Tuesday, June 28, 2005

Sennheiser HD215 headphones

(credit: Sennheiser)

The HD215 is part of Sennheiser's new line-up and is a mid-priced, closed circumaural headphone intended for casual, studio and DJ use.

It features fairly usual specifications for this type of headphone: 32 ohms nominal impedance, 12-22000hz frequency response range and 112db @ 1Vrms sensitivity. The single-sided coiled cable is detachable and is terminated with a low-profile stereo minijack at the headphone end, and a unimatch (3.5+6.5mm with a screw-on converter) plug. The cable is around 1m when normally coiled but will extend up to 3m. The DJ friendly part of the HD215 is that the right earcup swings 90 degrees either forwards or back.

The build quality is decent, the plastic is good quality throughout and there seems to be no obviously weak spots in the design. The HD215 continues the seeming tradition of the... um... 'special' look of some of Sennheiser's mid-priced headphones. While different from the 'head mounted spoiler' visuals of the HD280 Pro or 'seventies alien / bad hairband day' look of the HD497/HD212Pro, it does nevertheless look slightly odd when worn.

For transport and protection Sennheiser supplies a nice pleather drawstring pouch. Although reasonably light at 220g and good in isolation, portable use is not this phone's strong point as it's rather large and doesn't fold. But if you are walking down the street with one of these, it undoubtedly makes a statement. Quite what that statement would be, I'm not sure.

Sennheiser HD25-1, HD251 and Sony MDR-V700DJ

Sennheiser HD215 and Sony MDR-V700DJ in respective pouches

The HD215's earcups are fully circumaural and the headband has plenty of scope for adjustment. The noise isolation is good, cutting out decent amounts of outside noise, and sound leakage is a non-issue.

The phone is pretty comfortable and sits nicely on the head. The cups pivot slightly in all directions to account for variances in head shape, and overall adjustability is excellent for a wide variety of heads. The balance of the HD215 is good as the weight of the headphone isn't moved towards the top of the phone due to a heavy headband such as on the Sennheiser HD280 Pro. As a result it's very stable on the head.

Trebles can occasionally seem a little splashy, exhibiting a bit of 'cheap tin' in the sound but sibilance is well controlled. The midrange does not make a show of itself, but is well represented. The lows are very well articulated for a headphone of this price, but it is undoubtedly somewhat lean in the bass.

The sound of the HD215 reminds me a lot of the Sennheiser HD280. Even-tempered, good extension at both ends especially in the lows, pretty accurate... but a fairly flat and potentially 'uninteresting' frequency response, and a soundstage which is not hugely wide but nevertheless places instruments pretty accurately. While it is afflicted by some 'closed phone honk' (a resonance caused by the design limitations of making a closed phone) it's technically a competent headphone for the money.

From what I expected as a DJ-orientated phone, it turned out a lot less 'entertaining' than I presumed it would be. As a DJ-style / casual listening phone the HD215 could justifiably be accused of being a little flat, as it's very well-behaved and tonally quite neutral. However the HD215 does render very low bass much better than many other overtly DJ-style phones with boosted mid-bass. If you're listening to material that relies more on accurate reproduction with less emphasis on a euphonic sound, then you will probably like the HD215.

The neutral-ish sound does have distinct advantages for very long periods of listening. It's not overtly tipped up in the trebles and neither is it poundingly bassy, so it's an unfatiguing phone to listen to especially when combined with the decent comfort. It's very much a headphone you can stick on your head and forget about, so it might be a good choice for work if your environment allows you to listen to phones.

The low impedance and reasonable efficiency of the phone means that it can be powered from pretty much anything with a headphone socket. However the more powerful portables or a separate headphone amp will be more suitable to allow the full range of musical expression to be rendered by this phone. 'warm' sources with a boosted bass will undoubtedly liven up this phone a bit.

