Infinity Primus 150 spinorama measurements (CTA-2034)

[Floyd Toole]

Sorry to impose with such a trivial question sir, but do you recall who designed the crescendo line in the early 90s?.. And are you aware of any reliable measurements anywhere.. I can't find either.. I happened to acquire a pair of 3006's by pure chance and can't find much if any reliable info... Thanks

These were designed in the days before comprehensive, accurate, anechoic measurements were being done at Harman and Infinity. I joined Harman in 1991, so this is all unknown to me. In those days loudspeakers were highly variable in sound quality - no blind listening tests. Sorry.

 

[tw 2022]

These were designed in the days before comprehensive, accurate, anechoic measurements were being done at Harman and Infinity. I joined Harman in 1991, so this is all unknown to me. In those days loudspeakers were highly variable in sound quality - no blind listening tests. Sorry.

thank you sir ... i very much appreciate the response...i'll keep digging , and like the previous poster suggested , i may try to measure them myself or get them out to Erin or Amir...

 

[paulgyro]

Sorry to impose with such a trivial question sir, but do you recall who designed the crescendo line in the early 90s?.. And are you aware of any reliable measurements anywhere.. I can't find either.. I happened to acquire a pair of 3006's by pure chance and can't find much if any reliable info... Thanks

You can find the owners and technical manual here: https://www.hifiengine.com/manual_library/infinity/crescendo-cs-3006.shtml

Paul

 

[paulgyro]

Any component replacement/improvement scheme can improve sound quality only if it improves the anechoic measured performance of the loudspeaker. In many cases such replacements change the measurements, and therefore the sound. Is it an improvement? Psychologically, there is an expectation that more expensive capacitors and air-core inductors should sound better - lower non-linear distortion - but the reality is that what we hear is dominated by linear behavior: amplitude vs. frequency response. Even phase response is not audible. So, if the original electrolytic capacitors have deteriorated, a not uncommon phenomenon in old loudspeakers, it might - might - be enough just to replace them with new versions, assuming that the right values can be found. Otherwise the loudspeaker is being redesigned without the benefit of trustworthy engineering measurements. If such measurements are available, then have at it, and you might indeed improve the sound.

But humans are flawed, and if we believe we hear something, often we do.

Thanks for this insight, I've reflected on it much. I have a question, the Revel "PerformaBe crossover networks utilize all film capacitors and air core inductors in the midrange and tweeter circuits.". In what measurements would you expect to find the benefits of such high-end components?

 

[Floyd Toole]

Thanks for this insight, I've reflected on it much. I have a question, the Revel "PerformaBe crossover networks utilize all film capacitors and air core inductors in the midrange and tweeter circuits.". In what measurements would you expect to find the benefits of such high-end components?

Film capacitors tend to have better controlled values - a manufacturing benefit for consistent product performance. They also have longer life spans than electrolytics. Air core inductors won't saturate, and change their value or generate distortion if driven very hard, but frankly well designed iron core inductors work just fine. At some point it becomes expected in high-end products and the additional cost is not great.

 

[RobinOC]

I don't know if Infinity were highly regarded back in the day, but Stereophile seemed to like this speaker as well. I dont usually pay much attention to subjective reviews, but in this case I agree with their conclusion. At it's best, it sounds surprisingly open and detailed, especially on female vocals.

The Primus 150 has achieved a standard of performance at the $200-or-under price point that I didn't think was possible. Moreover, in the area of its greatest strength, its midrange detail and low-level dynamic resolution, it sounded like a $1000/pair speaker.

It was backed up by measurements as well:

Although I was a little bothered by its midrange resonances, the Primus 150's overall measured performance is excellent, considering the Chinese-made speaker's bargain price.

Infinity Primus 150 loudspeaker Measurements

Sidebar 3: Measurements

www.stereophile.com

The overall tonality could be described as a bit "cold", but not really v-shaped - It doesn't sound bright, but a bit thin due to the lack of bass below 80 Hz.

As for the cabinet resonance att 300 Hz, it could be audible, but maybe not. Those kinds of measurements are done with an accelerometer attached to the cabinet. It's not an acoustic measurement.

I bought these speakers after reading the Primus 360 review by Erins Audio Corner. I know this one is probably not as good, but still a nice budget speaker.

I bought the Infinity Primus 150s and years later the P163s, both times on closeout for less than $70 the pair. I also bought a pair of the Pioneer Andrew Jones designed towers, ver 2 model, on closeout, for $130 the pair. I keep rotating them out of my system and they are all enjoyable, but the bookshelf speakers do need a sub. Luckily I bought one of those on closeout too. (just call me Cheaperaudioman.)