DSR1 Practical Phase and Time Alignment Tricks
The DSR1 has a real cool trick up its sleeve for bikes that use more than one pair of speakers. It has the ability to reverse the phase of any speaker with just one tap of the screen. This is functionally the same thing as reversing the positive and negative wires at the speaker.
Why Would I Want to Do That If I Wired My Bike Correctly?
The primary reason why this is an important feature is because even if you wire the entire bike correctly the various speaker channels are still likely out of phase!
Yeah, when you make crossover and equalization adjustments to the DSR1 (or most any commercially available processor) the signal for that particular channel is delayed due to the added time it takes to process the signal. This delay results in a phase shift. The intricacies of digital delay and how it relates to speaker phase is a complex subject and this article is an explanation of a quick solution, so I am not going to get into all of the complexities here. Google it or just trust me.
The Simple Solution
The quick fix is real simple. Go to the time alignment section of the advanced tuning mode. Then select the channel you want to change by swiping the screen left or right. The time alignment icon can be found at the bottom of the screen in advanced mode only. It's the icon with the clock.
Above left, the red hand points to the channel indicator that shows which speaker channel you are adjusting. Now tap the invert phase icon (light blue hand). The icon will change to show that the phase for that channel has been inverted (yellow hand).
It is a good idea to flip phase on channels in pairs. Remember that even though we don't know how much phase has been affected due to crossovers and equalization we do know that on a Harley left and right channels always have the same settings, so they also have the same amount of phase shift.
Do the same for all the channels (one pair at a time) and listen to the difference in sound as you do it. Try different combinations to get the best results. Left and right should always use the same phase setting.
Things to know
The phase relationship between speakers dramatically affects the frequency response. So when you are flipping phase around on channels you want to be careful about making a judgement based solely on an improvement in frequency response. The following are other important attributes that are generally more important. Frequency response (bass, midrange, treble balance in relation to each other) should not be your primary concern at this point.
- Start with the woofers. If you have multiple woofers in the bags you should pay close attention to how the bass is affected by making phase changes on these speakers first. Harder hitting bass is a good indicator that your phase is more correct.
- Invert phase on the front speakers while you sit on the bike. You will notice that the sound appears to shift forward or backwards. Choose the setting that sounds best in the riding position and not when your head is turned towards the back of the bike looking at your bags.
- Invert the tweeters last if your tweeters are on their own dedicated channels. Use a recording with clear vocals. Choose the phase setting that makes the vocals seem more focused and bold.
- Don't worry about possible phase shift amongst speakers that share the same amplifier channel (as long as you wired them correctly). If they are connected to the same output channel on the amp then settings on the DSR1 can not change the phase relationship between the two.
- Finding the best phase settings should be done after all crossovers have been set but ideally before the EQ has been set. Then set your EQ and revisit the phase settings. It may take a few times of going back and forth if you want to squeeze every last ounce of performance out of your system
- Correct phase adjustments to all channels can add a lot to your total SPL.
The distance that a speaker is placed from the listener relative to the distance of other speakers in the system makes an audible difference in the sound. Ideally all speakers would be the same distance from the listener. When a set of speakers are far enough away in relation to another set of speakers this effect can be quite profound. A good example of this would be the distance of bag speakers to the listener vs. the distance of fairing speakers.
Fortunately we sit dead center of the left and right speakers, so distance relationships between left and right speakers on a bike is never an issue. However lowers and bag speakers can throw a wrench into the works.
Time alignment is a digital delay that you can optionally add to a channel in order to correct a speakers distance relative to another. For example: if the fairing speakers are 1 foot closer to you than the bag speakers, you can add a little delay to the fairing speakers and the sound from both sets of speakers will arrive at your ears at the same time. Using this feature of the DSR1 can make your bag speakers much easier to hear and will have the effect of making the sound appear to all come from the fairing speakers. It's a good way to get a bolder "in your face" kind of a sound.
Note: time alignment should be done only after basic phase has been adjusted as described above.
Time alignment can be thought of as incremental phase adjustments. Instead of flipping phase by 180 degrees, you can change it by smaller amounts. If you add enough delay using time alignment the speaker that you are adjusting will eventually become 180 degrees (or even more) out of phase in relation to other speakers in the system.
It's a good idea to first make your 180 degree phase choices and then follow up with some time alignment to fine tune each channel.
How to Adjust Time Alignment
Quick adjustments are made by using the slider in the center of the screen. As you slide upwards you add delay to that channel. The plus and minus buttons to the left are for fine adjustments. These are nearly useless in a Harley application but are very useful in a car where you would want to be able to make micro adjustments between left and right channels.
Things to Know
Just as with basic phase adjustments, all adjustments to time alignment should be done to both left and right sides before moving on to other channels. Left and right should always have the same settings.
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.
Owner of American Hard Bag