About these phones, Headroom has written "they do sound a bit too uneven for a strongly pleasureable listening session". Actually, the problem for some could be that as I've said above, they sound too even for a 'pleasurable listening session' (Sometimes I do wonder if Headroom's reviewers are all that experienced). But the HD215 works well in long listening sessions by 'getting out of your way'.

The pricing differences between Europe and US between the HD280 Pro, the nearest comparable headphone and this phone means that it's a much stronger recommendation in Europe. In the US, the HD280 may even be cheaper which makes it a better buy.

But on the whole the price is right, it's comfy and it's quite well built out of good quality materials. A polite sound which isn't overtly impressive on first listen means that it's not for everyone, but if you're a musical omnivore on a budget who needs isolation and values good accuracy over extraneous colouring in the sound, then it's worth a try.

Manufacturer link (UK site)
Headroom Link (US)
Askdirect.co.uk Link (UK)

Wednesday, June 22, 2005

'De-hardening' the ATH-W2002

The Audio-Technica ATH-W2002 is one of the few headphones out there which manages to look and feel like a work of art, and also sounds the part too. It features very resolving drivers and excellent technical performance, and on the art side also features Echizen lacquered earcups made of Asadazakura (cold weather cherry tree, more densely packed) wood. It's biggest failing is a tendency to sound rather hard in the midrange, and since this isn't really a routine 'tuning' of headphones, it explains the reason why many people say on Head-Fi that it's hard to match.

I know that many audiophiles have a dislike of EQ because it can introduce additional distortion into the sound. But using it sparingly is probably not a big deal, especially given a studio-grade EQ. Many amps do add their own flavour into the sound so do act as a mini-EQ in their own right, and rather than dropping thousands on trying different amps to see which flavour you like, it does make sense in situations like the ATH-W2002 where it does noticeably deviate from "completely agreeable". There's also an increasing contingent of audiophiles these days who use computers as their primary source... in which case sophisticated EQ is much more readily available.

Some people say the W2002 lacks bass. This is probably down to their perception concentrating on the hard midrange. The W2002 isn't bass heavy, but if the lows are examined on their own it's not exactly anaemic.

Just a ~2db smooth trough centered around the 1.5khz range makes a large long-term difference in making the W2002 sound a lot smoother. I also like a bit of bass added into that, but that's down to preferences. You can do a lot more with EQ, but this is the simplest 'fix' to start with that I know for the W2002.

Monday, June 20, 2005

HD5's Got A Secret

Having been voted the best sounding MP3 player must be a publicity coup...

...but, there's a rather calculated side to this apparent victory.

Take a look at the graph below*.

This reading was taken with all EQ turned off on the HD5. It's a shame I can't scale these graphs more to indicate the sort of impact it might have on hearing, but while for example the iRiver H320 has basically a flat response in the 20-100hz range, the NW-HD5 has a (very audibly noticeable) shaped boost. To implement a curve like this, you don't do it by accident or by inappropriate component choices. It's engineered.

The NW-HD5 therefore makes a mockery out of any listening tests with 'flat EQ settings'. I'm not trying to debate whether the bass boost makes things nicer, it is simply that like-for-like comparison must be just that, and the Sony tuning of the 'flat' sound is... well, for want of a simpler word, cheating. For example, would the HD5 still sound better in that "test" if the Cowon X5 was given a slight boost in the lows? You know, I think it might lose. Would slipping in '02' bass boost on the H320 make the iRiver sound 'better' to the test panel? Quite possibly. The big difference between the Sony and the rest is that the other players don't play this trick, so comparing with no EQ is a reliable test of sound quality for all but the Sony. Even the iPod with the now infamous fall-off has a flat response when loaded with high-impedance phones.

Although I make no definitive judgements which I'm prepared to publish here about the sound quality of the HD5, it is perhaps not quite as clean as at least two of the players on that comparison list. I put it to the CNET staff that they were fooled by the bass boost of the HD5... frankly, I'm quite surprised that no-one picked it up. I did within 10 seconds of hearing a track I was familiar with on the HD5, not as an improvement in quality but as simply a boosted bass.

