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

 

[The Knife]

As for Subwoofer(s) I have lately been looking at different options. Something that blends in front row in my living room which I also share with my wife and my German Shepard. I went to audit the Bowers & Wilkins DB1D and was very pleased with what this "little" Subwoofer can do. I say little because it is quite slim for hosting two 12 inch drivers. The DB1D host 2 active 12inch carbon drivers working back-to-back (opposed) . Implantation was done in 5 minutes. First it localizes it self in my room, calibrating it self via microphone, in order to cancel out unwanted frequencies that does not land well in my particular room. Second, the two active drivers cancel out cabinet resonances, ensuring that all power is used to create bass, not wasted vibrations (my Martin Logans bass drivers works the same way and this seem to be a proven way to ensure great results). Third, I trust the 2000 watt Class-D amplifier inside from well proven Hypex. Proportions make it an almost perfect cube of ca 17 inches per side. Finish is IMHO as perfect as a Subwoofer in this price range can be. As it comes with a hefty weight of 43kg and the amplifier is located in the bottom of the Sub, pointing toward the ground (and actually building some heat), I invested in a one Inch thick Black Angola granite stone (to be seen in one of the pictures). The stone serves not only as a stable foundation, it also lift up the subwoofer somewhat from the carpet, preventing any heat to reach the carpet. Most important the DB1D sound wise blends seamless with my ML´s. I feel (and hear) that the sound stage is much improved in all directions. I am connecting it via a (one) subwoofer cable from AQ, direct from my Line stage, the simple but elegant Greyhound subwoofer cable. I am very intrigued to go for a second DB1D, not only for the musical upgrade this could mean, but also for the visuals. To seek balance is pleasant. There is a certain beauty in having a 12 inch carbon driver facing you, and I assume doubling up, would be even more delightful.

 

[The Knife]

Some more pics…

 

[jeffreybehr]

Finally with the VERY-high-sonic-quality DIPOLE Sound Lab Majestic 745s in my room...

...I'm rethinking my SW situation.. I still have the Rythmik 18"-driver SWs in my system, at the back-wall (EDIT) 45-degree corners, with the lowpass filter still set to 25Hz, so they're really subwoofing.. I watched a fantasy-thriller movie named 'Moonfall' starring Halle Berry and Patrick Wilson (that's quite fun to watch as long as one maintains one's sense of humor) that has MUCH very low-frequency effects; the SWs were already turned on, and the spounds of large meteorites landing on Colorado's mountainsides were VERY low in frequency and rather loud.. I was reminded with each impact why I love the best of the sounds of SWs.

But again with dipole speakers, I'm strongly considering buying and having my woodworking buddy build a pair of GR Research's Triple Threat woofers/subwoofers.

Triple Threat Kit and Flatpack (Single) | GR-Research

gr-research.com

These are the 3-driver version of the 2-driver system that was built into the Serenity Super7s...

The OFFICIAL Super-7 thread

The OFFICIAL Super-7 thread

www.audiocircle.com

...that I used and loved for so long and that I still have but are now surplus.. The amp-and-drivers kit...

Triple Threat Kit (Single) | GR-Research

gr-research.com

...costs only $1500 or so (times 2, of course), and my friend could scratch-build attactive cabinets for a couple $K or so.. I'd place these 3-drivers-short towers behind the speakers somewhere.. Therefore I'd have the same general nature of bass that I have from the main speakers.. And moving the source of low bass to the front of the room would, I believe, allow me to move the SLs' bass-contour switch from +3 to flat, thereby adding some dynamic range to the SLs.

 

[DonH50]

My experience with open-baffle subs is that they do not perform as well as box designs, sealed or ported, and at such low frequencies are essentially a point source anyway thus offer no advantage in terms of integrating with dipoles. Danny (GR) has been using Rythmik amps so the servo will help, but I would stick with your current subs and spend the money elsewhere. Or give it to me and I will figure out something.

The 745's look awesome BTW.

 

[jeffreybehr]

My experience with open-baffle subs is that they do not perform as well as box designs, sealed or ported and at such low frequencies are essentially a point source anyway thus offer no advantage in terms of integrating with dipoles. Danny (GR) has been using Rythmik amps so the servo will help, but I would stick with your current subs and spend the money elsewhere. Or give it to me and I will figure out something.

The 745's look awesome BTW.

TYVM; they SOUND fabulous, too.
========================
I'm now considering a pair of GoldenEar SuperSub XXLs

SuperSub XXL | GoldenEar

SuperSub XXL Overview Housed within the gorgeous piano-gloss black enclosure are two horizontally-opposed 12˝ ultra-long-throw active drivers and two vertically-opposed 15˝ x 13˝ planar back-wave-driven radiators, driven by a 1600 watt Class D Digital amplifier. This dual-plane, patented*...

www.goldenear.com

...to replace my substantially larger Rythmik 18"ers..

Both would be placed on the front wall, as far from the 45-degree corners as I can and both firing left/right*.. The reviews for these GE SS XXLs were universally complimentary, and the price is RIGHT.

* These are stereo subwoofers driven by the front-L/R channels.

 

[Musical Bass]

Subwoofers are resonant devices that depend entirely on high moving mass and creating efficiency via of resonance! Common sense dictates that any form of resonance is not controlled by the input signal! Please read about the solution to resonance, physical size, integration and room issues.

www.tbisubwoofers.com

 

[sigbergaudio]

Subwoofers are resonant devices that depend entirely on high moving mass and creating efficiency via of resonance! Common sense dictates that any form of resonance is not controlled by the input signal! Please read about the solution to resonance, physical size, integration and room issues.

www.tbisubwoofers.com

I tried to read and understand what's on this website, but I am afraid I don't understand what this subwoofer is doing differently. Are you an owner of the sub or a representative of the company?