You have picked a difficult loco for sound which you are finding out. I know from experience.
Good sound usually requires a baffle behind the speaker even with a tender that is well sealed. I use styrene.
Go to You Tube and search for maybe DCC speakers. There are a couple fellows who have compared different speakers. Speaker quality vary a lot.
Iphones have nice speakers.
SoundTraxx lets us play with the sound quality.
I have never used TCS. I have a couple locos with LokSound.
Rich
I purchased an NCE D14SR decoder. It has the 8-pin NMRA connector but no harness. It came with a little 8-pin riser. It plugged right in and the engine runs fine, although it’s a tight fit. Being new to DCC I am dismayed at the high cost of the DCC decoders and DCC gear in general relative to other electronics. Compare the size and complexity of the $30 decoder which is a postage stamp-sized board that holds just a couple components with a $50 Raspberry Pi which is a full-featured computer.
It’s called volume, and also size. They sell more Raspberry Pis than any decoder. And the Pi is not ultra miniaturized. Just one of the USB connectors is bigger than an 8 pin decoder plug. One of those components on that decoder is a full computer, with both RAM and ROM (well, EEPROM). Another is a tiny speck that is still capable of controlling more than 1 amp of current.
This is also why it’s good to learn to wire in your own decoders instead of using factory boards and plugs - the wired type are usually less expensive.
Oh, and those Pis are mass assembled in factories in China, that decoder is actually made in the USA.
–Randy