diff --git a/release-packaging/Classes/FluidBufToKr.sc b/release-packaging/Classes/FluidBufToKr.sc
index 0e81386..84a0cb6 100644
--- a/release-packaging/Classes/FluidBufToKr.sc
+++ b/release-packaging/Classes/FluidBufToKr.sc
@@ -1,31 +1,64 @@
 FluidKrToBuf {
 	*kr {
-		arg krStream, buffer;
+		arg krStream, buffer, krStartChan = 0, krNumChans = -1, destStartFrame = 0;
+		var endChan;
+
+		// fix -1 default
+		if(krNumChans == -1,{krNumChans = krStream.numChannels - krStartChan});
+
+		// what is the last channel that will be used
+		endChan = (krStartChan + krNumChans) - 1;
 
 		if(buffer.isKindOf(Buffer).or(buffer.isKindOf(LocalBuf)),{
-			if(buffer.numFrames == 0) {"FluidKrToBuf:kr Buffer has 0 frames".warn};
-			if(buffer.numFrames > 1000) {
-				Error("FluidKrToBuf:kr Buffer is % frames. This is probably not the buffer you intended.".format(buffer.numFrames)).throw;
+
+			// sanity check
+			if(buffer.numFrames == 0){"% Buffer has 0 frames".format(this.class).warn};
+
+			// oopsie check
+			if(buffer.numFrames > 1000){
+				Error("% Buffer is % frames. This is probably not the buffer you intended.".format(this.class,buffer.numFrames)).throw;
 			};
+
+			// out of bounds check
+			if((destStartFrame + krNumChans) > buffer.numFrames,{
+				Error("% (destStartFrame + krNumChans) > buffer.numFrames".format(this.class)).throw;
+			});
+
 		});
 
-		^krStream.numChannels.do{
-			arg i;
-			BufWr.kr(krStream[i], buffer, i);
+		^(krStartChan..endChan).do{
+			arg kr_i, i;
+			BufWr.kr(krStream[kr_i], buffer, destStartFrame + i);
 		}
 	}
 }
 
 FluidBufToKr {
 	*kr {
-		arg buffer numFrames, startFrame=0;
+		arg buffer, startFrame = 0, numFrames = -1;
 
-		if(buffer.isKindOf(Buffer) or: {buffer.isKindOf(LocalBuf)}, {
-			numFrames = numFrames ?? {buffer.numFrames - startFrame};
-		}, {
-			numFrames = numFrames ? 1;
+		// out of bounds check
+		if(startFrame < 0,{Error("% startFrame must be >= 0".format(this.class)).throw;});
+
+		if(buffer.isKindOf(Buffer) or: {buffer.isKindOf(LocalBuf)},{
+
+			// fix default -1
+			if(numFrames == -1,{numFrames = buffer.numFrames - startFrame});
+
+			// dummy check
+			if(numFrames < 1,{Error("% numFrames must be >= 1".format(this.class)).throw});
+
+			// out of bounds check
+			if((startFrame+numFrames) > buffer.numFrames,{Error("% (startFrame + numFrames) > buffer.numFrames".format(this.class)).throw;});
+
+		},{
+			// make sure the numFrames give is a positive integer
+			if((numFrames < 1) || (numFrames.isInteger.not),{
+				Error("% if no buffer is specified, numFrames must be a value >= 1.".format(this.class)).throw;
+			});
 		});
 
+		// oopsie check
 		if(numFrames > 1000) {
 			Error("%: numframes is % frames. This is probably not what you intended.".format(this.class, numFrames)).throw;
 		};
diff --git a/test/FluidBufToKr test.scd b/test/FluidBufToKr test.scd
index b3c070c..3d2954c 100644
--- a/test/FluidBufToKr test.scd	
+++ b/test/FluidBufToKr test.scd	
@@ -93,7 +93,7 @@ s.waitForBoot{
 )
 
 (
-// FluidBufToKr
+// FluidBufToKr should throw error
 
 s.waitForBoot{
 	Routine{
@@ -154,7 +154,7 @@ s.waitForBoot{
 	Routine{
 		~synth = {
 			arg buf;
-			FluidBufToKr.kr(buf,5).poll;
+			FluidBufToKr.kr(buf,numFrames:5).poll;
 		}.play;
 
