well it depend on compression.
If it’s 128kbps for this stream, you can get 8 listeners for 1Mbps.
So, you will need 62,5 Mbps of bandwidth for 500 listeners.
Dreamhost is mainly a shared based web hosting, you can’t host a live audio stream on it (even just for 2 listeners).
For this amount of bandwidth, you should consider getting a dedicated server with 100Mbps bandwidth (or 2x50, one in US, another one in europe, because in streaming, distance may affect quality sometimes).
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