To Sub Or Not To Sub, That Is The Question

[kach22i]

Looking at your room, i can clearly see why you get the best results with just one subwoofer, where would you even put a second one ? Making general assumptions about subwoofers and their placement based one these conditions is somewhat of a stretch

Not a stretch or single experience as the same system was in the living room of my old house built in the very early 1900's, sprung wood floor (assumed balloon framing). In that situation it was impossible not to energize the entire floor system into a singing diaphragm, corner location was worst of all. I ended up having to disconnect the sub for music and used it only for home theater.

Best result was not with "one subwoofer", it was the only result, perhaps you missed that? I had the word NOT capitalized, how could you miss it?

 

[Lagonda]

From what I recall reading, the recording process does not encode low frequency information in stereo, therefore you need only one subwoofer.

From what I recall reading, multiple woofers cause multiple problems, more is NOT better, therefore you need only one subwoofer.

So your bold statements are not from real experience, just what you have been reading.

 

[kach22i]

So your bold statements are not from real experience, just what you have been reading.

From what I recall reading...............................

From what I recall reading..........................

From my own experimentation.............

I have been very clear, go back and reread what I wrote.

I know that I will never convince someone that has invested more in subwoofers than their entire system into accepting they could have spent less and got more.

Know this, you have very little chance convincing me spending more will result in more.

However I am still curious enough and not too arrogant to think there is nothing more to learn, there is always more to learn.

Most of the research I did ended five years ago, I'm sure something new or a new insight is out there.

Post it if you have it.

 

[Lagonda]

From what I recall reading...............................

From what I recall reading..........................

From my own experimentation.............

I have been very clear, go back and reread what I wrote.

I know that I will never convince someone that has invested more in subwoofers than their entire system into accepting they could have spent less and got more.

Know this, you have very little chance convincing me spending more will result in more.

However I am still curious enough and not too arrogant to think there is nothing more to learn, there is always more to learn.

Most of the research I did ended five years ago, I'm sure something new or a new insight is out there.

Post it if you have it.

As far as i can understand from your post you only have experience with one subwoofer at a time, so you do not have any experience with multiple subs, but still make bold statements about their uselessness. Why would i want to convince you to spend more ? I am not a dealer and do not really care how many subs you use. I have often abstained from using subs i already own, if the floor or room size was not up to the task. In a room of proper size/dimensions with adequate flooring, i hear a clear advantage to multiple subs, if they are adjusted right. I am speaking from my own experiences, not something i read.

 

[kach22i]

As far as i can understand from your post you only have experience with one subwoofer at a time, so you do not have any experience with multiple subs, but still make bold statements about their uselessness. Why would i want to convince you to spend more ? I am not a dealer and do not really care how many subs you use. I have often abstained from using subs i already own, if the floor or room size was not up to the task. In a room of proper size/dimensions with adequate flooring, i hear a clear advantage to multiple subs, if they are adjusted right. I am speaking from my own experiences, not something i read.

I never made bold statements, but apparently you have no problem continually making them.

Glad to hear that when you have had sub problems you abstained from using them, I've been there like I said.

Time wise and value wise; if you are only interested in a single listening position then it is my opinion that a single center and proud sub is all you need.

Put the extra time gained into listening or going to concerts, and put the extra money into the room and acoustics.
Just my opinion and value system, mileage may vary.

 

[DonH50]

I have not been following but was pinged on the peak vs. null measurement scheme. Mathematically a peak will add about 6 dB if the sources are equal in amplitude, but a null could be a complete cancellation resulting in no sound (-infinity dB). There is a discontinuity in the response curve at a true null. In practice nulls of -20 to -40 dB are common; furniture, walls, etc. tend to reduce null depth. As you slide sine waves across in phase, the peak tends to build gradually, whilst a null tends to appear more suddenly. These make it easier to detect a null than a peak. For pictures, look at my comb filter article, which shows what happens as signals combine constructively (creating peaks) and destructively (creating nulls): https://www.whatsbestforum.com/threads/introduction-to-comb-filter-effects.20633/

HTH - Don

 

[Johan K]

As far as i can understand from your post you only have experience with one subwoofer at a time, so you do not have any experience with multiple subs, but still make bold statements about their uselessness. Why would i want to convince you to spend more ? I am not a dealer and do not really care how many subs you use. I have often abstained from using subs i already own, if the floor or room size was not up to the task. In a room of proper size/dimensions with adequate flooring, i hear a clear advantage to multiple subs, if they are adjusted right. I am speaking from my own experiences, not something i read.

