52 posts / 0 new
Last post
quadpatch's picture
Offline
Last seen: 2 weeks 2 days ago
Joined: 28/03/2011 - 19:04
Posts: 881
RE: Just Discovered - Sennheiser HD650

You're welcome :). I saw the Meridian Explorer today for the first time, yeah it looks cool. I haven't heard it though, or the Dragonfly (I have heard lots of good things about the Dragonfly though). I guess the big question is: Does being USB powered hamstring a DAC/amp's abilities @ <£300? No I don't think that it does specicially. It can have an effect, but synergy is more important really. For example I find the £300 Fostex HP-A3 is a better match for the HD650s than the £600 Audiolab M-DAC, but that's not the M-DAC's fault, it just pushes the HD650 in the wrong direction. Also I find the £150 Arcam rPAC pushes the HP100 in a better direction than the Fostex HP-A3. Equally I'm not saying that the poorer combinations sound worse than connecting the headphones to a smartphone - no way!

As much as headphones change depending on what you plug them into, I think it's best to get your headphones before you get a DAC/amp.

To answer your other question: Yes I have bought several headphones on a whim, usually based on things I've read and I have mostly been happy. The first one I did that with was the Denon D7000 and I am immensely happy that I chose it now! I actually bought the AKG K550 after an audition and I absolutely hated it when I got it home. Those are two polar opposite cases, I'm not saying that you shouldn't try things, but you do have to be very careful.

 

Exoticsounds's picture
Offline
Last seen: 6 months 3 weeks ago
Joined: 01/01/2013 - 16:59
Posts: 69
RE: Just Discovered - Sennheiser HD650

HD650 seems very sensitive to the headphone amp used and if paired with the wrong one it can sound boring/bland while paired with a suitable one it sounds just great.

I recently tried HD650 with Cambridge Audio DacMagic Plus and Teac UD-H01 head to head, of those two i wastly prefered the sound via UD-H01.

bigboss's picture
Offline
Last seen: 5 hours 36 min ago
Joined: 25/03/2009 - 21:40
Posts: 12970
RE: Just Discovered - Sennheiser HD650

dalethorn wrote:

Once again, whathifi dumped my reply text saying "Comment feld required".

When typing your post, if the font looks different, the text will get dumped. You can disable rich text which works.

borland's picture
Offline
Last seen: 1 year 6 months ago
Joined: 13/02/2013 - 13:19
Posts: 3
RE: Just Discovered - Sennheiser HD650

This an opinion of the sound engineer Nuffink.

It beats me why people get so confused about headphone impedence.

The loudness of any transducer (headphone or speaker) for a given input is called it's efficiency. It's measured in Decibels per Watt Meter or dB(W/m). It most definitely isn't measured in Ohms.
The impedence of a transducer is measured in Ohms. This tells you almost nothing about the efficiency of the transducer.

If you take two pairs of headphones both with an efficiency of 90 dB(W/m) one having an impedence of 100 Ohms, the other with an impedence of 10,000 ohms and drive them with 1 watt they will produce equal levels of loudness.

The only reason that headphone manufacturers give an impedence rating is that some cheap equipment has a problem with low impedence loads. As the impedence of the headphone drops the amplifier finds it more difficult to supply enough current.

Even the kind of £10 MP3 players they give away with the cornflakes can supply enough current to drive a 10,000 ohm headphone. Plug in a 100 ohm set and the MP3 player will probably go pop.

I've got a pair of Senn HD600's (300 Ohm). An ultra cheapo MP3 player drives them to literally deafening levels. The HD650's (also 300 Ohm) are considerably more efficient due to a neodymium magnet. Sennheiser's tech specs give the efficiency of the 600's at 97 dB and the 650's at 103db. It doesn't say for what input or at what distance but that's marketing departments for you.

The bottom line is that the HD650's don't need a dedicated amp to drive them loud because they're efficient enough.
They don't need a dedicated amp because the have a high enough impedence not to stress the driving amp.
They might well need a dedicated amp because if you're paying for high definition headphones you may as well know that they're being diven by a low distortion amplifier.

