I haven't done that. Our field is in a rural setting, so noise really isn't an issue.

The unbaffled & drilled out TT muffler sounds about the same as the stock Tower "tuned" muffler, or GMS "tuned" muffler. Noisier than an OS AX box muffler, but not outrageously loud.

Speaking of the OS AX muffler -- that also gives the TT Pro a dose of extra power -- & it's quieter.

I've compared a TT 46 Pro, an OS 46 FX & an OS AX in a side-by-side static RPM test. Both of the OS engines out reved the TT when all were equipped with their stock mufflers. The AX had a whisker (~100 RPM) on the FX, which had a whisker (~150 RPM) on the TT.

I also measured each one, in turn, with the AX muffler & you couldn't tell the difference between them. On that day, at ~130M ASL, at ~ 20 C (as I recall) & using 10% Omega and an APC 11-6, each one turned ~13,600 static RPM with the AX muffler.