*Usual disclaimers apply... not guaranteed accurate, author indemnified against inaccuracies, yada yada yada. ATRAC3+ 256K & 320K LAME MP3 codecs, loaded with 16 ohms impedance and adjusted for typical listening levels.

Sunday, June 19, 2005

I hate you, iPod Shuffle.

Despite my initial reservations, I had began to like my iPod Shuffle. I really like the fact that I can just dock it, then it gets filled with a random selection and off I go with zero hassle. I've begun to carry it in addition to another DAP I might have because I'm warming to this type of listening on an occasional basis.

A friend had heard that the Shuffle was supposed to sound better than the regular iPod. She asked me if I could have a listen. I duly handed the Shuffle over. She fiddled with it, listened for a while and a strange look came over her face.

"I didn't know you liked Michael Bolton."

And surely enough, once she takes the phones off I can hear the earphones leaking and the Mulleted Baboon of Love bellowing "Love Is A Wonderful Thing". The evidence seemed inescapable. Unfortunately, I couldn't come up with a snappy enough answer that wouldn't seem as though I wasn't trying to explain away my embarrasement on being discovered as a closet Michael Bolton fan. In the end, although I mumbled the truth - "a friend shared some tracks with me and I hadn't sorted through them yet" - I realised that I didn't sound very convincing.

Call me paranoid, but when she meets friends who know me and they talk about me, I just know that Michael Bolton will be in there somewhere. Followed by sniggers. One of the few times that someone else has asked to hear the Shuffle, of course it dredges up a track that I would never willingly listen to.

You little treacherous bastard.

Thursday, June 16, 2005

Brief Look: iRiver H10 Cradle

I looked at the iRiver H10 earlier this year. While I was generally impressed by the hardware, the firmware and software provided a less lasting impression. That hasn’t changed by the way, but I thought I’d update the review of the H10 by adding a quick look at the H10 cradle accessory.

The first iRiver cradle I bought was for the H320. And I must say that it was an imposing piece of hardware, despite the fact that it was just a port extender. The heft of it and the solid design that went into it was rather impressive. On cutting out the H10 cradle from the blister pack, I was once again impressed by the standard of build and design for something that is for the most part rather inconsequential and usually an afterthought.

The H10 cradle ships with a standard USB > MiniUSB cable, and a 3.5mm jack to jack connection cable. The H10 cradle packs flat, can be considered 'portable', and the cradling part folds out to allow the H10 to sit on it.

The cradle connects to USB via a standard mini-usb jack. A socket for the power supply provided with the H10 is also present. However the H10 will charge from just USB using the cradle. A second battey slot is also provided, and allows for the charging of a second battery. This functionality is however unavailable when operating off just the USB socket… it needs the iRiver power supply.

The Line Output on the right hand side of the cradle is a fixed-volume affair, so is basically a ‘real line out’ all the time. Casual testing with a Porta Corda 2 portable headphone amplifier revealed that the Line Out performed well, given my slight reservations with the H10's sound.

The Line In socket on the left hand side allows the H10 to be connected to any line-level output. The Sony NW-HD5 below has been switched into Line Out mode, connected to the H10 using the supplied cable and was made to perform an act of copyright violation that Sony would no doubt hang me by the rafters for.

The recording quality is good, but does require careful monitoring of the volume level (which is difficult to set on the fly) not to clip. Top recording quality seems to be 320K MP3 for the Line input.

I said at the start of this Look by saying the iRiver hardware impressed. That continues with the H10 cradle… It’s well designed, properly put together and genuinely useful. Let’s hope the firmware and software guys at iRiver can eventually hold a candle up to what the hardware guys are doing…

Wednesday, June 15, 2005


I thought being an audiophile was weird. I thought being an audiophile who primarily uses headphones was weirder still. But this takes the cake. What next? Ummm... Actually I don't want to know the answer to that.

