Review of the Superlux HD-661 Headphones

 From submitted by "keanex"

Having received two other Superlux headphones in the past I wasn't expecting much outside of a no frills cardboard box. While I wasn't completely blown away, Superlux definitely took some notes from other companies and made the packaging much more appealing than the 668b or the 651. The 661 come in black box with red sides, what's interesting though is that on the front right half the 661 are exposed by a plastic window. The left side is a profile picture of the 661 in a glossier paint than the matte black, HD661 is also in this glossy print in black. Under the HD661 is says "Professional Monitoring Headphones." On the back Superlux has printed in white lettering the specifications and accessories in English as well as 3 other languages. 


The front of the box flips open to expose the headphones that are laying on red cloth, which turns out to be the carrying pouch for it. Also included are 2 headphone cables (1m and 3m), a 3.5mm to 1/4'' adapter and a cable clip. 

I'm very impressed with what Superlux has done here. The box is very appealing from a consumer standpoint, it isn't flashy yet it will catch your eye. The included accessories are a very nice touch as well, it's rare to see extra cables and an adapter in a $50 headphone package. I don't have one complaint about the packaging, well done Superlux.

Design and Build Quality


Superlux is known for making some great sounding headphones that are very hard to beat for the price, one thing no one has ever praised them for is the build quality though. With the HD661 I can honestly say I'm impressed with the build quality for the price. Everything is plastic, but has a very sturdy feel to it from top to the bottom. 

The wing system makes an appearance here in typical Superlux fashion. Thankfully it's been redesigned for some more flexibility and comfort in comparison to other models like the 651 and 668b. Unfortunately the wing system is still the worst part of the design, even though they've re-designed the wing they're still rigid and uncomfortable. I will say that they do a good job of allowing for fit of all head sizes though, which is necessary since there's no way to adjust the size of these. Holding the two sides together are two plastic pipes which flex decently with no worry of them cracking or breaking for those with larger heads, unfortunately though since they're plastic they can't be stretched to reduce clamp. 

The ear cups each have raised chrome text that says Superlux which stands out on the very glossy black paint. Below that the model number is printed in grey with an indicator, or lack of, for which side is which. What I mean by this is that only on the right ear cup is there an indication of which side is which, an odd choice. Another odd choice is that the ear cups can swivel, but not sideways, they can swivel vertically completely to turn the driver out. The ear cups are fitted with thin leather pads that can easily be taken off. On the left ear cup a 3.5mm male plug is exposed to allow the included cables to attach which is a nice touch.

Once put on the 661 aren't very comfortable. Part of this is the wing system being rather rigid creating some down pressure of the headphones, the other part is the clamp. The clamp is similar to that of the Sennheiser HD558, but the pads on the 661 are more thin and rather rigid. Due to this I wasn't able to wear the 661 for extended listening. They aren't terribly uncomfortable, but I couldn't wear them for more than an hour or two. I did find that the 661 worked decently for portable use though in non-noisy areas. I never worried about them falling off and they don't leak much noise. I wouldn't use these in a library or a train, but for a quiet walk around the neighborhood they work well.

The 661 aren't going to win comfort contests and I wish they would ditch the faux Audio Technica wing design in favor of something more comfortable. The build quality is a nice step up though from the 668b. The 661 feel solid with no creaks or worries about them breaking, I feel they could even stand a few drops with no worries. I also said that the paint was glossy, but I don't think I can stress it enough, it's almost able to be used as a mirror, take that as you will. The 661 also come in a variety of colors which should allow anyone to find a style for them.

Sound Quality

As always I gave these 50 hours of burn-in time. No significant changes were noted during burn-in.

The 661 have a bright, slightly aggressive, but balanced sound to them. They're very musical headphones that manage to blend that with good detail and not be boring to listen to. The lows are fantastic here with good upper and mid bass impact with good extension which gives kick drums a good thump. Unfortunately when it comes to the sub-bass though I find myself wanting a bit more. The bass extends well enough, but it's almost teasing as I can't feel it, the rumble just isn't there. The bass is rather quick though, keeping up with the quick fluctuations in James Blake's "Limit to Your Love," which isn't an easy thing to do.

