Sennheiser RS 40 wireless and RF headphones

In case anyone was looking at these cans(headphones), here is my experience of the Sennheiser RS 40 wireless RF headphones.

Well I saw these puppies on sale for a very cheap price of $70 so I figured I'd grab them. Practicing drums with headphones was becoming a major pain with the wire always getting in the way. Wireless... and from Sennheiser no less. A very well respected name in headphones and microphones. For $60 at Tigerdirect.com ($I30 MSRP) I figured I'd give them a shot as my first entry into wireless headphones. The order went smooth and I got the headphones as advertised.

First here are the specs of the headphones:
Open Transducer
Frequency: 900mhz RF
Wireless range: 100 meters (line of sight)
Rechargable battery approx 4 hours play time at medium volume
Jacks: 1/4" and 1/8"
Frequency response: 20-20000
THD: 7%
Noise: 68 dB
Light weight

Well here is what all that means in real life.

-Open Transducer
Open allows sound to come in and out. I prefer open air over closed since I want sound to escape out and not reverberate. In this case I also want to hear myself play drums or guitar.

-Frequency: 900mhz RF
Now here comes a major problem and my main beef with these headphones. All but a very few wireless headphones are 900mhz RF. 900mhz radio frequency is what most wireless items use nowadays use. It is prone to alot of noise and interference. These RS 40's were decent but the RF intereference was a problem from time to time and caused static noise. It wasn't a big problem but if I moved around alot, I would often run into interference. In a rare occasion I may have to move my head to find a clean patch with no static. Very annoying. Still, thats part of the give and take with wireless RF electronics.

Wireless range: 100 meters (line of sight)
100 meters? Maybe if the stars are right, planets are in alignment and the moon is full, etc. Basically this means NO. I could not walk a football feild away without losing sound. More like half that. 150' clear line of sight. Now the cool thing with RF is that it will pass thru walls and solid objects. I found that going to my 2nd floor or 3rd was not a probelm. It did drastically reduce the range as expected. I'd say about 50-70' with a wall or 2 in the way.

Rechargable battery approx 4 hours play time at medium volume
This would be about right at medium power but these are not very loud headphones. You will be at 75%-90% volume most of the time. I find the battery to be good for about 3 hours of play time while I play at 90% volume. Not bad.

Jacks: 1/4" and 1/8"
Standard deal. You know the little stereo jack and the big fatty adapter.

Frequency response: 20-20000
THD: 7%
Noise: 68 dB
OK well this all equates to sound quality. The sound quality was not bad at all. Very nice bass and treble considering. The mids were not so sharp. Muffled and far away. I don't like that but its a problem with alot of the cheaper audio equipment nowadays. The overall sound is solid but dark. Good for what it is; that is low-end cans converted to be "tamgle free". The noise is a problem though. I don't know if its due to the possible low power usage to save the battery or cheap transducers or the RF or a little of everything, but the noise is pretty bad when the volume is turned up. Playing no music and turning the volume up high shows alot of noise. If you pull the volume back to about 90% it becomes tolerable but silent parts of a song you will hear it. Its a definite problem if you wanna watch a DVD movie loud. The quiet parts of a movie will have a constant slight static. Luckily I never use these to watch movies. Now the noise is almost unoticeable at 80% volume or lower but I like my music loud. I tend to use them at about 75%-85% volume. The noise is not too much of a problem at that level.

Light weight
No problem here. Very light for full headphones. Comfortable too.


Overall opinion:
Overall, for the price I got them and the conveneince of being wireless, they are a good deal and, although I may not sound like it, I am satisfied. I am satisfied with what it is. Cheap headphones made wireless. They serve their purpse and do it moderatly well. The sound is satisfactory to the average listener and the street price can very welcoming for an entry into wireless headphones. I would recommend them for under $80 but not over. Over $80 I would not get these. If you need a pair of inexpensive wireless headphones, these seem to be the best buy for under $100. The few others I tried in a music store weren't all that much different until you spent over $200. They all had the same amount of drawbacks IMO. Now if you don't need the wireless and wired cans are ok, then I do not recommend getting wireless headphones AT ALL. Wired cans are much much better for the same amount of money.

I have tried much more expensive wireless headphones at the audio store. The most wallet burning model was the top model sony's that were over $450. I am not a big fan of Sony headphones but they were very good. High quality cans with a more powerful RF transimitter, but still... prone to the weaknesses of the RF design like interference. Now my next move is digital. Its a new wireless technology that uses an RF signal, but to send a digital signal that is decoded by the headphones. This means good sound or no sound. From the reports from reliable audio reviewers (no CNET/ZDNET moron paid reviewers but real audiophile reviewers) these were supposed to have a much cleaner sound without the typical noise and static problems of normal RF headphones. Advent makes a pair for $130 that I will probably buy. That is only 1 of 2 currently for sale that I am aware of that uses the digital technology. I'm sure the big boys are in production but until then, I will buy the Advents. They are another respected name in speaker/headphone labels.

until then, hope this sheds some light on wireless headphones.

<A HREF="http://www.sennheiser.com/sennheiser/icm_eng.nsf/root/8B0294CD5C202135C1256C3B006623EA/$File/04524_pro1.jpg" target="_new">view pic</A>