On another note, did you get a chance to try those config.ini settings to see if they help out with the loudness of the music in relation to the ttsd output? If it's really a problem and we need to scale down the ttsd samples, we'll have to find someone on the board who's comfortable tweaking the ARM assembly code that does that dirty work. None of the obvious tweaks I tried seemed to work. Any takers?

__asm__ (

    "stmfd  r13!, {r0-r12,r14}\n\t"



    // initialize registers

    "ldr  r1, %0\n\t"       // r1 = audio_overlay_bg_volume

    "ldr  r4, %1\n\t"       // r4 = pDstSample

    "ldr  r5, %2\n\t"       // r5 = pSrcSample

    "mov  r6, #2304\n\t"      // r6 = loop counter

    "sub  r6, r6, #1\n\t"     // r6 -= 1

    "mov  r7, #65280\n\t"     // r7 = ...

    "add  r7, r7, #255\n\t"   // r7 = 0xFFFF

    "mov  r8, #32512\n\t"     // r8 = ...

    "add  r8, r8, #255\n\t"   // r8 = 32767



    ".MixLoopStart:\n\t"



    // scale destination sample down by fixed-point multiplier

    "ldrsh  r0, [r4]\n\t"     // r0 = *pDstSample

    "mov  r0, r0, lsl#16\n\t"   // r0 <<= 16

    "smull  r2, r3, r1, r0\n\t"   // r2 = lo(r1 * r0), r3 = hi(r1 * r0)

    "adc  r2, r2, #32768\n\t"   // r2 += 32768 + carry

    "mov  r2, r2, lsr#16\n\t"   // r2 >>= 16

    "and  r3, r3, r7\n\t"     // r3 &= r7

    "orr  r0, r2, r3, lsl#16\n\t" // r0 = r2 | (r3 << 16)



    // add source sample to scaled destination sample

    "ldrsh  r2, [r5]\n\t"     // r2 = *pSrcSample

    "add  r2, r2, r0, asr#16\n\t" // r2 += (r0 >> 16)

    // clamp destination sample up

    "cmp  r2, r8\n\t"       // if( r2 > 32767 )

    "movgt  r2, r8\n\t"       //     r2 = 32767



    // clamp destination sample down

    "cmn  r2, r8\n\t"       // if( r2 < -32768 )

    "mvnlt  r2, r8\n\t"       //     r2 = -32768



    // put processed sample back to memory

    "strh r2, [r4]\n\t"     // *pDstSample = r2



    "add  r4, r4, #2\n\t"     // r4 += 2 (get next dst sample pointer)

    "add  r5, r5, #2\n\t"     // r5 += 2 (get next src sample pointer)



    // loop back

    "subs r6, r6, #1\n\t"     // r6 -= 1

    "bpl  .MixLoopStart\n\t"



    "ldmfd  r13!, {r0-r12,r14}\n\t"

    : // no outputs

    : "m" (audio_overlay_bg_volume), "m" (pDstSample), "m" (pSrcSample) );

}

.