IBasso CF01 Bluetooth IEM Adapter Review

IBasso has been quite the talk here on MajorHiFi, where we’ve gone through the SR2, IT04, and the AM05. This manufacturer doesn’t just make headphones and IEMs though. This time to change things up a bit, I’m going to talk about the CF01, a Bluetooth IEM adapter. This isn’t the first of its kind, but wireless adapters for IEMs are still a new concept that only a select few brands have tried out. Now, IBasso has joined the club trying to make your high-end IEM’s a wireless experience, more popular of an image. 

There was a point where IBasso wanted to just make a true wireless earbud, but they decided against it for a few reasons. Mainly, why downgrade their current driver technology in order to support a smaller shelled design? Having a true wireless that drives as well as current high-end IEMs is almost impossible. Even when accomplished, the battery wouldn’t be able to handle the driver’s power, so battery life would be very small. So Instead IBasso has opted to design an adapter that just makes their current line of IEMs wireless. 

Packaging contents

What You Get

When looking at the packaging, you can get a good glimpse of what the wireless adapter is going to be like if you’re unfamiliar with how they work. You can see what the device actually looks like on the front of the box, which may already answer a few questions you might have about the adapter. Opening the box reveals the charging case, which kind of looks like a case for sunglasses. The only other items you’ll find are a handy manual and your USB charging cable.

In hand

Look and Feel

The adapters themselves are made up of these short wrap around cables attached to short stem receivers. The receiver rests on the back of your ear pretty easily and doesn’t cause much of a disturbance if you’re sitting still. Even walking around didn’t prove to be discomforting. They don’t seem like they’d be too comfortable on the outside, but the stem is compact and light enough to not be a nuisance. Using your high-end IEM as a workout earbud might not be ideal though. The charging case is quite large and will probably take up a lot of room in your pants pocket, but the CF01 is still easily portable in its case. A positive attribute of it being so big is that you can actually store the IEMs you have attached along with it. 

Design and Functionality

The most important thing to consider about the CF01 is that it uses an MMCX connection, so your 2 pin IEMs won’t be compatible here. IBasso’s own selection of earphones are probably the best candidates for pairing with the CF01, and that’s probably by design. However, if you find any IEM with an MMCX connection the adapters should still work. 

The CF01 features a Qualcomm QCC3020 chipset that contains the latest true wireless technology, as well as an amplifier chip that allows for a more powerful drive. I found that the volume control on my iPhone barely needed to reach halfway to get a good sweet spot in gain. The amp is able to control dynamic range quite well, though if you’re not a fan of a little hiss you might be disappointed. 

In terms of controls, the CF01 doesn’t exactly offer much. You get one button on each side that controls play/pause, skip, and phone calls. I would have liked to see some sort of volume control issued here, especially since the output can be pretty powerful. 


The connection goes without a hitch, as pairing is very simple and immediate. The CF01 supports SBC, AAC, and aptX CODECs and Bluetooth 5.0. Other forms of aptX and LDAC are absent here, but the CF01 still exhibits some high-resolution bandwidth with no dropout.


You’ll get 4.5 hours off a single charge, and 20 hours when considering the charging case. The device takes about 2.5 hours to charge completely and 1.5 hours for just the adapters themselves. You’ll find the CF01 has enough of a charge to get you through the day, and long trips might be made a bit easier now that you have your wireless IEMs with you. 

With IEM

Sound Quality

For this review, I tested various IEMs with the CF01. This includes the IBasso IT04, AM05, and the ever so revered Campfire Andromeda. For the most part, the CF01 does a fantastic job matching the fidelity of each earphone, including its soundstage, imaging, and overall timbre. Some IEMs can’t reach as much detail potential compared to a cable since the adapter can only handle a frequency response of 20Hz-20kHz. However, you’d need to be very analytical to spot the difference.

On the Andromeda, I found the image to be a bit thinner than what I’m used to hearing. Bass isn’t as present, and the sub-bass is mostly attenuated, though it still retains some neutrality. I couldn’t spot any major difference in the mid-range, the richness and clarity were still as excellent as usual. The highs have a tad more brightness to them but retained their sheen well enough. The soundstage was still just as layered, and maintained its fullness. 

The IT04 keeps most of its fidelity, and most importantly, keeps its grand soundstage. Again, the bass takes a small dive, the IEMs punchier nature isn’t as impactful here. In my review for the IT04, I felt the highs were a bit too tight, but when using the adapter they really start to come more alive and even show some airier textural qualities.  

Finally, there’s the AM05, which was probably the least affected by using the wireless adapter. The sound signature on its own is pretty neutral and analytical, and the CF01 mainly brings everything more forward when amplifying more of the dryer bands. 


I think the CF01 is a very worthy product. Being able to listen to your more prestige IEMs wirelessly is pretty novel, and with little in the way of dropped fidelity could prove useful to some. I’d imagine they’d be perfect for just taking a walk, or using them for your commutes. If this adapter is for making portability of IEMs easier than it more than does the job.

Pros and Cons

Pros: Fit, sound quality, Bluetooth, portability

Cons: No volume control, no LDAC support

The IBasso CF01 TWS Bluetooth IEM adapter is available at Audio 46

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Alex S. is a sound designer and voice-over artist who has worked in film, commercials, and podcasts. He loves horror movies and emo music.