Last week during my stroll through the AES Conference in New York I came across a small booth with a tiny little device connected to a Sennheiser HD 800 on display. As it turns out it was the Radsone EarStudio Bluetooth Receiver. I was immediately drawn to the booth to try this unlikely combination of Bluetooth audio connected to a 300 Ohm open back headphone. After just a minute of listening I was hooked and convinced them to let me take one of their pre-production models home to test and review. Let’s take a look and see what the EarStudio is all about.
About The EarStudio
The Radson EarStudio Bluetooth Receiver was first introduced to the market through a very successful Kickstarter / Indiegogo campaign. This incredibly small device promises Hi-Res audio via Bluetooth connection. The initial fundraising campaign closed on October 12, 2017 and at that time the EarStudio managed to raise 550% of their goal according to the Indiegogo page. The popularity of this portable Bluetooth receiver is not surprising considering the elimination of the headphone jack on the latest iPhone models as well as rumors that Android devices may soon do the same.
Main Features
The Earstudio is a small device but it’s got an incredible amount of features. Here’s some of the most noteworthy highlights.
- 3.5mm & 2.5mm (balanced) headphone jacks
- 14-hour battery life
- Play, Pause, Track Advance and analog Volume controls
- Analog Volume Control (for extra volume after D/A conversion)
- USB DAC (connects via USB to any PC)
- Smartphone App
- 2 External DAC’s (AK4375a)
- Noise Free, Jitter Free using patented DCT technology
- Supports SBC, aptX and aptX HD audio codecs
- Can stream up to 48kHz/24-bit audio
- Weighs only 20 grams
- Device Firmware Updates
Build
Considering I only have a pre-production model of the EarStudio it’s tough to tell exactly what the final construction will be. As it is, the EarStudio is fairly typical for a small electronic device these days. The housing is made from relatively durable plastic and the buttons feel decent. If it were up to me though I’d want a sturdy aluminum housing or something that would last a very long time. The clothing clip could also be a little stronger.
I’m told there are several improvements that will be made to the final production including a brighter LED light. Overall it’s not to shabby when you look at what this device is doing.
Wireless Range
I tested the Radsone EarStudio Bluetooth Receiver in several settings and was impressed with the results. Indoors I found the wireless range to be easily 30 feet without any dropouts. This does require line of sight and the connection can break-up with obstacles in-between the receiver and the source.
Connectivity
The best way to test a Bluetooth device like this is out in the “concrete jungle”. Making my way to and from the office on the streets or the train I found the connectivity of the EarStudio receiver to be exceptional. In fact it performed better than average with no dropouts during my journeys. Like any Bluetooth device you’ll get some interference from intense Wifi hotspots and other RF.
EarStudio App
The EarStudio application for smartphones is a powerful tool that gives you all kinds of features including a comprehensive band EQ as well as predetermined EQ settings. On the Home tab you’ll find volume controls, battery level and sample rate on the incoming signal. In addition there’s a Sound Control tab that allows you to run four different roll-off filters on the AK4375a DAC chip. This is a very handy feature.
It’s Not Just A Bluetooth Receiver
The Radsone EarStudio isn’t just a simple Bluetooth receiver, it’s also a USB DAC and amplifier. Connect it to your computer and you’ve got a powerful soundcard that will likely sound better than your built-in audio output. And it’s capable of powering your higher impedance headphones. In addition, the EarStudio can be used as a receiver for your non-Bluetooth devices. I plugged it into my old Apple iPod speaker (with 3.5mm input) and streamed high quality music directly from my smartphone.
How Does It Sound?
Getting down to the most important part I decided to break down the sound output of the Radsone EarStudio into different sections to reflect the aspects I found to be most important.
Using 3.5mm Jack
When using the 3.5mm headphone jack with an assortment of headphones (from Audio Technica ATH-M50x @ 38 Ohms to Beyerdynamic DT-1770 @ 250 Ohms) and the results were quite good. To my surprise the quality of the audio coming from the EarStudio sounded even better than the audio from my smartphone’s headphone jack. Maybe it’s the 2 external DAC’s or DCT technology but whatever it is I like it. The best way to describe the sound coming from the EarStudio is “clean and smooth”.
Using 2.5mm Jack
When I tried the 2.5mm headphone jack I was limited at the time of the test so I used a Final Audio Fi-BA-SST25. Once again the EarStudio sounded amazing. Clean streaming audio through a balanced 2.5mm output. Very nice.
Output Power / Volume
In both instances, the output power was very good. I find that many Bluetooth devices have trouble getting ample volume but the Radsone EarStudio kicked out serious volume. As demonstrated at the AES Conference, the EarStudio Bluetooth Receiver could confidently power most headphones up to 300 Ohms.
aptX vs. SBC
When sampling the sound quality of the EarStudio streaming from the aptX enabled DAP I found just what I expected. With aptX connected I got increased audio quality and even a perceived volume increase as well. The Bluetooth range suffers a little (as always) when streaming via aptX but the sound quality is quite good.
Final Analysis
In conclusion I found the Radsone EarStudio Bluetooth Reciever to be a really impressive piece of gear. And considering this one is only a pre-production model I’m hopeful that the final product, which due for shipment in November 2017, will be well worth the money spent by faithful funders of the Kickstarter campaign. I do think the casing could be built to be a little bit more sturdy but considering the incredible sound quality I can’t complain too much. The overall quality of the sound, output level and connectivity were all on-point. But the best part about the EarStudio Bluetooth Receiver… is the size.
Crowdfunding disclaimer:Â P.S. Please note, not all projects hosted by crowdfunding platforms come to fruition. Before making a purchase you should read the FAQs of the hosting platform as well as our article on the risks associated with investing in a crowdfunding projects.
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