I'll start by saying that I think there are many more accessible pairs to try in this price range that others would find more enjoyable. I'll get to why in this review, but it's going to take more than a few words if you can bear with me. I couldn't find many reviews on the GMP 8.35 and I actually really like them for my particular use case. Frankly, I bought these because they're easy to drive and near indestructible. I travel and record and wanted a good pair on the go that I wouldn't feel terrible about abusing and also wouldn't require me to bring an amp around. For reference, my daily drivers are a Focal Elex driven with a Massdrop x Cavalli Tube Hybrid and I have also owned the 6XX, 58X, and 4XX. Yes, I love Massdrop collabs.
I'll try to make this review as straightforward as possible, mainly addressing sound and comfort.
I've tried both the stock pads as well as the velour pads which come with the "advanced" edition. They do sound noticeably different, mostly due to the foam used in the stock pads. The stock pads sound better to me, but it's more difficult to get a proper seal; I found rotating the cups about 45 degrees helped the pads conform to my ears better. They're still awfully shallow though. The velour pads are a little more comfortable, but they're round as opposed to ear shaped and somewhat large. Getting a good seal is surprisingly difficult for me. If I don't push them forward, I end up with a small gap by my neck. While I'm partial to the stock pads, each has pros and cons. I still find myself switching back and forth after months of ownership.
As mentioned, I prefer the sound of the stock pads. With a decent seal, the bass is controlled and punchy with some slight emphasis. They don't extend especially low, but the bass that's there is awfully good. I would think along the lines of the 6XX here with maybe a touch more emphasis, but I haven't done a side by side. The mids are well balanced and offer decent clarity in this range. It's hard for me to speak here because I'm mainly comparing them to the likes of the 6XX and Elex, so it's not quite fair. I was surprised by the treble -- it's actually pretty great with the damping material! Soundstage is decently wide for a closed back with no "cavern" effect like some closed backs suffer from. Bigger than the 58X/6XX for certain. I can't think of much to touch on other than this. Overall, I'd describe the sound as at least above average in just about every category without being really impressive at any one thing.
Many seem to feel the velour pads sound better. The bass and mids are similar as the stock pads, but the treble is much brighter with the velour pads. I'm not treble averse -- I don't mind the 4XX or KZ ZS6 which are both notoriously bright -- but the proximity between my ear and the drivers makes the treble uncomfortable for me over an extended period. This is why I prefer the stock pads. I've yet to try a foam mod with the velour pads, but I've been planning to.
- These are probably easier to drive than some of my IEMs.
- You could run these over with your car and I'm pretty sure they would still function.
- The left driver is about a decibel louder. Not especially noticeable but it's there. I'm sure Massdrop or German Maestro would have happily replaced my pair.
- The clamp is a little tight. Oddly, it feels tighter on one side of my head than the other.
These have already survived 10 flights packed in a duffel bag with absolutely minimal signs of wear. I will say that all four of the other pairs I mentioned at the beginning of this review have superior qualities in certain categories, but there's nothing the GMP 8.35 Mobile is really bad at by any means and there are many things it does better than particular headphones. For general use, I believe this is an unassuming pair that could use a little more attention. I could see myself using these a lot more if better pads were available.