(mindless ramble follows)
So, in the “olden” days, before VCR, you had TVs. If you wanted to watch more than one thing, you had more than one TV. You could say, “more than one tuner”. Back in those days only the very rich had more than one TV. But it was easy. You could “see” what tuners were available for use. No mystery.
Then comes the VCR (the general type). This added an extra tuner that could be used to record. While you might be able to use the VCR’s tuner for “watching”, viewing while recording at best allowed you to view the station being recorded. No way to fast forward or rewind while recording was happening. Because the end viewing device was likely a TV, in general, you were either using the TV’s tuner, or you were using the VCR’s tuner to “watch”… and when watching a recording, while the VCR’s tuner was “free” it couldn’t be used to record while a recording was being watched (just one tape slot). So, while nice, didn’t really get rid of the need for extra TVs if you wanted to watch different shows and required multiple VCRs if you wanted to record more than one thing or playback recordings at the same time. Again, noting you could both record and watch on any VCR (again, just one tape slot). Because of the inherent limitation of how a VCR did its thing, number of tuners at least for live TV was still pretty obvious.
TVs (one each)
VCRs (one each, recording requires the tuner, recording playback doesn’t use the tuner, but limited since output was limited to just one end device (TV).
Then comes the “set top box” age… well we’ll jump there anyhow. Now you have distribution set top boxes for display. Depending on implementation, you might have one central box handling distribution, or you might have a tuner in every set top. The medium is cable, satellite and/or IP TV (U-verse). Regardless of distribution, one set top (though you could sometimes have more than one) was special and used for recording. Without “apps” and such (yet), you could still figure out how many live tuner places were available. But multiple sources in one “TV” (picture in picture, U-verse) and lots more flexibility recording wise.
(TV’s have tuners, but they aren’t used and aren’t compatible)
Set Top box tuner
Special Set top box capable of a fixed number of simultaneous recordings (usually something like 4).
side note on U-verse In many ways this was amazing technology. You have really a streaming (though not streaming) like experience in that channels are pumped via IP TV. This allowed for more simultaneous viewing (picture in picture) and simultananous recording that was really limited by the infrastructure (bandwidth) in house and from the provider. This technology was so amazing that ATT ditched it to go back in time to satellite technology (??) with the purchase of Direct TV. My point is people that never experienced U-verse have a radically different view of what was possible back in that day… it was really ahead of its time.
Now we have the age of streaming. The idea is to have all media content streamed from a source (e.g. Internet, or local media server) to your end device. Noting that the end device had to be “smart” to handle a streaming application. At first, limited to PCs, tablet, smart phones, and streaming appliances (e.g. Roku) but now all TVs are “smart” and have some sort of network connectivity and apps for streaming.
What’s a tuner?
Cord cutting, the OTA edition. One way to get content that is HD (higher than what was even streaming at the time) and avoid cable, satellite or even U-verse TV (which again ATT killed so they could use 70’s technology) was to use a good ole antenna and a TV (assumed to have a tuner).
TV (1 per TV)
We’re saving money, but perhaps a bit too “stone age”. My goodness, there’s not even a VCR. So we “stream” (no recording at the time, well, without some PC work usually) and we watch HD OTA. We’re happy, but limited with regards to streaming sources (Netflix). Plex and XMBC offer the opportunity to house our own media server for streaming… we’re still saving money (apart from sweat equity of ripping our old media DVDs and such… or using the Internet to obtain media content without actually paying for it (via copyright violation). The age of copyright infringement… plus OTA plus ripping (CDs ok, DVDs a federal crime in the good ole USA).
(both perhaps landing on your own media server)
Limited streaming sites
OTA (still a lesser known option)
And of course, back to cable, satellite, etc… (the option of keeping the cord, but we’re still doing one or more of the above anyway, except maybe OTA)
I sort of skipped over Tivo, Replay-Tv and such. And probably shouldn’t have.
Enter the Tablo. Rather than a device per TV (end user viewing device)… why not take TV tuners and make them streamable things. Like a local Plex server streaming live TV content, but always recording so you could pause and rewind live TV and you could also schedule and record TV. Provide more than one tuner so that more than live TV and or more than one recording could be done. How many tuners to you want? Probably 12… but that’s a bit too expensive for most, so Tablo came out with 2-tuner and 4-tuner units, noting that under their EPG subscription (optional) it can support up to 10 devices (40 tuners anyone?).
Time has passed, long dead are our parents (well, not dead, we just don’t understand them) and their parents… we don’t remember the “TV age”. so we’re not used the “fighting over what is going to be watched on TV” problem. Tablo’s model makes it possible to avoid some of that, but still has the same limitation with regards to number of tuners, just more flexible with regards to end viewing devices.
Maybe what we want is a 12 tuners with 4 tuners dedicated to live TV watching (can’t be used for recording). Of course, many use the fact that most TVs still have a tuner and use that to avoid some of the “watching” problem with regards to tuners leveraging the extra tuner there instead of leaning solely on the Tablo. It’s not a bad idea at all. But obviously that limits somewhat the end viewing device of choice in that it favors old-school TV’s with tuners for Live TV watching.
Regardless of approach, either buying more Tablos (possibly dedicating some for just Live TV watching) or leveraging TV’s to help (a TV always has a tuner… sorry Vizio), there are “ways” to “keep a tuner free”. With that said, and like I said, and since we’re spoiled, I’m not opposed to a Tablo 12 tuner model (perhaps called an 8) with 4 tuners dedicated for Live TV. And of course I want it for less than $500 and in time for Christmas. But maybe more realistically, buy another Tablo while the price is low (?).
I see that @sfgower has said this likely better and in a much more succinct way.