<html> <head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> <div class="moz-cite-prefix">On 06.05.2015 04:17, golden wrote: </div> <blockquote cite="mid:554979A7.6030304@gmail.com" type="cite"> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <meta http-equiv="content-type" content="text/html; charset=utf-8"> <pre style="white-space: pre-wrap; color: rgb(0, 0, 0); font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">Dear PulseAudio folks, We are using PulseAudio in our automotive project, the progress is pretty good so far. I need some help for solving the sync problems between two speakers. </pre> The pic below is the data flow of the two speakers: <img src="cid:part1.00090305.08000206@chini.tk" alt=""> without any syncing method, what we hear from the front-speaker is ahead of the rear-speaker (real-spear is slower for sure), our goal is that make the rear-speaker almost sync with (or catch up) the front speaker. </blockquote> Hi, with your manipulation of the audio and with module-loopback you introduce quite a lot of latency into the first path. Maybe you can simply set the latency of alsa-sink.1 larger than that of alsa-sink.0, not sure if this works. Otherwise I would suggest to make the paths look more or less equivalent, that would mean putting a module-loopback into the front speaker path. You could also try and use my (not yet reviewed) patches for module-loopback at <a href="http://thread.gmane.org/gmane.comp.audio.pulseaudio.general/22956">http://thread.gmane.org/gmane.comp.audio.pulseaudio.general/22956</a> which allow a better control over the latency introduced by the module. If you use the patches and have a module-loopback in both paths you should be able to fully synchronize them by adjusting the latencies of the two modules. Regards Georg </body> </html>