Backing Tracks Issues

I've just acquired a used Bose L1 Model ll with Tonematch T1 and B2, and at the moment I'm trying good tracks from my phone into Channel 3.

With some tracks the sax solo or guitar solo, and even backing vocals are pretty much lost.

I've tweaked the low, middle and high in the Tonematch T2, with losing most of the low and it improves somewhat, but doesn't really match what I would hear directly from phone through headphones.

Will a good factory reset solve the situation, or is something more needed.




Hello Donie,


Congratulations on acquiring your L1 Model II system.


What kind of cable are you using to connect your phone to Channel 3?  If you are using a 1/8" TRS plug to 1/4" TRS plug, that usually produces the sound you describe, sometimes a "hollow" sound.  The T1 is a mono mixer, and all its jacks are mono jacks.  Ideally, you should use a 1/8" TRS plug to two 1/4" TS plugs (as pictured below) into the two Channel 4/5 jacks.   Channel 4/5 is really just one channel with two jacks, and works well for combining two signals, such as the left and right stereo signals.

Dual Quarter Inch TS to Eighth Inch TRS.jpg

The phone is putting out stereo L and R signals, and since the T1 is mono, it's probably only picking up either the L signal or the R signal and ignoring the other, or cancelling them against each other.  The Channel 1-3 combo jacks are balanced connections, expecting and - signals rather than L and R signals.


Several manufacturers also make DI boxes that convert a stereo "consumer" device like a phone or MP3 player to a balanced XLR pro audio signal.


Does that help?

Hello Fish-54,

Thank you so much for your informative reply.

It makes perfect sense, and I quickly realise that, having become so accustomed to stereo sound, you lose sight of the fact that mono is still alive and well.

I will source the required cable, and report back.

Thanks again for taking the time and trouble to assist me.

Go into your phone settings (is it an iphone?).. General/to the Accessibility setting and scroll down to mono it's used for the hearing impaired to combine both right and left channels into one mono output..Try it..That's what I use.

Hello Fish-54, and Bongos46,


Bongos46, on my android phone I couldn't find any way to change to mono sound.


Fish-54, I bought a 3.5 TRS to TS standard mono 6.35 jacks  lead,  and the imbalance situation is sorted.


Thanks to you both for your input.

Hello Donie,


Thanks for letting us know that took care of your sound!


By the way, my "mono" choice for Android is under Settings, Accessibility, Hearing, Audio Channel, then select "Mono" or "Stereo".  I'm on an LG V30, so your version of Android may be slightly different.  Of course, if using this option, you would constantly be switching back and forth going between T1 or earbuds (unless your device is dedicated to one of the other.)