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Overview
First, let's define the AV receiver. This is short for audio video receiver, aslo commonly called surround sound receivers These devices receive in signals from other devices and process and transmit the video through a monitor out jack to your TV monitor and "process the sound" and amplify it and sending the power down your speaker wires to your speakers. Input devices for your AV receivers include cable & satellite boxes (we won't call them receivers for now to eliminate confusion), Blu-Ray DVD players, DVD players, CD Players, VCR's, IPOD docks or IPOD cables, Apple TV's, cassette players, turn tables, etc. I left off tuners (radios) because most AV receivers come with one or more built in tuners, (like AM/FM, HDFM, Sirius, XM and even internet radio.
Audio
So let's discuss the audio portion of the receiver.
Earlier generation receivers were audio only and you can still find stereo receivers today. In fact many traditional audiophiles still prefer PURE DIRECT stereo for listening in their acoustically designed sound rooms. Since our customers don't have acoustically designed sound room nor are they audiophiles, suffice it to say that current receiver technology and it's ability to process sound to accommodate for less than ideal room conditions, is one reason why you no longer have to spend a fortune to get great sound.
Music
From stereo receivers, we saw quadraphonic systems, a short lived 4 channel format. We've seen audio processing to recreate room acoustics to match famous sound halls from the ROXY on Sunset Strip to famous sound halls in Vienna. Yamaha was truly the pioneer in mass marketing sound field processing. While Sony unsuccessfully pioneered a multi-channel audio format, SACD (Super Audio CD), audio formats like 5 & 7 channel stereo and Dolby Music are the most commonly used. These later formats really grew out of the changes to home audio for video sources.
Movies
The idea, in its crudest form, was to create an environment in your home, like you were at the theater. As high-end customers began to experiment with in-home theaters using projector technology to create large images DOLBY and THX emerged as the leaders in the audio side of things. While THX focused on the high end audiophile market and movie soundtracks, DOLBY Laboratories focused on the mass market and developing audio chips to sell and license to electronics manufacturers. Dolby Pro-Logic was the brand name of a chip that could decipher (although somewhat crudely) common signals between the left and right channels and remove those common signals under the assumption they were dialogue and redirect them to a center speaker. Other algorithms were used to create a mono rear channel (although it usually used two speakers playing identical signals). Eventually Dolby Pro-Logic became the standard for the DVD industry. Movies like Top Guns with the jet buzzing the tower became favorites to show off to family and friends. Initially locating processors in the devices (like DVD players and Laser discs); they migrated into the make up of the AV receiver. AV receivers now had to have connections for front (2), center (1) and rear (2) speakers requiring new types of audio amplifiers. Dolby and a small speaker manufacturer called Bose capitalized on each others technology as consumers wanted to move away from bulky tower and book shelf speakers in favor of smaller cube speaker systems. Remember seeing those 3' tall wooden boxed speaker cabinets housing 12" or even 15" woofers?
Since the goal was to create a feeling like you were in the movie, manufacturers learned quickly that the high frequency sounds produced by the smaller and much less expensive speakers, were responsible for giving directionality to sound. Whether it was bullet ricochets or breaking glass, these high frequencies sounds created by the small tweeter could trick your mind into making you feel like you were in the scene with the actors.
The era of HTIB was born and in still thrives today. What is HTIB; simply put Home Theater in a Box and really Bose has to get the credit for popularizing this concept. Bose used their proprietary speaker technology to skim out low and mid bass frequencies sounds out of the front, center and rear speakers allowing use of little cube speakers. Without low frequencies mixed into the sound source for these speakers, Bose could preserve their clarity even at high volumes for the mid and high frequency sounds. The duty of producing the bass and mid bass was based onto a bass module we would now call a woofer. Since the woofer didn't have a significant impact on movie audio imaging, this was a huge win for Bose. As long as it thumped good when the helicopter flew over, your ears couldn't tell the location of the low frequency sound, instead the crisp snapping of the blades cutting the air make you want to duck for cover for fear of getting just a little too close and getting scalped!
Somewhere along the way, Dolby unveiled AC-3 which grew in popularity and was remarketed as what we now call Dolby Digital 5.1. This new digital technology changed everything and ushered in the modern era for AV receiver. Instead of a stereo soundtrack with a computer chip to analyze what sound goes where (guess with rules is a more accurate way of putting it), now 6 channels of sound would be recorded onto the DVD using digital technology and special cables like a optical audio cable or a digital coaxial able. Now AV receivers had to change.
