Harley Sound System Upgrades: Recent Episodes
Rob Gomez
How to Use RTA App
To use the Peek-A-Boo you will need to find an RTA app for your phone. RTA stands for Real Time Analyzer and it is an app that listens to the phone's microphone port and slices up the audio it hears into 31 bands just like the 31 bands of a standard equalizer that range from low frequencies to high frequencies so that you can instantly see any and all level differences amongst 31 slices of the sound spectrum. The RTA app that I recommend for the Peek-A-Boo is actually called RTA and is developed by Andrew Smith. This app is only available for iOS but fret not, there are lots of other RTA apps out there for Android as well.
Important RTA App Settings
Any good RTA app will have a settings section that allows you to load a microphone calibration file so that any deviations in a microphone used with the app can be accounted for. When you buy a microphone that is designed for laboratory testing the microphone comes with this calibration file which is just a text file containing performance data for your specific microphone and formatted so that it conforms to an industry standard.
When we use this app with the Peek-A-Boo we will not be using a microphone. Instead we will be physically plugging directly into the bike’s stereo system. But we still need to be concerned with the microphone calibration file because by default most RTA apps will load a calibration file for your phone's internal microphone, and that will totally throw off the accuracy of the app. So I have written a special calibration file that has a flat response for the microphone input. This file conforms to the industry format standards, so you should be able to use it with any RTA app. You can find the download link in the article below.
Now the Peek-A-Boo is ready to plug in and use as is but there are two more simple adapters that we are going to want to make that will allow you to connect to additional parts of the bike.
The first adapter you will want to make is a short female 2 pin molex to RCA cable. This will allow you to plug into any RCA connection. A good example of when you would need this is if you are using a sound processor like a Rockford Fosgate DSR1. You will be able to plug into the RCA outputs of the DSR1 and clearly see the frequency response of the signal exiting the DSR1. You can then use the EQ and crossover of the DSR1 to flatten out or shape that signal before it makes it to the amplifier. Additionally you can also use a free oscilloscope app on your phone to check for clipping, noises and other types of distortion. I will make a dedicated article soon that covers that topic. The important thing to understand is that now you have the physical connections to connect your phone to various parts of your audio system and there are all sorts of apps out there that you can use with your phone. Your phone is a very powerful computer and now you have many options that you did not have before.
The last adapter that we want to make is a 4 pin female Molex with 2 two pin female Molex plugs on the other end. This adapter will plug directly into your Harley radio’s rear speaker output as well as several American Hard Bag wire harnesses including our lid speaker wire harnesses. The adapter uses two separate 2 pin plugs so that you can choose to look at the right or left side signal. Or in the case of our lid speaker harness you can plug into the tweeter speaker lines or the 6x9 woofer speaker lines and see what's going on with each individual circuit. If you get your molex connectors from us with an order, we will have this adapter already assembled for you. For those of you who are sourcing your own connectors you can find a parts list and pinout diagram in the article below.
XLR cables have three conductors
- Ground wire. This is the shield around the cable and it has continuity with the metal XLR connectors as well as pin number 1 inside the XLR connector. Strip this shield back to access the remaining two conductors (red and black sometimes red and white) and cut the ground shield off entirely and insulate it so that it can not make contact with any part of the audio system or bike. This ground conductor is the return path for a 48 volt phantom microphone power circuit and plays no part in our project. We want to eliminate it all together.
- Red wire (XLR pin number 2) is the positive audio signal line and should be connected to pin number 1 on the two pin male Molex connector.
- Black (or in some cases white) wire (XLR pin number 3) is the negative signal line and should be connected to pin number 2 on the Molex connector.
You can make a Peek-A-Boo tool by connecting an XLR adapter to your phone. XLR is a three pin audio connector that is the industry standard connection type for the pro audio industry. It allows you to plug many different types of equipment together with a universal connection. XLR adapters for smartphones are designed to allow you to plug a very wide variety of audio devices right into your phone that range greatly in audio signal strength. And that makes XLR the perfect interface for this project, because they allow you to feed an unmodified audio signal directly to your phone and that signal can range anywhere from extremely weak and very low in level like the RCA outputs of your DSP to very high voltage such as at the amplifier output terminals without overloading your phone. The XLR adapter has an internal battery powered circuit that isolates the signal from the phone and it automatically regulates that signal level for you.
