[John Casler]

OK, I don't want to cause Big B's cranium to Hypertrophy any more, but I have to share some of my bass experiments, based on a Cheney set up suggestion of 10 years ago (or more).

First off, I several weeks ago ended up with 4 LARGER subs.  Now many would say that I'm likely to blow my walls out and I probably could, but my goal was "real" bass.

Years ago (mid 70's) in talking to Lee Kuby from Harman Kardon, about bass, he said that "real bass" surrounds and envelopes you, and even shakes the air at high volumes.  He also said that it has detail, impact, and warmth.

Fast forward to today.  It seems that HT has blown the lid off Subwoofers.  There are now tons of "Explosive" subs.  But I find few of them "musical".  This is not a condemnation of Monster Subs, but more a recognition of what I was attempting to produce.

I wanted "Musical, Deep, 3-D, Enveloping, BASS!!!

Well, after much "fooling around" I now think I have it  

First I stacked the subs to make 2 "SUPER LARGERs" and placed them on my front wall, between my 626Rs.  Was it impressive?  Yessiree Bob!!

But, I still felt that it could be better.

Next, I placed a single LARGER "under" a 626R (it is a perfect stand) and musically it was incredible.

Then I ran all four (two on the front wall, and two as stands for the 626Rs) and the different paths seemed to add the lower Hz's due to loading the room from different planes of launch.

Well, the Genius of Big B, has always been that he is about 5-10 years ahead of most of the rest.  Over 10 years ago B, wrote how to place a sub in the front and a sub in back and run them "anti-phase" (out of phase).

While I had tried this with HT to an excellent result, I had not ever used it for my Audio Only System.

Well the effect is tremendous.  The envelopment, clairity, and depth has erased all room boundaries.  The who listening environment is now "filled" with solid, impactful, bass.

Thank goodness for occasional rainy days in California  

I have heard many great reports about "DIPOLE" woofers and SubWoofers, but have not heard them.

Well in essence a "dipole" sub would seem to be generating a similar radiation pattern, or room loading, except in this case "YOU" are inside the woofer.

I could be way off there, but it seems one of the "downsides" of Dipole Woofage is they don't play very loud and they can't play very low.  Well hold onto your Fedora (does anyone know what that is? ) this system will hit the low notes.

It is like being inside the bass, if that makes any sense.

And this is a "preliminary" report since I have't yet begun to play much with placement (who knows, I might end up with the woofs sitting in the center of the room!!)

And all my evaluations are "ear only".  I haven't pulled out any test tones, or sound meters.  I want to get it "just right" before looking at any numbers.

I might add that this arrangement also performed another Big B, treat.  The improved bass made a nice improvement in the rest of the frequency spectrum.  I noticed female voices are a touch smoother and male voice (Josh Groban) have richer body and tone.

And as a final note, because of the "sonic envelopment" this seems to generate, I notice almost a "surround sound" type of soundstage.

One of my refernce cuts is the first perfromance off the "Blue Port offering of Carl Saunders Sextet Live in SF".  The reality now of this soundstage surpasses my abilities to describe it.  Imaging, depth, and the surround sound effect now is mind boggling as well as "smile"    producing.

So my fedora is off to Big B on this one.   It is "trick", and it is effective, and you don't need 4 subs to do it.  Two will do the job.

Drag out Bad Plus, BlackLight Syndrome, Bela Fleck's Flight of the Cosmic Hippo and be amazed.

[zybar]

John,

Did you see the thread in the acoustics circle where we were discussing sub placement?

Click Here

Harmon has some white papers that basically state that the best sound was by having the subs at the midpoints of the walls (both L/R and F/B).

I want to try this, but I am not sure I can do it with my current physical setup (those darn Largers are pretty darn big!)

Anyway, glad to hear that your results are consistent with the white paper and what denverdoc reported.

George

[ted_b]

John,
Great stuff.  And the midwall front and back postions concur with another thread regarding Harmon Kardon's megamanyear/megasubwoofer study.  
(Edit: oops, George beat me to it)
Couple of questions:
Do you run the 626r's full-range?  Regardless, what are the Largers crossed at?  I'm toying with using subs (probably not my current two Sunfire truesubs, but I'll start with them) for 2 channel listening (with my RM/X's currently) especially when my DEQX arrives.  Wondered what you thought the RM/X rolloff will be measured at.....thx,
Ted_B

[mac]

John, I don't generally post in your forum so feel free to delete this if you'd like.  I wanted to offer a correction to what you said.

