Review By Harald Wittig Of Professional Audio Musik & Equipment
Download The German PDF File Of The Review
The American company Equation Audio is a manufacturer of microphones and headphones and is already enjoyed by many in the USA. Equation Audio products are known for their sensational cost to performance ratio by professionals. The manufacturer is accordingly self-confident and promises the buyer of microphones and headphones an especially high value.
In other words, Equation Audio products supposedly can compete with way more expensive competitors in both the workmanship and, most notably, the sound quality. That Equation Audio does not just blow smoke was proven by tests of the Equation microphones DS-V9 and F.20 in Professional Audio. Whilst the DS-V9, for only 86 Euro, turned out to be a good vocal microphone, in the large comparative test, the F.20 Super-Electret microphone (see test in issue 11/2009) shines with excellent workmanship, exquisite measurements, high sensitivity, and fine resolution. Even though the F.20, at a price of around 500 Euro, is no cheap microphone, the editorial staff thought it could be at least twice that expensive.
Equation Audio RP-21 Headphones
Due to these positive test experiences, we also wanted to know if the Equation headphones could also offer a comparable high quality at low prices. Of the three models that Equation Audio offers, we chose to review the RP-21, because this model is supposedly fit for recording and monitoring, a truly versatile product. They are offered by the German distribution for only 70 Euro. The low market price is two-fold: The RP-21’s are produced in China, but experienced engineers and workers closely control the production. Secondly, according to David Cassidy of D.C.Electronic, there are no middlemen for the Equation Audio products. These come to Europe via direct importing which keeps the costs and therefore the price to the ultimate consumer low.
The RP-21’s are closed dynamic headphones. They were developed as a further refinement of the now discontinued model RP-20, which users and specialized press compared with acknowledged studio professionals like the AKG K271 Studio or the Sony MDR7506. For the RP-21, Equation Audio developed a new transducer, with a light fifty-millimeter membrane and a high output neodymium magnet. That is why, according to the manufacturer, the RP-21 has a significantly better efficiency and finer resolution than its predecessor. Also new is the single-sided detachable, replaceable cable. In contrast to other manufacturers, namely AKG and Sennheiser, the cable is connected to the left ear cup by a mini catch. It is not just simply put in, but locked with a twist-lock joint. This keeps the three-meter long cable attached even with extreme movement. In case of damage, like when the director’s chair rolls over the cable, it is quickly removed and can be replaced by a new one.
The ear cups themselves are rotatable and the mounting seems solid, albeit maybe not the long-term stability of the spring steel holders of the way more expensive Beyer dynamic professional headphones. The headband comes with a thin cushion and is extendable for individual adjustment.
Equation Audio RP-21 Headphones
An important criterion for headphones, besides sound, is also the wearing comfort. The RP-21 is not really a lightweight at 350 grams, the AKG K 271 MkII for example weighs just about as half as much, and still the RP-21 is comfortable to wear. Actually, it seems to be even lighter than the AKG K 702, which weighs about the same. The leatherette ear pads fit comfortably on the ears and does not cause discomfort during long listening sessions. Whilst recording, depending on how hard the instrumentalists and singer work, the RP-21 can heat up, but that’s unavoidable with closed coverage type headphones.
Let’s get to the pivotal question. How does the RP-21 sound? Sound-wise, they are quite surprising. In fact, it sounds much better than its low price would make you think it should. It reacts to percussive and transient material with an ease that would even suit some considerably more expensive headphones. In fact, it just barely ranks behind our benchmark of closed coverage headphones, the AKG 271, which are only slightly more precise.
The RP-21’s are high sensitivity headphones, so for direct comparison, we used it with the high quality Violectric V200 headphone amp, which allows precise volume regulation with its pre-gain-function. The resolution of the RP-21 is at a good to very good middle class level, only when it comes to high-frequency sounds, like brass or cymbals, are there any reservations. Still the difference to the AKG 271 MkII is not as big as one might have thought. The RP-21 is even as good as the AKG regarding the spatiality. The RP-21 pushes the bass and low medium notes a bit harder, though even here it’s rather low-key. All in all, it still sounds balanced. And, if the user knows of it’s small bump in the low frequencies, it is also suitable for monitoring. The primary use though is surely in recording and, in this regard, we have come to appreciate it. For example, it is a big help when positioning microphones, since it is difficult to distort the transducer, and therefore makes locating the best microphone positions easier.
