I'll preface this by saying that I work in audio.
I just purchased a brand new 2015 Corolla a few days ago. I had a 2009 Corolla and thought it would be a nice update. I started playing some music after buying it and I was dismayed. The sound quality was some of the worst I've ever heard in any vehicle. It actually sounded like the speakers were wired out of phase! I brought the car back and told them I thought the polarity of the speakers on one side of the car was inverted. I did the phase test (Google one, there are many) and the car's audio was definitely OUT of phase.
After a bit of back and forth, they told me to come back in and pick up the car the following day. They essentially said it was wired correctly and they couldn't do anything. I brought the car home again and did some tests and found out that the Corolla/Entune has some kind of stereo imaging processing that deliberately puts certain frequencies out of phase to make the sound "wider". This is something common on 90's boom boxes. "SRS WOW" was one of the main ones. The difference being that these items almost always had an option to turn this function OFF!! How could this not be an option!!
For proof, I used a matched stereo pair of Mics on each of the door speakers and recorded a mono signal being played through each speaker at various frequencies. Essentially, the waves below should all appear identical but they are not. The phasing at different frequencies is apparent.
I attached an image of the waveforms.
Is there a remedy for this? Is there some mode switch that I am missing? Does the JBL/Premium Audio have this issue as well? Any input is welcome. Thanks!!
I just purchased a brand new 2015 Corolla a few days ago. I had a 2009 Corolla and thought it would be a nice update. I started playing some music after buying it and I was dismayed. The sound quality was some of the worst I've ever heard in any vehicle. It actually sounded like the speakers were wired out of phase! I brought the car back and told them I thought the polarity of the speakers on one side of the car was inverted. I did the phase test (Google one, there are many) and the car's audio was definitely OUT of phase.
After a bit of back and forth, they told me to come back in and pick up the car the following day. They essentially said it was wired correctly and they couldn't do anything. I brought the car home again and did some tests and found out that the Corolla/Entune has some kind of stereo imaging processing that deliberately puts certain frequencies out of phase to make the sound "wider". This is something common on 90's boom boxes. "SRS WOW" was one of the main ones. The difference being that these items almost always had an option to turn this function OFF!! How could this not be an option!!
For proof, I used a matched stereo pair of Mics on each of the door speakers and recorded a mono signal being played through each speaker at various frequencies. Essentially, the waves below should all appear identical but they are not. The phasing at different frequencies is apparent.
I attached an image of the waveforms.
Is there a remedy for this? Is there some mode switch that I am missing? Does the JBL/Premium Audio have this issue as well? Any input is welcome. Thanks!!