The mids have a nice intimate warmth to them with excellent presence. I honestly find the miss to be almost perfect here with good clarity and a nice slightly forward feel to them. To put it simple, rock music is an absolute joy to listen to with these, I find Coheed and Cambria and At The Drive-In to be hard to not listen to through these. The highs are the focus here and with great extension and sparkle. They are clean and detailed with good presence to them while managing to not cause fatigue.

Every aspect of sound is well represented here and while the 661 is a tad bright, that doesn't mean the lows are lacking, unless you're a bass head that is. It's rare for me to find a headphone like this with excellent lows, but great highs and mids that aren't recessed. Part of what makes these so fun to listen to though is how the music is presented. The music has an intimate feel to it and has an aggressive forward edge that makes alternative rock come to life. The sound is actually presented similar to how the Grado SR80i present sound, but less in your face with better instrument separation. Another thing that impresses me is how great these sound from an iPod despite it's 68 ohm impedance. These are very efficient, more so than the 668b even. 

Onto the songs:

At the Drive-In - 198d

This song has great dynamics to it with it's soft intimate verses to the heavy intense bridge. The 661 handle this song almost perfectly. During the verses the hushed sound of the song is handled perfectly with each instrument able to be heard with great clarity, but the restrained sound of each is heard. When the chorus hits the guitars explode, the cymbals crash, the vocals come to life. The dynamics of this song are handled perfectly. The guitars have great crunch to them, and the vocals sound intimate as if I'm in the same room.

Sara Bareilles - Vegas

This song has a nice bluesy vibe to it as well as a talented singer. Right away the HD661 expose some mastering problems with the bass being a bit too boomy, it actually hurts the song a lot more than I thought. Moving on though Sara's voice sounds good, slight sibilance here, but it's more of a recording issue than an issue with the 661. While the 661 aren't incredibly detailed they certainly expose some bad mastering here, take that as you will, but I don't like this song through these.

Sufjan Stevens - John Wayne Gacy Jr.

Hushed vocals, a fuzzy acoustic guitar and a winterized sounding piano are the primary culprits here. I have to say it sounds wonderful the piano weaving in an out giving a cold vibe to the song with the guitars bass notes adding some warmth to the song. Sufjan's vocals sound incredibly smooth here. This is a song I've listened to hundreds of times and I am enjoying it a lot through the HD661.

Hot Chip - I Feel Better

A cheesy electronic mock track with a thumping kick drum and filled with synths and auto-tune. This song carries a lot of energy and definitely relies on every instrument to come through clean and with authority to sound good. The bass is thumping more than sufficiently thanks to the mid-bass impact. The synth sounds full and fulfilling as it repeats itself. The vocals are clean and intimate. This song is just living through these headphones, it sounds absolutely fantastic. I'm nodding my head and can't stop, thumbs up here.

Pretty Lights - NIN vs Nirvana vs Radiohead

This song has a nice blend of panning, sub-bass and atmosphere to it. The HD661 aptly handle this song. The panning is done well, not as 3d as the Brainwavz Beta, but it has some depth. The bass has nice extension, but I don't feel the rumble, this is a disappointment because it takes some of the raw sound of the song away. Overall the song is very clean sounding though, great production value and it comes through with the HD661.


The HD661 are an excellent addition to Superlux's already impressive budget line up. The HD668b will suit those who want a more flat sound with a tad more bass response while the HD661 will cater wonderfully to those who favor treble, but still want a clear balanced sound with good bass response. The build quality is great for the price, though I wish Superlux would consider a leather band or another option in place of it's wing system. The Samson SR850 are much more comfortable than the HD668b, for example, because of that and are still able to be found for the same price. Either way Superlux seems to have found it's niche, making excellent products at a budget minded price. I highly recommend the Superlux HD661 for it's suggested retail price of $50 for it's versatility though I have to say I highly enjoyed alternative rock the most through these.

Edited by keanex - 10/30/11 at 4:57pm