Virtually all headphones work using air conduction, that is by creating sound waves that spread through the air and hit your ear drum. If the volume is too high, the hearing damage can occur. The Rumble K (as well as other Pineapple Electronics' headphones) feature bone conduction. In Rumble K, the mid and high frequencies (treble) are produced and transmitted using air conduction, but the bass and mid frequencies are produced in a separate BCT unit and are being transmitted through the skin and bones directly to the middle ear. Not only does this potentially reduce hearing damage from playing music too loud, it also creates a different sensation, most beneficial when playing computer games, watching movies and playing bass-heavy music.
I usually employ inexpensive headphones. My "collection" includes models such as Sennheiser HD201, Sennheiser HD202, Koss KSC75, Koss SparkPlug, Philips HS500, Creative EP-640, etc. Being completely new to the bone-conducting headphones, I was intrigued. After a nonstop 45-hour burn-in in my iPod connected to the AC jack with a power adaptor, I was ready to test the Pineapple Rumble K.
About Pineapple Rumble K
The Pineapple Rumble K is an in-ear headphone with a Bone Conduction Transducer for bass and midrange combined with a conventional mid and treble Air Conduction speaker. The BCT unit is rather large and rests on the outside of the ear canal, while the ear bud is in the ear canal. The hybrid silicone rubber ear buds provide a secure fit and good sound insulation. The lack of ports in the back of the headphone further contributes to sound insulation.
The headphone comes with three sizes of ear buds (medium pre-installed on the headphone, large and small supplied in the box). The headphones are black, look stylish and have replaceable ear pads (see above). The fit, finish and build quality are great.
Some specs from the box: 20-20,000 Hz frequency response, impedance of 7 Ohms, rated power of 5-12 mW, 55-inch unbalanced cord with a 3.5-mm gold-plated plug for use with portable gear. A leather carrying pouch is included.
Relatively large and hefty, the Rumble K has ear buds that are located at an angle to the BCT (bone conduction transducer) unit. I used the silicone ear buds that the headphone came pre-attached with (medium size). The good sound insulation and comfortable fit were immediately apparent.
I have played a variety of music through them, including classical, Euro-dance, pop, rock, electronic music, rap, audio books. I also listened to movie soundtracks. I used my iPod, a CD player and a laptop. For comparison purposes, I also alternated between the Rumble K, the Koss KSC75 and Creative EP-640.
I immediately noticed the low sensitivity of the Rumble K. Vibrating the bone through the skin probably requires some significant energy and I had to crank my iPod up to about 85-95% of its maximum volume, whereas I normally use 65-80% with my other headphones. The portable CD player I used at times required 100% of the volume (depending on material).
The headphone sounded warm, featured good bass, midrange and lower treble, but limited upper treble. It sounded open, even though it is technically a sealed in-ear design. The Rumble K did not struggle with complex music. But the frequency response is a bit uneven and that made me hear some instruments in my classical music recordings I haven't heard before, but also mildly suppressed some others.
The sound overall was somewhat similar to being at a rock concert or in a club. The Rumble K worked very well with rap, producing excellent bass that was not only heard but felt as well. And I could crank it up without fear for my hearing, which is a definite plus. I had to use my Panasonic SA-XR57 receiver's headphone out for that though, since my portable CD player couldn't play very loud with the Rumble K.
The movie playback was excellent. The excellent bass combined with bone conduction produced an almost 3-D effect. Explosions and car chase scenes were the best ways to experience the new technology.
While alternating between the Rumble K, the Koss KSC75 and Creative EP-640, I noticed that I preferred the Rumble K when watching movies and sometimes for listening to rap. For general music listening at lower volumes though, I prefer the Koss KSC75 (over the ear) and the Creative EP-640 (in-ear design). But if I listened to loud music with a lot of bass, or while being on an airplane, the Rumble K would work very well because of its good insulation, powerful bass and vibrating BCT. Reduced chance of the hearing damage is also appealing. Lots of bass with low ear drum pressure via the patented Sonic-Vibe EX technology cannot be beat in this application.
The Pineapple Rumble K comes with an impressive 10-year warranty. They are well-made and should be durable.
Pros: Lowers the chance of hearing damage, powerful bass and vibrations, good for movies/games/rap
Cons: Uneven frequency response and treble
The bone-conducting Pineapple Rumble K provides powerful loud bass while reducing the chance of hearing loss. It is ideal for watching movies, listening to rap or for listening to movies/music while traveling by plane. It might also be a great investment if you already have some hearing loss.