 		2.wait;
@@ -197,7 +197,7 @@ s.waitForBoot{
 			arg buf = 999;
 			FluidKrToBuf.kr(SinOsc.kr(Array.fill(5,{rrand(0.0,1.0)})),buf);
 
-			FluidBufToKr.kr(buf,5).poll; ////////// this will work becaues it knows how many frames the buffer will be
+			FluidBufToKr.kr(buf,numFrames:5).poll; ////////// this will work becaues it knows how many frames the buffer will be
 		}.play;
 
 		2.wait;
@@ -208,3 +208,155 @@ s.waitForBoot{
 	}.play;
 };
 )
+
+// test start frame:
+
+
+(
+// should skip the 0
+s.waitForBoot{
+	Routine{
+		var buf = Buffer.loadCollection(s,[0,1,2,3,4,7]);
+
+		s.sync;
+
+		{
+			var sig = FluidBufToKr.kr(buf,1);
+			sig.poll;
+		}.play;
+	}.play;
+}
+)
+
+(
+// should be 2,3,4
+s.waitForBoot{
+	Routine{
+		var buf = Buffer.loadCollection(s,[0,1,2,3,4,7]);
+
+		s.sync;
+
+		{
+			var sig = FluidBufToKr.kr(buf,2,3);
+			sig.poll;
+		}.play;
+	}.play;
+}
+)
+
+(
+// last four slots should be 0
+s.waitForBoot{
+	Routine{
+		var buf = Buffer.loadCollection(s,0.dup(10));
+
+		s.sync;
+
+		{
+			FluidKrToBuf.kr(LFDNoise3.kr(1.dup(6)),buf);
+		}.play;
+
+		1.wait;
+
+		// defer{buf.plot};
+		buf.loadToFloatArray(action:{
+			arg vals;
+			vals.postln;
+		});
+	}.play;
+}
+)
+
+(
+// middle slots should be not zero
+s.waitForBoot{
+	Routine{
+		var buf = Buffer.loadCollection(s,0.dup(4));
+
+		s.sync;
+
+		{
+			FluidKrToBuf.kr(LFDNoise3.kr(1.dup(2)),buf,destStartFrame:1);
+		}.play;
+
+		1.wait;
+
+		// defer{buf.plot};
+		buf.loadToFloatArray(action:{
+			arg vals;
+			vals.postln;
+		});
+	}.play;
+}
+)
+
+(
+// should throw error
+s.waitForBoot{
+	Routine{
+		var buf = Buffer.loadCollection(s,0.dup(4));
+
+		s.sync;
+
+		{
+			FluidKrToBuf.kr(LFDNoise3.kr(1.dup(2)),buf,destStartFrame:3);
+		}.play;
+
+		1.wait;
+
+		// defer{buf.plot};
+		buf.loadToFloatArray(action:{
+			arg vals;
+			vals.postln;
+		});
+	}.play;
+}
+)
+
+(
+// should be 0,0,200,3000,0,0
+s.waitForBoot{
+	Routine{
+		var buf = Buffer.alloc(s,7);
+
+		s.sync;
+
+		{
+			var sig = 3.collect{arg i; DC.kr((i+1)*100)};
+			// sig.poll;
+			FluidKrToBuf.kr(sig,buf,1,2,2);
+		}.play;
+
+		1.wait;
+
+		buf.loadToFloatArray(action:{
+			arg vals;
+			vals.postln;
+		});
+	}.play;
+}
+)
+
+(
+// should be 100,200,300,400
+s.waitForBoot{
+	Routine{
+		var buf = Buffer.alloc(s,4);
+
+		s.sync;
+
+		{
+			var sig = 4.collect{arg i; DC.kr((i+1)*100)};
+			// sig.poll;
+			FluidKrToBuf.kr(sig,buf);
+		}.play;
+
+		1.wait;
+
+		buf.loadToFloatArray(action:{
+			arg vals;
+			vals.postln;
+		});
+	}.play;
+}
+)