The RHA CL750 is the second unit of the three RHA has lent to me for review, and it is the least expensive model in their CL series. Priced at 140USD, I do not think it is quite worth the listed price. While RHA has been a wonderful company to work with, I have to keep my reviews honest, and that includes giving a negative review of a product by a wonderful company.
The included accessories are 6 pairs of silicone tips, 2 pairs of double flange, and 3 pairs of Comply tips, and a branded shirt clip. Also included is a very nice carry case, which feels plenty sturdy to keep these IEMs safe. The IEM itself has a round stainless steel housing, the same size and shape as the MA750i I previously reviewed. The cable has the same sort of memory wire as the MA750i, where it tries to loosely hold one shape. The cable itself feels plenty sturdy, but is a little rubbery, and is a bit microphonic. It has a few kinks in it, but it feels like it would straighten up with time and regular use. Unfortunately, the cable is non-removable, which at this price, I would normally skip an IEM for that point alone, but with RHA’s legendary customer service and warranty program, I could get past that. The CL750 is also quite comfortable; as it has the same size and shape housing as the MA750i, this came as no surprise.
With an impedance of 150 ohms, and a sensitivity of 89dB, you would think these would be quite hard to power, but they really are not. 9 o’clock on my Magni 2 on low gain puts these at a bit above where I would normally listen. However, I was getting a bit of hiss out my Magni 2, and I surprisingly was not out of my SMSL SAP-9, so my evaluation of the sound is based on it being powered by my SAP-9.
The sound, however, is where is start to take issue with this IEM. It has an overall upward tilt to the entirety of the sound, which itself is not bad, but it is just poorly executed here. The bass is a bit rolled off and distant sounding, lacking impact. The midrange is pretty nice, sounding plenty detailed and natural. The upper midrange is elevated relative to the lower midrange, which I personally enjoy the sound of. Vocals sound very natural and appealing, and are doubtlessly this IEM’s strongest point. The treble, however, is where I take the most issue with this unit. The lower treble is alright, sounding adequately resolving and detailed, if elevated; however, as you go up in frequency, the treble gets more elevated, and also more and more hazy and indistinct. The treble is not peaky, but it does have an upward slope to the entirety of it. This IEM is the only one that has managed to make treble hurt my head. This is the first example I have heard of treble sounding thick. The treble just fills the entire sound. I am far from treble sensitive, but this treble just hurts. Imaging is poor at higher frequencies, sounding like half the soundstage is violently shimmering all at once when cymbals hit. Imaging at lower treble, and midrange frequencies, however, is nice and accurate. Soundstage is adequately wide, but with such elevated treble, it could benefit from a wider soundstage.
All in all, I cannot see myself recommending this IEM. At 140USD, there are better options for a brighter sound signature, the TFZ King being the first to come to mind at ~100USD. If RHA could quell the higher treble, fix the haziness, perhaps by experimenting with BA drivers, and bring the bass up a bit, they could have a solid product on their hands. While a future revision of the RHA CL750 could be worth buying, I simply do not think that it is worth its salt in its current form.