diff --git a/csdr/chain/rtl433.py b/csdr/chain/rtl433.py
index e0fa6850..2feffc56 100644
--- a/csdr/chain/rtl433.py
+++ b/csdr/chain/rtl433.py
@@ -5,7 +5,7 @@ from csdr.chain.demodulator import ServiceDemodulator
 
 class Rtl433(ServiceDemodulator):
     def getFixedAudioRate(self) -> int:
-        return 250000
+        return 1000000
 
     def __init__(self):
         super().__init__(
diff --git a/htdocs/lib/Demodulator.js b/htdocs/lib/Demodulator.js
index ddc1e1a6..3cbb2725 100644
--- a/htdocs/lib/Demodulator.js
+++ b/htdocs/lib/Demodulator.js
@@ -17,6 +17,8 @@ Filter.prototype.getLimits = function() {
         max_bw = 4000;
     } else if (this.demodulator.get_modulation() === "dab") {
         max_bw = 1000000;
+    } else if (this.demodulator.get_secondary_demod() === "ism") {
+        max_bw = 500000;
     } else {
         max_bw = (audioEngine.getOutputRate() / 2) - 1;
     }
diff --git a/owrx/ism/rtl433.py b/owrx/ism/rtl433.py
index 5ca46ef2..1d2e534c 100644
--- a/owrx/ism/rtl433.py
+++ b/owrx/ism/rtl433.py
@@ -7,7 +7,5 @@ class Rtl433Module(ExecModule):
         super().__init__(
             Format.COMPLEX_FLOAT,
             Format.CHAR,
-            ["rtl_433", "-r", "cf32:-", "-F", "json", "-M", "time:unix", "-C", "si"]
+            ["rtl_433", "-r", "cf32:-", "-F", "json", "-M", "time:unix", "-C", "si", "-s", "1000000"]
         )
-
-
diff --git a/owrx/modes.py b/owrx/modes.py
index 09e928f4..61b1569b 100644
--- a/owrx/modes.py
+++ b/owrx/modes.py
@@ -179,7 +179,7 @@ class Modes(object):
             "ism",
             "ISM",
             underlying=["empty"],
-            bandpass=None,
+            bandpass=Bandpass(-125000, 125000),
             requirements=["ism"],
             squelch=False,
         ),