A better pair of infinities- what to look for...

[thedelihaus]

I've got some Infinity Reference Threes, a nice three way, with the carbon-black cones and a polycell dome tweet.

They are a good looking speaker with a nice sound, good bass, and nice cabs. I'm not thrilled about the highs, but I'm pretty picky about the highs anyhow. And these are by no means bad.

My question is, what does a fella look for in an affordable Infinity? By affordable, let's say at average prices- not those great thrift finds, and not the occasional bloated ebay overprices. More of a fair price for seller and buyer. I know that can be elusive.

and by affordable, I mean working-class wages with family, mortgage, coolege fees and mouths to feed budgets. I'd say the sub-$100 range, $00-$200 range, $200-$300 range, and $300-$400 range.

The EMIT tweeters are a given, no?

What else? what about cone material? Model line? Holy blessings?

how does one get the most Infinity "bang for buck"?

Seems the Infinity line offgered a zillion models. More confusing then the Jensen period of Advent.

For reference (no pun intended- honest), I've seen my RS3s sell for anywhere from $50 to $150, usually the $80-$120 range.

Whether they are worth it or not, who knows. But if that's what they sell for, all the best...

[Arkay]

I'm sure others here will give more and better advice than I can, but currently owning four sets of vintage Infinity speakrs, having owned a couple more, and considering adding another set I've found, this is what I've observed/learned so far:

(1) As you say, EMITS are a given to look for. EMIT-K tweeters came after the plain EMITs, and are a bit better --they have stronger magnets and they seem a bit more durable, but all EMITs sound similar. The better Infinities have rear-facing EMITs, in addition to the front-facing ones. To sound best, though, these should be positioned 4 to 6 feet away from the back wall, for the reflected sound waves to properly do their stuff. Try to test the speakers before buying: a lot of people fry their EMITs by trying to drive the older Infinities with under-powered, modern amps. EMITs CAN usually be repaired, but it is much easier to get working ones in the first place.

(2) The translucent poly mids and woofers pre-date the black ones. All the translucent poly woofers I've seen are the dual-coil Watkins type; these are generally better than the single-coil ones that came later. Some early black woofers were also Watkins, but the later non-Watkins woofers are nowhere near as good. The way to identify these Watkins units is simply that there are TWO separate sets of wire connections in the back of the woofer, because they have two separate voice coils. Hard to see through the black cones, of course, uless you can remove the drivers to peek at their backsides [Ew, that sounds kinky!], but you can see these duaL connections through the poly cones, esp. with the help of a flashlight.

Incidentally, the translucent polys tend to get more opaque and white over time. You can restore their translucency simply by warming them up with a blow-dryer, like you use to dry hair with. Be a little careful, but don't worry; they do not melt very easily!

(3) The "RS" and "IRS" and "Kappa' designations have been recycled a lot by Infinity, including for automotive speakers, making names extremely confusing. [The "Beta" designation seems to have been less abused, so there are usually good, I think.] The BEST speakers from these series that I've seen --nearly always the earlier ones-- use either solid Oak or heavy and real Oak veneer for the cabinets. Some use solid fluted oak pieces along the front edges, and veneer on the flat surfaces. Of course, for the top-end IRS series like the IRS-V speaker columns, they usually used Brazilian Mahogany or something exotic like that, but speakers like those are so obviously high-end, you don't need any advice or help to identify them!

The later series tended to use oak-colored or black vinyl ""veneer", instead of real wood veneer. That said, some of those "vinyl" veneered ones still used good EMITs and decent polydome mids... but most I've seen have regular woofers, not the Watkins type, and Infinity's post-Watkins woofers just do not sound as good. Generally, the earlier good Infinities were Oak colored, and the later, crappier ones were black, probably to match the ubiquitous BPC... BUT some of the good earlier ones were available in Black Ash, and I own one good early pair that are in black-stained Oak, although I'm not sure if thiis was factory-original or an after-sale modification.

(4) The best early Infinities used the translucent poly Mids and/or the EMIMS. Generally any Infinity speakers with those -- and especially ones with EMIMs -- are good, and worth grabbing. Anything with ROWs of EMIMs are wroth grabbing, for certain. Others later on used the "polycell dome" tweeters and/or mids. IF they speaker has one or more large woofer(s), polycell mid AND EMITs, it will sound decent, especially if the woofer is larger (12"). Avoid the narrower models with two smaller (8") woofers in the fake-veneer cabinets; the bass on those is not so hot.... but they can be a source of mids, tweets and crossovers for a DIY upgrade, as it is only the woofers (and to some extent, the cabinet designs) that disappoint a lttle. That said, woofer size is not always a reliable indicator by itself: the bass on the early RS-III with the two 8" poly Watkins woofers is great! Oh, I should point out that those are a sealed-box / acoustic-suspension design (no port).