Saturday, June 11, 2005

The iPod Bass Fall-Off

NOTE: THIS ARTICLE IS ABOUT THE 3RD and 4TH GENERATION IPODS. The issue does not affect post-4G iPods in the same way.

This is something that gets asked often, and when it's asked on anything but an iPod specific board, it gets lost in 'X is better than iPod' arguments. So let's clear it up here.

The iPod is said to have a bass fall-off (i.e. decrease) with low impedance phones. This is most probably due to the component chosen as the DC blocking capacitor in the headphone output stage of the iPod. It's said to be particularly noticeable on the 3rd Gen iPod. How actually noticeable is the falloff? With very low impedance phones like many portable-orientated earphones, very noticeable is the answer. However, the higher up the impedance range you go the less noticeable it is.

So let's take said 3rd Gen iPod and hook it up to a no-budget soundcard like everyone else does to run their RMAA tests. I've chosen the Edirol UA-25. Since this question is asked often with canalphones, I've taken the Shure E2c, an increasingly popular choice and justifiably so. Here's how I connected everything up:

The iPod is plugged into a headphone splitter which allows me to connecto both the soundcard and the earphones. By doing this, the iPod 'sees' the headphone as an impedance load and allows me to measure the effect that has on the iPod with the soundcard. For each test, I set the iPod to the same comfortable listening volume using a piece of music for the most realistic possible results. The methodology used for the test is not rock-solid and I would say that it is only a relative guide.

The test doesn't end there though. I'm going to add one more item to the chain:

Look at where the E2c is plugged in. See the extension cable? That contains four resistors, two each for left and right channels, which adds 92 ohms of additional resistance. The E2c has as standard an impedance of 16 ohms. With the 92 ohm extension cable, what you end up with is a 108 ohm impedance phone. Why 92 ohms? Well I just needed to take total impedance to beyond 100 ohms for the test and I just matched the most suitable resistors I had :)

Now I'm going to show you the RMAA result for the frequency response between the 'unloaded' (i.e. the E2c just by itself) and the 'loaded' (the extension cable installed) set-ups.

Right. First you'll be saying 'man... that's a severe falloff even for the loaded E2c'. The key here is interpreting graphs properly and correlating it to real world experience. Note the numbers on the side and the frequency at the bottom. Take iTunes or Foobar on your PC, play your favourite tune and use the EQ to replicate the above. For example, to hear the effect of the bass falloff on the 'loaded' E2c, dial in 1db less on the EQ at 30hz. Do you hear different? Is it a big deal? I'll leave that up to you to decide.

Note that the above graph only shows the response of the iPod, not the phones being used. We're only looking at the effect that the phone has on the iPod. What you hear with the E2c will be different, because to you the effective response will be the response of the E2c (and it isn't flat) plus the above graph.

How do the iPod buds fare? Well, they have a higher nominal impedance (32 ohms) than the Shure E2c so the onset of the bass falloff is delayed. 'Loading' the iBuds with the same extension cable, you can see that the higher cumulative impedance (now 124 ohms) also further reduces the bass falloff.

Of course, if you choose a high impedance phone in the first place like the Koss KSC-75 and the Portapro (both 60 ohms nominal impedance), the Sennheiser HD25-1 (70 ohms), etc then you've gone a long way towards solving the issue. All phones up to a couple of hundred ohms will register some degree of bass falloff, but at around 70-80 ohms the falloff is negligible enough. Here's the iPod's behaviour with the 70 ohm Sennheiser HD25-1 compared with the iBuds and the E2c:

Once again, you're not seeing what you'll hear, because the above response gets coloured further by the response of the headphones. The HD25-1 has a fairly prominent treble and bass so you can bend the green line further with that in mind to arrive at an idea of how it might sound like to you.

