The firm announced that from May, four models sold between 2006 and 2015 - including the Connect and Connect:Amp - will be affected and eventually lose functionality without the updates.
Access to other services will be limited, and newer products connected to the older ones will also miss out on future updates.
In a lengthy blog post, Sonos explained: "We're extremely proud of the fact that we build products that last a long time, and that listeners continue to enjoy them.
"In fact, 92% of the products we've ever shipped are still in use today. That is unheard of in the world of consumer electronics.
"However, we've now come to a point where some of the oldest products have been stretched to their technical limits in terms of memory and processing power."
The company advises users that there are two options, with the first being to simply continue using the products in the knowledge you won't get any software updates or new features.
The second option is to "trade up to a new Sono product with a 30% credit for each legacy product you replace".
However, one Sonos owner told BBC that after spending £1,000 on two Play 5 speakers, the upgrade discount could still leave him paying around £700 for replacements.
He said: "This is money my family and I just don't have.
"There is a feeling among the community that if Sonos gets away with this then they will do the same with all kit over time."
Another user added on Twitter: "Rather unimpressed with this, @Sonos. I am still using the loudspeakers and amp that I bought as a teenager; audio equipment is expected to be long-lasting."