HDMI Switching

Allows you to connect multiple high definition HDMI Sources to your reciever and then out to your HDTV. This is a useful feature if you have an High Defintion Set Top Box and Next Generation DVD Player or game system, but only one HDMI input on your television.

HDMI Conversion

This is a different feature than HDMI Switching. HDMI Conversion allows you connect any type of video source - component, S-Video, etc, and send the video out to the television via HDMI, reducing the amount of cables going from your receiver to your TV.

Some receivers featuring HDMI Conversion:
Denon AVR-3806 • Denon AVR-2307CI

5.1, 6.1, 7.1 Channels of Amplification

How many surround channels do you need? 2, 3, or 4? That's the question here. Each

• 5.1 Channels: Just two surround channels, a left and a right. Currently the most "minimalist" surround sound configuration.
• 6.1 Channels: Adds a third surround "center" or "back" channel to
• 7.1 Channels: Two pairs of surround channels! That's a lot of speakers!

Remember that most movie soundtracks have only 5.1 or 6.1 audio tracks, and for most people, that's quite enough. But if you have to go BIG, 7.1 is the way to do it!

Surround Sound Formats

There's bunches of them.

• Dolby Digital
  The original digital 5.1 channel surround sound format. They really got it right with this format, and it's managed to stay the standard for may
• DTS
  A not quite as common format to Dolby Digital, DTS boasts better sound quality due to lower compression and higher bit rate audio soundtracks.
• Dolby Digital EX and THX Surround EX
  The "EX" here means that there is a seventh discreet channel in the soundtrack for the rear center.
• Dolby Pro Logic II and IIx
  DPL II will take old (circa 1990's) dolby soundtracks and two channel sources and create a convincing 5.1 presentation IIx adds a rear center channel, making it 6.1 presentation.

more on formats from Audioholics.com

Power Ratings

People often tend to get hung up on power ratings. They are important, but they're not always what they cracked up to be. It's hard to judge a receiver based on manufacturer's power ratings. What's more important is the quality of the unit's construction and power supply.

Some things to look for when looking at Power Specs:

• "RMS", which refers to the amplifiers ability to continuously provide the power stated. Sometimes a manufacturer will simply say "700 watts" but that is actually the amplifier's total output capability for one channel at one moment. It can't really deliver all that power.
• OHMS Check to see if the amp's specs give a rating for 4 ohm loads as well as the standard 8 ohm. If they do, this is a good sign. An ideal amplifier should be able to provide double the power into a 4 ohm load. But if they even LIST a 4 ohm rating, then that's a good start.

Digital Inputs

• Coaxial
  Uses the "RCA" type connector, but a Coaxial digital cable is not the same as an analog RCA cable. The actual cable constructions are a bit different because they are passing completely different signals. They just happen to have the same type of connector.
• Optical
  Passes the digital audio signal via light transmission. A fine choice although audiophiles tend to prefer coaxial for best sound quality. Most likely, you'll be hard pressed to hear a significant difference between the two.
• HDMI
  Transmits both audio and video signals via single cable. Sounds great right? Well we'd be a bit wary about viewing this as your all in one solution just yet. First, HDMI is a still evolving standard. The latest is HDMI 1.3, but most recievers only offer 1.2 compatibility. Second, some of these receivers will only pass video, not audio.

USB Input

Allows you to connect to your computer to your receiver. Listen to music files and internet radio on your big, bad, home audio system. A very cool and handy feature. If the reciever you want doesn't have it, don't fret. There are plenty of ways to get your computer's music onto your audio system. Check out our guide.

Some receivers featuring a USB Input:
Yamaha RX-V2700 • JVC RX-D411

HD & Satellite Radio

They are different!

HD Radio is a method of transmitting a digital signal over standard FM and AM airwaves. It allows multiple streams and promises improved signal reception with less noise over standard FM. You're limited to your local radio stations that have actually adopted the format. Also, be skeptical of claims of "CD Quality Sound". It uses lossy compression and transmits at a bandwidth of about 96kbps, which sounds okay, but certainly not CD quality. Also note that "HD" DOES NOT stand for "High Definition". It stands for "Hybrid Digital" and they're attempting to capitalze off the HD buzzword..

Satellite Radio is a completely different system. Broadcast over - duh - satellites, you get a completely different selection of programming. In fact, there's quite a diverse selection, with many choices no matter what your tastes. Quality is good, but not great. There are a varying degrees of lossy compression. Satellite Radio is also nowhere near the "CD Quality" it advertises itself to be.

Receivers with HD Radio capability:
Denon DRA-697CI

Receivers with Satellite Radio capability:
Sony STR-DG800 • Yamaha RX-V459

Phono Input