Heir continues to produce a wide array of products aimed squarely at the IEM market. From the new Rendition One portable headphone amp to a five-driver universal called the IEM 5.0, Heir has pretty much all the bases covered when it comes to both custom and universal in-ear listening. Among the broadening product line of universals sits the Tzar line of high impedance IEMs. The nominal impedance at 1k Hz for the Tzar 90 ($370) is 90 and the Tzar 350 ($400) follows suit at 350.
Both varieties offer a similar design and look as the 4.Ai universal. I very much like the design that Heir utilizes within this IEM family. The shiny purple shell sits comfortably within the ear and seems a bit more stable than your typical bullet-shaped universal. The casing also includes a standard removable IEM cable connection that you usually see on the higher-tier custom models, allowing the user to swap out the included cable for more exotic fare or even balanced cables should you be so inclined. For the sake of this review I will be focusing on the Tzar 90, which does not bare any outstanding markings other than the standard Heir logo in a reddish hue.
I have mentioned this before in other reviews, but it is worth reiterating: proper fit with a universal IEM paramount. Poor fit can hollow the sound out, push the treble forward, bleed the bass out or even bloat the low end. Bass is particularly susceptible to augmentation due to both its proximity to your eardrum (how far its pushed in your ear canal) and the seal against your ear. I highly suggest trying out several types of ear tips to find a match that is right for you. Not only for fit, but also for sound. In my time with the Tzar 90 I tried as many tips as I had on hand, luckily Heir includes a good selection and many more are available online. I found that a single flange style was not really up to my comfort level. While this is the most common style you usually find included with IEMs, I have rather large ear canals and it becomes a bit cumbersome to find a good seal. The curve of the material seems to have a little too much give to it to allow for optimum comfort. I found more comfort and a better seal with a double flange style (for my ears, individual results should vary). Additionally, the size of the ear tips hole seemed to have an effect on the sound. Small changes became evident throughout the mid band and into the treble as I alternated between sizes. Although it wasn’t quite as obvious, I also felt that a larger ear tip opening allowed for a greater sense of air and openness in the music as well by comparison. A soft sponge tip allows for the greatest level of comfort to my ears, but I found a solid seal to be more elusive.
Once you have the fit hammered out, the Heirs prove themselves to be quite revealing for the price. I found the Tzar 90s to share a similar treble-forward slant tonal signature as 4.Ai. This signature does include a nice, balanced bass-end grip that reaches fairly low with out being too forced or bloated (as IEMs can sometimes get). The top-end tilt helps enhance a sense of detail and resolution. The overall signature is slightly V-shaped in that regard. The mids are present and fairly smooth, but placed ever-so-gently between the thump of the drums and the sparkle of the cymbals.
The amount of treble is just as subject to ones taste as bass. Not unlike the polarizing preferences of the low end, treble is the ongoing debate of many a headphone. One man’s “ruler flat” presentation is another man’s veiled headphone. A lot of options can be had in the $400 price range for IEM. Indeed, Heir offers 4 models to choose from in that range without even having to leave their website. Check out the Tzar 90 if you like a detailed presentation with some spice on the high end, it might just be your cup of Earl Grey.