(5) Personally, I have mixed feelings about the "polydome" mids and tweets... they were used on some good Infinities, but also on some that I thought sounded disappointing. Some people swear by them, but I tend to prefer the earlier models with cone-type mids. I have one pair that came with replacement mids (AR, I believe) AND the original polydome mids, in case I wanted to restore them to the original state. After restoring one side and doing an A/B comparison, I decided to leave the replacement cone-type midranges in. As they say, your mileage may vary on this, though: I have another pair of Infinities with the polydome mids that sounds pretty good. If the speakers have polydome tweeters and NO EMITs, the high end will not be up to the level of the ones with EMITs. No domes can reach the frequencies that those Emit membranes can (in fact, only some ribbons or Heil units can come even close).

(6) Weight is also an indicator: all the best early Infinities are fairly heavy for their size. Unfortunately, a few of the later ones that dion't sound so great also have some weight, but not as much as the early, great ones. If it hurts your back to lift, it sure won't hurt your ears!

(7) If you have the time and can do so without losing out on a bargain buy, try posting on this board with a pic -- someone here will let you know very quickly if the particular speakers are good ones.

(8) I strongly recommend you look at Bobby Shred's website on Infinities and the German-based Vintage Infinity site, and study the pics there. [See the sticky thread on info sources at the top of this forum, or do a web search for the links.] All the models talked about on those pages are good ones, the ones you want to get if you can find them.

That's what occurs to me now (at nearly 3:00 a.m.). I'm sure others can add more, and correct any mistakes I've made.

[thedelihaus]

Arkay,

just what I was looking for. Thanks!

Here's a link to my quick review of the above mentioned Reference Threes (the single woofer model). Pics are included, a few posts down in it...

http://audiokarma.org/forums/showthread.php?t=66682

[birddog]

Hiya Deli! Just a quick thread-jack here to let you know all is set for tommorow, tests at Winchester at 7:30, then down the highway to BMC for more tests! See ya there!

[mywifespissed]

#5 Today, 10:09 PM
mywifespissed
AK Member Join Date: Aug 2005
Location: Everett, WA
Posts: 17

Hey thedelihaus,

I want to give you a heads-up on two great affordable older Infinity models. The RSa (2 way Emit w/ 10" woofer) and RSb (3 way with same Emit and woofer, but with a 5 inch poly midrange) are sweet sounding. Smooth, clear highs, and those 10 inch bullet-cap woofers make clean, deep and tight bass. NEVER boomy with a quality amp behind them. These are heavy, and have high-quality crossovers. You can expect to find them on Ebay, Audiogon etc. for between $120.00 and $250.00 a set. Some of Arkay's info. is not correct regarding woofers. Only the 12 inch woofers on Infinity RS1.5, RS2.5, RS4.5, better Quantum and Infinitesimel models had dual coil Watkins woofers. I'm sure the Watkins are more efficient, but they also dip to below 2 ohms at times, which can kill a lesser amp. and cause clipping, exposing those Emits to possible damage.

[thedelihaus]

#5 Today, 10:09 PM
mywifespissed
AK Member Join Date: Aug 2005
Location: Everett, WA
Posts: 17

Hey thedelihaus,

I want to give you a heads-up on two great affordable older Infinity models. The RSa (2 way Emit w/ 10" woofer) and RSb (3 way with same Emit and woofer, but with a 5 inch poly midrange) are sweet sounding. Smooth, clear highs, and those 10 inch bullet-cap woofers make clean, deep and tight bass. NEVER boomy with a quality amp behind them. These are heavy, and have high-quality crossovers. You can expect to find them on Ebay, Audiogon etc. for between $120.00 and $250.00 a set. Some of Arkay's info. is not correct regarding woofers. Only the 12 inch woofers on Infinity RS1.5, RS2.5, RS4.5, better Quantum and Infinitesimel models had dual coil Watkins woofers. I'm sure the Watkins are more efficient, but they also dip to below 2 ohms at times, which can kill a lesser amp. and cause clipping, exposing those Emits to possible damage.

You're from Everett, I'm now residing in Abington. I'd love to have you over for the refoaming party planned this summer if you'd like to attend. If not to re-foam, which is not mandatory by any means, than to meet up with some local AKers. You are more than welcome!

Yhank you for all your tips and info.

I've got to say, I have a burning desire to hear that famous EMIT tweeter, and must say Infinitys really deliver some outstandingly clean and robust bass, something I didn't expect when I landed mine.

I'm going to venture even their lower-end models are an outstanding speaker, regardless.

Thanks for the model names. I'll be attending many yard sales, flea markets, ect this summer, and it's good to know what to keep my eyes open for.

Thank you.

[mywifespissed]

Sounds good. Where is Abington? I know where Arlington is.

