Safari audio HTML5 issue - ios

Question

I'm working on an iOS/MacOS issue.
I'm trying to play a simple audio file through a HTML5 audio element, and everything is working as expected except on iOS/MacOS.
My app is built on Symfony, using Nginx and custom PHP controllers to serve the audio resource. The audio element's given source is a link to a route that handles the streaming.
My logical is the following :
Get the file from url ID
Read request headers to find expected range and length
Setting up the good headers to force 206 Partial Content behaviour
Writing expected file chunks and returning a 206 response.
Here is the code for this:
public function getAudio(Request $request, $audioId)
{
/*
* Getting the file
*/
$em = $this->getDoctrine()->getManager();
$voice = $em->getRepository("CoreBundle:Audio")->findOneById($audioId);
$media = $audio->getFile();
$path = $this->container->get('sonata.media.twig.extension')->path($media, 'reference');
$file = $this->get('kernel')->getRootDir() . "/../web$path";
/*
* Setting length and offset for serving the right chunk
*/
$offset = 0;
$requestedRange = $request->headers->get("Range");
$size = $media->getSize();
$length = $size;
if($requestedRange){
preg_match('/bytes=(\d+)-(\d+)?/', $requestedRange, $matches);
$offset = intval($matches[1]);
if(count($matches) > 2){
$length = intval($matches[2]) - $offset + 1;
}
else{
$length = ($size) - $offset;
}
}
if(file_exists($file) && $length) {
$file = fopen($file, 'r');
fseek($file, $offset);
$data = fread($file, $length);
fclose($file);
if($requestedRange){
header('Content-Range: bytes ' . $offset . '-' . ($offset + $length-1) . '/' . $size);
}
else{
header('Content-Range: bytes 0-'.($size-1).'/'.$size);
}
/*
* Forcing some headers in the response to fit request attempts
*/
header("Pragma: public");
header("Expires: 0");
header('Content-type: audio/mpeg');
header('Content-Disposition: inline');
header('Accept-Ranges: bytes');
header('Content-Length: '.$length);
header('X-Pad: avoid browser bug');
header('Cache-Control: no-cache');
print($data);
return new Response("",206);
}
else{
return new Response("",200);
}
}
Again, everything is working fine on Firefox and Chrome, file is streamed and played perfectly.
But when it comes to IOS and MacOS, the file just doesn't play. A peek at network console shows two subsequent requests, with the last one in error (see next links).
However, no error is logged in PHP and I'm now completely stuck.
first-request
second-request

Answer 1

The logical was fine but the management of the response wasn't.
After reading the Symfony documentation about Response, I just changed every header() function to:
$response->setHeaders()
And every print($data) to:
$response = new Response($data);
Returning the complete Response object did the job.