AV receivers starting building in the Dolby Digital processing chips and using 5 separate amplifiers for each of the 5 main speakers inside the AV receiver and provided a low level output to connect a separate amplifier for the 6th channel or the .1 in Dolby Digital 5.1, or what we call LFE (Low Frequency Effects) or subwoofer. Traditionally these sounds below 80 Hz required 1.5-2.5 times as much power in watts RMS than the other five speakers and freestanding subwoofers used the space inside the sub speaker cabinet to house this amplifier.
Eventually Dolby Digital 5.1 became the standard for all DVD's and even most of the digital television you watch today (if you have a digital audio cable connected to a device that decodes the digital soundtrack.
One of the interesting developments in this evolution of sound was the fact that many consumers recognized the weakness of HTIB's to produce full sound for many of their music tracks. For years, receiver manufacturers gave consumers an "A" and "B" speaker option. This allowed users to connect another pair of speakers up to drive sound in another room without overloading the receiver.
Many consumers used the "B" to connect a pair of those large tower or bookshelf speakers for use when listening to music as their HTIB speakers never quite did the job.
Now with full range sound going to all five channels and an option to even send the LFE soundtrack to those 5 speakers, cube speakers could not handle the job.
Aesthetics meets Acoustics
This drove a major evolution in home speaker technology called flush mount speakers or sometimes called the in-ceiling or in-wall speakers. For more info on that area, we have an entire section, click here to go to that section.
In short, flush mount speakers with the use of airspace located between wall studs or between the ceiling joists allowed significant improvements in bass performance without the bulky tower or bookshelf speakers. Finally one system could handle dramatic movie soundtracks to the kick drum thumping bass of rock and roll.
Remember earlier I mentioned how special music formats like 5 channel stereo, 7 channel stereo, Dolby Music, and other formats really grew out of the changes to home audio for video sources. This is why. All the pieces came together, Soundtracks for video that required full range sound through the use of Dolby Digital 5.1 processing, AV receivers that had separate amplifiers for each speaker and flush mounted speakers that could create that bass without the aesthetic annoyance for many a spouse of those dorm room box speakers with the 15" woofers!
So if most of your system could be hidden, wouldn't you want to take advantage of those 5 speakers and subwoofer for your music? These sound processors allowed you to get that benefit with your music as well.
Going Overboard
As with almost everything, people assume if a little is good, more must be better. As the AV receiver market started to mature for Dolby Digital 5.1, Dolby introduced generation after generation of "new and improved" chips. Dolby added 6.1, 7.1, 9.1 and even 10.2. THX even redirected itself more to the consumer market, yet there really is only one standard across the board for audio in a home AV receiver and its Dolby Digital 5.1, everything else is pretty much a gimmick unless you are building an acoustically engineered sound room or theater.
That being said, we still recommend a DD 7.1 system to the majority of our customers, but that's for a different reason. Read on...
Dual Zone = Whole Home
I am not even sure which manufacturer first pioneered the ability to change the setting for a Dolby Digital 7.1 receiver and make it a Dolby Digital 5.1 system PLUS a second stereo powered zone. Whoever it was, it revolutionized our business.
See the industry has always wanted to move the audio and video out of the TV room and into the whole house. It doesn't take too much insight to figure out that this drives sales of speaker wire, speakers, volume controls, cables and amplifiers.
The problem is that each source device had to have its audio split between a rack of whole house amplifiers and while there are many deviations on this theme from touch pad controlled systems to computer controlled systems, they basically work the same. The labor to retrofit a house with speaker wire and speakers is already expensive; add a rack of additional equipment and few would spend the money in the large upper middle income market.
By allowing the consumer to turn off the 7.1, make it a 5.1 system, the additional stereo amplifier could be wired to am impedance matching speaker switch and drive as many as 16 pairs of speakers with just the AV receiver and a couple input devices like a cable box and DVD/CD player.
Future enhancements allowed for independent source control (you can watch the football game in the family room and put music on in the backyard) and even independent volume control.
Referencing a Room
This is a term we use to describe the acoustic reshaping of your room. When a new system is set up a primary listening area is determined. I call this the "king's chair" unless the "Queen" is there. An installer must measure the distance from the primary listening location to each speaker and input it into the receiver. This makes sure you ear gets the sound from each speaker in just the right time to make you thing you're sitting in a correctly shaped room (which few are).