[thedelihaus]

Opposite direction of Arlington.

Near Brockton/Braintree.

cheers,

paul

[Kencat]

I've got to say, I have a burning desire to hear that famous EMIT tweeter, and must say Infinitys really deliver some outstandingly clean and robust bass, something I didn't expect when I landed mine.

I'm going to venture even their lower-end models are an outstanding speaker, regardless.

Thanks for the model names. I'll be attending many yard sales, flea markets, ect this summer, and it's good to know what to keep my eyes open for.



thedelihaus,

Study the Infinity-classics.de site, maybe even print the pages and make a book that you can take with you. The tech information on each model is very telling (I especially like the frequency ranges showing down into the teens and 20 something Hz's :music: ). Also tells which models have the Infinity/Watkins Woofer :thmbsp: .

You mention wanting to hear those Emits, ......well in combination with those you really want (well I would recommend anyways) to hear the Watkins along with those Emits. Yes siree.

Speaking of Emits, just for interest check out the page on the Quantum Reference Standard, http://www.infinity-classics.de/infinity/models/Quantum-series-1976/Quantum-Reference-Standard/body_quantum_reference_standard.html
18 - 32,000 Hz.........WITH 20 Emits in each box. That should satisfy the Emit craving eh?

Anyway, good luck on your Infinity hunting, and I will catch your posts on the booty to come.

[Arkay]

Mywifespissed, thanks for clarifying that about the Watkins woofers. I always just look for the two sets of connections, and had assumed that some of the earlier 8" woofers from the same years would also be Watkins, but when I think about it, you seem dead-on right about where they are found... the 12-inchers. Thanks!

[Nakdoc]

Mywifespissed, thanks for clarifying that about the Watkins woofers. I always just look for the two sets of connections, and had assumed that some of the earlier 8" woofers from the same years would also be Watkins, but when I think about it, you seem dead-on right about where they are found... the 12-inchers. Thanks!
Watkins woofers are flat in impedence as far as the amp is concerned. The "magic" is a crosover that switches from one voice coil to another at the woofer's resonance point. At resonance, speaker impedance rises quite high, so the Watkins crossover to a different coil with a different impedance, flattening out the overal impedance of the woofer system. While the second coil is technically 2 ohms or so, the combination of crossover and woofer had a near constant impedance. I hope this clarifies things.
I wanted to vote for the RSb over the RSa. This is a rare case where the 3 way sounds better than the 2 way. You may luck out and find an RSm, which is an RSb with adjustable crossover.

[Negotiableterms]

Watkins woofers are flat in impedence as far as the amp is concerned.

They are? I thought the major problem with the Watkins models was that they dip down to 2 ohms and below at certain frequencies. What am I missing here?

[Charivari]

They are? I thought the major problem with the Watkins models was that they dip down to 2 ohms and below at certain frequencies. What am I missing here?
You're correct. What Nakdoc speaks of is what the Watkins theory holds as the ideal and what the marketing department was sure to promote. In actual application, too many variables interact for this to work exactly as prescribed and so the notorious impedance dip exists. It's not much of a problem with the smaller units and in those the Watkins principle is closer to the ideal, but in the progressively larger designs where the system resonance closes in on the woofer resonance the 2ohm impedance gnomes show their ugly faces and tear into amplifiers. The Quantum Line Source is most notorious for this as the system resonance coincides with the woofer resonance (18Hz) causing the Watkins to dance on the knife-edge of going out of control.

I wanted to vote for the RSb over the RSa. This is a rare case where the 3 way sounds better than the 2 way. You may luck out and find an RSm, which is an RSb with adjustable crossover.
Up until last week I had a pair each of Reference Studio Monitors (RSM) and RSbs. I let the RSMs go and kept the RSbs. While larger, the RSMs are not near so well balanced with that conventional 12" cone not behaving near so well as the uniquely designed deep 10" with the bullet dust cap in the RSb. I found the RSbs to be fair bit more coherent overall. Also, the RSM does not have an "adjustable crossover" such as found in the larger Infinities where the crossover frequency of the tweeters and, sometimes, other drivers can be selected. It merely has a couple of potentiometers on the baffle to adjust the midrange and treble levels. The RSb has these as well, but they're on the back instead of the front.

Of this particular Reference Series, I'd recommend the RS 1.5 with the Watkins woofer or the RSb.

- JP

[Vitopanch]

The Quantum Line Source is most notorious for this as the system resonance coincides with the woofer resonance (18Hz) causing the Watkins to dance on the knife-edge of going out of control.

- JP

JP,
Interesting information. Can you elaborate on this a bit, meaning, when it goes out of control, what happens and what is the damage.
Vito

[Damage]

I love my RSbs. They were a big hit at the Austin gathering too.