Amplifier Setup Basics
It’s amazing what just a little bit of attention to the initial setup of your audio equipment will provide in the way of equipment longevity and acoustic satisfaction. However basic the initial setup of an amplifier may seem, the fact remains the majority of amp and subwoofer failures we see come through our service department are a direct result of amplifier clipping and/or improper crossover utilization. Both of which can be corrected during the initial setup.
If you’re now asking yourself what exactly we’re talking about when we reference clipping or improper crossover utilization, here is a quick summary of the techspeak.
Clipping: Clipping happens when you overdrive a piece of audio equipment’s outputs. This usually happens because the gain is set too high in an attempt to maximize the amp’s output potential. When the gain is set too high for the application the amp will produce a squared or clipped sound wave, and the amp and the speakers attached to it will generate a large amount of heat trying to reproduce the clipped signal. This can result in catastrophic damage to your equipment.
Lucky for you, DD has made the act of equipment preservation easier by implementing an output clipping monitor on the remote gain knob that can be used with our C, SS, and M Series Amplifiers. Once you’re amp is set up, you simply watch for a red blinking light. If you see the light blinking turn it down, and voila you’re no longer clipping. Our clipping indicator is as accurate as an oscilloscope, but it gives you the ability to monitor the dynamic source material we call music in real time. If you set your gains with an o-scope, it’s all good until some factor in your system changes. This change could be in headunit volume, charging system voltage, source recording level, etc. If any of these factors change from when you initially set your gains with an o-scope, the amplifier’s clipping point will change as well.
Crossovers Utilization: If you’re one of the guys who thinks you get the best performance from your amp if you open up all your crossovers to feed the maximum amount of sound to you subs, this is directed at you. In reality, if you want to maximize your system’s output, while protecting your subwoofer at the same time it’s as simple as adjusting the audio bandwidth to match your source material and your car’s acoustic transfer function. You can do this by strategically adjusting the Lowpass and Highpass filters (subsonic) to create a bandpass filter. This lets your amp direct the frequencies that sound best with your system to your subs, while taking away frequencies that you don’t like or can’t hear. At the same time, proper crossover settings can eliminate subwoofer damaging excess excursion caused by ultra low frequencies.
Now that we’ve defined two of the most important things to address when setting up your amp you can view a quick 10 step amplifier setup procedure or click here for a written version. When followed, these steps combined with a little attention paid to the system while listening, you’ll have many years of clean enjoyable bass in your future.
1. Set LPF to 100-125Hz
2. Set Subsonic to 30-35Hz
3. Set Master/Slave switch to Master
4. Set the amp gain to minimum (all the way to the left)
5. Install the remote gain knob and turn it 1/2 way up (the midpoint on the dial)
6. Set all headunit EQ settings and bass controls to 0
7. While playing one of your favorite tunes via the source you use most commonly turn the headunit volume to ¾. This will be your max volume for general listening. At this time you will have no output because the gain on the amp is turned down.
8. Slowly turn the gain on the amp until the clipping indicator on the remote starts to flicker as the frequencies in the music change. Do not allow the clipping indicator to glow solid, flicker continuously on constant music, or stay red on transients. If the aforementioned is happening your amp is clipping, and we know what happens to those who clip.
9. While playing the system at the predetermined max volume with an occasional flicker on the clip indicator (see steps 1-8), start edging up the subsonic filter up until the sound audibly changes. Depending on how far it was moved, you may see the clip indicator no longer flickering. This means your amp and speaker were wasting energy not needed by your car’s transfer function. Now you can turn the amp gain up until the clip indicator starts to flicker again.
10. Repeat the same procedure for tuning the low pass filter.
Keep in mind if your Subsonic and LPF filters are set too closely together you will greatly limit your amps musical output.