Hi again,

This little demo patch illustrates seamless recording as well as the suggested [z~]-hack for seamless playback:

best, flo.H

#N canvas 0 0 918 623 10; #X obj 132 338 bng 15 250 50 0 empty empty empty 17 7 0 10 -262144 -1 -1; #X obj 76 464 readsf~; #X obj 132 518 readsf~; #X msg 36 410 1; #X msg 122 491 1; #X obj 67 582 dac~; #X msg 76 410 open test1.wav; #X obj 355 67 loadbang; #X msg 49 170 stop; #X obj 110 180 osc~ 220; #X msg 215 170 stop; #X obj 26 217 writesf~; #X obj 192 217 writesf~; #X obj 145 71 bng 15 250 50 0 empty empty empty 17 7 0 10 -262144 -1 -1; #X msg 26 143 open test1.wav , start; #X msg 192 143 open test2.wav , start; #X obj 145 106 del 2000; #X obj 215 106 del 4000; #X obj 67 503 *~ 0.2; #X obj 132 545 *~ 0.2; #X obj 36 373 del 500; #X obj 132 582 writesf~; #X msg 355 94 ; pd dsp 1; #X msg 336 518 start; #X msg 195 545 stop; #X msg 132 437 open test2.wav; #X msg 205 518 open merged.wav; #X text 94 374 Give soundfile time to load; #X text 13 16 (A) Seamless recording of two (16 bit) files works fine (which one can see and hear when merging test1.wav and test2.wav e.g. with 'sox test1.wav test2.wav merged.wav'):; #X text 8 269 (B) But seamless playback does not work: recording the result to a file 'merged.wav' and inspecting it in an audio editor yields a gap of exactly one audio block at the transition point (64 samples if Pd's standard blocksize is used):; #X obj 633 112 bng 15 250 50 0 empty empty empty 17 7 0 10 -262144 -1 -1; #X obj 577 238 readsf~; #X obj 633 292 readsf~; #X msg 537 184 1; #X msg 623 265 1; #X obj 508 356 dac~; #X msg 577 184 open test1.wav; #X obj 509 280 *~ 0.2; #X obj 633 319 *~ 0.2; #X obj 537 147 del 500; #X obj 633 356 writesf~; #X msg 837 292 start; #X msg 706 319 stop; #X msg 633 211 open test2.wav; #X obj 509 253 z~ 64; #X obj 509 226 readsf~; #X text 476 32 C) A seamless playback hack with zexy's [z~]: At the cost of an additional [readsf~] object , we delay playback of the first file by 64 samples using zexy's [z~] , and use the original (undelayed) [readsf~] only for the 'playback done' bang at its right outlet. This allows for seamless playback.; #X msg 706 292 open merged.wav; #X connect 0 0 6 0; #X connect 0 0 25 0; #X connect 0 0 20 0; #X connect 0 0 26 0; #X connect 1 0 18 0; #X connect 1 1 4 0; #X connect 2 0 19 0; #X connect 2 1 24 0; #X connect 3 0 1 0; #X connect 4 0 2 0; #X connect 6 0 1 0; #X connect 7 0 22 0; #X connect 8 0 11 0; #X connect 9 0 11 0; #X connect 9 0 12 0; #X connect 10 0 12 0; #X connect 13 0 14 0; #X connect 13 0 16 0; #X connect 13 0 17 0; #X connect 14 0 11 0; #X connect 15 0 12 0; #X connect 16 0 8 0; #X connect 16 0 15 0; #X connect 17 0 10 0; #X connect 18 0 5 0; #X connect 18 0 5 1; #X connect 18 0 21 0; #X connect 19 0 5 0; #X connect 19 0 5 1; #X connect 19 0 21 0; #X connect 20 0 3 0; #X connect 20 0 23 0; #X connect 23 0 21 0; #X connect 24 0 21 0; #X connect 25 0 2 0; #X connect 26 0 21 0; #X connect 30 0 36 0; #X connect 30 0 43 0; #X connect 30 0 39 0; #X connect 30 0 47 0; #X connect 31 1 34 0; #X connect 32 0 38 0; #X connect 32 1 42 0; #X connect 33 0 31 0; #X connect 33 0 45 0; #X connect 34 0 32 0; #X connect 36 0 31 0; #X connect 36 0 45 0; #X connect 37 0 35 0; #X connect 37 0 35 1; #X connect 37 0 40 0; #X connect 38 0 35 0; #X connect 38 0 35 1; #X connect 38 0 40 0; #X connect 39 0 33 0; #X connect 39 0 41 0; #X connect 41 0 40 0; #X connect 42 0 40 0; #X connect 43 0 32 0; #X connect 44 0 37 0; #X connect 45 0 44 0; #X connect 47 0 40 0;