There are a few basic concepts to be aware of before setting your EQ that will get you better result much quicker than just playing with the EQ until you think it sounds better.
Simple EQ Tips for Harley Davidson Baggers
Step 1 - Get Yourself a Few Good Recordings
Your selection of music should be dictated by particular aspects of the recording (wide range of bass tones, clear vocals .etc) that have nothing to with the type of music you like. Forget about your favorite artist or album for now.
Here are my recommendations for music tracks to use for tuning a bike system. You can use any number of services on your smartphone (such as iTunes) to download the following tracks.
- Billy Jean - Michael Jackson. This recording was done particularly well for many technical reasons. It's a great track to set your amplifier gains with, due to the relatively high recording level and low distortion, clear vocal, and a wide range of bass tones. The bass track in this recording is great for assessing the performance of your woofers and how well they are (or are not) working together. If you listen you will notice that the bass line goes up and down in frequencies giving you a wide range of bass tones. Most popular music will focus on just one bass note. That makes it really hard to tune a system that will sound great with a wide variety of music. The hard drum strike in this song is a good one for identifying speakers that are out of phase (signal phase) with each other. I wrote an entire article about that topic that you should read and follow before attempting to set your EQ. You can find that article here. Now listen to how hard each drum strike sounds. Use the phase control to invert each set of speakers until you get the most impact from those drum strikes. A harder impact is indicative of proper phase alignment amongst your speakers as a group. Harder impact in the bass region is a great indicator that you are headed in the right direction. Beyond the Bass. There is more to this music track than just bass. Listen to Michael's voice. He should sound clear and focused. He should not sound distant and should not sound like he is singing into a coffee can. Most anyone from planet earth is familiar with this song and how it normally sounds. That makes this song a valuable tool when setting your system up. This track is also good for setting up tweeters and evaluating all of the highs for proper level in general. For final EQ settings for highs though I tend to use other tracks that are a bit more vocal based.
- The Breakup Song - Greg Kihn Band. This song is another great recording that displays a very wide range of tones and vocals. I like to use this song mostly for equalizing vocals and setting amp gains.
- World on Fire - Stick Figure. This is the go to track for bike systems with subwoofers. I really only use this track to setup subwoofers. It's a good track to use to make sure that your lid speakers are in phase with your subs. Its very apparent when that speaker phase relationship is correct or not when playing this track. Because this track produces a lot of air pressure inside the bags it is also good for detecting leaks and rattles. If your bags are properly mounted and gasketed, you should not have a problem with air leaks or rattles of any kind. Be aware that the lid hinges and locks can be a source of rattles. Neoprene gasket in the hinge can be a great way to eliminate hinge rattle on older '13 and down bikes.
- Use any track that you are familiar with on a big sound system. Being familiar with how a track sounds is important. Getting a bad or mediocre music track to sound the way you want is not the goal here. That's a waste of your time and frustrations. And has nothing to do with properly tuning a sound system.
Step 2 - Defeat Any Sound Related Feature on Your Smartphone
Turn off Sound Check. Turn off any EQ or sound related effects. Do not use these features that are built into your phone or you are asking for trouble. The digital sound processing in your phone is made and optimised for ear buds and not a big bike system.
Step 3 - Turn Your Phone Volume All The Way Up
Most all phones do not distort with the volume all of the way up. You want the highest undistorted volume level possible to go to your radio. This is always the case.
Step 4 - Check That All of Your Crossover Settings & Amplifier Gains Are Correct for Your Speakers & Check Speaker Phase
The EQ is the last thing that you should set. All of the EQ magic in the world will not do you any good if you haven't first set your crossovers, gains, and checked for speaker phase. Speaker phase must be checked both at the wiring level as well as at the acoustic level. You can find the article about checking phase at the acoustic level here.
Step 5 - Double Check the High/Low Input Switch on Your DSR1
This step is important enough to be a step all of it's own. This setting should be on high if using a factory radio. Even if your radio has been flashed.
Quick and Dirty Tips for Actual EQ Settings
- Keep your adjustments minimal. If you find that you have to make big adjustments on the EQ to get a result, then you are probably missing something important. Because that should not be the case.
- Don't Boost Bass Frequencies. The most common mistake we see people doing is boosting bass frequencies. You can get away with this in a car, but on a bike you are just asking to overdrive your speakers and have them eventually fail on you. Remember that every 3db of boost on an EQ will force the speaker to endure twice the amplifier power and 6db of boost will force the speaker to choke 4 times the power at that frequency. Want to blow up a speaker really quick? Besides; the most effective way of getting more bass that you can hear, so that it sounds loud, is to allow the speaker to do what it is designed to do. Play over a wide range without peaks in any single part of the bass range.
- Always reduce the frequencies that are too loud instead of boosting the frequencies that you want louder. This is hard to do in practice because a boost will sound instantly gratifying and but will not ultimately add up to what you are after. When you boost EQ bands you put a lot of unnecessary demand on your speaker for that frequency range. This can lead to early distortion and even speaker failure. You will notice that Rockford only allows you to boost any given band by 6db but you can cut any band by up to 24db! This is because the guys at Rockford are smart and know what they are doing. Cutting instead of boosting is a critical skill to acquire if you want to master the EQ.
