Infinity RS-IIIa manual, and official recommended amp specs

So, I'm going to drive over 1000 km (600 miles) tomorrow to pick up a pair of beautiful Infinity RS-IIIa speakers. Very exciting to get these babies home

Would anyone have or know where to get the manual (electronic version or paper copy , anything goes) for these speakers?

In particular, my current amp is at lower end (Onkyo TX-8522), and I needed to know what were Infinity's original amp requirements. I see that on the page #4 of the RS-IIa/b manual Infinity states that the amp should deliver "between 75 and 400 W per channel into 4 Ohms" when driven by a single amp (not bi-amped). So what are corresponding specs for RS-IIIa?

The RS-IIIa spec sheet simply states that the speakers are 4 to 8 Ohms, and power is 50 to 200 W. But I would like to get the more specific info available on the manual itself.


Now, my current Onkyo is only an entry level receiver, but it has been designed with good 2 channel audio in mind. The official specs are as follows:

100W / per channel minimum continuous power across the whole frequency range at 8 Ohm.

Dynamic Power
North American:
170 W + 170 W (2Ω)
135 W + 135 W (4Ω)
140 W + 140 W (8Ω)

So it looks to me that my receiver should be safe for RS-IIIa's. Far from perfect, but at least I won't be breaking the speakers if I stay say below 12 O'clock in volume?

My Onkyo also has this WRAT tech, which seems to have been designed to handle rapidly varying impedance loads with grace.

Also, for what I have read, RS-IIIa's are not as demanding amp killers as the higher end RS's. The woofer's are in series, and are not Watkins type.

For what I have read, these Infinity's need to be 'controlled' for them to really show their full potential and for that one needs close to 200 Watts of effortless power at 4 Ohms. One day I hope to be there, but for the moment I need to stick with my current Onkyo.

You should be okay. They will do better with some head room though if they are anything like the II's which have the same woofers. An amp with more current will tend to open things up and that zoomy midrange will calm down a bit. Enjoy what you have and keep an eye on the classifieds for a bargan ss amp that has a nice big power supply. Something in the 40-50 pound range will generally have a nice heavy ps. They would normally be 150wpc or higher. At four ohm the wpc should nearly double it's 8 ohm rating.

Great speakers btw. Well worth that trip...good luck!
Jim

Livin4 said:

Infinity Classics

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Lots of great info there but no manual, just a tech. sheet. I have several manuals for infinity speakers and most are the same yada yada yada as others. No fancy crossover or eq with the IIIa/b so really no need for more than what you already know.
Jim

Seppo said:

For what I have read, these Infinity's need to be 'controlled' for them to really show their full potential and for that one needs close to 200 Watts of effortless power at 4 Ohms. One day I hope to be there, but for the moment I need to stick with my current Onkyo.

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What do you mean by "controlled"? I run my IIIa's on an Onkyo Integra M504 with no issues at all. The IIIa's are not 'that' demanding in my opinion. I have ran them on a lower end Onkyo avr, HK integrated, Pioneer VSX-5000 etc with no issues at all either.

halo71 said:

What do you mean by "controlled"? I run my IIIa's on an Onkyo Integra M504 with no issues at all. The IIIa's are not 'that' demanding in my opinion. I have ran them on a lower end Onkyo avr, HK integrated, Pioneer VSX-5000 etc with no issues at all either.

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That's just what I read in some comments...I have no first hand experience.

I just got back from the trip and have the babies home. Will do some proper benchmarking tomorrow, and see how my Onkyo is able to handle them.

slimpikkins said:

Lots of great info there but no manual, just a tech. sheet. I have several manuals for infinity speakers and most are the same yada yada yada as others. No fancy crossover or eq with the IIIa/b so really no need for more than what you already know.
Jim

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Thank you @slimpikkins and everyone for your comments. Good to hear that the consensus seems to be that I am all set and not going to break things.

I just got back from the trip, and got the speakers setup. Will do some testing hopefully tomorrow. The space is tight, but for the moment that has to do...

