PIONEER GM-D8604 GM Digital Series 1,200-Watt 4-Channel Class FD Amp Review

Building your first car audio system is an exciting adventure, and you will always remember your first build. That’s just the way it is. However, being new to this hobby means that you still don’t know a lot of things, and you’re mostly relying on others to tell you which brand to go for, or what kind of system to choose.

If you look at any hobby, there will always be those several brands that have the reputation of delivering tried and tested performance. So what happens when that is taken away from you?

This grim introduction might sound like a cheap attempt at creating drama, but the tone is completely warranted. The brand we are talking about here is Pioneer – one of the oldest and most trusted companies in the industry. The amp which shook the foundation of that trust is the Pioneer GM-D8604. Before we cut into this model, we are just going to preface our critique by saying that this is a solid amp, when it works as it’s supposed to.

Pioneer GM-D8604 Review

Buying your first amp is all about the type of information you are able to gather prior to your purchase. That first unit is going to be the one you will use to sharpen your teeth and learn. Since amps can get expensive, most newcomers go for the affordable segment. Budgets are often tight and you don’t want to over-commit to something you are not even sure you will be interested in a year or two down the road.

These and many other are just some of the reasons why affordable amps are so popular. When Pioneer makes an affordable amp, you would think that a company of their caliber would use their extensive knowledge and experience to deliver a rock solid model. Was that the case with Pioneer GM-D8604?

Features of This Pioneer Amp

Right out of the box, Pioneer GM-D8604 looks pretty attractive. It features a more complex design that will definitely look good in any car. All of the connectors and controls are nicely clustered on the back panel and are easily accessible.  The amp is rated for 1500 Watts split across its four channels.

In reality, you get 100 Watts per channel at 4 Ohms or 150 Watts at 2 Ohms. Since it’s a bridgeable model, you can push 300 Watts on two channels. Still, not that bad.

There is not dedicated subwoofer channel, so don’t count of pushing a large volume of air. With that said, this is a great OEM system booster that will get you started with automotive amplification.

Frequency response range is pretty wide. It goes from 10 Hz to blistering 35 kHz, which should be more than you will ever need. THD is within acceptable limits and signal to noise ratio sits above 95 dB. The rating for this amp is something Pioneer calls Class FD.

In simple words, they claim to have developed a Class D amp that is more efficient than anything you can find in this category. For the most part, that is true. In terms of other available features, you are looking at a low pass and high pass filters which operate within the 40 Hz – 500 Hz range, a good amount of protection and speaker level inputs. Nothing too outrageous, but still a comfortable spec sheet.

Does This Amp Perform?

Pioneer credits their Class FD amp for the compact size of the Pioneer GM-D8604. It’s very easy to install, and it fits just about anywhere. This makes it great for stealthy builds, or if you are tight on space for whatever reason. That amp seems to be efficient enough since the temperatures never really go into the red. With that said, even if you push GM-D8604 hard, it won’t give you too much trouble.

The quality of sound is impressive for an affordable unit such as this one. There is an abundance of volume and you are going to love listening to this thing every time you get in your car. At this point, you are probably wondering why we started our review so negatively.

Well, what looks good on paper doesn’t necessarily work all that well in practice. This amp would be great if only Pioneer didn’t cheap out on their quality control. Imagine installing everything and finally being able to enjoy the fruits of your labor only to find out that you have only two channels? That is something you don’t want to deal with.

Unfortunately, a small but significant number of Pioneer GM-D8604 owners are in this world of hurt at the moment. Even though issues of this type don’t arise often, we still expected better from Pioneer.

Our Verdict on the Pioneer GM-D8604

At the end of the day, Pioneer GM-D8604 is one of those models that will keep you awake at night. On one hand, it’s a great amp that delivers great performance, but on the other, it might fail on you within a short period of time. Whether or not you would want to deal with this type of reputation is something you need to decide for yourself. On our part, we are mostly just disappointed with Pioneer on this one.

When you are at their level, you can’t afford to have things like this happen to you. Their usual quality control would have prevented any of the issues we have mentioned today from happening. However, it seems that Pioneer got a bit too greedy with this one. Unfortunately, the beginner crowd is the one who is going to suffer the most.

Summing up, just be sure you get a warranty with this purchase and you can rest easy that you’re getting a good performing amp at a good cost.