There's also another way of looking at this issue. Headphones like the Sennheiser HD212 Pros have excessive bass response. The Sony MDR-V700DJ is another one with a hiked up mid-bass. The MDR-EX71SL earphone is also pretty bloated in the lows. All of these are low impedance phones and are affected by the iPod bass falloff. But the net result of the falloff is to control the 'bloat' response of these headphones and effectively tighten up the bass, so you might not notice anything particularly amiss. So it's sort of a workaround.

Does the iPod have less bass than many other players when used with low impedance phones?
Most certainly.

Is it like a 'totally no bass' problem?
No. You can certainly still hear it. It's just not as present.

Are Apple eejits for not taking care of this issue?
Yes. Especially as it's the only thing which contributes to the 'poor sound quality' that many who don't like the iPod complain about.

So why haven't they fixed it?
You got me there. The 'word on the street' is that they might fix it in the next version. Who knows, they might.

Does the iPod have poorer sound quality than other DAPs?
No - it actually has better sound quality than some DAPs out there. But the determination of 'sound quality' is different among people, and not just to do with the subjectivity of these things. Some people just have the interpretation wrong. For example, the overall sound quality of the new Sony NW-HD5 is not appreciably better than the iPod. However, Sony have knowingly (or cynically?) dialled in a mid-bass boost even without EQ. Therefore, to many people it 'has higher sound quality'.

Is the bass falloff curable?
I think we established in the above test that it more or less is possible. You'll notice though that in addition to the bass recovery, with the E2c other changes have taken place further up the frequency range. So adding additional impedance to an existing low-impedance phone will cure the bass issue, but it might also change the sound of the phone in other ways. The ideal way to cure it will be with a pair of higher-impedance phones. However, if you actually want a large amount of boosted bass it's fair to say the iPod ain't the player for you. You're better off looking at the iRiver players.

So does this mean the iPod is no good and I shouldn't get it?
The differences in the bass delivery might put you off, but the iPod has decent core sound quality, the best playlisting facility in the business which really does change the way you listen to music, a very easy to use and pretty powerful management software which takes a sensible approach to anti-copying, and the best user interface. There's also the dock port, which allows much easier and better connection with home speakers and car audio. Some of the things which Apple haven't taken care in avoiding are strange, but on the whole it's a more mature, better thought out product than others on the market. I wouldn't dismiss it.

I'm also adding an additional requested point...

Is the bass falloff present if I amp the iPod through the Sik Din / Pocketdock and something like a CMOY, PIMETA, Porta Corda, Airhead amps, etc?

No. First of all the Line Out provided by the Din and Pocketdock (and the Apple dock) is designed to drive a Line Out load, so it all works fine. Actually, you won't get the bass falloff even if you plugged the amp into the headphone socket. It's an interesting thing, amping the iPod. Because the iPod has this bass falloff, and the falloff is fully recovered on connecting an amp, it causes a lot of people to say "OMG!!! It sounds so good through an amp! Amps are the best!!!" The truth is that the amps are being helped by the iPod in this sense, and the actual sonic improvements offered by a portable amp if there was no bass falloff are considerably less than what you may hear on an iPod. That's something that you don't get the amp manufacturers talking about on a regular basis.

Note: RMAA results are not necessarily absolute. These graphs serve to show you a relative measurement of the iPod's behaviour with the headphones. If you link to the graphs, you MUST post the adjacent explanatory text.

Friday, June 03, 2005

Dead iPod Chronicles, Part 4

It's alive. The iPod is back from the dead. The HDD swap worked given a little trial and error jiggery pokery in reconnecting it to the PC and cranking up the iPod Restore utility. It doesn't seem to work from the Firewire port so far, but it seems to be working fine through USB2.0. The 3G doesn't charge from USB of course, so I will need to keep my dual header cable or the PSU with me. Still, worth it since for less than the cost of a 1Gb iPod Shuffle I have a working player again :D