Second step is to use the speaker test tone to send an audio signal to each speaker and allow volume adjustment so that each speaker is referenced to same loudness. The length or wire and room acoustics can affect this and in all my years, I still cannot do it by ear. Buy a $39 sound meter from Radio Shack, it's worth it. A new generation of receivers now come with a microphone and built in software that allow the receiver to listed to the acoustics of your room and adjust sound setting to compensate for it's short comings. This makes perfect sense to me, but doesn't work consistently in the real world. I would guess 2 out of 3 times I see an improvement and the third sounds horrible. We do not use them and prefer referencing by hand.
Audio Wrap Up
Hmmm, what else have I forgotten...Power, boy is that over rated. Any system with 100-120 watts RMS per channel will rock your world at even 75% volume. Receivers with 170, 200+ are just plain a waste of money.
There's certainly a lot more discussion you could have on the audio portion of AV receivers, but in my mind that's the important stuff. Remember as a segment matures, manufacturers keep adding features to differentiate themselves from their competitors and keep their product from becoming commoditized. That's the death spiral for a product's lifecycle. When it's a commodity, you just shop based on price. One new receiver we saw debuted boasted 980,000 sound settings and a weight of 75 lbs. Can you say, Law of Diminishing Marginal Return?'
Video
Switching, Up-Conversion and Up-Scaling
One of the changes in receiver technology has been the handling of video switching duties. In the old days you simply changed the TV source button to Video 2 and put in your video tape. With more and more devices this becomes quite cumbersome and leads to systems being complicated and frustrating to use. I can remember those customer service calls, "what should I do? I have the picture of the video tape and the sound of the cable box!"
So one critical feature is video switching and most AV receivers provide that functionality. A little less know function, but just as important is video up-converting. This refers to the receiver's ability to output video from various types of connectors (composite video, s-video, component video, DVI, & HDMI to a single monitor output usually the highest quality. It is especially important that your receiver output its HDMI as HDMI 1.3a.
Another feature you'll hear about is video up-scaling. This is one of the most over rated features you can find on any device. The idea is that you take a low resolution signal and make it look like high def or at least better. This can only be done with some sort of mathematical algorithm that multiplies the base resolution up to the scale of the TV monitor. Remember that saying, "Garbage in, garbage out?" You cannot increase the resolution you can only guess what to fill in the gaps as you blow up the image. I personally have seen much improvement in up scaling devices. You can go into Wal-Mart and get a $60 DVD player with up scaling for the "look of near HD." Yeah right...
Inputs
As far as inputs, how many and what type do I need. I recommend 3 HDMI (Blu Ray DVD, X-Box 360 or PS3, HD Camcorder) and 3 Component Video Inputs (Apple TV, Cable box, Satellite box). Even if you don't have quite that many devices, it really sucks when you go to add one a few years from now and find out you don't have a place to connect it and that little bit you saved on the smaller receiver comes back to bite you with the price tag of a new receiver.
Video Wrap Up
So this section is a little shorter, but you want an AV receiver with video switching and HDMI 1.3 up-conversion. Did I mention that this is up-conversion is rarely listed in the manual or in the specifications and most retail clerks will just assume you mean up-scaling. This is the benefit in dealing with someone who has experience in hundreds on the same systems!
Receiver Wrap Up
Mid to Large Room Receiver
I like the Yamaha RXV-863 as it's a 120 watt, Dolby Digital 7.1 dual zone receiver with independent source and volume control that supports HDMI 1.3a video switching, up-scaling and up-conversion and includes connections for an optional IPOD dock, XM & Sirius satellite radio, a built in HD radio tuner. It has 3 HDMI + 3 CV inputs. It's a $999 receiver at MSRP, with a MAP price of $919 that we sell for less after an in-home consultation. Best bang for the buck for a large room system (typically family room, theater room or kids bonus room with lots of devices) or when driving more than 4 speaker zones. Click here to go to product page and check out this receiver INSERT LINK TO YAMAHA RXV-863
Small to Mid-size Room Receiver
I like the Yamaha RXV-663 as it's a 105 watt, Dolby Digital 7.1 dual zone receiver with independent source and volume control that supports HDMI 1.3a video switching, up-scaling and up-conversion and includes connections for an optional IPOD dock, XM & Sirius satellite radio, NO built in HD radio tuner. It has 2 HDMI + 3 CV inputs. It's a $599 receiver at MSRP, with a MAP price of $559 that we sell for less after an in-home consultation. Best bang for the buck in a small room system (typically den or master bedroom) or when driving 4 or less speaker zones. Click here to go to product page and check out this receiver INSERT LINK TO YAMAHA RXV-663
Call if you have questions. We've installed thousands of AV receivers and our design consultants would be glad to answer any questions you have, even if you're a "do-it-yourselfer" and just want to buy equipment.
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