Audio & DSP Tuning

 

Tuning an audio system properly goes beyond listening to your favorite song and playing with settings until you say to yourself that sounds good. To start the majority of people in the world do not have perfect hearing and that level of non perfect hearing various by each individual. Even the physical aspects of a persons ear can change how one person hears something to the next. Also every song is recorded differently, so tuning to that one song may sound good for that one song, but may sound bad on others.

How do we verify that our audio tuning is accurate? We are able to achieve accurate tuning because we invest and use the proper tools for audio tuning. Our most frequently used test equipment are the Oscilloscope and RTA ( Real Time Analyzer ).

Radios, External EQs, External Crossovers, DSPs ( Digital  Sound Processors ), and amplifiers have a point where the signal coming out is distorted. This distorted signal is referred to as a clipped signal. Clipped signals can makes the music sound distorted and can be harmful to speakers / subwoofers. Our Oscilloscope allows us to look at the amplitude of the audio signal coming out of each component so we can send maximum volume without any clipped signal to the next component. It will also give us an idea of where we should not go with volume levels to avoid heavy distortion or damage to speakers / subwoofers. Once those gain adjustments have been measured & properly set we now know what the proper operating range of your radio / stereo system is.

The next step varies on whether or not we are dealing with an aftermarket radio or if the audio system is being integrated into the OEM factory stereo system. To achieve the best sound, the goal is to have your radio send a flat full range frequency response to the rest of the audio equipment. When some people hear the term flat they think of it in a negative way because they do not want their music to sound flat. In reality flat is a good thing! Humans, if we have perrfect hearing, hear from 20Hz up to 20,000Hz. If the audio signal being played is flat from 20Hz - 20,000Hz then you are hearing the most accurate representation of that musical track you are listening to! You are now hearing the song the way it was when it was recorded in the studio! So flat should not be thought of as a negative term and you should think of flat as being an accurate representation of music.

The benefit to an aftermarket radio is that any reputable radio manufacturer will be providing a full range of output with a relatively flat frequency response. So with an aftermarket radio there is no additional work that needs to be done to the radio's output signal. Once we have set gains with the Oscilloscope we can move onto using the RTA to tune the speakers output to the listening position. If we are dealing with an OEM factory stereo system then we need to use the RTA to evaluate the electrical audio signal to see what kind of audio signal we are starting with.

More than 90% of the OEM factory stereo system do not provide a flat full range audio signal. Many OEM factory stereo systems do their own changes to the electrical audio signal so they do not blow the factory speakers frequently or sometimes to make us think the car is not as noisy when driving. In an OEM factory stereo system the audio signal output is usually not anywhere close to flat and then we add the signal processing built into the stereo system and it adds a whole other world of issues that are big reasons for poor sound quality. To give an example of some of the signal processing issues found in OEM factory stereo systems are things like Bass Roll Off, Fixed  or Automatic EQ, All Pass Filters, Phase or Polarity, Time Alignment, just to name a few. Besides the signal processing done for the audio side of things there is also signal processing done for other aspects of the vehicle, things like ANC ( Active Noise Cancellation ), Fake Engine Noise, etc. 

The following step to the Oscilloscope measuring / adjusting when using an OEM factory stereo system is to use our RTA to measure the electrical audio signal to see which + how many of types of signal processing the OEM factory stereo has. This the step we refer to as our OEM Integration Analysis. This step we do prior to designing an audio system as the OEM Integration Analysis will give us the information needed to know if you can simply add an amplifier to your OEM factory stereo system or if you will no some form of DSP to properly integrate an audio system. 

Once everything before and at the amplifiers have been set up we can now use our RTA to adjust the speaker's outputs to the listening position. Our RTA utilizes a 5 headed microphone that simulates a human head and our RTA microphone does averaging of each of the 5 microphones for a much more accurate view of the sound versus a single microphone RTA set up.

Whether you are looking for the most realistc sounding audio system or the loudest sounding audio system SoReal Sounds has the capabilities to tune your audio system as close to your goal as your equipment + installation + vehicle will allow! We do not guess when we say we are tuning for a certain result, we use our test equipment to ensure that!