Technology tends to move forward in tiny increments; a little improvement here, a slight gain there. But occasionally a product comes along that changes everything, accomplishing in one giant stride what would have otherwise taken hundreds of small steps.
And that, says audiophile gear expert Jude Mansilla from Head-Fi TV, is exactly what Shure has achieved with its KSE1500 Electrostatic Earphone System.
“When a company like Shure marshals its resources the results can be amazing,” says Mansilla in his video review. “Products like the KSE1500 show that legends can be born from efforts like this.”
It’s fair to say Mansilla is pretty hyped about these earphones – in fact, he says he’s “madly in love with them” – but before we get into the reasons why, let’s first hear the backstory.
“You have to understand how cool it is that this product even happened,” says Mansilla. “When Shure began working on these years ago, it was well before the premium in-ear monitor (IEM) market had grown into what it is today.”
Breaking New Ground
Electrostatic technology is, of course, nothing new for speakers and headphones. But until now, no one had ever managed to compress these special drivers into a groundbreaking in-ear system.
“Electrostatic drivers use a super thin diaphragm that is drawn tight like a drum skin and suspended between two conductive plates,” explains Mansilla. “Because the diaphragms are so light you get a much better signal response. The result is amazing detail and incredible transients.
“The problem though is that the drivers require tremendous precision as well as specialized high voltage amplification. But Shure, with their decades of experience making high fidelity microphones, are up to the task.”
Spec-wise, the KSE1500 system uses one full range driver per side, with a response frequency from 10Hz – 50kHz and a maximum sound pressure level of 115dBs.
“Since the KSE1500 is a sound isolating IEM, and because it’s an electrostatic headphone, you get some very unique qualities,” says Mansilla. It is kind of like listening inside an isolating chamber – all the details that would be lost due to ambient noise are uncovered.”
In fact, the sound isolation is rated up to 37dBs, which means all the everyday sounds that surround us are completely cut out, leaving only what you want to hear: the music.
“When you get rid of 37dB of distraction that means no ventilation, no air conditioning, no computer fans, no phones ringing, no breathing. You lose all of that, and it takes you right into the recording. There is nothing to distract you,” Mansilla says.
“Frankly, it’s an entirely unique experience that no other in-ear headphone I have ever used, even ones that isolate as much as this, has ever given me.”
Aside from its incredibly small size, another way in which the KSE1500 differs is in the cabling. Whereas other top-end electrostatic headphones use a wide, flat cable, the KSE1500 looks more like a regular lead, even though it provides the extra amplification that this technology requires.
“This cable took Shure’s team literally years to get where they wanted it,” enthuses Mansilla. “Because they needed a cable that goes right up to your ear it had to have a round profile. They ended up creating a Kevlar-reinforced cable, which connects to the amp via a six-pin LEMO connector.”
As for the amplifier itself, Mansilla praises its premium performance and build. Without the extra power, electrostatic headphones simply won’t work. But the KSE1500 amp also acts as a digital-analog convertor (DAC), allowing it to process any source you care to use.
Furthermore, the amp allows you to refine and customize your listening experience. “It is nice to be able to tailor the sound,” notes Mansilla. “The 4-band parametric EQ is easy to use, and there are some presets that allow you to simply alter the sound: flat, low boost, vocal boost, loudness and a de-esser.
“For example, I was listening to the Alice in Chains track ‘Would,’ and I wanted a little bit more thump, so I just dialed it in with the low boost. I’ve also used the de-esser on some Alanis Morissette songs just to take out some of the sibilance.”
Now we come to the most important part of the KSE1500 review: the sonic performance. How would Mansilla describe the tone? “I’d call it a rich neutral,” says the audiophile expert. “There’s definitely a harmonic richness, a timbral richness, and the treble extension is fantastic. And of course, you can accommodate for different recordings with the parametric EQ.”
So, where would he rate the earphones on his all-time list?
“The KSE1500 is, to my ears, the best sounding, most resolving in-ear headphone that I have ever heard,” Mansilla affirms. “It sounds like an exceptional electrostatic headphone, only fully closed and with lots of isolation.”
Calling it the most significant audiophile product in years, Mansilla has clearly been won over by the Shure KSE1500: “They are that good. An electrostatic headphone you can fit in your ear? That’s pretty amazing.”
Watch Jude’s full review here.