“Mighty Bass” says the prominent label on the box for the Panasonic RB-M700B headphones. Underneath that, “Basses Pusissantes”, which is of course French for “Mighty Bass”. Think Panasonic might be trying to tell us something about the intended market? Especially when you add in something called the “Bass Reactor”.
About: Panasonic is a Japanese company established in the early years of the 20th Century. It has been a strong presence in Australia for many decades.
About the Panasonic RB-M700B Bluetooth headphones
The Panasonic RB-M700B Bluetooth headphones are the top of a new range of three models on the verge of being rolled out. The higher up in price, the more the features and the shorter the battery life. The $229 RB-M300 headphones are rated at 50 hours of battery life. The $269 RB-M500 headphones get the Bass Reactor and only 30 hours, while the Panasonic RB-M700B headphones add active noise cancellation and the battery life shortens to 20 hours.
A USB Type-C connection is used for charging. It can add 1.5 hours of run time with a 15-minute charge.
The headphones use 40mm “Free Edge” drivers. The website describes these as using “a highly elastic nanofiber diaphragm to generate serious bass response with maximum precision and minimal distortion”. Hmmm. You do not want your headphone diaphragm to be elastic. The design aim must be for maximum stiffness, otherwise it will not faithfully follow the signal. Marketing speak I guess.
I gather than the “Mighty Bass”, or “Deep Bass” or “XBS Bass” as it seems to be variously called is a design feature of these headphones. The “Bass Reactor” is something extra. I’m not sure if it uses a separate actuator or simply pushes the drivers harder, but it adds a vibration that you can feel through your fingers if you place them on the earcups. A rocker switch provides for three levels or off. Note, the 20-hour life is for ANC on and Bass Reactor off. Expect a shorter life if you use it.
Panasonic RB-M700B Bluetooth headphone connections
The Panasonic RB-M700B Bluetooth headphones used Bluetooth 5.0 to connect. They support the standard Bluetooth SBC codec, but add the Apple-friendly AAC codec for higher quality. (The battery life is specified for SBC, not AAC.) Panasonic says that the operating distance is “Up to 10m”. It is being way too modest. I paced out perfect reception to 45 metres in my usual measuring spot.
Of course, the Panasonic RB-M700B Bluetooth headphones have a 3.5mm input so you can use them when the battery is flat. If the battery is not flat, you can switch them on even with the cable connected. Bluetooth won’t work, but both the Bass Reactor and active noise cancellation do. The latter is important for use on a plane.
A hard slider switch is provided for active noise cancellation on the Panasonic RB-M700B Bluetooth headphones. I like that. It means that you can have the headphones switch on with ANC either on or off according to your preference.
A voice prompt is used for certain things. In particular, the battery level is announced whenever you switch off the headphones. That makes for a convenient reminder when it gets low.
The effectiveness of the ANC
There is no flying these days, but in the hope that we may one day be able to do that again, I played my standard in-flight noise test on my desktop speaker system. Average level 100dB, slow meter settings, C-weighted. The noise cancellation was fairly strong, bringing down that oppressive noise level to something far more tolerable. It was far from class-leading, but still effective. In quieter environments it did produce a clearly audible hiss when in operation. That, combined with the occasional clunking of the drivers when the headphones were subjected to a shock while ANC was working, inclined me to have it switched off unless significant external noise needed to be dealt with.
Listening to the Panasonic RB-M700B Bluetooth headphones
First things first. Bass reactor? No, I’d strongly suggest. In fact, the essential sound signature of the Panasonic RB-M700B Bluetooth headphones was already one of quite strong bass. They did not need that additional vibration.
Let me clear about this: it sounded as through the whole frequency range was in balance – mids and trebles were good, and indeed for quality classical music, were actually quite sweet and pleasing. Except, that is, for a significant bass boost. And not an even boost. I’d say the octave from 40 hertz to 80 hertz. How much? I’d estimate about ten decibels, perhaps more.
On the album Script for a Jester’s Ear by Marillion, for example, the kick drum and bass line was up very loud and easy to follow, although the bass sometimes seemed almost monotonal, punching the bass as far forward as it was.
I didn’t like it. There’s no adjustment available, except perhaps in your phone’s music player. I found that the bass overwhelmed the music much of the time and, for me, made for a tiring experience. But I think that’s because these headphones are not designed for the likes of me. I want high fidelity headphones – that is, ones that reproduce the sound accurately, as it was recorded. If I did too much listening with these headphones, I feared that my ears would be recalibrated to these headphones, and thus make other equipment sound bass deficient.
Using the connecting cable, the sound was very different and quite inferior. The bass was not as prominent, but a lot of definition was lost in the midrange, making the sound somewhat hollow.
Gadgetguy’s Take – Panasonic RB-M700B Bluetooth headphones are for a particular market
Look, these headphones aren’t for me. But I have no doubt that there’s a strong market for them. Many people look for bass above all in their sound gear and I think those people will quite enjoy these headphones. They will benefit for a comfortable fit, very nice build, effective noise cancellation and a superbly stable connection.
You can read our coverage of active noise cancelling headphones here.