In this article I explain a simple hack that allows you to use your smartphone as a Harley stereo system x-ray. This hack allows you to actually see the audio signal at multiple stages of an audio system. And I’ve made it Harley plug and play. I call it the Peek-A-Boo. This hack will work for any type of audio system but the cables and assemblies that I explain here are very specific to Harley stereos and are totally plug and play.
Use an RTA app on your smartphone to tune your Harley audio system like a boss. Why tune blind when there are great apps that let you see it all on screen?
Factory Harley Radio Integration Secrets For ‘14 & Up
It is very possible to get great sound out of your ‘14 & up factory Harley radio. In fact, there are several sound performance advantages to keeping the factory radio that you could never get with an aftermarket radio. However there are a few things to know before you get started. This article is intended to be an aid to anyone looking to upgrade their Harley audio system with the new generation of radio (2014 and up). This article will give you a good grasp on how to properly perform a quality upgrade and how to avoid some of the bad information and practices that we see out there. The information in this article applies to all '14 & up Harley radios regardless of which model radio you have (touch screen, no touch screen, GTS, nav, no nav etc.)
In This Article We Will Cover
Factory vs aftermarket radios
How to properly integrate with your factory radio (connections)
Clarify what radio flash you need
Explain how to tune aftermarket equipment to perform with your factory radio
Factory vs Aftermarket Harley Radio
Why don’t people like the factory radio? The number 1 reason people want to switch their factory radio out is that they incorrectly assume that it will just be better. And that simply is not the case.
Performance Advantages of the Factory Radio
Volume Dependent Loudness Curve. Makes the system sound much better while riding than any aftermarket radio can.
Modern Features. CarPlay, Bluetooth, and USB make factory radios very functional in today's world.
Made for Riding. A display that you can see in the sun, native hand controls, and high weather resistance makes the factory radio a practical choice.
Performance Advantages of an Aftermarket Radio
More, yet very limited audio adjustments built into the radio.
Faster boot time compared to the old Harley GT radios but not compared to the GTS radio (2019 and later).
Nicer display than the old GT radios (not in the sun!), but not nicer than the newer GTS radios.
RCA outputs make connecting to aftermarket gear simpler but you lose the factory radio’s balanced audio signal and volume dependent loudness curve (huge deal!).
Connections
To properly integrate an aftermarket sound system with a factory Harley radio you need the right wire harnesses to make your connections. It is important to understand that the best integration wire harnesses for your factory radio do not change the radios output voltage or frequency response. Those two changes are made with a radio flash and should never be done with any passive device (a dummy part that does not require battery power). American Hard Bag makes two types of integration wire harnesses
Radio T Harness
This harness is the best option for most systems. It connects to your Harley audio system by intercepting all of the audio circuits directly at the radio. This way you not only get signal from the factory radio from all four channels but you also get access to the bikes factory speaker circuits. And that can eliminate the need to run new aftermarket wires through the bike. The radio T harness also gives you access to the bikes 12 volt accessory circuit that you can use to automatically turn your amplifiers on and off through the bikes ignition switch.
Front signal Only Harness
This harness is perfect for any system that does not need to use factory rear speaker circuits because you are either not using rear speakers or you are adding rear speakers that were not factory so there are no factory wire runs available.
Digital Sound Processor (equalizer)
Do you need a DSP in your system? The simple answer is yes, but that depends on what your expectations are and what speakers you plan to use. If you are building a system that is anything but mild then you need a DSP. Also if your system uses horn loaded tweeters you need a DSP. Pro audio type speakers that u
Jesse and Rob discus the nature of horn loaded tweeters and how they fit into the world of Harley audio systems.