diff --git a/src/mb/app/main.py b/src/mb/app/main.py
index 0678a0d..7d2e71e 100644
--- a/src/mb/app/main.py
+++ b/src/mb/app/main.py
@@ -187,6 +187,7 @@ async def download_single_random_waveform(normalised: bool = False):
         endpoint="/waveform/jackpot",
         time_interval=interval,
         waveform=record.tolist(),
+        processed_data_unit="cm/s/s",
     )
 
 
@@ -229,6 +230,7 @@ def _populate_waveform(result: Record):
             endpoint="/waveform",
             time_interval=interval,
             waveform=record.tolist(),
+            processed_data_unit="cm/s/s",
         )
 
     return ListRecordResponse(
diff --git a/src/mb/app/process.py b/src/mb/app/process.py
index dc0bb07..12899b4 100644
--- a/src/mb/app/process.py
+++ b/src/mb/app/process.py
@@ -33,7 +33,10 @@ def process_record_local(result: Record, process_config: ProcessConfig):
         )
 
     record = ProcessedResponse(
-        **result.model_dump(), endpoint="/process", process_config=process_config
+        **result.model_dump(),
+        endpoint="/process",
+        process_config=process_config,
+        processed_data_unit="cm/s/s",
     )
 
     time_interval, waveform = result.to_waveform(
diff --git a/src/mb/app/response.py b/src/mb/app/response.py
index 7bbe30a..bc771c9 100644
--- a/src/mb/app/response.py
+++ b/src/mb/app/response.py
@@ -102,12 +102,11 @@ def normalise(cls, values):
         return values
 
     def filter(self, window, up_ratio: int = 1):
-        new_waveform: np.ndarray = apply_filter(
-            window * up_ratio, zero_stuff(up_ratio, self.waveform)
-        )
         self.time_interval /= up_ratio
         # noinspection PyTypeChecker
-        self.waveform = new_waveform.tolist()
+        self.waveform = apply_filter(
+            window * up_ratio, zero_stuff(up_ratio, self.waveform)
+        ).tolist()
 
     def to_spectrum(self):
         if self.time_interval is None or self.waveform is None:
diff --git a/src/mb/client.py b/src/mb/client.py
index 4696aaa..dd83f6a 100644
--- a/src/mb/client.py
+++ b/src/mb/client.py
@@ -164,26 +164,25 @@ async def download(
             async with anyio.create_task_group() as tg:
                 for r in record:
                     tg.start_soon(self.download, r)
+        else:
+            record_id: str = record.id if isinstance(record, MBRecord) else record
+
+            async with self.semaphore:
+                result = await self.client.post("/waveform", json=[str(record_id)])
+                self.current_download_size += 1
+                if result.status_code != HTTPStatus.OK:
+                    self.print(
+                        f"Fail to download file [green]{record_id}[/]. "
+                        f"[[red]{self.current_download_size}/{self.download_size}[/]]."
+                    )
+                else:
+                    self.download_pool.append(MBRecord(**result.json()["records"][0]))
+                    self.print(
+                        f"Successfully downloaded file [green]{record_id}[/]. "
+                        f"[[red]{self.current_download_size}/{self.download_size}[/]]."
+                    )
 
-            return
-
-        record_id: str = record.id if isinstance(record, MBRecord) else record
-
-        async with self.semaphore:
-            result = await self.client.post("/waveform", json=[str(record_id)])
-            self.current_download_size += 1
-            if result.status_code != HTTPStatus.OK:
-                self.print(
-                    f"Fail to download file [green]{record_id}[/]. "
-                    f"[[red]{self.current_download_size}/{self.download_size}[/]]."
-                )
-                return
-
-            self.download_pool.append(MBRecord(**result.json()["records"][0]))
-            self.print(
-                f"Successfully downloaded file [green]{record_id}[/]. "
-                f"[[red]{self.current_download_size}/{self.download_size}[/]]."
-            )
+        return self
 
     async def upload(
         self,
@@ -259,7 +258,9 @@ async def jackpot(self) -> MBRecord | None:
     async def search(self, query: QueryConfig | dict) -> list[MBRecord] | None:
         result = await self.client.post(
             "/query",
-            json=query.model_dump() if isinstance(query, QueryConfig) else query,
+            json=query.model_dump(exclude_none=True)
+            if isinstance(query, QueryConfig)
+            else query,
         )
         if result.status_code != HTTPStatus.OK:
             self.print("[red]Failed to perform query.[/]")
@@ -289,11 +290,10 @@ async def status(self):
 
 
 async def main():
-    async with MBClient("http://localhost:8000", "test", "password") as client:
+    async with MBClient("http://170.64.176.26:8000") as client:
         results = await client.search(QueryConfig())
-        await client.download(results)
         fig: Figure = None  # type: ignore
-        for result in client:
+        for result in await client.download(results):
             fig = result.plot_spectrum(fig)
         fig.legend()
         fig.tight_layout()