Prepare the drum roll. How good do the Grado PS1000s sound? Predictably, they sound utterly fantastic.
Most obviously they provide the open airy sound associated with their open-backed design, but also supply the voluminous bass that sets of this type often lack. The sheer volume and power of the low-end surprised us, even if Grado is known for the powerful, forward sound of its headphones. Put your hand over the grilles of one of the cans at decent volume and it's not unlike placing your hand over the bass port of a subwoofer - you can feel the air being pushed out.
If you have tried the Sennheiser HD800 and found them a little light in the low end, the Grado PS1000 are an excellent alternative. They do cost around £800 more though - hardly small change however you look at it.
This bass, which extends very deep (these 'phones have an astonishing 5-50,000Hz frequency range, compared to a more typical 20 - 20,000Hz) as well as offering huge presence, doesn't infringe upon the rest of the frequency bands either, as you might expect of a lesser headphone. Here there's just so much space that each frequency band can stretch its legs without invading another's space.
This aural impression of spaciousness is provided on two fronts - sound stage and sheer detail. An open, airy sound is common to virtually all decent open-backed headphones, but the sound stage is particularly wide here. Normally when we talk about detail in our headphone reviews, we're referring to the high-end - where the finest sonic details are expressed - but in the Grado PS1000 the level of detail across the board is stunning. Separation is incredible, letting you perceive discrete instruments and other sonic elements much more clearly than you would even with an excellent pair of £200-500 headphones.
Assessing particular genres that work well with the Grado PS1000 sound is something of a fool's errand, because it's rare to find anything it doesn't excel at, and enhance. Classical orchestrations sound full and lush, and beautifully refined when they need to be. Strings are sweet and textured, and the orchestral "hits" of brass and string sections are imbued with a power that's rare to hear outside of a concert hall.
Similarly, the distorted guitars and insistent drums of Queens of the Stone Age's Songs for the Deaf album are doubtless powerful enough to put a smile on singer Josh Homme's face. We noticed precious few sonic slip-ups. The only criticism we could muster was that the PS1000 bass was occasionally a little too ripe for drone-y indie music, such as The Pains of Being Pure at Heart's Belong, where we'd have dialled back the low end a notch or two given the choice.
Smooth, insightful and as high-end a headphone as we've ever heard, where most high-end headphones let you hear the proverbial strings, the Grado PS1000 lets you hear between them too. Some may still prefer a set with lighter bass, such as the Sennheiser HD800 or Audio Technica ATH-W5000, as their lighter sound can supply a slightly greater impression of "airiness", but to call them categorically better is plain wrong – no other headphone we've tested comes close to replicating the full range, detail and clout of a high-end Hi-Fi. What's more, the refinement of the sound means these cans never sound tiring. Not only are they physically comfortable enough to wear for hours, your inner-ears will also love every moment.
On the subject of value, the Grado PS1000 are a tough sell. They're a lot more expensive than the HD800, Sennheiser's top-end model, the Denon AH-D7000 and the Audio Technica ATH-W5000, not to mention Grado's own GS1000 (a snip at £1,000). The only mainstream headphone that can compete in sheer price tag terms is the Ultrasone Edition 10, which retails for roughly the same price. When matched with the right amp, some claim it's the best set of headphones in the world.
However, it's also a trickier set whose aggressive treble can turn sibilant. The extremely efficient and easy-to-drive PS1000, on the other hand, can even be powered by a lone MP3 player with still immensely enjoyable results. For the best output you will want to plug it into a nice valve headphone amp, to add a touch of that valve warmth. It's worth noting, though, that we tried it with a powerful solid state amp and could barely turn the volume dial without risking hearing damage - that's how sensitive they are.
The Grado PS1000 are one of the most expensive pairs of headphones you'll find, but they're also one of the best. Powerful bass, wonderfully subtle-but-intense levels of detail and an incredible soundstage make this pair an unbridled joy to listen to, no matter what musical genre you throw at them.
Drawbacks are few, but that price is something that's hard to swallow when key rivals like the Sennheiser HD800 cost significantly less. However, with a superb metal and wood build, these headphones are built for life.