There is a relationship, it's just nowhere near as simple as high impedence = low volume. Other things being equal (which they never are) the driving amplifier will pump twice as many watts into half the impedence. So a typical headphone amp that pumps (say) 1 watt into a 600 Ohm headphone will, providing it's up to it, pump 2 watts into a 300 Ohm load, 4 watts into a 150 Ohm load etc. This doubling continues until the amp gives up because it can't supply the current. This is where dedicated headphone amps score (because they can supply the current) and why low impedence headphones are harder to drive.

Now take a look at the efficiency figures on the Sennheiser cans I mentioned earlier. The HD650 is 6dB more efficient. Double the wattage of the amp and you'll get a 3dB increase in volume. So in order to produce the same output as the HD650's my HD600's would need an amp producing 4 times the watts. Yet they have exactly the same impedence - 300 Ohms.

borland's picture
Offline
Last seen: 1 year 6 months ago
Joined: 13/02/2013 - 13:19
Posts: 3
RE: Just Discovered - Sennheiser HD650

And from Rohan some crash course (this one and the above post are to destroy urban myth that the HD-650 are difficult to drive because they are 300 Ohm):

Generally, a properly designed desktop headphone amplifer can drive high and low impedance headphones and can drive headphones of any efficiency.

Do high impedance headphones sound better than low impedance ones?

No, there are many very good low impedance headphones available and many very good high impedance headphones available.

In headphones, the sound also depends upon the following:

Frequency response, this is a representation of volume decreasing or increasing with frequency, this is actually the magnetic field pulling and pushing with different amount of force at different frequencies, impedance affects this in complex ways. Distortion, represents the amount of "change" from the actual signal to the real signal (i.e. input signal to output signal).Build and design, i.e. sealed vs. open, etc. Diaphragm design, voice coil design

 

To conclude:

 

High impedance headphone:  requires more voltage but less current

Low impedance headphone:   requires less voltage but more current

Amplfier output impedance: the lower the better for any impedance headphone

higher efficiency (for example:  102 dB/1 mW) less power required

​lower efficiency: (for example: 91 dB/mW) more power required

How they effect sound is dependent on the magnetic field generated and diaphragm construction (physical response of diaphragm).

 

We hope this clears the air.

 

A few notes:

 

Some people prefer the sound of vacuum tube headphone amplifiers which usually have higher output impedance relative to solid state (transistor)  amplifiers, and therefore have poorer damping factor and hence, fuller bass. Voltage is electrical pressure, current is flow of electrons Resistance is constant with frequency, capacitance creates lower impedance at higher frequencies, inductance creates higher impedance at higher frequencies Headphone impedance is actually quite complex and different driver designs have different impedances at different frequencies and (to a lesser extent) voltage amplitude Assumes diaphragm construction to be similar and magnetic field to be similar Assumes linear response at all frequencies (not possible for dynamic driver headphones) Assumes that impedance increases with change in coil characteristics only. Assumes speed of electrons in an electrical circuit is constant, it does not change with voltage or current or power. Other headphone types which do not have a voice coil (for example, those sold by Hi Fi Man, Audeze and Stax) can also characterized by their electrical impedance.
quadpatch's picture
Offline
Last seen: 2 weeks 2 days ago
Joined: 28/03/2011 - 19:04
Posts: 881
RE: Just Discovered - Sennheiser HD650

Thanks for the info borland! I will go over that a few times and see if it sinks in. Until now I had gone along with Impednace because that seems to be what people often use. I always thought it was very unreliable for communicating efficiency so I had gotten used to just trying to describe it. Blum 3

quadpatch's picture
Offline
Last seen: 2 weeks 2 days ago
Joined: 28/03/2011 - 19:04
Posts: 881
RE: Just Discovered - Sennheiser HD650

borland wrote:

Now take a look at the efficiency figures on the Sennheiser cans I mentioned earlier. The HD650 is 6dB more efficient. Double the wattage of the amp and you'll get a 3dB increase in volume. So in order to produce the same output as the HD650's my HD600's would need an amp producing 4 times the watts. Yet they have exactly the same impedence - 300 Ohms.