OK, I have been playing with the system today, and have to say that I am very positively surprised. The speakers of course are great, but it turns out my humble Onkyo is able to drive them very well. After 9PM volume the power just keeps on coming, and I never had to go beyond 10PM position. At that point the amp was delivering living room full of effortless power with no need for more. And I like my music loud. Unbelievable. Dire Straits, Pink Floyd, Bryan Adams, Avicii all sound great. Beautiful, airy mid- and high range, and excellent, tight, but not boomy bass. I am one very happy camper

Looks like you have them fairly tight to the wall, and in around the TV.
Mine have no WAF, so they have been banished to the Cave for ever.
I have found they don't like being against a wall or in a corner.
If I'm in a real listening mood, I put them as pictured, out in the middle of the floor, about 6 feet apart, toe'd in just a pinch, make sure you can walk around them from any direction, and let'm rip. The sound stage is incredible.
If i'm sitting, it'll about 6 ft in front, most of the time I'm working on something, so I'm walking around, and it's really cool, to walk in between them and around front to back as they are playing, it's like walking around on a stage in a concert, you can sense the music all around you. Really cool. :thmbsp:

my 2 cents Stu

I have a scan of the owners manual. PM me our email address and I'll send it to you.

srb02 said:

Looks like you have them fairly tight to the wall, and in around the TV.
Mine have no WAF, so they have been banished to the Cave for ever.
I have found they don't like being against a wall or in a corner.
If I'm in a real listening mood, I put them as pictured, out in the middle of the floor, about 6 feet apart, toe'd in just a pinch, make sure you can walk around them from any direction, and let'm rip. The sound stage is incredible.
If i'm sitting, it'll about 6 ft in front, most of the time I'm working on something, so I'm walking around, and it's really cool, to walk in between them and around front to back as they are playing, it's like walking around on a stage in a concert, you can sense the music all around you. Really cool. :thmbsp:

my 2 cents Stu

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Thanks for the tip. Wow, I moved my speakers away from the walls today, and indeed the sound got much better. These are just amazing speakers. I ended up spending 1.5 hours of my work day (I run my show from home) just listening to my favorite CDs. This hobby is dangerous for productivity And even the better half was impressed when she got home when I played her some of her favorite songs, sitting her down exactly on the sweet spot, at the focal point. This is how music is supposed to sound...

I have to keep the speakers in the corner most of the time (kids running around), but from now on for serious listening away from the walls it is.

I just received a reprinted RS-4b review (from 1986 Audio magazine) I ordered from eBay, and they say in that review also that these speakers are particularly sensitive to walls. At least 2 feet, preferably 3 feet out. Also the grille cloth should be removed (which I have noticed too). They also say that the distance between speakers should be slightly more than the distance from each speaker to the listening position. To quote: "...These recommendations apply to most closed-box speakers, but the RS 4B is of sufficiently high quality that the resulting benefits will be more dramatic..."...indeed.

I had this mind blowing listening session today. I spent the whole day working on my laptop on the couch, blasting Nightwish, Springsteen, Avicii at quite high volume levels but nothing too bad. I certainly noticed how my Onkyo got better at one hour mark or so, having warmed up. I previously did not really believe that, but have to say that the effect is for real.

Now, later in the afternoon I am listening to Avicii, and ramping up the volume, and again and again appreciate just how absolutely amazing these speakers sound (having moved them to the middle of the living room and listening and working from some 6 feet away on the couch). And then this tight, absolutely controlled bass hits in "Hearts Upon My Sleeve"...I stop working, move on the couch to a better position, and like in hypnosis crank up the volume, and then some more. And the sheer volume and absolute clarity of the whole dynamic range just hits me. I get goose pumps in the middle of this field of sound, and start panicking, not due to the volume being simply too loud, but the shear purity of the sound combined with the absolutely enveloping intensity causes this primal feel of something almost supernatural happening...after the piece is over I am happy as a clam...these RS-IIIa's are just amazing...I have never before experienced such an absolute pleasure listening to music on any home audio system, ever.

I know this sounds crazy to most people but thought that perhaps here I might find a few fellow souls to share my experience with...

And yes, a better amp is on my shopping list (perhaps Onkyo A9070), I want to see how much further these speakers can fly, they certainly have potential...

Shoot, dude, I'm with ya. Scoping a pair of those myself. (I have the 4b's, with a bad woofer refoam job and not proper electronics.)

This stuff can really grab you more than you expect, even if you expect a lot.

Congrats!

PS. Get a better amp and be done with it. Don't obsess too bad/too much. You know what that leads to...