Beyerdynamic Headphones

I’ve come up on a small work problem. I’ve broken my wonderful Beyerdynamic DT-660 headphones. They’ve made a great entry into the world of audiophile grade listening equipment.

The problem that I’ve run into is that their build quality just isn’t up to the task of supporting someone who uses their headphones at work. It’s not because the environment is abusive to headphones. Well, not in a manner that I thought of when I made the purchase. The problem I ran into is that through the repetitive on and off of the headphones from my head during the normal course of work the DT-660’s plastic ‘U’ shaped piece which holds the earcup to the headband broke at a ball-in-socket coupler.  It’s enough of an issue that I have broken the same piece three times in the course of a few years!

I decided that it was time for a new, different set of headphones, but I have come up on two issues that require some feedback. The first issue has to do with the sound produced by two different headphones that I am considering and the second is the question of impedance of those headphones.

My Choices

I decided to stick with Beyerdynamic because I was very pleased with the sound produced with my 660’s, I just felt that the physical design of the headband could be better. I narrowed my search down to the DT-880 and DT-990 models because of their difference in design when it comes to how the earcups are mounted to the headband. The steel piece holding the earcups looks to be much sturdier than the DT-660’s.

DT-880

I headed out to my local HiFi shop to test these models and ask the same question I posed above. An awesome salesman named Paul at my local shop, Sound Ideas, was able to help me above and beyond what I would expect from most shops. During my visit I was able to try both of the models. Each of them were the 32 ohm version. Here’s my initial impressions of each of these headphones:

I love the the neutral sound that the 880’s provide. Going from the closed back of my 660’s to the semi-open back of the 880’s gives the voice a huge improvement. My first impression was that I was sitting in a sound stage listening to a live performance. It really was beyond a night and day difference!

Another difference that I noticed right off the bat is the overall feel of the headphones. By feel I’m not describing an aspect of the sound produced by the headphones but the actual feel of the headphones on your head. The tremendous weight difference is amazing! The 880’s feel light and unobtrusive. The earcups fit nicely around the ears and the plush fabric feels great against the skin. Wearing these for 8+ hours a day shouldn’t prove difficult. Taking them off was difficult, not only for the sound, but for the sheer pleasure of the fit and feel.

The 990’s offered the same wonderful fit and feel when placing on my head. When I started listening to my music selection the DT-990’s I noticed was an immediate difference in base response from the 880’s. It was a huge difference! Doing my research before heading in for my own personal listen I expected to hear a difference in color and response at different frequencies but what I expected was differences along the lines of better treble response.

DT-990

The bass was shockingly more expressive. At some points it felt punchy and helped the representation of the genre of music I was listening to at the moment. At other points I did feel like it was bordering on too much.

To give you an idea I started listening to each set with Vampire Weekend. This band tends to have a good full range sound in a band with a pop type sound in the indie style. The thump, thump, thump that starts Horchata sounded very nice and responsive, big and deep. Much different than sounding than I have listened to it previously. However, when moving over to Eminem the bass sometimes felt oppressive. Instead of providing a clear sounding representation of the bass line I often thought it sounded muddled.

I stopped my first listening experience there. Why only listen to two songs? Well, I had brought with me some CDs that represent my normal listening but after a conversation with Paul about my next topic, impedance, I decided that I would put off judgement of the headphones until I had my amp with me. It didn’t seem prudent to keep listening to tracks from Google Music via my phone when I would not be doing so in 90% of my use case.

Just as a note: While I do use Google Music my collection tends to be from personal rips. I keep these to a high quality. I also keep a collection of FLAC on my computer as well.

What Type of Impedance Should I Purchase?

Some people will spout out a quick and dirty response to this question. “Purchase the impedance that can be driven by your amp or if you’re using an iPod or other mobile device get the cans with the lower impedance.” Now this makes a great catchall response to most people who are new to the world of premium performance headphones.  The question I am asking assumes this point, but is looking at the premise from the point of view that I will have an amp or source that can drive any impedance level which is chosen. In other words, does the impedance level of the headphones have an appreciable affect on the quality of sound.

Each of the models I listened to are available in 32, 250, and 600 ohms. In a rather obscure spot on Beyerdynamic’s site they break down the use cases for each impedance level as thus:

32 Ohms

Maximum power for battery-powered devices (e.g. MP3/CD/DVD player, laptop, PDA); also suitable for many mains-operated devices

250 Ohms

Standard impedance for universal applications, maximum power with mains-operated devices, a little bit lower with battery-powered devices

600 Ohms

Especially for hifi enthusiasts and studio applications, minimal moving mass, ideal for mains-operated devices with a high headphone output level.

I’m currently waiting for my headphone DAC/amp to arrive from JDSLabs. I ordered the O2+ODAC Combo which is designed to run impedances up to 600 Ohms. Since I’ve bought the implementation of NwAvGuy’s O2 amp I also decided to go to his site for his explanation on headphone impedance differences.

Objective 2 Headphone Amp Specs

• Frequency Response: +0.01, -0.01 dB (20Hz-20kHz)
• THD 1 Khz 150 Ohms: 0.0016%
• IMD CCIF 15 Ohms: 0.001%
• IMD SMPTE: 0.002%
• Noise (ref 400 mV): -105 dB
• Max Output (33 Ohms): 613 mW
• Output Impedance: 0.54 Ohms
• Crosstalk (15 ohms): 65 dB
• Channel Balance (at 50% volume): 0.6 dB

Full specs from NwAvGuy’s website.

According to NwAvGuy:

HEADPHONE LOAD IMPEDANCE: This article talks about two different kinds of impedance—the impedance of the headphones (usually easy to find) and the impedance of the source (usually difficult to find). A “perfect” source has an output impedance of zero ohms. This means it will always deliver the same output into any load. In practice, any output impedance below about 1 ohm approximates a “zero ohm” source. The blue circle on the left above represents a “perfect source”, the blue resistor (zig zag line) in the middle represents the output impedance. And the resistor on the right represents the load impedance (the headphones). If the output impedance is not zero, the voltage produced by the source will be reduced when a load is connected. The higher the output impedance, the greater the drop in voltage at the load. This drop is given by the formula: Load Voltage = Source Voltage * ( Load Resistance / ( Load Impedance + Output Impedance) ). For more information see Wikipedia Voltage Divider:

Using this as a guideline it seems that the O2 amp should be able to drive the any of the versions of the DT-880’s or DT-990’s. Again, does it make any real difference? 90% of the time I will be using these headphones with my amp. However if I get the 32 Ohm cans then I can use them with my phone. Is there going to be a big difference between 32 and 600 Ohm? Let me know what your opinion is in the comments!