Hiquphon 20mm - 3/4 inch soft dome tweeter type OW I, OW II, OW3, OW4, the new OW3 and OW4 and more. Designed and produced in Denmark since 1983.

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Differences between types


Understanding the differences between the 3 main OW-types OWI, OWII, OW3/4

It may be difficult to fully understand the differences in performance of our three main OW types. The following will explain the most important characteristics for each dome tweeter type.

OW3 and OW4: (below called OW3/4 as they are acoustically identical).
First you may want to know why our "old" OWIII has now fully faded out of our standard program (there are certain exceptions though - read here).

In 2006 OW3 and OW4 were introduced to replace the OWIII.
The main reasons being the coating substance used on OWIII.
It seemed to change toward a darker color during time under certain environmental conditions.

New coatings, colored as gold and platinum, were developed and thus the new OW3 and OW4 were born.

Now and then someone ask:
"What is the difference between the OWII and the OW3/4)?"
"Are the OW3/4 simply just colored versions of the OWII?"

These questions are of course very understandable. When you compare the two frequency response curves they do look very much the same, but the tweeters are in fact acoustically different. They sound different, especially in the low frequency area.

The OW 3/4 tend to be more clean (lower distortion) at very low frequencies and can in fact be used like the OWI in two way systems using rather low dividing frequency from say 2-3 kHz if only power handling is properly accounted for.

OWII is not well used that low. It has its advantage in being very analytic and "fast" (see below) from 3-4 kHz and all the way up to above 20 kHz.

OW3/4 and OWII (and OWI) share several design details in their construction. These are the basic magnetic and housing details, typical for the Hiquphon OW series.
But they are also quite different in other design details. For instance the dome material, the coating and coating procedures are VERY different for these different models.

OW3/4 is coated in 6 single steps with different types of coating! Each step is an important part of the resulting high quality. The result is a heavier coating and is in fact more like the coating used with the OWI.

As you may have guessed by now, the coating process is very important.
In my opinion coating is THE ONE most important issue with soft dome tweeters and materials and methods to control the uniform result from batch to batch is essential and when properly done, will secure the high performance of these tweeter types.

Our tweeters are coated 3, 4, 5 or even 6 times. Each coating step use unique selected substances to achieve a specialized purpose.

The sound picture of the OW3/4 does lean towards a softer and low distorted output at lower frequencies than does OWII.

The coating and other damping inside the tweeter is the secret behind the high quality we offer!
It takes most of a life time of experience to understand coating and damping in all details.
Consistency really is a major problem, as all involved materials are soft and difficult to "measure" from batch to batch. Temperature, humidity and raw materials differ all the time.
To control production of soft domes at the highest quality level does not come easy.

We at Hiquphon have "learned by patiently doing" and we like to think that we "know how to".

The OWII has lower moving mass than any other OW type and is therefore more "fast".
When I say "fast" I am not talking of "sound speed", I am talking "fast to settle" after being exposed to a music impulse. This means the voice coil is ready for the next pulse while being in a neutral position. A bit popular explained though but it is just about what happens.
In that way TIM (Transient Inter-Modulation distortion) is reduced more than otherwise.
Thatĺs probably why some people find OWII more distinct in the upper end compared to OWI.

The OWI and OW3/4 are all heavier damped than the OWII. Heavier damping contributes to perfect asymmetric behavior in the impulse response domain. After a pulse has been fired the dynamic moving mass is going to rest very fast without over swing (well damped). Again, settling is important here. A good speaker unit goes silent without ripple (multiple over-swings) after having responded to a pulse signal. This is especially important with tweeters as they reproduce the high frequency area in which the most important information about instrument positions in the complex sound stage is generated.

The OW3/4 was born as multiple coated and gold/platinum colored domes. They are rather difficult (and thus time consuming) to produce and therefore more expensive.

Many customers asked if we could supply OWI or OWII as gold coated versions.
As a consequence we invented a new special method a couple of years ago to produce the OWI as well as the OWII as gold domes. Many customers like the golden dome design, so it was kind of a must. As for the OWI-G and OWII-G they are sonically directly comparable to the black versions, only adding the golden finish to the dome and the "G" to the name. Adding the gold coating of course is more time consuming to produce than the black types (thus also higher priced) but it is manageable. The golden layer is very thin and thus makes (almost) no contribution to sound picture. If you sense a small difference it will be to the warm side. The sonic difference and the difference in frequency response are almost non-existing.
Finally the gold color is a bit brighter on the OWI/II-G types where the OW3 has a warm gold color.

The old (now obsolete) OWIII:
We will under certain conditions continue to produce our "old" OWIII (not the same as the newer OW3 and OW4) in campaigns for old customers to cover their eventual need for spare parts.
DIY-customers and small scale manufacturers/distributors/dealers will have the option of buying from these production campaigns as minor surplus stock quantities are generated with each order-production.
These are available for those customers who absolutely MUST have the good old OWIII gold dome!

Final comment:

Are you still uncertain and indecisive what to buy?
If so, please email me with further questions.
I shall then try to help if at all possible.

Kind regards,
Oskar Wr°nding

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