diff --git a/impl/src/sdr/sdr.c b/impl/src/sdr/sdr.c
index 828f41e..e6d497b 100644
--- a/impl/src/sdr/sdr.c
+++ b/impl/src/sdr/sdr.c
@@ -36,7 +36,7 @@ static int rx_callback(hackrf_transfer *transfer)
 
 	for(size_t i = 0; i < nsamples; i++) {
 		liquid_float_complex sample =
-			0.0078125f * (transfer->buffer[2*i + 0] + I * transfer->buffer[2*i + 1]);
+			0.0078125f * ((int8_t)transfer->buffer[2*i + 0] + I * (int8_t)transfer->buffer[2*i + 1]);
 
 		int result = cbuffercf_push(sdr_ctx->rx_buf, sample);
 		if(result != LIQUID_OK) {
@@ -158,6 +158,8 @@ static result_t stop_streaming(sdr_ctx_t *ctx)
 		fsleep(1e-3);
 	}
 
+	fsleep(10e-3); // ensure all asynchronous USB communication has stopped
+
 	ctx->status = SDR_STATUS_IDLE;
 
 	return OK;
@@ -221,12 +223,13 @@ result_t sdr_start_rx(sdr_ctx_t *ctx)
 {
 	int result;
 
-	result = hackrf_set_freq(ctx->hackrf, SDR_RX_FREQ - SDR_RX_IF_SHIFT);
-	CHECK_HACKRF_RESULT(result, "hackrf_set_freq");
-
 	result = hackrf_set_sample_rate(ctx->hackrf, SDR_RX_SAMPLING_RATE);
 	CHECK_HACKRF_RESULT(result, "hackrf_set_sample_rate");
 
+	result = hackrf_set_freq(ctx->hackrf, SDR_RX_FREQ - SDR_RX_IF_SHIFT);
+	fprintf(stderr, "Set RX frequency to %f Hz.\n", SDR_RX_FREQ - SDR_RX_IF_SHIFT);
+	CHECK_HACKRF_RESULT(result, "hackrf_set_freq");
+
 	result = hackrf_set_lna_gain(ctx->hackrf, SDR_GAIN_RX_LNA);
 	CHECK_HACKRF_RESULT(result, "hackrf_set_lna_gain");