The Sennheiser HD 650 headphones provide reference-quality performance -- at a price. Reviewers describe music as smooth, natural and open. Bass is a particular strength, though some experts say that definition isn't the best, meaning that some sonic details occasionally get lost. These headphones require a lot of power so they're not suitable for portable players, and they have an open design, meaning sound leaks in and out. Users and pros alike recommend using an amplifier to get the best performance. The HD 650s are comfortable, though bulky at just over 9 ounces. If you have less to spend, the AKG K702 (*Est. $260) is well received, but while it does a better job of delivering some sonic details, bass response isn't as impressive. If price is no object, the Grado PS1000 (*Est. $1,700) deliver breathtaking sound, but are more expensive than just about any other set of consumer headphones.
CNET and PCMag.com offer comprehensive reviews of the Sennheiser HD 650 headphones with comparisons to other models, as does the U.K.'s TechRadar.com. More than 80 Amazon users rate these headphones, and those opinions will give you an idea of the HD 650's performance on a day-to-day basis. A few audiophiles writing at AudioReview.com also provide useful input. OnHeadphones.com offers useful information about the HD 650 across music types.
CNET praises the styling, bass response and comfort of the Sennheiser HD 650. For high-energy music like rock, however, reviewer Steve Guttenberg thinks they're "tame." Cost is also a concern, though the review calls them "fit for a king."
Review: Sennheiser HD 650, Steve Guttenberg
The Sennheiser HD 650 receives an Editors' Choice award and 5 out of 5 stars for clean, rich sound. According to the review, they create a direct connection between the music and the listener. Mike Kobrin doesn't think they're heavy but admits they're bulky. He warns users, though, that imperfections on low-quality tracks will stand out.
Review: Sennheiser HD 650, Mike Kobrin, March 8, 2006
Of the 80-plus reviews on Amazon.com, the majority of users give a perfect 5-star rating to the Sennheiser HD 650 headphones. Owners echo pros in praising the HD 650's stellar sound quality. "These headphones are quite possibly the most fantastic sounding bit of kit you can buy," writes one user, who says he works as a musical engineer. Some are less enthusiastic about comfort, claiming these headphones can be tight, while others complain of sound leakage.
Review: Sennheiser HD 650 Lightweight Open-Air Dynamic Audiophile Headphone, Contributors to Amazon.com
The 20 or so users who have posted reviews here thus far agree that the Sennheiser HD 650 headphones excel in sound quality. This site attracts audiophiles, and several users recommend an amplifier to get the most out of the HD 650. Some also say a cable upgrade (the included cable is detachable) is worth the money.
Review: Sennheiser HD650 Headphones Reviews, Contributors to AudioReview.com
Though it's named an Editor's Choice here, this brief and somewhat superficial review admits that the Sennheiser HD 650 headphones are not a good choice for the casual listener thanks to their price. However, they are "an audiophile's dream," with sound "that is at once crisp, rich, warm, and inviting."
Review: Sennheiser HD 650 Headphones Review, "Headphone Girl", Aug. 12, 2011
Richard Black awards the Sennheiser HD 650 headphones a 5 out of 5 star rating, calling the sound excellent, with little distortion and great detail, though not as flashy at high and low frequencies. "Among a number of fine headphones on the market today, this is a particularly attractive one," he writes.
Review: Sennheiser HD650 Review, Richard Black, Sept. 2, 2008