The HD650's (also 300 Ohm) are considerably more efficient due to a neodymium magnet. 

Both the HD600 and HD650 are listed as having neodymium ferrous magnet systems. The HD650 is described as using better materials but it's not specific and the rest is just marketing fluff  (HD600 = for recording classical music / HD650 = emotion + precision)

I managed to find a pair of HD600s at work so I 'borrowed' them for the evening and am now comparing them side by side with the HD650. I'm driving them from the Arcam rPAC at the moment, as I switch I don't notice much difference between volumes, I can just tell that the HD650 is louder, but it's really close.

On a different note: I was prefering the HD650s with the Fostex HP-A3 but the HD600s sound a bit nicer on the rPAC. 

quadpatch's picture
Offline
Last seen: 2 weeks 2 days ago
Joined: 28/03/2011 - 19:04
Posts: 881
RE: Just Discovered - Sennheiser HD650

Utterly enjoying both Sennheisers on the Schiit Modi and Magni!! I am struggling to pick an ultimate favourite between the two Sennheisers actually. The HD600 has a little bit less emphasis in the bass (more neutral) and with most amps I am leaning towards this as slightly superior, but the HD650 really shines with movie scores (of which I am a total nut for) as well as a couple of other genres, so it isn't easy. Here is a photo of the bringers of happiness. These Sennheisers are very plasticy for their price but they're a nice weight and I love seeing the driver assembly, pure bad-ass!

Schiit Modi & Magni + HD600 / HD650

eggontoast's picture
Offline
Last seen: 2 days 6 hours ago
Joined: 23/02/2011 - 15:21
Posts: 1434
RE: Just Discovered - Sennheiser HD650

There is definitely an argument to have both of these headphones in your collection given the different presentations they have.

Helmut80's picture
Offline
Last seen: 6 months 3 weeks ago
Joined: 08/01/2011 - 12:25
Posts: 490
RE: Just Discovered - Sennheiser HD650

A great picture quad! The Schiit amp and DAC look so small next to the Sennheisers.

Jason36's picture
Offline
Last seen: 5 months 3 weeks ago
Joined: 23/07/2008 - 10:40
Posts: 1001
RE: Just Discovered - Sennheiser HD650

Helmut80 wrote:
A great picture quad! The Schiit amp and DAC look so small next to the Sennheisers.

The Schiit Magni and Modi have an extremely small footprint (ideal for office desks or where space is at a premium, it also means if using the Modi DAC in a bigger system it can, if required, be hidden away very easily).

There is another photo on my thread "Some New Schitt" and my HD650 dwarf the Magni and Modi.

Having said that, and I am sure Quad will back me up, for its size, the Magni doesnt half kick out some volume. I have the volume knob set at just past 9 O'clock and with my HD650 even this is too loud sometimes.

I'm sure Quad will post a more in depth review of the Schitt Combo in due course, but I must say that personally this is one of the best combo's I have heard for a while, especially with the HD650's which seem to shine with the Schitt combo. Solid Bass and excellent mid range with a treble that I dont find to fatiguing. Since I bought the Schitt combo I am also hearing a slightly wider soundstage and a more open soundstage.

Currently listening to Alice in Chains Unplugged album and I am blown away  Dance 4

quadpatch's picture
Offline
Last seen: 2 weeks 2 days ago
Joined: 28/03/2011 - 19:04
Posts: 881
RE: Just Discovered - Sennheiser HD650

Jason36 wrote:

Helmut80 wrote:
A great picture quad! The Schiit amp and DAC look so small next to the Sennheisers.

The Schiit Magni and Modi have an extremely small footprint (ideal for office desks or where space is at a premium, it also means if using the Modi DAC in a bigger system it can, if required, be hidden away very easily).

There is another photo on my thread "Some New Schitt" and my HD650 dwarf the Magni and Modi.

Having said that, and I am sure Quad will back me up, for its size, the Magni doesnt half kick out some volume. I have the volume knob set at just past 9 O'clock and with my HD650 even this is too loud sometimes.

