Home Theater/Dolby True HD/DTS master
I own the Athena Micra 6 speaker system (http://www.soundandvision.com/content/athena-micra-6-speaker-system
). I have a non-HDMI receiver, which means it does not output Dolby True HD or Dolby DTS Master audio. It outputs both Dolby Digital and DTS. Regardless of this I think the speakers sound fine, but was wondering if it would be worth it to upgrade to a HDMI receiver that handles Dolby True HD and Dolby DTS Master audio. Would I hear a difference with the Athena Micra 6 speakers, or would I need higher end speakers to really hear a difference? I know Dolby True HD and Dolby DTS Master are lossless sound as compared to lossy Dolby Digital and DTS. Some people say they hear a difference whereas other people say they don't. I was wondering if it really was the speakers that make the difference in the quality you hear, and was wondering if I will hear a difference with the Athena Micra 6 speakers, given that they are not very high end, but good nonetheless. Thanks very much for your help.
I think there might be some confusion regarding these formats, at least based on your question (that, or I'm not fully understanding what you're asking - if that's the case, feel free to point that out). The receiver does not "output" any sort of digital format (unless it has a digital repeater, which many older models included, in order to integrate with a CD recorder); it receives and decodes digital audio signals from whatever you're using as a media transport. Whether or not you get Dolby TrueHD or Dolby Digital (etc) depends on the media being played back, for example if you're sourcing from a DVD player, Dolby Digital and DTS are the only audio signals you will get with DVD movies. So having a decoder that can handle TrueHD is of no benefit - there will be no quality improvement by being able to decode another format, if that format is never available.
If you're sourcing from a Blu-ray or HD-DVD player, playing Blu-ray or HD-DVD videos, you will likely encounter TrueHD, DTS-HD Master Audio, and in many cases "straight" multi-channel PCM (which is also lossless, it takes up considerably more space on the disc though; many early generation HDMI receivers will decode multi-channel PCM where they will not decode TrueHD or DTS-HD; fortunately most Blu-ray and HD-DVD players can transcode from TrueHD/DTS-HD to PCM and output that via HDMI for compatibility). These players will also output a legacy Dolby Digital or DTS signal, depending on the specific player and the media presented (DTS-HD will mean the DTS-CA ("normal DTS") core being sent out, which is the same thing you get on some DVDs (DTS is relatively rare on DVD), TrueHD and Dolby+ can mean either a Dolby Digital signal, or in the case of some HD-DVD players, a DTS signal) - this is the exact same audio signal you would get if the receiver was decoding the TrueHD or DTS-HD stream, but is a lossy signal that fits within the S/PDIF bandwidth limits; its usually somewhat higher in bitrate than what you could expect from HDTV or DVD though.
The quality differences here are generally very small - Dolby Digital and DTS are very high quality lossy codecs, and do a very good job with encoding audio into a compact and quality stream. In general, it isn't anything I would worry about by itself - you aren't missing any content (at least in the most general sense) from a Blu-ray or HD-DVD by not supporting TrueHD or DTS-HD, however there are some features that HDMI supports which may be an upgrade to an older system. For example, both TrueHD and DTS-HD support 7.1 discrete audio, which is not possible with legacy formats (although do keep in mind that 7.1 titles are relatively rare; it's a fairly new trend and generally only the newest and biggest productions will sport 7.1 soundtracks); if your theater supports 7.1, or if you want to support 7.1, it may be worth consideration. HDMI would also mean a single connection for all of your devices, and in many cases this connection can also carry remote control signals, and for some devices networking features as well. This can simplify the wiring and hook-up of your equipment. None of these features, by themselves, are enough to justify the cost of an HDMI equipped receiver (at least in my view), but are all worth consideration.
Another important point to consider is the quality of the receiver itself - how good are the amplifiers in the model you currently have? And how good would the amplifiers be in the models you're considering? If you currently have a relatively high quality receiver (generally speaking, take this to mean something $600 or over when it was new) and are looking at something cheap (there are plenty of $200 models out there), you would probably notice a net decrease in overall quality because of the lower quality amplifier and pre-amplifier sections in the new receiver. By contrast, if your current receiver doesn't sport that robust of an amplifier, and you were looking at moving up to something much fancier, you would probably notice an improvement - again, owing to the improved quality of the pre-amplifier and amplifier sections more than anything else.
As far as "what makes a difference in the quality you hear" - there are no absolute rules, but generally as a rule of thumb, the speakers themselves take the highest priority, followed by their placement/configuration within the room (this means setting them up in the right places, and picking the right speakers for the size room you have), followed by the amplifier driving them (it should be appropriately powerful and able to handle the load they present, and able to drive them to a loud enough volume for the room and your listening tastes), followed by the quality of the media being played back (in other words, a big budget movie like Avatar will generally be of higher quality than a direct-to-DVD B-movie). The media transport and decoder are near the bottom of the list overall, because generally speaking as long as they're compatible with whatever formats you'd like to play, they're interchangeable. If you spend majorly big money (five figures) you can get into equipment that is measurably improved over "normal" components, but even there the differences are very subtle compared to changes in speakers, speaker placement, or amplifiers. Differences between speakers generally are more dramatic, and generally don't require huge investments to realize - even modestly priced speakers can sound very good if they're appropriately chosen and configured for a given room, and expensive speakers can sound bad if improperly set-up as well. There's also a large degree of preference here - while amplifiers, decoders, etc tend to target flat or transparent performance, speakers are more personal; different models from different makers at the same price will generally still be relatively different from one another, and knowing what you like is important when selecting new speakers.
If everything is working the way you would like, I would probably not worry about this too much overall. If there's something that isn't quite satisfying you, I would try to identify what specifically isn't up to par, and then we can try to determine if it's something that can be addressed or not (in some cases the problem does exist with the media, and there's nothing that can be done for that unless the studio/film-maker decides to re-master and re-release the movie with fixes; this has happened a fair number of times over the years, but there's probably an equally large number of home releases that have (usually minor) flaws that go unaddressed (and in some cases un-noticed by all but the most eagle-eyed of viewers))).
If you have further questions, or want clarification, feel free to ask.