Infinity Speakers crap or cool

It sounds very much like a poorly aligned enclosure for the driver. I few things though :

With your sig gen do a signal sweep (30 - 150 Hz ) with a 4 - 8 ohm resistor in series with the speaker and monitor the signal voltage across the resistor with a CRO or wideband DVM. If you're looking at a driver / enclosure resonance then you will see the signal voltage rise to a maximum at resonance (ie. 60Hz) and with basic math you will also be able to calculate and plot the impedance Vs frequency. This will merely confirm whether or not the perceived peak is actually a resonance. If it is, then getting around it with a passive notch is probably not a viable solution. Firstly, you would need to flatten the impedance by conjugate load matching and to make a sufficiently high Q notch / low loss correction filter the caps and inductors would need to be unreasonably large and expensive.

I'm not familiar with the Kappa 5 but if the LF enclosure is ported then you could experiment by blocking the port with a pair of socks (or something similar to stop the air flow) and then conduct the impedance sweep again and note changes. This should modify the alignment to something more like an overdamped acoustic suspension and will make it far easier to integrate to a sub woofer.


good luck

 

You can do a lot better for the same amount of dough. These things are made in China. Infinity is *NOT* the same speaker company it once was, pre-Harman International.

If you are in the $650.00/pair price range, I would look at models from Paradigm, Mirage, PSB, Energy, Triangle. NHT too, although they, apparently, have moved their manufacturing "offshore" as well.

 

Did the "Q" series sound good? Occasionally I see a pair of Qa, Qb or Qe's on Craigslist or whatever; I lusted after those in the '70s, but never got 'round to affording them back then. I imagine the reason I liked them then (uber-detailed tweeter) might be fatiguing to me now. How was their midrange?

 

I had a pair of Quantum Jr., which is the sound I referenced against for the rest of my life. Yes, I do remember how they sounded. The EMIT tweeters were Peerless, and when Peerless dropped that line of tweeters, there was not a replacement, so Infinity started making the Cerwin-Vega-style speakers. I had a chance to buy a case of the things, and stupidly didn't. They also had the Watkins woofer, which was wonderful. Infinity WAS great, but in later years they became less than they were, nothing really special.

 

I have and have had many pairs of Infinity speakers

I'm currently in the middle of restoring/modding a set of Quantum 2's from the late 70's



which are going to take the place of these RS IIIa's (which i also restored/modded)





all speakers are a personal taste...

 

I once bought a pair of Infinity towers to replace my Technics SB-L80s (don't recall the model) but they were 3-way floorstanders with 15¨woofers and they didn't sound any better than the Technics !!! Little bass from the massive woofers and matte sound. I returned them and kept the Ts for years thinking I should spend a fortune on speakers to upgrade the sound. I returned them asap.

Thanx to PWK that wasn't the case. My Ts cost U$ 400 in 1993 and the Ks U$ 700 in 2008

 

probably the SM series...they were cheap...known as the keg party line of speakers...

 

Yep they were SM series. Looked terrific; sounded no good.

 

I had a pair of Quantum Jrs in the 80's as my first step up to a quality system.

Beautiful speaker and gorgeous sound.

My problem was that they were paired to a low powered Sansui receiver and they were subjected to clipping and EMIT tweeter burnout in my attempts to push them to 'concert level'.

A hard lesson to learn - took several lessons sadly.

I'd love to get a set of Jr.s to pair now with my MF int amp.

 

Crossovers in decent speakers, which I assume these probably qualify, are typically tuned for the acoustic and electrical characteristics of the specific drivers being used. Neither crossover is going to match a non-original woofer, but the RSjr crossover will at least be tuned for the RSjr tweeter. So I guess that one? But you'll get the most reliable answer by trying both and listening with a variety of music to listen for missing or boosted frequencies in the upper midrange and lower treble.

