied to anything that goes over 8 KHz or so.

But, where the AH-D1000 can go hoppy-happy in the lower midrange, losing some of it in the process, the AH-D501 are stable. Maybe the most precise reproduction of A3-A5 saw wave, out of all headphones that have been through here.

That helps the AH-D501 play synth-pop, electro, rock, and pretty much anything not blessed with strings, delicate breath instruments, etc. Again, good gift for a kid, but not one into serious music.

Nice impression
Thanks!!

i had these thought i should add that you can easily tighten the headband. if you look under the bottom band you will see that you can pop the inside out. you will then see a sprung cog with two racks of teeth. bend out the racks and crank up the tension on the cog. place the racks back down and use something thin and flat (knife) to hold them down as you replace the cover. i know this is a bit hard to understand but will become clear as soon as you open it up. hope this helps.

Hey thanks, that's very welcome.

Quote:

ddashk said:

i had these thought i should add that you can easily tighten the headband. if you look under the bottom band you will see that you can pop the inside out. you will then see a sprung cog with two racks of teeth. bend out the racks and crank up the tension on the cog. place the racks back down and use something thin and flat (knife) to hold them down as you replace the cover. i know this is a bit hard to understand but will become clear as soon as you open it up. hope this helps.

Click to expand...

Hi. I'm new here but just to say if you can unclip the side lugs which will totally free up the tension which then means you don't need to use the knife. Cheers for the insight though. It need to be done. THANKS

Quote:

eldersteve said:

Hi. I'm new here but just to say if you can unclip the side lugs which will totally free up the tension which then means you don't need to use the knife. Cheers for the insight though. It need to be done. THANKS

Click to expand...

hi how do u do it? do you open the plastic sheet that is covering the underneath of the headband? how do u open it i am afraid that it will break
 

hmm i twiged the spring tighter and it works thanks alot for the tip =)