[twriter]

With data from 2 devices, and iPhone X and a Pixel XL, I feel confident in saying that it's the Bolt that for some reason plays sound via Bluetooth orders of magnitude lower than from any other source, including from the same devices connected via CarPlay/Android Auto. with both devices, now, I've been playing music that was stored on the device via CarPlay/Android Auto, disconnected the cable, and selected the sound source as the device via Bluetooth. What once was a reasonable volume becomes barely discernible--and that's with the car parked in a quiet garage.


On another thread, someone claimed that the volumes are set separately, that you can adjust the Bluetooth volume only when Bluetooth is connected. I disagree. Multiple times I have increased the volume while playing from Bluetooth and switched sound sources, only to be practically blasted out of the car.

 

[SodePop]

I definitely agree. The FM/XM radio sources are a lot louder than USB and Bluetooth. Well, I haven't messed around with Bluetooth much, except a bit with Android Auto connected. That's pretty much the same thing. I mainly listen via USB player. But yeah, these sources are a huge difference in volume and much quieter. This has been discussed in various forums and even on Reddit. Nobody seems to know anything. I honestly think it's the head unit and/or just how GM powers these sources or something. In my experience, Bluetooth and USB are always much louder than radio sources, but this vehicle it's the opposite. I think we're stuck with this crap. UGH. I'm not an electrical engineer, so I have no clue. LOL.

 

[Albemarle]

This is probably not a solution to this problem, but sometimes on the iPhone with Bluetooth, the phone volume control is also active. Don’t know if this applies to the Bolt but worth trying turning up the iPhone volume, if you haven’t, but you undoubtedly have.

 

[Raymondjram]

This may be a deficiency in the Bluetooth protocol, since it uses FM to transmit sound and the volume is limited to the FM bandwidth used in the transmitter. All my Bluetooth headphones (one brand is Samsung) have low volume, so I have to increase my smartphone volume a bit. Regular plugged in headphones can be extremely loud at the same volume setting.

 

[ArizonaJon]

I definitely agree. The FM/XM radio sources are a lot louder than USB and Bluetooth. . LOL.

FYI, I have a 2019 and switch between FM/XM and USB with no change in volume. I have never tested Bluetooth.

 

[SodePop]

FYI, I have a 2019 and switch between FM/XM and USB with no change in volume. I have never tested Bluetooth.

Interesting. Do you have a premier or the LT trim? Might make a difference, as the premier would have a factory amp. Also, what type of USB device are you using to play music? Just wondering. I did use an iPod, then now I am using a SanDisk flash drive. Both experience the same volume issue.

 

[ArizonaJon]

Interesting. Do you have a premier or the LT trim? Might make a difference, as the premier would have a factory amp. Also, what type of USB device are you using to play music? Just wondering. I did use an iPod, then now I am using a SanDisk flash drive. Both experience the same volume issue.

I have a Premier. I use a SanDisk Cruzer Fit in USB 2. See attached photo.

I use this type of flash drive as it only extends about a half cm beyond the console. I have also included a photo showing the flash drive inserted into the USB port.

I noticed in the settings I have Auto Volume (see page 166 of 2019 owners manual) turned on. This is not described as having anything to do with changing between sources, but who knows for sure?

From you question, I believe you have an LT. Is this correct?

 

[SodePop]

I have a Premier. I use a SanDisk Cruzer Fit in USB 2. See attached photo.

I use this type of flash drive as it only extends about a half cm beyond the console. I have also included a photo showing the flash drive inserted into the USB port.

I noticed in the settings I have Auto Volume (see page 166 of 2019 owners manual) turned on. This is not described as having anything to do with changing between sources, but who knows for sure?

From you question, I believe you have an LT. Is this correct?

That's the exact same flash drive I am using as well, just the 3.1 equivalent. And yes, I do have the LT. So that might be the major difference. Not sure. I also don't have USB ports in that location, as mine are inside the center console area. Auto volume has always been turned off since day one. I think I'll turn it on and just see if it makes any difference. Thanks for the info.

 

[Sibilance]

I personally have a 2019 Premier. i don't use USB drives, but I have noted that the Bluetooth media volume is much lower than local FM station volume.

In my case I have just got in the habit of tuning the car to a local classical station. Classical music stations tend to have a very very wide dynamic volume range, because that is best suited to the music in question. The vast majority of the time it is playing music at a lower volume than the rock station. Unless they are playing something with cannonade.

During the brief window before the bluetooth audio is up and running, at least I'm not blasting my ears.

 

[rlhammon]

That's the exact same flash drive I am using as well, just the 3.1 equivalent. And yes, I do have the LT. So that might be the major difference. Not sure. I also don't have USB ports in that location, as mine are inside the center console area. Auto volume has always been turned off since day one. I think I'll turn it on and just see if it makes any difference. Thanks for the info.

I have a 2019 LT, a similar USB flash drive, and 90+% of all of my music I do over Android Auto. I have the same issues in that the volume is simply too low on AA and switching to other sources the volume is then greatly increased. My usual AA volume level is 25, and all other sources is 15.

