Thursday, March 15, 2012

Subs In Your Living Room

I used to blog about family type stuff and was part of a neat little community that swapped stories and ideas.  A long lost bloggy friend followed me over here and posted a question on an early post about subs.  He's looking to invest for his living room and wanted to know if I had a brand preference.  I don't.  I have a sub in my home setup but it came with a dirt cheap surround system that I got so I could hear the Winter Olympics in all their 5.1 channel glory.  

What I did though was write him a short novel as a reply comment that I thought would make a good post.  Home theater guys are always posting on pro audio boards and generally get laughed at and sent away.  But it's all the same, your living room is just a smaller venue with its own set of challenges and gear designed to suit different situations.  So I told him what to look for and how to apply some techniques once he's got a little thumper in his possession.  Here's the conversation.

  1. Followed you over from your The Mister blog - and glad I did. I know you generally deal with professional grade equipment - but do you use a subwoofer(s) at home? And, if so, do you have a brand or model preference?

  2. I tend to deal with subs that can handle hundreds if not thousands of watts but a lot of the same information applies to home stuff. The first thing is to use an amp that's bigger than the speaker you want to drive. Excess wattage doesn't blow woofers, DC current in the coil from clipping distortion does. So get a setup that gets loud enough before the pedal is on the floor. Self powered subs are great because the amps are usually well matched.

    I like to stay away from band pass boxes. All subs are ported but band pass boxes are sort of all port. They make a lot of bass but they seem to make the same note no matter what you play through them. Good butt shakers for game systems but not to listen to anything with rich bass tones.

    Position is important as well. A sub placed up against a wall reflects half of the energy back into the room and you get a 6 dB boost for free. Every surface counts so you can make a little sub do a lot of work on the floor in a corner. If you've got a huge living room and it's going to take two boxes to get the level you need, put them in the same location, stacked or side by side. Not only will they couple together and give you more apparent volume than if they're separated but you also won't get areas of addition and cancellation that cause uneven bass throughout the listening area.

    The last thing is EQ. If your stereo has a really good EQ section you can tone down the signal at the resonant frequency of the room so that one bass note isn't a lot louder than the rest. That really bugs me when a bass line runs down the scale and two notes make my teeth rattle while the rest are smooth and creamy.

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  1. Interesting thoughts. I had a longer comment but lost it trying to authenticate

    I've heard some use these just as parametric EQs for their home theater subs, to smooth the response.

    I hadn't thought about the chance of cancellation. I think some high-end receivers could actually send different signals to different subs (filtered from different channels, unless you have very full-range speakers). That might mitigate that effect a bit. However, lows aren't really directional anyway.

  2. They can be made somewhat directional by stacking multiple speakers and creating delay either mechanically or electrically. But when you've got two subs, there's going to be a power alley where ever you're equidistant from them and then there's nulls on either side of that. It may not be that pronounced in a living room but you can definitely feel it in a venue where you're getting slammed walking up the center aisle, and then step into the seats and find a few where there's almost no bass, and then step into an area where it's better balanced.


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