As should be expected of any ATSC tuner, the SIR-T451 can output in 1080i, 720p, 480p, or 480i resolutions via its DVI, RGB, and component outputs. To set the desired output resolution, there's a selector button on the back of the unit--which means you pretty much have to set it at one resolution. We would have preferred the ability to change the resolution using the remote, but for most people, this probably isn't a big deal--you'll lock into the resolution that's the most compatible with your monitor. Also note that if you decide to change resolutions, the system will automatically reboot itself. Similarly, there's a selector in the back of the unit to choose between outputting through the component-video output, or the DVI and RGB output. Again, being able to choose this with the remote would be nice, but most people will just use one connector and forget all about it.
Unfortunately, the Samsung box does not offer parallel video output, which is found on the competing Humax HFA100. Parallel video output allows you, for instance, to output a high-def signal to your TV, while simultaneously outputting a standard-def signal via S-Video or composite video. This is particularly useful for owners of a VCR, a DVR, a DVD recorder, or a Slingbox-style device that cannot accept a high-def signal. With the SIR-T451, you are forced to make a compromise. You must watch everything on the TV in standard-def 480i and be able to use standard-def devices, or you can watch TV in high-def and give up the ability to use standard-def devices. We think this might be a deal breaker for a lot of people. We put the Samsung SIR-T451 up against a number of other tuners. Our first test pitted it against the internal HDTV tuners of the Vizio GV42L and the int="/Samsung_HP_R4252/4505-6482_7-31396047.html">Samsung HP-R4252. Traditional wisdom made us expect the stand-alone SIR-T451 to best the integrated tuners, but that wasn't the case. In terms of reception, both integrated tuners topped the SIR-T451 by a channel or two, using same antenna in the same position. The greater difference was in the speed of the tuners' ability to pull down channel data, navigate the EPG, and change channels. The SIR-T451 was considerably slower than the internal tuners, enough so that most people would probably find it annoying. When we reviewed the similar Humax HFA100, we found overall performance to be much snappier.
The SIR-T451 also handles QAM signals, which means it can decode unscrambled digital cable signals without the need for a cable box. We compared the performance to the
Image quality, as with all HD tuners we've tested, was excellent. HD channels looked at least as good, if not better, than their counterparts on HD cable. Standard-definition channels looked great, too; free of the interference that often creeps into analog reception. Using the same antenna to pull in analog stations yielded unwatchable results, which speaks volumes about the benefits of digital over-the-air reception.