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Question: The RS 180 doesn't have surround sound, and the RS 170 does.  SS is great for TV viewing. Why was this not a deal breaker for you?
Document: Surround option is decent but just Dolby Headphone isn't bad either. And RS 180 has better bass quantity and quality than RS 170 anyway, partly due to the velour ear pads though. The HD 598 is like marginally better than RS 180 except for thumping bass but then the bass with everything nearly as good makes the RS 180 a clear winner if you can afford it. Especially since it is wireless.But all this was with the Lehmann amp which costs about 750 pounds.
Awesome sound! The Sennheiser RS 180 Digital Wireless Headphone System has been one of the most worthwhile purchases I've ever made. Because our TV viewing area is open to the main part of our home and my dear husband seems to be a bit hard of hearing, this headset has been worth it's weight in gold. The sound is amazing for him and the peace and quiet has been wonderful for me!! The price seemed a bit high, but I wanted to invest in a headset that wouldn't compromise sound quality.
I bought this headphones for our TV. The RS 170 was reported with a delay between the headphone and the TV sound so I decided to go with the RS 180. In fact I couldn't recognize any time delay in the sound.The sound in general is OK as well as the comfort wearing the headphones there is nothing to complain about.I gave 3 stars because the price/quality relation seems to be significant imbalanced.
After reading other reviews I chose the Sennheiser RS 180 headphones for TV viewing. The noise-free clarity of spoken words was just as I had read about, and they are extrememly simple to operate. The head set is light for its size and quite comfortable. I saw some comments that suggested that it was best for spoken word but I have been satisfied with the music quality as well.
I bought this Sennheiser RS 180 Wireless Headphone System for my husbands Christmas present.It has the sound of surround sound.They have the clearest sound with no back ground noise.I highly recommend them.I also bought an extra set of Sennheiser HDR 180 for myself that works off the same transmitter.The sound is great.
Despite Amazon lists this item as "Sennheiser RS180 Digital Wireless Headphone System with Dynamic Surround Sound", this is NOT the model with surround sound. If the surround sound feature is important to you, RS 170 is the one you want.I purchased the RS180 from Amazon. No until I openned the item, read the manual, and confirmed with Sennheiser's website, I realized that Amazon made a mistake on listing it as "with Dynamic Surround Sound".
Sennheiser made no claim to have surround sound feature in the manual or their website for the RS180. Unlike the RS 170, the Dynamic Bass Boost & Surround Sound on/off buttons do not exist on the headset. RS 170 is the one with Dynamic Bass Boost and Surround Sound simulation features.Amazon promptly accept our return request and we placed the order for the RS 170. Good customer service! Hope they fix the listing title soon. Very miss leading.
I am not an expert on headphones but I can only tell you my experience with the RS 180 Digital Wireless Headphones. When I was searching for the headphones, my requirements were long charge life: I used the RS 180 viewing movies and listening to music for more than 12 hours and no sign of power loss or sound quality but now and then you hear a break in the sound for just a half a second; not an issue.
I own both the 170 and 180's and use them for different reasons. The headphones for the 170's block out a bit more ambient noise than the 180's and I use them when I need to block the world out a bit more. For anyone looking, I use the base for the 180's to transmit to both the 170 and 180 headsets. I have never tested if the "extra" features of the 170's (surround and bass) actually work in this configuration.
Pros: I enjoyed the RS 180 a lot after connecting it to my Blu-Ray player. Comfortable and great sound qualityCons: It takes a lot of use to be able to adjust the volume without having to take the set off of your head and it is notvery obvious how to have them work for TV broadcasts, also
Answer: Two reasons;  One, the RS-180 has ALC instead of "Surround".  ALC is Auto Level Control.  It makes quiet things louder and loud things quieter to even out the volume.  Very nice when you have a hearing problem or you want to keep the volume at a minimum for whatever reason.  Such as sensitive ears or wearing these headphone in bed next to a sleeping person.Two the 170's don't really have surround.  They imitate surround sound by delaying certain sound frequencies and other subtle adjustments.  It's called Psychoacoustics, look it up on wikipedia for a good explanation.  It's the same thing the Bose Wave Radio does, listen to one next time you're strolling through target.  It's a very different sound.  Some people, like me, intensely dislike the manipulated sound that comes from psychoacoustics.  So the 170s aren't a good fit for people like me.  On the other hand lots of people (most?) really love that sound.   There is nothing wrong with psychoacoustics, it's a great thing and for most people it's very enjoyable.