YOU @Lagonda of all people know what you’re talking about!! People (should) listen to your experiences… They might learn something !!!

/ Jk

 

[DonH50]

I never made bold statements, but apparently you have no problem continually making them.

Glad to hear that when you have had sub problems you abstained from using them, I've been there like I said.

Time wise and value wise; if you are only interested in a single listening position then it is my opinion that a single center and proud sub is all you need.

Put the extra time gained into listening or going to concerts, and put the extra money into the room and acoustics.
Just my opinion and value system, mileage may vary.

A single sub cannot counter all room modes even for one seating position. You might counter the one that bothers you the most, but in general and depending upon the room and seating position(s), additional subs can significantly improve the frequency response. I use four small'ish subs in my relatively small media room, not for output, but to counter some significant nulls at the MLP (which I cannot move much due to constraints of the room, things like doors and such).

Time wise it doesn't take much more effort to align additional subs, and is a one-time thing done at initial purchase and set-up, then the rest of the time is spent listening to a better overall sound. Changing room size is usually more expensive than adding a sub. Acoustic treatments are rarely effective at subwoofer frequencies due to the size of treatments required, and active treatments often cost as much or more than buying another sub.

IME/IMO/YMMV/etc. - Don

 

[Johan K]

A single sub cannot counter all room modes even for one seating position. You might counter the one that bothers you the most, but in general and depending upon the room and seating position(s), additional subs can significantly improve the frequency response. I use four small'ish subs in my relatively small media room, not for output, but to counter some significant nulls at the MLP (which I cannot move much due to constraints of the room, things like doors and such).

Time wise it doesn't take much more effort to align additional subs, and is a one-time thing done at initial purchase and set-up, then the rest of the time is spent listening to a better overall sound. Changing room size is usually more expensive than adding a sub. Acoustic treatments are rarely effective at subwoofer frequencies due to the size of treatments required, and active treatments often cost as much or more than buying another sub.

IME/IMO/YMMV/etc. - Don

Best write up I’ve read in a long time.. You are sooo right @DonH50 !! That is one of the reasons I have 8 subwoofers in MY room… It was a PITA to set them up, due to the special configuration I have, but once it was done, it was done - no need to touch the subs again… it just work flawlessly !

/ Jk

 

[DonH50]

Best write up I’ve read in a long time.. You are sooo right @DonH50 !! That is one of the reasons I have 8 subwoofers in MY room… It was a PITA to set them up, due to the special configuration I have, but once it was done, it was done - no need to touch the subs again… it just work flawlessly !

/ Jk

Thanks!

Here is a picture showing what happens as you take two cosine waves and vary their relative phase. For this plot, the first signal is a fixed 80 Hz tone at 0 degrees, and the second signal is another 80 Hz tone but with phase varied from 0 to 360 degrees. You can see at 0 degrees and 360 degrees the two signals are in phase and add to create a signal that is 6 dB higher in amplitude. At 180 degrees, the two signals completely cancel, resulting in a large null. In between, the signals gradually change amplitude as the phase is varied, with slope increasing as you approach the null. This may make it easier to understand why a null test is more revealing for this case.

HTH - Don

 

[Robh3606]

I use four small'ish subs in my relatively small media room, not for output, but to counter some significant nulls at the MLP (which I cannot move much due to constraints of the room, things like doors and such).

Hello Don

This is a good read I posted in the other thread. Reaches the 4 sub recommendation. The null is much easier to see thanks for posting the graphic.

Rob

 

[DonH50]

Hello Don

This is a good read I posted in the other thread. Reaches the 4 sub recommendation. The null is much easier to see thanks for posting the graphic.

Rob

Thanks, I have posted the Welti presentation many times, not sure I have in this thread, done it so many times I lose track! He has a number of other AES papers but you may need to pay for those (or be a member).

 

[Holmz]

LL21, putting a link to your member system would help me specifically address your room and situation. That said, like most everyone else here I have an opinion, and personal experience in this hobby, best to keep an open mind on all things and don't get suckered into group think.

From what I recall reading, the recording process does not encode low frequency information in stereo, therefore you need only one subwoofer.

I think you missed room modes.
And the position of the sub would affect the timing and phase at the listening position.

From what I recall reading, multiple woofers cause multiple problems, more is NOT better, therefore you need only one subwoofer.
….

OK