To answer the original question, I got a pair of Infinity Reference-3 to take to college, and I thought they were great at first (I picked them out, after all). Later I felt they were lacking in bass and could be quite shrill, plus they were difficult to drive for my Yamaha integrated amp, 100wpc into 8 ohms. I think the low impedance was the trouble there. One day I went to the electronics supplier and got some high power resistors (somewhere in the 1-4 Ohm range), and put them in series with the speakers. That had two effects: I could turn the amp up much louder and have the speakers actually play louder, and the low frequency response of the speakers really fattened up. Later when I learned more about loudspeaker design and modeling, I figured out that the change in the bass was because the resistor reduced the effective damping of the woofer. But at the time, all I knew was that the speakers sounded better and played louder. Eventually, in the course of college use, that led to one of the tweeters getting fried. Shortly after, I replaced them with Vandersteens, which sounded MUCH better and were much easier to drive (without my custom in-series power resistors).

 

Thanks!
Bargain! I'm happily using Infinity 360's now.

 

And I like the way your post jumped 10 years!

 

To me, the metal dome tweeters Infinity uses are too harsh, piercing almost. The silk dome tweeters are pretty nice. Go give a listen, there are worse and of course better speakers.

 

One of the best systems I ever heard was a friend's large pair of Infinitys (bought cheap on a divorce sale) powered by B&K mono amps. Absolutely liquid midrange. It delivered the most convincing guitar sound I ever heard.

 

I got a great deal on a demo pair of kappa 8's in the late 80's. They didn't come alive until I got a high current amp about a year later - van alstine omega II. They are a musical speaker but they are not the last word in resolution. I still have them as my back channel speakers. I had the woofers reformed a few years ago

 

Some interesting observations... I actually find the current Infinity metal tweeters to be soft in the treble...I have owned Primus, beta, Interlude, and alpha series...all of which incorporate a version of this tweeter...and bright is the farthest adjective from my mind. If anything, the mid-bass is overly exaggerated at times, which can give the impression of bloat. The Primus series are the most balanced in this regard. That being said, Infinity offers good value (especially second hand), and the bass can be rectified with a decent sub. I would avoid the polycell tweeter models from the 80s/90s.

 

Brings back some memories of when I worked at a Stereo store in the late 70's/early 80's that sold Infinity Speakers. We had several different models, but we had a love/hate relationship with the big floor standers. They sounded very good with good source and a really good amp. The problem was that the amps we sold at the time weren't really up to the task. We'd hook them up the the big Phase Linears (we called them Flame Linears). They would be very good for awhile, then almost invariably either the amp would blow up or some of the Drivers would let go. Sigh...

Would have been nice if we had better amps, but it was a decidedly Mid-Fi store at the time. I think they had potential. Haven't heard any Infinity's in many many years now.

 

When I was in high school I loved the SM120s and SM150s. Of course I quickly threw them over for Snell and Vandersteen. Back then I didn't have the room or money for the big Klipsch I really wanted.

 

Giving away my RS1.5s is still my biggest regret in my audio life. Right there with my JVC A-X9 which drove them brilliantly, and my X-1000R. I went totally brain dead when I downsized after getting married.

 

@BK Photo: I am interested in your Q2 restoration, I have a pair of Q3's that I'd like to restore. Prive-message me when you have a chance. I'm nearby in Queens, NY.

 

ps: the last great Infinity speakers were made 20 years ago, but they dont come cheap:

http://www.ebay.com/itm/INFINITY-IR...978659?hash=item3d10ce9363:g:NmoAAOSwjVVV5T~g

 

I have a pair from the late 80s and they sound wonderful. I redid the foam surrounds and they now sound different - still good but different. The two are used are rear channels in a 5.1 setup. I have 100 watts per channel so they never go hungry or a wanting for power fed them. Truth be told my speakers do not sound as great when played at low levels after refoaming. They no longer have the effortless sound, and need to be cranked up good and loud to bloom like I like them to. But with some juice applied and a good source like vinyl or DVD-A, I have no complaints. No desire for an upgrade at this time.

 

Never heard a pair, but I think these are cool . . .

 

I used to own Reference IIIb's and they made for nice sounding speakers when I owned them, especially once I hooked them up to a powerful amp, as they like a LOT of power!

 

Primus 363 is one of the very best values in audio today!