I'm sure Quad will post a more in depth review of the Schitt Combo in due course, but I must say that personally this is one of the best combo's I have heard for a while, especially with the HD650's which seem to shine with the Schitt combo. Solid Bass and excellent mid range with a treble that I dont find to fatiguing. Since I bought the Schitt combo I am also hearing a slightly wider soundstage and a more open soundstage.

Currently listening to Alice in Chains Unplugged album and I am blown away  Dance 4

Thanks Helmut80! I was inspired by Jason's pictures it must be said, but they are kind of difficult to take images of together, especially while showing the drivers. Is it just me or is there something about the HD600 / 650 that looks even cooler than the HD700 / 800? I am certainly enjoying the sound even more than the HD800, but most of that is the bass being so much more full sounding, the HD800 was weak in that area when I heard it last. I've heard people suggesting the new HD800 has more bass, but that's entirely unofficial I must add.

Anyway, yes the Modi & Magni kick out a huge amount of power! They are a pretty great combo for either the HD600 or HD650 too, so far it has been a nicer experience than the M-DAC, but I haven't done a lot of comparison testing yet. The M-DAC is a weird, weird beast! It makes some things sound fantasic and other things overly harsh and emphasised in the wrong places. So far the M-DAC has done wonderful things with the Denon D7000, Beyerdynamic DT770 Pro LE and oddly enough the £17 RHA CA200, but so many other things have been less favourable - like the Sennheiser. Funnily enough the only time that I have heard the HD800s was through the M-DAC and I'm beginning to wonder if it's the M-DAC's fault that they didn't sound way better. Actually one time I did hear the HD800 through a Resonessence Invicta and that sounded absolutely dreamy!! Now I'm wondering how the HD600 / 650 would sound through that machine. Then again, if you're spending £3500 on a DAC, the chances are you can afford the HD800 and the HD600 anyway :P.

Right now I am listening to the HD650, with the HD600's cable (just for the hell of it). This is then connected to the Arcam rPAC and using the iFi iCAN headphone amplifier (which I got today). The bass and soundstage control on the iCAN is really cool I must say!! I'm listening to the Crysis soundtrack - the imaging and sepration are stunning! - me likey!!

 

OK Babble mode off for now, have a good weekend everyone and happy listening! Smile

dalethorn's picture
Offline
Last seen: 3 days 22 hours ago
Joined: 07/12/2011 - 21:10
Posts: 1207
RE: Just Discovered - Sennheiser HD650

quadpatch wrote:
Is it just me or is there something about the HD600 / 650 that looks even cooler than the HD700 / 800? 

You noticed that too?

AKG K812/K712, Beyer T1/T90 Jubilee/DT1350, v-moda M100/XS, Beyer A200p/v-moda Verza/Microstreamer DAC/amps, Portaphile Micro/PA2V2 amps.

Inter_Voice's picture
Offline
Last seen: 4 months 4 weeks ago
Joined: 05/10/2010 - 21:50
Posts: 654
RE: Just Discovered - Sennheiser HD650

For me unfortunately HD650 is not my cup of tea.  I owned it for just a few months and sold it in the eBay.  I found the sound from HD650 is veiled and HF is rolled off by too much. I also tried AKG Q701 but it was also not to my taste.  Also sold it in the eBay afterwards.  Now I own HD800 which I really love them.  IMHO the SQ from HD800 blows HD650 and Q701 by miles away but of course the price is also a few times more expensive.  The soundstaging of HD800 is exceptional and I can also hear a lot of fine details that I have not heard before using HD650 or Q701.

The HD800 is connected to my Yulong D18 DAC and A18 headphone amplifier.  They are perfect matches  Smile  Headphone cable is presently using Cardas.  I am consodering to try pure silver headphone cables from Toxic Cables.

Inter_Voice's picture
Offline
Last seen: 4 months 4 weeks ago
Joined: 05/10/2010 - 21:50
Posts: 654
RE: Just Discovered - Sennheiser HD650

Don't know why the same post appeared many times ?

Pages

Log in or register to post comments