In an earlier post, we discussed tonearms, and why two individuals with identical tastes and systems might be best suited to two different tonearms.
It all boils down to the fact that tonearms are tools that we interact with, and two people my have different preferences in this regard.
As with tonearms, you may achieve a better setup with headshell "A" vs. headshell "B".
On our headshells page, you'll note that we carry several headshells that wouldn't be our first choice (as outlined below). It's entirely possible that what doesn't work in principle is a perfect match for your tastes in your system, and we'd be the last ones to steer you away from this.
With that caveat out of the way ...
Some headshells have adjustable azimuth, and others don't. Some have traditional cartridge mounting slots, and others have fixed mounting positions.
Materials and mass differ as well, which in turn affects compatibility in several ways. Selecting the right mass can help you match your arm to the compliance of your cartridge.
Material (alloy, carbon fiber, wood) can affect the energy transfer between the cartridge and the tonearm.
Azimuth - Interacting
Perhaps the single adjustment feature which is least exploited by the user is azimuth adjustment.
This is where it can get tricky, in the same way that adjustment features in a tonearm can be intuitive for some, and confusing for others.
In general, headshells with azimuth adjustment achieve this by rotating the headshell after loosening a locking screw. The Ikeda headshell shown here is typical of this design.
The challenge in working with these headshells involves the difficulty in working at the necessary precision level.
In theory, you have the potential for "locking" in the sound. In practice, it takes time, patience and a tool we developed for this purpose.
A contrasting example may help explain this better ...
The Kuzma 4Points and Stogi Reference tonearms have the most precise azimuth adjustment mechanisms I've encountered. Adjustment is made with a worm gear with essentially zero lash (play).
Establishing your azimuth with the Feickert software involves taking a series of readings at fixed orientations: level headshell, headshell rotated 0.5 degrees, 1.0 degree, etc.
The azimuth scale we developed helps with setting repeatable positions. When used in conjunction with the Kuzma tonearms, it takes us 2-3 minutes to achieve a desired setting.
In contrast, with headshells like the Ikeda, Jelco, etc. we can take 10-15 minutes to establish a single setting.
Does it mean we don't do it? Of course not. Is it a painstaking process? Absolutely.
The point is that those who are unaware of how little movement is required to rotate the headshell by 1/2 degree or less, will be endlessly hunting for the correct azimuth setting - overshooting it in one direction, and then the other.
Whether you use a tool like the Feickert or AnalogMagik software, or you hunt for azimuth while listening to a mono record, the tendency will be to leave good enough alone, for fear that you can't return to the previous best setting.
Azimuth - Recommendation
So, for many individuals, using the azimuth feature can do more harm than good.
I would still recommend a headshell with azimuth adjustment, knowing that you can set it to a "level" headshell, and explore this feature at some future time when the urge to experiment strikes.
To reset the headshell to zero degrees (parallel to the platter), remove the cartridge, and position a block of some sort on the platter underneath the headshell. Using the block as a reference, rotate the headshell until it is parallel to the platter (rests "flat" on the block).
If you haven't subscribed to our mailing list, our downloadable setup guide has a parts list and instructions for building the azimuth gauge shown above. A subscription link is in the footer of any page on our website.
Other Features to Consider
As far as materials are concerned, a bit of insight into a cartridge's design is helpful. For example, Soundsmith's designs are outliers, in that Peter Lederman advocates wooden headshells. I'd trust Peter on this, although as with any tweak, your system and tastes should supersede Peter's or my recommendation.
Without further knowledge, it's safe to assume that a cartridge was designed to interface with 99% of the tonearms made, which is to say, an alloy of some sort.
I wouldn't exclude carbon fiber, graphite and wood from consideration, but it wouldn't be my first assumption.
You'll also note that some expensive headshells have either fixed mounting holes or otherwise limit precise adjustment of zenith and overhang.
Two highly regarded cartridge manufacturers are guilty of this with their top of line headshells: the My Sonic Lab SH-1Rh and the Ortofon LH-10000.
I don't know what to make of this, and my tendency would be to stay away from them - especially if I wasn't using it with cartridges they've designed them for.
Now, one can safely assume both My Sonic Lab and Ortofon designed these headshells, taking the stylus offset of their cartridges into account (for correct overhang), but this still doesn't take zenith (toe-in / toe-out) into account.
Do the energy transfer characteristics due to material match of these headshells supersede the lack of adjustability? I can't say.
In the realm of tonearms, the modern SMEs are similarly guilty, having mounting holes instead of alignment slots in their headshells. These tonearms allow for mounting distance adjustment, so you can adjust two of the three geometric parameters (pivot to spindle distance and overhang), although (as with the above two headshells), you can't adjust zenith.