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How Do I Switch Between an AVR and Stereo Amp?

Al Griffin  |  Dec 28, 2017

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Q I currently use a receiver for watching movies in 5.1 surround and for listening to stereo music. I’d like to expand my system with a dedicated stereo preamplifier and amplifier for music playback but have realized that I would need to switch the cables of my main left/right speakers from the receiver to the amplifier every time I changed over from movies to music. Is there some type of switchbox that would enable such a setup? If so, is there an audiophile-grade version that wouldn’t negatively affect the sound? One more question: Would I be able use my subwoofer with both configurations? —Raphaël Rainville / via e-mail

A Speaker selector switches do exist, but these are mainly used to route the speaker-level output of a single amplifier to different speaker pairs. Also, I’m not familiar with any options that could be considered audiophile grade. A high-quality solution for the type of scenario you’re describing would be to buy a stereo preamplifier or integrated amp with a home theater bypass feature (sometimes called simply a bypass), which is basically a stereo analog input with a fixed gain level.

Here’s how a home theater bypass feature works. You connect the main left and right preamp outputs of your surround receiver to the bypass input on the preamp or integrated amp. Next, you connect the amplifier’s speaker outputs to your main left/right speakers and adjust the levels of all channels for surround sound using the receiver’s auto-calibration feature (or manually using an SPL meter). The higher-quality stereo amplifier will now power the main left/right speakers when playing both movies and music. The only difference is that you will need to switch between them using the preamp or integrated amp for music playback, and the receiver when watching movies.

Incorporating a subwoofer for both movies and music in such a setup is more problematic. One recommendation would be to buy a high-quality surround receiver — one from Anthem’s MRX Series, for instance — that provides preamp outputs to connect a more powerful stereo amp for the main left/right channels and lets you store multiple bass management/EQ configurations. With such a setup, you could create one preset optimized for 5.1 movie playback and another tailored specifically for music listening using your front left/right speakers plus subwoofer.

Another option would be to use a stereo preamp like the Parasound Halo P 5 ($1,095), a unit that appears unique in its provision of both a home theater bypass and a subwoofer output with bass management.

COMMENTS
itsratso's picture
Submitted by itsratso on December 28, 2017 - 5:51am

I used to have a preamp with a ht bypass. I had a full on 2 channel rig integrated with my HT setup, separate power amps, bass control, the whole enchilada. then I was on a HT forum and a person bet me that I could just use the stereo setting of my denon AVR and I would never know the difference. he was absolutely right. I dumped it all, simplified and my listening life is a whole lot simpler now. before drinking the kool aid, just try the stereo setting on your AVR. bonus, you get bass management too. see if you like it.

JimmeQ's picture
Submitted by JimmeQ on December 28, 2017 - 10:29am

It appears Raphaël could use a simple switch. I have a need to switch between an AVR and a tube amplifier with one set of speakers.

I use the TC-7220 Amplifier / Speaker switch. It is a high quality, well built device. Metal case. Quality feeling switches. Good quality banana jacks. There is no switch noise whatsoever. While I have not opened the unit, the TEC TC-7220 switches' feel and sound mechanical. I purchased the TC-7220 through Amazon and I found more information about the switch at http://www.homehifi.co.uk/S/tc-7220.htm It appears mine is an OEM version of the Beresford TC-7220 or is it Home HiFi that is the OEM? I find this to be a high quality solution for speaker and amplifier switching without affecting the quality of sound.

Puffer Belly's picture
Submitted by Puffer Belly on December 28, 2017 - 12:00pm

You could always connect your subwoofer to the front speaker connections and connect your front speakers to the subwoofer. Set on your AVR the subwoofer to off and the front speakers to large. Better yet, use two subwoofers for better stereo imaging. See the Get Better Sound website.

Rich67's picture
Submitted by Rich67 on December 30, 2017 - 5:23pm

Sub woofers are typically crossed over at 80hz or below. They can provide no stereo, at those frequency, any stereo information that a human being can hear. This is true for everyone unless your head is 2ft wide and your ears are in the normal places. Your brain cannot interpret the difference in time arrival to determine direction when the size of the compression is larger than the distance between your ears. Stereo or more sub woofers may even the response in some rooms and provide a more pleasant reproduction, but they proved no stereo information. Let's bury this myth. No human can get stereo information from a note lower than 80 Hz just like no human can do a 60' high jump.

Puffer Belly's picture
Submitted by Puffer Belly on December 30, 2017 - 5:55pm

Try it, and a good subwoofer has an adjustable crossover to blend with the main speakers. I'm not talking about LFE, which is not musical, I'm talking about the front speakers.

Rich67's picture
Submitted by Rich67 on January 1, 2018 - 8:09pm

You miss the point entirely. I didn't say that multiple sub woofers cannot smooth a room response. My point was that they cannot provide STEREO information due to the physical limitations (i.e. the ability to judge directional information below 80 Hz). It doesn't matter that they can blend with the associated speaker. They cannot provide any stereo information below 80 Hz, whether they are crossed over with a main speaker or not. The SUB WOOFERS, below 80 Hz cannot provide any directional ques. They can smooth room response, but directional ques, for the aforementioned reasons, cannot be provided by a sub woofer. Unless your ears are physically further apart than the normal 10-12" on a normal adult human head what you are asserting is physically impossible, due to the mechanism of how human hearing determines direction. This isn't an opinion, this is science. However, if you think you can hear the difference in stereo response below 80 Hz, it's your money. Buy as many sub woofers as you like, if that makes you feel better. It doesn't cost me anything.

Puffer Belly's picture
Submitted by Puffer Belly on January 1, 2018 - 8:36pm

...and I don't disagree that it shouldn't work, but 2 subwoofers sound better, including the images they create. I have the Get Better Sound book and didn't believe it when I read it. I found a matching subwoofer for a good price on eBay and the book was right -- 2 subwoofers do sound better for stereo for a lot of reasons.

true audio's picture
Submitted by true audio on December 29, 2017 - 3:16am

If I were to start over with a two channel system, the Halo P5 & the A21 would be on my gotta have it list. I wish my Peachtree nova 220 was a 2.1 I would get a pair of SVS subs to go with my towers. Now that system with the right towers would make any audiophile grin ear to ear. If you have the room, its nice to put two different systems together. Your theater room or man cave may not be a open,bright and relaxing listening environment. Unless your music selection is nothing but Grunge and death metal. Take your time, the right system will last a couple of life times.

mikesul's picture
Submitted by mikesul on December 29, 2017 - 12:33pm

I had the same situation. I use the Niles SPK-1 to allow the left and right main speakers to be used by both my AVR and integrated amplifier. I use the 12V trigger out on my integrated amplifier to trigger the switch (via control input) to use speakers connected to B posts (integrated amp mains). The AVR mains are connected to A posts (which are used by default). A very inexpensive solution with no sound degradation. Simple speaker wire conections. If you have a switched 12V outlet on either the AVR or stereo amp, you can use that instead of a 12V trigger output.

df190765's picture
Submitted by df190765 on January 9, 2018 - 3:55pm

Try the Russound AB-2.2. It is designed as an A/B switch for two amps left/right speaker outs connected to one set of left/right speakers.

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