The transducer is encased by stainless steel, while the headband and headphone mounting utilises the most advanced materials developed in the aerospace industry for high strength with minimal weight.If the headphones have sound in only one ear or differing sound levels in each ear or the sound in general is not what you expected then it needs to be determined where the issue lies - with the headphones or with the audio source.Headphones are designed to fit the widest percentage of the general population however every person is different and some wearers may feel the headband of the headphones is initially too tight upon the head.If you need the speakers active so others can be enjoying the same audio we recommend connecting your headphones to the audio outputs (ie: RCA outputs, digital optical audio output, digital coaxial audio out, etc) of the audio component rather than the headphone output.The next thing to do is to try the headphones on a different audio source to check that it is not the original audio source (or a setting on the audio source) that is creating the issue. No doubt in order to soften the harshness of the brightest mixes that can exhaust the listener during extended listening sessions.DISCLOSURE: We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com, affiliated sites and sponsors.The Focal Utopia is slightly heavier and features a more traditional headphone approach. Silver coating of the strains minimizes resistance for sound transmission. It is important to remember though to go little by little because too much stretch in a short time could cause a break or crack in the headband if it is stretched too much.The frequency response certificate for a specific HD 800 S can be found in the USB stick which is on contained in the product package.”Headphones are designed to fit the widest percentage of the general population however every person is different and some wearers may feel the headband of the headphones is initially too loose.For amplifier recommendations Sennheiser suggests that our customers check out this headphone forum (www.head-fi.org) where the moderators and member test a variety of different amplifiers of varying costs and features and can provide feedback on how the different amplifiers perform under different circumstances.For additional information regarding the theory of "burn in" there is plenty of discussion at Head-Fi.org (http://www.head-fi.org).With Sennheiser headphones the audio will always be accurate and responsive and is sure to please no matter what situation you need it for.Some argue that over period of time a user will become more accustomed to the particular headphones.
A properly connected cable should not wiggle. The HD 800 S play the best with the solid state DAC/AMP while the HD 800 work best with the tube amp.