FAQ: Converting a Room to a Home Theater

This month's FAQ comes from a new subscriber to Audioholics and he asks how best to convert a regular room to a home theater listening space.

I am a recent subscriber of your current 2015 newsletter. I have been reading a lot of your in depth reviews and extensive testing on many of the products on your official website, as well as the many YouTube videos yourself and Mr. Hugo Rivera produced. I appreciate the detailed information given in the testing of specific products, which gives consumers like us  practical knowledge on  purchasing devices. I like to encourage you and your team to continue the efforts on providing the quality information to us the consumers, and which I know others like myself are contented on the information you have provided thus far. Nevertheless I have a few questions which have been plaguing my mind and I would appreciate if you can shed some light on those questions.

I am transforming an existing room to a home theater room / multi purpose room. The first question is based on products reviewed on your official website . The second is relevant to wiring in walls and the third question is methods of acoustic treatment in audiophile rooms which I was not able to find on your official website, but related to audiophile enthusiast.

Q: Pertaining to the Emotiva XPA-5 power amplifier you have reviewed; it's been suggested that it should be placed on a 20 amp dedicated breaker for usage. My question is added to this can an active subwoofer / powered subwoofer such as SVS PB13 Ultra be efficient for usage on the same 20 amp breaker as the power amplifier or would I need a higher rated breaker to support both devices? If yes what rated breaker would you suggest?

I have also read the review on SVS PB13 Ultra subwoofer which you have placed on a dedicated 30 amp breaker for exclusive testing.

Also after doing this exclusive testing what amperage or wattage did the subwoofer consume?

A: Emotiva recommends a dedicated 20A line to utilize the maximum potential of their XPR series amplifiers. However, the XPA series should be fine with regular 15A service.   In steady state conditions you will likely NEVER use that much power but I’d error on the side of caution and run a dedicated 20A line just for your XPA-5 and maybe some other low power AV components.  If you're having an electrician come in to run cable for the 20 amp circuit, they can simply use 12/3 with ground and run two circuits at the same time to cut down on your installation cost.

Audio and subwoofer amplifiers are not continuous draw devices, and you can connect all of your AV components including your SVS PB13-Ultra to a single 120V 15A with no problems at all.  For the most stable performance from your AV system, we recommend keeping lighting and continuous draw appliances (like hair dryers or vacuum cleaners) on a different circuit. 

If you are trying to determine if you need a 15A or 20A circuit, as a rule of thumb take the rated power of all your audio/subwoofer amplifiers and divide by four. 

This will be about the average power draw of the entire system at loud volumes with demanding source material.  You’ll see that most systems (even with a high-power subwoofer like the PB13-Ultra) will be perfectly fine with a single 15A line (which can support 1800 watts) or a 20A line (which can support 2400 watts).

We only used a 30A line on the SVS sub to do max SPL testing to insure the power outlet wasn't the limiting factor in our controlled measurements.  In my dedicated listening space, I have two very high powered subs running on one dedicated 15A line and NEVER run into a problem of lack of power.  However if you use a shared outlet that also connects to your rooms lighting, you may find they will flicker or dim when your subs are driven hard with bass intense music or movies.

Prewire AV cables behind Drywall

Q:  I have read information about wire installation on your site.

All of this information is bases on wiring in drywall. Do you have any reference of the same nature pertaining to block work or concreted walls wiring?

A: The same principles that govern routing cable through drywall also follow with block and concrete walls.  I would however run conduit as much as possible for block/concrete applications to ease the installation and/or changing out cables (such as HDMI) if one goes bad.

Q:  I have not seen any information on acoustic treatment in home theater room setup on your website. Such as bass traps high frequency absorbers and diffusers etc, to achieve audiophile quality. Was this discussed in previous articles which I missed and do you support this as a method of creating and audiophile listening room?

Corner Loaded Bass Traps

A:  We do have an entire section of the site dedicated for Room Acoustics.  However we typically recommend  minimal usage of bass traps since they tend to be big, bulky and expensive and also needlessly sacrifice system efficiency by turning bass energy into heat.  Since speakers and subwoofers are minimum phase devices, deploying multiple subs in the right locations with proper setup and EQ will flatten frequency response across multiple seats and minimize associated time domain problems as well.  This helps cut down on the need of using passive low frequency treatments.  Please check out our multi-subwoofer calibration basics for more information.