A Little Info about the Type of EQ the DSR1 Uses

This article assumes that you will be using the advanced mode that the DSR1 offers in order to overcome some very common issues that we encounter when installing an aftermarket stereo system on a bagger. Particularly when keeping the factory Harley radio in play. 

Old School EQ

The EQ section of the DSR1 is a lot like the old school EQ's from back in the day. The sliders on the left side control low frequencies (bass) and the sliders to the left control the high frequencies (treble). All of the sliders in the middle are something in between. 

Parametric EQ

Rockford took this a step further and gave us a type of EQ called a parametric EQ. The difference between a graphic EQ (pictured above) and a parametric EQ is that with a parametric EQ you can choose any slider and change the center frequency of that slider to be at a higher or lower frequency if you like. This particular feature is more useful when used with equalizers that do not have many bands. The DSR1 however has 31 bands of adjustment for each of it's 8 channels of output! As cool as this feature is, it has little to do with adjustments that are typically made on a Harley stereo system. It is worth being aware of this feature, though it is not very likely that you will need to use it. The really exciting useful feature of the DSR1 is explained next. 

Did You Know?

When you that when you make an adjustment to just one slider on an EQ it also effects some surrounding frequencies on either side? Well it does. 

Enter the Parametric EQ

Besides being able to fine tune the center frequency of each slider, a parametric EQ has one more very powerful trick that comes with it. You can also adjust how much the surrounding frequency bands are affected by your adjustments. That is very important! It is important because when used correctly this feature can make the EQ much more friendly to adjust. 


DSR1 Q adjustments

Adjusting the Width of an Individual Slider

One of the most powerful features of the DSR1 processor is also one of the most unknown and misunderstood. It's all pretty simple once you understand the concept of a Q value. 

What is a Q Value?

A Q value describes the width of the eq band that you are adjusting. In the picture above you can see the effect that a low Q (wide) value has on the frequency response on the left vs. the effect of a high (narrow) Q value has on the right side. Both of these screenshots depict a -18 db cut at 1,000hz. as you can see, a lower Q value will affect a much broader span of surrounding frequencies. 

Why adjust the Q value?

There are two very good reasons.

  1. Equalizers are used to correct for deviations in a stereo systems frequency response. Typically when there is a deviation that is caused by speaker placement, factory radio frequency response, or a speakers particular frequency response. There are a lot of reasons why the final output of a sound system will have large variations from the original recording. Most of these anomalies occur gradually and span wide ranges of frequencies. Therefore it is a good practice to counter with EQ adjustments that also cover wide ranges of frequencies.  Hence the adjustable Q feature.   
  2. It is much easier to hear wide (low Q) adjustment in real time. You can get to the end result that you are looking for much quicker by adjusting just a couple or few frequency points rather than a zillion narrow (high Q) adjustments to do the same thing. Additionally there are some very real technical drawbacks to having too may adjustment points in any EQ setup. The name of the game here is to get to the sound that you want with as few adjustment points as possible.

Some Practical Application for Harley Baggers

Update: The EQ information below assumes that you did not buy your DSR1 from us and are not using our free Harley Anti-EQ file available here. All DSR1 units we sell ship with an anti-EQ curve already loaded for '14 through '18 Harley radios. "19 and up Harley radios require an entirely different file that can be found here. Using our Anti-EQ file for factory radios effectively eliminates the need to adjust your DSR1 to compensate for the factory radio. The file fixes the factory radio EQ issues. However, you will still want to use your DSR1 EQ to adjust for whatever speakers you are using. Speakers are far from perfect and a little well executed equalization can make a world of difference.   

 It is well known that Harley programs an EQ curve into their radios and that this curve is quite unfriendly to aftermarket amplifier and speaker systems. To make matters worse, there are several different versions of EQ curves that Harley uses. Therefore there is no single counter EQ curve or file that can be used to solve this issue with all bikes. 

Here Is the Good News

The EQ adjustments that Harley uses are not very complex. Two or three properly executed adjustments with the DSR1 will render some wonderful results. 

Step 1

The first thing that we want to do is select two sliders on the EQ and adjust the Q on each of those sliders to a more usable value than the default value of 4.320 which is insanely high. 

DSR1 Q Adjust

The picture above shows a couple of screenshots of the DSR1 advanced EQ. Use the arrow buttons on the lower left side to move the adjustment cursor left and right to select the adjustment band. Use the + and - buttons on the right side to adjust the gain, Q, or center frequency of the band that the cursor is on (green pointer). To select whether you are adjusting gain, Q, or center frequency, tap the corresponding feature at the top of the screen (white pointer). 

The Low Adjustments

  1. Move the cursor to band #8 (100hz) using the left and right arrows. 
  2. Tap the Q at the top of the screen (white pointer).
  3. Tap the - button at the lower right of the screen to decrease the Q value for the selected slider (slider #8). This will take several taps. Keep going until the Q value is at 1.520. 
  4. Now you can use this particular slider to effectively adjust the bass response of the factory radio signal. Harley uses a ton of boost right at 100hz on most of their radio flashes. To counter that boost you will want to cut at 100hz. Harley uses up to 20db of boost here. It might take a lot of cutting to get the results you need. Note: not all radios will require a lot of adjustment here. Play a clean recording that you are familiar with, and remember that now is not the time to see how hard you can get your bike to hit. That will come later. For now, get the speaker system to sound true to the recording. 

The High Adjustments

Repeat the same for band #28 (red pointer 10.00K Hz). But this time lower the Q all of the way down to .570 (yellow pointer). This will allow you to boost or cut the entire high frequency range at once. 

Fine Tuning

We have now set two of the most important frequency ranges up for success. You have another 29 bands of equalization at your fingertips to use for more adjustments. So go nuts! 


Use only two or three bands (max) with super wide Q values like we did at 10Khz. For the rest of your adjustments a Q value of 1.120 - 2 is a more usable range for fine adjustments. The default of 4.320 though is almost useless on it's own. 


If I have missed something important here or have not done a good job explaining, please email me and I will see about editing this article.

-Rob Gomez-
Owner of American Hard Bag