Unfortunately the dang radio swaps over sources everytime the car is started. So... I finish a drive with AA playing, when I start up it's back to the radio despite having my phone connected prior to starting the car. Then... I start to increase the volume again. I wish the auto volume limit was set per source, and was smart... OR leave the source alone and I don't have to manipulate the volume all the time. If I unplug my phone prior to opening the driver's door then I'm blasted with the radio at Volume level 25. The whole setup is rather stupid in regards to how the volume is setup IMO.

 

[ArizonaJon]

I have not used bluetooth for audio. But as I said before, no problem if I use a usb flash drive. However, if you have not set the volume correctly on the recording, it can cause a problem. I always check and adjust the volume as necessary. I use a free audio editing program called Audacity.

I found several youtube video explaining how to edit the audio using Audacity.
You can download Audacity free from https://www.audacityteam.org/download/.
A video at

is a very short video on how to install the codac.

 

[Sean Nelson]

This may be a deficiency in the Bluetooth protocol, since it uses FM to transmit sound and the volume is limited to the FM bandwidth used in the transmitter.

The FM carrier transmits a digital data stream - it's the number of bits per sample in the data protocol that determines the dynamic range of the signal (minimum to maximum range of volume), not the carrier.

 

[Terry Hancock]

I do not think that my situation exactly affects the USB level part of this discussion. But, just in case, I use predominantly a USB drive. All my songs are at 320 mbps. That is only slightly less than CD quality. With XM, before it was turned off, I noted only a slight difference in volume between my USB drive and the XM/Sirius channels.

When switching to standard FM reception, I noted that the stations are much louder than my USB. But, that is because they all are highly compressed. Besides being loud, they also, of course, have very little dynamic range.

With my sampling, the USB has been the standard to judge other modes by. While only a couple of clicks lower than the volume of XM, the USB gives me a decent dynamic range.

 

[SodePop]

I do not think that my situation exactly affects the USB level part of this discussion. But, just in case, I use predominantly a USB drive. All my songs are at 320 mbps. That is only slightly less than CD quality. With XM, before it was turned off, I noted only a slight difference in volume between my USB drive and the XM/Sirius channels.

When switching to standard FM reception, I noted that the stations are much louder than my USB. But, that is because they all are highly compressed. Besides being loud, they also, of course, have very little dynamic range.

With my sampling, the USB has been the standard to judge other modes by. While only a couple of clicks lower than the volume of XM, the USB gives me a decent dynamic range.

Yeah, I experience very different results. XM and FM are much louder when compared to music on my USB drive. All songs are also encoded to about the same as yours, but I hear a very significant change in volume levels...and range. I would presume that you have a premier model? That might be the difference with others that have an LT model. Anyways, I did experiment with the auto-volume setting, which I've disabled since taking it off the lot...and it makes a HUGE difference. The volume is a lot louder when I'm driving. I switch from just medium to off while going say 35ish MPH and the volume levels are way different. Still, I don't think this is anything I'd want to enable because I see no point. I can change the volume on my own. LOL. Ultimately, USB sucks in this car, or mine at least, and all other vehicles I've experienced the complete opposite. Very odd. And it bugs me. UGH

 

[Terry Hancock]

I have an LT.

I could hardly tell the difference between XM level and the USB level.

With its heavy compression, local FM is much louder, on average, than my USB. But the ratio never changes. It is always the same db difference.

Did you know that you can set your own overall degree of compression for any source? It is in the EQ section of audio settings. If you want, you can make everything LOUD...just like they master today's music, by changing those settings. I wanted dynamics, so I use about the lowest setting. BUT, you can choose a compression level that will make you hear every detail, at 60 mph with the windows open. At that level of compression, there is little or no difference between a bass drum kick and a whisper.

 

[SodePop]

I have an LT.

I could hardly tell the difference between XM level and the USB level.

With its heavy compression, local FM is much louder, on average, than my USB. But the ratio never changes. It is always the same db difference.

Did you know that you can set your own overall degree of compression for any source? It is in the EQ section of audio settings. If you want, you can make everything LOUD...just like they master today's music, by changing those settings. I wanted dynamics, so I use about the lowest setting. BUT, you can choose a compression level that will make you hear every detail, at 60 mph with the windows open. At that level of compression, there is little or no difference between a bass drum kick and a whisper.

Hmm. I'm not quite sure what you mean? If you are talking about the tone settings, I have the [3] options set to the middle. I don't mess with that because I have a DSP that does my EQ's. In regards to compression level, are you talking about the auto-volume setting?? Overall, though, my system is plenty loud. Loud enough where you can't hear yourself talk. And it's also extremely clear. I'm not looking to make it louder...I just notice a very big difference when switching inputs. That is what's bugging me.

Also, out of curiosity, what USB device do you use to play your music??

 

[Terry Hancock]

Yes, the auto volume choices are compression choices.

I use a Lexar 32gb drive.