I have heard many great reports about "DIPOLE" woofers and SubWoofers, but have not heard them.

Well in essence a "dipole" sub would seem to be generating a similar radiation pattern, or room loading, except in this case "YOU" are inside the woofer.

To simulate a diploe woofer radiation pattern with sealed box woofers you would place two of your woofers back to back and drive one out of phase with one the other.  I say simulate because this 1) will not exactly produce a figure-eight radiation pattern, and 2) dipole woofers by convention don't use a sealed box (and don't have the associated box resonance problems that plague most sealed designs).

You may want to give that a try and see what you think.  Your end result may be similar or even better.

I could be way off there, but it seems one of the "downsides" of Dipole Woofage is they don't play very loud and they can't play very low. Well hold onto your Fedora (does anyone know what that is? ) this system will hit the low notes.

It depends entirely on the design.  Playing loud can be a shortcoming if the proper driver isn't used or the "box" is too small.  For instance, my dipole woofers are flat to 18Hz in my room.  I'm not sure how loud they'll play at that frequency but I can tell you that things start to rumble off the walls before the woofers show signs of giving up.  

[John Casler]

John,

Did you see the thread in the acoustics circle where we were discussing sub placement?

Click Here

Harmon has some white papers that basically state that the best sound was by having the subs at the midpoints of the walls (both L/R and F/B).

I want to try this, but I am not sure I can do it with my current physical setup (those darn Largers are pretty darn big!)

Anyway, glad to hear that your results are consistent with the white paper and what denverdoc reported.

George

Hi George,

While I have "skimmed" the Harman white papers, they generally are so wordy, technical and encompassing, that I didn't spend too much time with them.

Additionally, the consistency of room boundaries plays such a large part in the modal distribution that my modes are so different than their examples that it was hard to follow.

My basic room is 30' x 20', but some of the walls are "non-parallel" one side has openings into the kitchen and a large foyer, so "computing" bass response is a nightmare.

Plus I have my speakers set up on the "LONG" wall so I have a short "mode filled" 20 foot listening position.

I gave "credit" to B, in this case since he wrote about this (the push pull part) long before anyone else that I know of.

If you get to try it, you might find front corner to opposite rear corner the way to get the most, excitation.

But that said, I have the fronts 4 feet (to the front of the phase plug) out into the room, while I have the rears, backs against the wall.  This probably causes different "modes" for each set.  I would guess that this would give me a smoother response, or it seems to.

As I mentioned earlier, this is a "first report", and much more "set up and movement" is expected, but the preliminary results are "EXCEPTIONAL"!!!!

And as far as the foot print of the LARGER, I have the bottom plate attached to the slot, so I can play them up on end.

I will also mention again, that the surround effect is "very nice" and "impact" and "shake factor" (while not my goal) is as strong as I have felt (literally) in my room.

[John Casler]

John,
Great stuff.  And the midwall front and back postions concur with another thread regarding Harmon Kardon's megamanyear/megasubwoofer study.  
(Edit: oops, George beat me to it)
Couple of questions:
Do you run the 626r's full-range?  Regardless, what are the Largers crossed at?  I'm toying with using subs (probably not my current two Sunfire truesubs, but I'll start with them) for 2 channel listening (with my RM/X's currently) especially when my DEQX arrives.  Wondered what you thought the RM/X rolloff will be measured at.....thx,
Ted_B

Hi Ted,

Yes I run the 626R full range, for a couple reasons.  

1) I would rather keep the signal more pure by not running it through so much more wiring and electronics
2) The 626R bass is "GREAT" and very easy to blend with the subs

The NHT crossover is set to stereo and the dial is set to 32Hz.  I will be playing with this over the next few weeks.

I don't know the roll off of the RM/x, but Brian had me post some graphs several months ago.  If you do a search, they might offer some details.

[John Casler]

John, I don't generally post in your forum so feel free to delete this if you'd like.  I wanted to offer a correction to what you said.

