diff --git a/granulator.scd b/granulator.scd
index 3763f76..a06c831 100644
--- a/granulator.scd
+++ b/granulator.scd
@@ -14,6 +14,7 @@
 
 ~granulators = Array.new(4);
 ~grainmodes = [ 0, 0, 0, 0 ]; // keep track of mode so don't swap if not needed
+~speeds = [ 1, 1, 1, 1 ];     // hacky speed quantisation
 ~posb = Array.new(4);
 ~rectriggerb = Array.new(4);
 ~patterns = Array.new(4);
@@ -35,14 +36,10 @@
 });
 
 // set up the Patterns which drive the position synths
-
 (0..3).do({ |i|
-	~patterns.add(~makePattern.value(i, 0));
+	~patterns.add(~makePattern.value(i, 0, ~speeds[i]));
 });
 
-// play the four patterns
-// to-do - will these need separate tempoclocks?
-
 (0..3).do({|i|
 	~players.add(~patterns[i].play(~tc, quant: ~beatsperbar))
 });
@@ -53,15 +50,29 @@
 		~grainmodes[track] = mode;
 		~players[track].stop;
 		~patterns[track].free;
-		~patterns[track] = ~makePattern.value(track, mode);
+		~patterns[track] = ~makePattern.value(track, mode, ~speeds[track]);
 		~players[track] = ~patterns[track].play(~tc, quant: ~beatsperbar);
 	});
 };
 
+~setspeed = {
+	arg track, speed;
+	[ "setspeed", track, speed ].postln;
+	if( ~speeds[track] != speed, {
+		~speeds[track] = speed;
+		~players[track].stop;
+		~patterns[track].free;
+		~patterns[track] = ~makePattern.value(track, ~grainmodes[track], ~speeds[track]);
+		~players[track] = ~patterns[track].play(~tc, quant: ~beatsperbar);
+	});
+};
+
+
 ~makePattern = {
-	arg track, mode;
+	arg track, mode, speed;
 	var ptrig, ppos, synth = ~modes[mode][1];
-	[ "makePattern", ~track, ~buflen ].postln;
+	// note: trigger is going off the base tempoclock, not the playback speed - I think this is
+	// the right thing to do but I'm not sure yet
 	ptrig = Pbind(
 		\instrument, \trigger,
 		\dur, ~beatsperbar,
@@ -69,8 +80,8 @@
 	);
 	ppos = Pbind(
 		\instrument, synth,
-		\dur, ~beatsperbar,
-		\length, ~buflen,
+		\dur, ~beatsperbar / speed,
+		\length, ~buflen / speed,
 		\out, ~posb[track]
 	);
 	Ppar([ptrig, ppos]);
diff --git a/interface.scd b/interface.scd
index dba2364..9c5a0b2 100644
--- a/interface.scd
+++ b/interface.scd
@@ -36,25 +36,6 @@ OSCdef.freeAll;
 };
 
 
-// control ganging is hella laggy, do it in TouchOSC
-
-
-
-// ~setspeed = { | track, v |
-// 	var speed, qv = if(~speedquant > 0, { ~quantspeed.value(v) }, { v });
-// 	speed = qv / ~buflen;
-// 	if(~speedlock > 0, {
-// 		(0..3).do({|n|
-// 			~possynths[n].set(\speed, speed);
-// 			if( n != track, {
-// 				var url = ("/grains/speed" ++ n).asSymbol;
-// 				~to.s_(url, v);
-// 			});
-// 		});
-// 		},
-// 	{ ~possynths[track].set(\speed, speed) });
-// };
-
 // setrecord: toggles record on (1) or off (0) for a track, and also sets the
 // track's input mix to 0 so that it doesn't start fadeing out. If the track
 // is the currently selected track, set its touchosc control to 0.
@@ -89,11 +70,13 @@ OSCdef.freeAll;
 ~to.button('/grains/mode1', 0, { |v| ~setmode.value(1, v) });
 ~to.button('/grains/mode2', 0, { |v| ~setmode.value(2, v) });
 ~to.button('/grains/mode3', 0, { |v| ~setmode.value(3, v) });
-//
-// ~to.slider('/grains/speed0', 1, TouchOSCScale(0, 2), { |v| ~setspeed.value(0, v) });
-// ~to.slider('/grains/speed1', 1, TouchOSCScale(0, 2), { |v| ~setspeed.value(1, v) });
-// ~to.slider('/grains/speed2', 1, TouchOSCScale(0, 2), { |v| ~setspeed.value(2, v) });
-// ~to.slider('/grains/speed3', 1, TouchOSCScale(0, 2), { |v| ~setspeed.value(3, v) });
+
+// needs work
+
+~to.slider('/grains/speed0', 1, TouchOSCScale(0, 2), { |v| ~setspeed.value(0, ~quantspeed.value(v)) });
+~to.slider('/grains/speed1', 1, TouchOSCScale(0, 2), { |v| ~setspeed.value(1, ~quantspeed.value(v)) });
+~to.slider('/grains/speed2', 1, TouchOSCScale(0, 2), { |v| ~setspeed.value(2, ~quantspeed.value(v)) });
+~to.slider('/grains/speed3', 1, TouchOSCScale(0, 2), { |v| ~setspeed.value(3, ~quantspeed.value(v)) });
 
 
 ~to.slider('/grains/passthrough', 0.75, TouchOSCScale(0, 1), { |v| ~grainmixer.set(\passthrough, v) });
@@ -105,7 +88,7 @@ OSCdef.freeAll;
 
 ~to.button('/grains/lock',   0, { |v| ~speedlock = v });
 
-~to.button('/grains/quant',   0, { |v| ~speedquant = v });
+~to.button('/grains/quant',   1, { |v| ~speedquant = v });
 
 ~to.button('/grains/metronome', 0, { |v|
 	if( v == 1, {