Room gain

[Jeff R.]

What principles factor into room gain? Is it more than room size and subwoofer location? Does a sealed sub have a higher potential than a ported sub? I am just curious about this phenomenon. Can it be approximated before you put a sub into a room? Only measured?

I have an ungodly sized area in my main home to fill with sound and I have no issues with my current 3.2 setup. See my signature....yet I have enough bass to vibrate wall and floors and fill the entire house with very loud music that is to my ears fantastic. So do I have a room with exceptional room gain??? Based on the Audioholics room rating guide, I would be past the Extremely Huge rating, yet nothing I own in the subwoofer category should be able to do much in my area.

Thanks

Jeff

 

[Steve81]

What principles factor into room gain?

To the best of my knowledge, it is largely a matter of room size and how rigid the boundaries are.

Does a sealed sub have a higher potential than a ported sub?

A sealed sub tends to be better able to take advantage of room gain as it's natural rolloff of 12dB/octave lines up quite well with the theoretical 12dB/octave boost you'll get from room gain. Conversely, a ported sub rolls off at a rate of 24dB/octave below tuning, and is usually filtered against such inputs to prevent driver damage.

Can it be approximated before you put a sub into a room?

You can always try to approximate it, but how close it is to reality is a whole different ball of wax. Basically, you divide the speed of sound by twice the longest dimension of your room, in my case 24 feet, to find the frequency where room gain should start to kick in. So for my room, were talking a little under 25Hz. As mentioned above, gain is a theoretical 12dB/octave. However, my room boundaries aren't exactly ten inch thick steel plates, so there will be losses.

I have an ungodly sized area in my main home to fill with sound and I have no issues with my current 3.2 setup...So do I have a room with exceptional room gain???

You're probably not experience room gain; while your subs aren't necessarily output kings, they aren't pansies either. I'd fully expect them to be able to generate sufficient output to shake things up a bit.

 

[j_garcia]

Believe it or not, a larger room can be better for bass than a small one. Why? Less cancellation and you will get full development of the waves at frequencies that are shorter than the length of the room. I experienced this in a friend's place who has a HUGE great room too, and a single SVS cylinder was able to provide solid performance. I've heard bigger subs than that in smaller rooms and it doesn't work as well. Though I understand how sound works in a room, until I heard that sub in that room, I had no idea just how MUCH of a difference it can make on the bass. That's one of the reasons why when I am looking at a new place to live, I go for the places with the largest rooms. Room shape is a factor as well, as the exact ratios play into how cancellation does or does not occur at various frequencies, so in your case, you probably do simply have a room with good acoustics.

 

[Jeff R.]

Very good info guys....

So if my room is large, irregularly shaped and has a variety of solid and soft surfaces these are all traits that may lead to a room with less cancelation and a more balanced listening experience in various seating positions.

 

[SnowmaNick]

Josh Ricci has an interesting article on this on his Data-Bass site, if you want some additional info.

 

[eljr]

What principles factor into room gain? Is it more than room size and subwoofer location? Does a sealed sub have a higher potential than a ported sub? I am just curious about this phenomenon. Can it be approximated before you put a sub into a room? Only measured?

I have an ungodly sized area in my main home to fill with sound and I have no issues with my current 3.2 setup. See my signature....yet I have enough bass to vibrate wall and floors and fill the entire house with very loud music that is to my ears fantastic. So do I have a room with exceptional room gain??? Based on the Audioholics room rating guide, I would be past the Extremely Huge rating, yet nothing I own in the subwoofer category should be able to do much in my area.

Thanks

Jeff

Just what is room gain? What does this term mean? Refer to?

Thanks

 

[shadyJ]

A distinction should be made here of pressure vessel gain and boundary gain, both can be called 'room gain'. Here is a post that explains it more succinctly than I can.

 

[Basshead81]

If your room has a dimension longer then 20ft then most likely you will not see much room gain...ported would be the best solution for deep bass. Also as mentioned, larger rooms tend to have less modes and cancellation issues.

 

[lsiberian]

If your room has a dimension longer then 20ft then most likely you will not see much room gain...ported would be the best solution for deep bass. Also as mentioned, larger rooms tend to have less modes and cancellation issues.

Unless you can go IB.

 

[Basshead81]

Unless you can go IB.

True that!