- Always start with adjustments at lower mid frequencies and move your way up. Don't touch any bands below 250. The math behind the physics of sound waves dictates that a lot of frequency related issues actually occur at lower frequencies, and then those same issues cause problems at higher frequencies. So if you start with making adjustments to high frequency bands, you will often not be solving the core issue at all. You could even make things worse! Horn loaded tweeters are an exception (sort of). This is because most all horn tweeters have at least one really huge spike that needs to be adjusted before anything else can be done. To find this spike, go up and down with every band, one at a time starting at 4khz and working through 8khz. The goal is to identify the band that has the most profound effect on the tweeters sound. You will find that one band in particular will make the horn (tweeter) go from better sounding to unbearable. Once you find that band, you should make an appropriate cut in gain and then move on to changing the Q on that band (lower it) until you get the best sound. Adjusting the Q to a lower number (try 1.4 first and then go up or down from there) will widen that band so that more frequencies are effected. With horn tweeters it is not unusual to need cuts of up to 10 or 12db at the frequency range where the horn is most efficient. All horn designs are different.
- Use the basic EQ in the DSR1 app first. Then move on to the advanced EQ. Remember that the goal is smooth transitions and small adjustments.
- Don't adjust "Q" factors for the individual bands until you have already gotten to the point that the system is close to dialed. Even very advanced users don't normally have to use an Q adjustments at all most of the time. The Q adjustment can be a very handy and powerful tool for an advanced user, but it is not usually a necessity.
- Make your adjustments in the advanced EQ in groups (bands close together). Refrain from dramatic peaks and dips between bands. Most valid adjustments will be gradual between bands. Sharp adjustments between adjacent bands can cause other more complex problems.
- Rely on your ears for the final judgement. Even when using test equipment like I describe below, your ears should always have the final say.
Important Frequency Ranges to Pay Attention to First
Pro Tip: If you are using an equalizer that has a parametric feature (adjustable Q), set the Q for each band mentioned below to 1.4 before you start. Don't change the center frequency on any band. Leave them be. There is a very good reason for this. Most popular EQs are 1/3rd octave (30 to 32 bands). It is well documented that humans hear in octaves (doubling or halving of frequencies). The human anatomy has a difficult time detecting changes at a smaller level. There are 10 octaves in the human hearing range. a 1/3rd octave EQ slpit each of those octaves up into 3 segments. The idea is that you not only get an adjustment at every octave, but that you can also shape each octave. But remember that humans have a very difficult time evaluating those changes at that small of a level. So, save your self some time and frustration. Start with single octave adjustments (Q set to 1.4-ish). Then move on to smaller adjustments between if needed.
- 100hz range. This is the bass range that can be heard best on a bike. That makes it important.
- 1khz - 2khz range. This range has a lot of impact on vocals and can make them sound bold or thin.
- 4khz range. This range has a lot of impact on how spacious the vocals sound.
- 6 to 8khz range. This range is particularly important to any system that uses horns. Horns typically have a 8 to 12db spike in this range and that is what makes them sound shrill. Cut the correct amount in this range and you can get horns to sound great and still have a sound system that is three times as loud as any system without horns. Horns are the turbo charger of the audio world. They get you huge leaps of efficiency but they also require more tuning to get the final result you are looking for.
- 10khz range. This range is the best place to start when making the high brighter or duller. Frequencies above this range can make a system sound very harsh if not kept under control.
Want to See Exactly What Is Going on with Your Sound?
It's cheap and easy to do using a second smartphone. Not everyone really needs to do this, but if you want to get it right down to a gnat's ass, this is how you do it. Go to Parts Express and order the Dayton Audio iMM-6 microphone ($14.50). And while you are at it get yourself a 6 foot 4 pole 3.5mm extension cable so that you can hold the smartphone in your hand while you use it to tune your bike. The idea here is that you can play a test track called "Pink Noise" through your system and the microphone picks up that test tone and displays a frequency graph in real time. In the picture above the result is displayed on the tablet. Then using a second smartphone or tablet you can adjust the EQ(s) in the DSR1 to flatten that frequency graph out in real time.
This is a very powerful tool that allows you to quickly discover and accurately identify frequency based problems so that you can correct them. But remember, the small adjustments should be based more on what you hear and not just on what the graph says.
When using an RTA (Real Time Analyzer) system like this, you typically go back and forth looking at the graph and listening to music several times before you get to a result that you are looking for.
You can find the microphone here: https://www.parts-express.com/dayton-audio-imm-6-calibrated-measurement-microphone-for-tablets-iphone-ipad-and-android--390-810
You can find the cable here: https://www.parts-express.com/parts-express-35mm-four-conductor-trrs-extension-cable-for-mobile-devices-6-ft--240-002
You can find the RTA app to use on your smartphone here: https://studiosixdigital.com/audiotools-modules-2/acoustic-analysis-modules/rta/
This is my favorite app to use but there are many many RTA apps out there to chose from.