Antimode X4 configuration and listening impressions
Disclaimer: We are a distributor of Antimode products. As such this is not an objective review. However, we do use the Antimode X4 actively in our demo / test room, and this is a summary of our impressions of the product.
The Antimode X4 is a high-end preamplifier, DAC and advanced EQ / room calibration device. That's a lot in one box. What makes it different from other preamplifiers is obviously the onboard DSP (Digital Sound Processing) capabilities. We'll get back to that soon.
It also has 4 individual output channels (all 4 supports both RCA and XLR), which makes it one of the few high-end devices out there that can properly handle a setup with one or even two subwoofers. It can be configured to run with dual subwoofers in either dual mono or stereo, and crossovers can be defined either manually or automatically.
Initial listening impressions and sound quality
The X4 uses top-shelf Burr-Brown PCM1792A DAC chips that are individually measured and hand selected. Distortion (THD) is extremely low at 0.0008%. And boy can you tell. Before we even get to the DSP capabilities of this device, it's immediately obvious that the sound quality is extremely good. Many are reluctant to add DSP to their expensive stereo systems, worried that it will reduce the overall sound quality. You need not worry with an X4 in your setup. We've had 4,000USD preamps in our setup before, and the X4 easily sounds as good or better.
Antimode Room Calibration / DSP
One of the major selling points of the X4 is the advanced onboard room calibration. It's extremely easy to set up, and everything you need including microphone and microphone stand are included in the box. As opposed to the other Antimode products, the X4 operates in the entire frequency range. The main focus is still on the bass/midbass area, and rightly so. Due to the way high frequency reflections work in a room, it's almost impossible to properly correct for room issues in the higher frequencies. The result after running the calibration process also shows that the Antimode makes few and very light touches above 1khz. If you want to actively limit how high the X4 attempts to correct the response, this is user selectable. The entire process is fully automated, and takes 5-10 minutes to complete. The included quick start guide is easy to follow.
In our room with two Sigberg Audio SBS.1 active speakers and dual Sigberg Audio 10D subwoofers, the result is an almost ruler flat response from 20-120hz, and above that some peaks have been evened out. Otherwise the response has been left largely as is. The resulting sound was breathtakingly good, with tight, dry bass and clear mids.
The Antimode X4 also offers many options for manual tailoring of the sound, including bass tilt / treble tilt, 9 band parametric EQ and individual adjustment of the subwoofer level. After the automatic correction, we used the bass tilt feature to add a bass shelf that restored some of the bass level that was lost after straightening out the response. We also spent some time applying individual EQ filters in the parametric EQ to fill out some of the dips in the midbass area that Antimode had decided to not fix. After a few rounds of listening, it turned out that it actually sounded better when it was left alone, the way the automatic correction initially did. So we ended up dialing back on the manual EQ. We finally settled on a configuration that was pretty close to what the X4 did automatically. The careful approach of the X4 obviously works, and this is the first time we've tested an automatic room correction device that we couldn't easily improve upon with manual adjustment.
The Antimode X4 is the perfect companion for a high end system (with or without subwoofers), and the room calibration capabilities will without doubt vastly improve the sound of your system.