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Review of Hiquphon Tweeters

 by Joel J. Kozlowski, USA, September 12, 2008

The Backdrop

   As an audiophile and more recently a loudspeaker designer, I have been listening to Hiquphon tweeters for nearly twenty years now.  My first encounter with them was back around 1991 when I purchased a Fried C3/L loudspeaker kit based on a listening session at a friend’s house.  At the time, I had no knowledge of what a Hiquphon tweeter was or what made it so special.  All I knew was that the Fried C3/L monitor was the best sounding loudspeaker I had ever heard in my life to that point and I had to have a pair.  Only later, through experimentation on my own designs, would I truly learn that it was the Hiquphon tweeters that were largely responsible for making that Fried speaker sound so fantastic.  As an aside, Bud Fried himself thought it to be a marvelous tweeter, often stating it was the best in the world.   

   Through my more serious commercial loudspeaker journeys, I always stuck with the better offerings from Fried—the C’s (in conjunction with various Fried subwoofers), the Valhalla ’s, the Studio MARS 5’s, etc.  The running theme in all of them was their exclusive use of the Hiquphon tweeters.  On top of using Frieds in my main system, I would always have a secondary system (or third or fourth!!) running with different manufacturers loudspeaker offerings.   I was always trying to find “that live, clear and unrestrained sound” that I got from my Frieds/Hiquphons.  I could not find it.  I won’t list the names of the speakers over the years that had fallen by the wayside in my secondary systems, there are too many to list.  Suffice it to say, I could never achieve the clarity, air, transparency, detail, openness, spaciousness or sheer dynamics in the treble that the Hiquphon tweeter provided me in those Frieds.  They always sounded so “right” and non-fatiguing in the treble and so pleasing to the ear.  Even ribbons and planar magnetic designs I owned (and still do!) could not/cannot compete with the Hiquphon treble.  Yes, some sound great on axis, but if my head isn’t in a vice in the listening position, things fall apart.  It’s a very narrow sweet spot to say the least.  More on this later…..


by Joel J. Kozlowski


Fast-Forward to 2003

   By this time I was quite comfortable with assembling loudspeaker kits and wanted to try my own hand at designing and building my own speakers from the ground up.  My goal was to see if I could improve upon my reference Fried designs. With the help of some good friends, I have designed and built several very serious high-end offerings the past 5 years for personal and fellow-audiophiles use.  During this time, I experimented with many different tweeters (who will remain nameless) from different manufacturers just to see if I could find something better than or perhaps equivalent to the Hiquphons I have been listening to for the past 20 years.  I could not.  I tried many different dynamic types: the ring radiators, the 1” domes, the metal types, etc. but could not find anything that stood up favorably to the Hiquphons!  As an aside, in my current reference design, I use the newest Hiquphon OW/4 tweeters. In my trials and tests the OW/4 compared favorably against the OW/2 I had previously been using.  The OW/4 offers slightly more extension, air and transparency than the OW/2 and I believe the OW/4 to be the best model Oskar has made to date by far. 


Why do I like them?

   The one aspect that is very important to me about the Hiquphon tweeters is their sheer robustness and bulletproof build quality.  I use 1st order series filters in my designs which put a mass amount of strain and demand on the tweeter being used as it is a "slow-slope" 6dB octave rolloff circuit on the tweeter.  A single coil in the circuit shunts the bass away from the tweeter---so you need a great coil, and a great tweeter (low Fs) to use this type of design.  While other tweeters I used in my trials spit at me, distorted on me, strained at me, blew up on me, etc. the Hiquphons always played through effortlessly and without incident.  The Hiquphons always remain controlled, composed, smooth and life-like.  I’ve even pumped full-range short term bursts in the Hiquphons during testing and they never gave way on me!  No, they are probably not indestructible, but I have never blown a tweeter and I’ve done some dumb things in the past 20 years to the poor things!  As a bonus, as each tweeter is custom made, Oskar can even provide ferrofluid to the tweeters at an extra charge for those who REALLY want to get stupid loud and need greater power handling.  Of course, there are tradeoffs sonically with adding the fluid, something that Oskar can explain to you if you opt for it.

 The other thing that makes the Hiquphons special to me is their off-axis response.  Because they are ¾” domes, they image like the dickens no matter where you are seated.  The loudspeakers simply disappear into the soundstage and it’s nearly impossible to determine where the sound is coming from. A deal breaker for me with other tweeter designs (the ribbons, the rings, and to a certain degree the 1” domes) is that when you stand up, or move off axis you lose the extreme top end and airiness to the sound.  With the Hiquphons though, this is never an issue.  You get the same open, airy, detailed and smooth response no matter where you are! 

   On top of this, the Hiquphons have the ability and resolution to provide a “wrap-around” or “surround” experience when the program material warrants it. This is one of my acid-tests for judging a tweeter.  Just put on a copy of Delerium’s “Semantic Spaces” or Praise’s “Praise” or Michael Stearns “The Lost World” all with their processed surround recording techniques. Listen closely as cymbals, sounds and synthesizers circle around you and behind you.  Yes, other speakers/tweeters will pull off this same effect with this type of manipulated material, but not to the pin-point accuracy DEGREE or DETAIL that the Hiquphon does.  It is simply breathtaking stuff----the Hiquphon's dispersion is truly world-class.


A True Story

   A certain current loudspeaker manufacturer (who shall remain nameless) switched from Hiquphon tweeters to a competing brand a few years ago.  You see, the new brand had an esoteric new type of tweeter design which was written about favorably in Stereophile and was a slight rage in the DIY loudspeaker building circles when it was released.  I had already tried the tweeter in one of my designs, and was totally unimpressed by it.  The only thing I could think of was this loudspeaker manufacturer wanted to go with something “new” and “hot” with their new line and decided to switch tweeter brands.  I thought to myself at the time that certainly nobody there did a listening comparison to conclude these new tweeters sounded better then the Hiquphons and it must have been a marketing move or a “in with the new” type philosophy.  Well, long story short, an audio dealer friend of mine went out and bought one of these new (very expensive) loudspeakers which contained this new tweeter.  I went to listen to it, and just couldn’t get over how poor the treble sounded compared to what I was used to.  It sounded just as I have remembered in my own experimentation:  Off axis, the highs disappeared quite severely and mass detail and air was missing in the treble. No life, no extension, no openness, and no clarity like the Hiquphons have. They simply sounded constrained and constricted to me.  Well, he lived with those speakers for a few months and ended up concluding the same as I did---the manufacturer should have NEVER moved away from the Hiquphon tweeters.  He ended up selling those speakers and now owns my latest loudspeaker design which uses the Hiquphon OW/4!!!


A Final Note

   I must also note the phenomenal packaging and attention to detail that Hiquphon provides.  The packaging and paperwork provided are exemplary.  For instance, when you buy a pair of Hiquphons you receive a matched pair.  I cannot understand why all tweeters are not sold this way (even VERY expensive ones!!!!).  You also receive a graph for each individual tweeters response curve.  Oskar also keeps record of each tweeter so that if you do happen to blow one, he can build and send you an exact replacement without having to buy another matched pair!  I have bought some expensive tweeters in the past and NONE of them ever came with the type of documentation or beautiful packaging as the Hiquphons!!  Everything just oozes “quality”.

   Well, that is my story and I wanted to take the time to tell it so that others can “discover” the Hiquphon brand like I did oh so many years ago.  I think the fact that I am still committed to these designs after all these years is a true testament of the incredible sound and great service that Hiquphon has always provided me.  Try a pair for yourself, you will not be disappointed.


Best Regards,

Joel J. Kozlowski


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