Infinity RS 1B - How does the 'old dream speaker' compare to today's speakers?

@cleeds: While I heard the IRS once (Mike Kay of Lyric Audio brought his pair to the Stereophile Show in L.A. one year), the highest-level model I have lived with was the RS-1b (my first Infinity’s were the company’s entry-level speaker---the Model 1001, bought new in 1971. I lusted for the Model 2000A---with it’s RTR ESL tweeters, but didn’t have the $). If you find the Beta to be built to a standard you consider high end, I’ll take your word for it!

The planar-magnetic panels of the RS-1b are attached to their bases with mere wood screws, and the panels sway fore-and-aft with the slightest breeze. Paul McGowen has given his opinion of the woofers that came in the IRS bass towers (about the same quality as the woofers found in Tekton loudspeakers), and of the quality of the outboard crossovers.

One listen to the ET LFT-8b was all it took for me to decide to ditch the RS-1b’s.

Sounds like the IRS are still competing well with modern speakers. I would have guessed that they had fallen behind due to decades in material (and electronics) development). 

I echo @cleeds 

I have had owners of very high end (and very expensive) modern speakers listen to my Betas and walked out in awe!

Mine are also with the original stock diaphragms, woofers refoamed and replaced the Solen caps on the crossovers.

Wish I knew how to check the tune of the Servo Controller.

"updated" EMIMs are incoming followed by updated LEMIMs.  I am saving the originals untouched.

bdp24

... Infinity's were not built to high end standards.

Hmmmm, I bought my IRS Beta system around 1990 and it has been in use since then. I've refoamed the woofers a few times and repaired the servo/xover controller once. I have some spare NOS EMIMs as well as some upgraded diaphragms from Apogee Acoustics but I've never installed them.

Since trading a set of RS-1Bs on the IRS Betas, almost my entire system has been upgraded - some components more than once. The system has sounded better with each upgrade.

Demos I hear at my local dealer always sound excellent, but they don't outclass the IRS Beta.

There are good reasons that so many people keep these old Infinity systems running.

What replacement diaphragm are you using

I'm with @cleeds I own and enjoy my IRS Beta.  Been around many other great speakers and only kept my Beta and on my secondary system my Aerial 8b.

Replaced the Solen caps all else is in-spec! on the crossovers.

as an experiment I am getting spare EMIM's rebuilt with very modern diaphragms (not current copies of the originals).

I have purchased AVA replacement diaphragms just in case for the future and to sponsor AVA's dedication to the brand.

I bought Brooks Berdan’s personal pair of RS-1b’s in the late-90’s for $2,000, and sold them back to him in 2008.

Anyone contemplating buying any of the Infinity’s that contain the EMIT/EMIM drivers should be prepared to have some restoration done. Paul McGowan spent a LOT of money fixing his IRS’es.

From one who’s been there, before you buy a pair of RS-1b’s, give a listen to the Eminent Technology LFT-8b (and/or -8c). Imo a better loudspeaker employing planar-magnetic drivers, one whose drivers don’t fail. Infinity's were not built to high end standards.

Just in case you want to buy a pair of IRS speakers (IRSV fully refurbished and updated): https://www.youtube.com/watch?v=oXU9xIgv_DI

Interesting video by Paul McGowan of PS Audio.

I have only heard the irs reference speakers modded by ps audio at the ps audio factory.

Their listening room was on the small side for these speakers. If you have a large listening room, they could keep up with today’s flagship speakers or beat many of them.

Paul McGowan’s new Aspen FR30 ain’t beating that infinity, no matter what his sales pitch is.

I love line source speakers.  Keep in mind you must have a room they will work well with. Expansive sound means a larger room.

mark200mph

Have several irs infinity have rebuilt some of the ribbons rewired and changed to electronic crossovers.they are tri amped.that is one amp for woofers ...

The planar drivers in the Infinity IRS systems (IRS 1-V, Beta, Delta, Gamma) were not ribbons. All of the IRS systems were intended to be biamplified and were shipped with electronic crossovers that included an active servo system for the bass. Maintaining the servo is essential to get the bass performance for which these speakers are famous.

I heard the new IRSs when they were formally introduced.  It was the first truly mind-boggling experience I had as a young audio enthusiast (a developing "audiophile").  They single-handedly catapulted me into the arena of realizing concert-hall realism (quality AND quantity) IS possible at home. A 40+-year career followed, and continues today.

We provide performance mods for audio equipment and recently reworked a pair of modest Infinitys.  There is a replacement EMIT diagram that at least as good as the original.  

I can't image these being anything less that spectacular with the right equipment pairing in a large room.

Have several irs infinity have rebuilt some of the ribbons rewired and changed to electronic crossovers.they are tri amped.that is one amp for woofers and one for mids and one for tweeters. 200 hz to 5000 hz for mid frequency range.5k above for tweeter. If you buy a used set plan on doing this.new speakers many of which have ribbons for mids and tweeters.the ribbons are faster in response mass is momentum x velocity and the ribbons ie kapton or metal are light and move fast and are responsive because thier weight. Some have lower spl so many in line array increase spl. They have good horizontal dispersion but poor verticle.one more reason for line array.i like the sound of ribbons some like cones.find someone who has a set and listen.enjoy the music.

I have two pairs of RS1B woofer towers, and I have been listening to Infinity EMIMs and EMITs for decades. They are still pretty good but I needed a change after all these years so I have been listening to other speakers. I really like my Triangles and just stopped short of ordering a pair of Signature Deltas.

I mean the 'big' system Infinity Reference Standard IRS. 

The speakers in your pic aren’t RS-1Bs. It’s the big IRS system.

I owned the RS-1Bs for years, then traded them in for a set of IRS Betas, which I still enjoy and think is a much better speaker overall.