Hey everyone, owner of the GS9 here. Thanks to Amir for testing it and accommodating a quick turn-around while we are working on my car. I wanted to reply to a few points and express my perspective on things a bit. It came out a bit longer than anticipated, so...
TLDR:
A car is a harsh, complex environment for accurate sound reproduction. Getting a car to sound amazing is a fascinating and rewarding challenge combining critical listening, music appreciation, acoustics, electronics, signal processing, and fabrication in order to be effective.
Yeah, the design of the unit may seem a bit strange at first with the large volume control and a small screen. It is usually not referred to as a "head unit" but as a "receiver". Pretty much all of the installations with it I have seen also have a tablet or phone used as the control interface, either playing directly in DAC mode or using the Sony Music Center app to control playback. Physical unit controls at that point are mostly just volume and sometimes source selection. It is a pain and limited to use on its own without DAC mode or the app.
I use the GS9 in DAC mode with an Android phone with USB Audio Player PRO for bit-perfect output (and Tidal integration). I have it mounted in the lower center dash, where a lid/pocket thing used to be. I have a 2015 Honda Accord EX-L, and like mentioned the factory control system integrates with some vehicle diagnostics and features I did not feel comfortable giving up. So it is still there and remains off almost always, and the audio system control is all the GS9 below it and a mobile device (wired hidden through center console to USB-C Power Delivery hub and charger for data and charging). I also have steering wheel controls integrated, which is nice.
The DAC mode was one of my primary reasons for picking the GS9 over a traditional head unit. I come from more experience with desktop digital audio, so having a generic USB audio input compatible with many source devices seemed like the best idea. Additionally, I have yet to see a head unit with a quick, responsive interface and effective media management system. Having to wait for clicks to register and screens to change is absurd. I really do not understand why there seem to be zero quality units when powerful mobile devices are so common.
Yes, road noise is loud. When I first designed the system, I did a lot of research into acoustic treatment, and ended up treating the whole vehicle (as possible) with Sound Deadener Showdown, CLD tiles to reduce resonance and MLV sound barrier decoupled with CCF. It definitely both reduces road noise and improves audio performance. The doors feel nice and solid and heavy too. The weak point, as mentioned, is the glass. Unfortunately, I do not have acoustic glass.
Regarding high-end audio performance versus background noise... This is probably a bit weird, but I actually use the system in the garage with the engine off a fair bit. We installed an Anderson quick-connect port in the back underside connected to the power system, and I have a charger with a matching connector. So, I can fully appreciate high-end performance. When we first built the system, it sounded great. Now that I have learned to optimize the DSP configuration, it sounds awesome. Great instrumental separation, clarity and details, good staging and imaging and placement. Definitely better and more fun than my living room or headphone setups (not that they have anywhere near the level of investment though).
This car has become a personal project and hobby. Yeah, I am definitely a fringe case enthusiast. I did not ever think I would be a car guy. Audio though... A car is a harsh, complex environment for accurate sound reproduction. Getting a car to sound amazing is a fascinating and rewarding challenge combining critical listening, music appreciation, acoustics, electronics, signal processing, and fabrication in order to be effective. I expect others whom are as involved as I am feel the same. I have learned a great deal about acoustics and measurement and sound reproduction and many other things in the year or so I have been doing this seriously, and I feel I am just beginning. It has also spread my interest out to other aspects of audio, such as studio recording and mastering, and video production.
I have heard some cars do incredible things. Stage and space beyond the bounds of the vehicle, height above the speakers, center imaging from both seats... The two-seat ones are impressive. It almost seems to transcend what should be possible.
There are even organized car audio competition leagues with objective judging and different divisions and points and yearly finals. Some of these people have the best ears I know, and they consistently give helpful advice on what issues they can detect and what could be done to improve things.
And then at the end of the day, I drive home and my music sounds incredible. Every drive is fun now.
As for the rest of the system... The GS9 connects to an Arc Audio PS8 processor, then to Mosconi AS 200.4, 200.2, and 300.2 amplifiers, then to Morel Elate Ti three-way front stage and Morel Ultimo Ti subwoofer mounted infinite baffle. We are currently working on a few things, though.
As for the GS9 test results, I am not too surprised really. I was hoping it would do better, yes. Many people in the industry/community do not like the GS9 too much though.
Photos:
https://drive.google.com/drive/folders/19evoMgtnVYMHlkeDKgnHqMZsOfAZQHmj