Bass Response, Room Size and Speaker Size

[dolifant]

<font color='#000000'>Is there a relationship between room size, apeaker size and bass response?

I have been told that large speakers (large woofers?) in a small room blunts the bass response. Something about the sound wavelength being too big for the room.

That is, he said that if you have speakers too large for the room the bass response is less than smaller speakers in the same room.

Makes no sense to me, but I thought I'd put this up for comments.</font>

 

[Rip Van Woofer]

<font color='#000000'><table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>

dolifant : I have been told that large speakers (large woofers?) in a small room blunts the bass response. Something about the sound wavelength being too big for the room.

That is, he said that if you have speakers too large for the room the bass response is less than smaller speakers in the same room.
Makes no sense to me, but I thought I'd put this up for comments.

You're right -- it makes no sense because it's wrong! If it were true, you couldn't get bass from headphones because the distance from the transducer to your eardrum is lots shorter than the frequencies involved! For that matter, so are the cabinet dimensions of nearly all speakers (I think the wave lenghth of the lowest audible bass notes is over 20 feet).

In a small room, the resonant frequencies of your room (that can reinforce the bass and make it &quot;boomy&quot are higher, generally in the region where you don't want so much bass reinforcement, so proper positioning to correct this (and maybe even worse, the nulls that can cause huge dropoffs in the upper bass) can be more of a challenge, especially if your speakers or sub are large. Not due to their acoustical characteristics, mind you...it's just harder to figure out where to put that big freakin' box where it will sound best in a small room, but so you won't trip over it or arouse the wrath of your significant other.

However, the dimensions of your room need not be equal to or greater than the wavelength of the lowest frequency you wish to reproduce even though it seems logical on its face that it should.

Large speakers are overkill for a small room, however -- besides being physically intrusive, you just don't need to move that much air in a small room to get the loudness you want. That's why I would not put an 18&quot; sub in my 10' x 13' den, for instance!

For an intro to the basics of room/speaker interactions, I suggest a look at &nbsp;
Siegfried Linkwitz's page on room acoustics.</font>

 

[JAB]

<font color='#000000'>The wavelength of a 20hz bass note is twenty feet. To play a true low base note (20hz and below) you will need a large room to accomplish this, as well as a great speaker or subwoofer that is flat to 18hz or lower. Very few speakers will play &nbsp;20hz or lower - most people equate low bass with loud 60-80hz frequencies (the guys with the roof bender bass in cars live in this region - the bass outside the car is actually lower because the flexing of the car metal acts like a huge woofer.P.S.:hearing aide sales people rejoice - these guys will coming!). A true subsonic note is something you feel more than you hear, and most subwoofers are -3db at 20 hz and falling fast in the lower frquencies. Get the Avia or Digital Video Essentials disc and do the low frequency sweep to see how your speakers and/or sub wimp out pretty quickly.

I have experienced true low bass - I once owned a pair of Infinity IRS Betas with the bass towers powered by a Mark Levinson &quot;arc welder.&quot; They were flat down to 16hz with powerful subsonic bass. The pressure in my listening room was incredible when I found a record or CD with really low bass. Some people actually feel ill ( something to do with the inner ear) when they are subjected to very low bass notes for any length of time.

Get into the 25 -30hz response area and be happy!!

Al</font>

 

[bobdehunt]

<font color='#000000'>The wavelength of a 20hz bass note is twenty feet. To play a true low base note (20hz and below) you will need a large room to accomplish this, as well as a great speaker or subwoofer that is flat to 18hz or lower.

Al</font>

You're correct in everything except that a 20 Hz tone is 20 feet long. It's closer to 17 and some meters. There's an equation for wavelength out there, but unfortunately I don't remember it. In a perfect world, all dimensions in the room would have an aspect ratio of 17,9,15 if I remember correctly, or the room's smallest dimension needs to be as large as the lowest wavelength you are planning to play. The room being smaller will cause the bass to double up on itself, for lack of a better term, and therefore you will feel a 20 Hz note, but hear a fourty. The aspect ratio, which as I said may be wrong, helps to eliminate nodes and the problem with the bass doubling up with itself, but the placement has to be perfect for it to really work. I think the outdoors is probably the best place for music if possible. I'd like to make a way to have audiophile quality speakers outdoors for listening in warm weather without risking damage to the speakers. Unfortunately though that's a tough task.

 

[lovinthehd]

Bass in a room is subject to what's called the Schroeder frequency. Maybe have a read of this article for an introduction. Having the bass/sub fixed in the same spot as L/R speakers doesn't often deal with room modes well.

 

[shadyJ]

You're correct in everything except that a 20 Hz tone is 20 feet long. It's closer to 17 and some meters. There's an equation for wavelength out there, but unfortunately I don't remember it. In a perfect world, all dimensions in the room would have an aspect ratio of 17,9,15 if I remember correctly, or the room's smallest dimension needs to be as large as the lowest wavelength you are planning to play. The room being smaller will cause the bass to double up on itself, for lack of a better term, and therefore you will feel a 20 Hz note, but hear a fourty. The aspect ratio, which as I said may be wrong, helps to eliminate nodes and the problem with the bass doubling up with itself, but the placement has to be perfect for it to really work. I think the outdoors is probably the best place for music if possible. I'd like to make a way to have audiophile quality speakers outdoors for listening in warm weather without risking damage to the speakers. Unfortunately though that's a tough task.

Although your reply is 14 years late, here's to hoping that poster does manage to read it somehow, and it corrects his long-held misunderstanding. Cheers!

 

[lovinthehd]

Although your reply is 14 years late, here's to hoping that poster does manage to read it somehow, and it corrects his long-held misunderstanding. Cheers!

LOL hadn't noticed the date...but the odd formatting probably was a clue.

 

[bobdehunt]

Although your reply is 14 years late, here's to hoping that poster does manage to read it somehow, and it corrects his long-held misunderstanding. Cheers!

Lol, I had no idea this thread was so old. I should probably start making it a habit to check dates before I post eh?