 

Hi Mac,

Are you kidding? I wouldn't delete anything.   I need correction regularly

You are 100% correct (of course) and my choice of words was totally incorrect.

Dipolar "radiation" IS not what I have.  My point, which is still hard to make, is that you have a pair of roughly "inline" woofers, working together in a "push pull arrangement" which can be compared to the action of a dual set of drivers in some dipole subs.  The "radiation" actually has nothing to do with it, my bad choice of terms because I was rushing to get back into the room and listen some more

In this case the "room" becomes the box, and the individual subs become the drivers.

To simulate a diploe woofer radiation pattern with sealed box woofers you would place two of your woofers back to back and drive one out of phase with one the other. I say simulate because this 1) will not exactly produce a figure-eight radiation pattern, and 2) dipole woofers by convention don't use a sealed box (and don't have the associated box resonance problems that plague most sealed designs).

You may want to give that a try and see what you think. Your end result may be similar or even better

Glad you mention that config, since I was also thinking of it as a possiblity.  That is, placing the subs "back to back" and placing them "midroom" to the left and right of the listening position.

Then I would try "out of phase" (DIPOLE) and in phase (BIPOLE) to see what happens.

Too much fun here

Playing loud can be a shortcoming if the proper driver isn't used or the "box" is too small. For instance, my dipole woofers are flat to 18Hz in my room. I'm not sure how loud they'll play at that frequency but I can tell you that things start to rumble off the walls before the woofers show signs of giving up.

My experience with DIPOLAR SUBS is not first hand, I have only read about them.  Most who use them swear that they offer the most "real" bass available.  I am all for that.


 But I know what your saying about the walls shaking.  I had to go around again and "secure" a few more things after this new episode, and happily so...

PS, feel free to post here anytime with posts (even to correct me ) like above.  Actually thanks for jumping in.

[sfpepper]

OK, I don't want to cause Big B's cranium to Hypertrophy any more, but I have to share some of my bass experiments, based on a Cheney set up suggestion of 10 years ago (or more).

First off, I several weeks ago ended up with 4 LARGER subs.  Now many would say that I'm likely to blow my walls out and I probably could, but my goal was "real" bass.

OK...Now picture THIS...(Will only work with NEO Original, unless you convince Big B to mirror image NEO Larger)...

Take 4 Neo Original...2 per channel.  Set 'em up on end.  Push 'em together.  See how you have a by-design front slot firing?  Run 1 out of phase...or whatever.  Set your 626 on top.  Interesting?

[John Casler]

OK...Now picture THIS...(Will only work with NEO Original, unless you convince Big B to mirror image NEO Larger)...

Take 4 Neo Original...2 per channel.  Set 'em up on end.  Push 'em together.  See how you have a by-design front slot firing?  Run 1 out of phase...or whatever.  Set your 626 on top.  Interesting?

Hi Steve,

I'm not getting the "picture".  What is a NEO Original?

I'm prepared to wear the "dunce" cap

(I owe you an e-mail by the way)

[sfpepper]

OK...Now picture THIS...(Will only work with NEO Original, unless you convince Big B to mirror image NEO Larger)...

Take 4 Neo Original...2 per channel.  Set 'em up on end.  Push 'em together.  See how you have a by-design front slot firing?  Run 1 out of phase...or whatever.  Set your 626 on top.  Interesting?

Hi Steve,

I'm not getting the "picture".  What is a NEO Original?

I'm prepared to wear the "dunce" cap

(I owe you an e-mail by the way)

Maybe I'm the Dunce, in losing the 'vernacular'  The sub with the single front firing 12", 15" passive in the horizontal cab is the Neo Original, no?
As the Front firing active 12" and 15" w/passive 15" is the Neo Larger?
Hell...I've got 2 of the former...lemme know if I'm talking wrong.  Aside:
You don't owe me anything except your continued outstanding support/advice/and Pricing! (heh-heh)  (Cheerios for a great show!)

[Horizons]

I am a little dense.

Are you saying the jist of this concept is to have two identical subs with one on the front wall between your main speakers firing in phase and the other sub behind the listening position in the rear of the room firing out of phase?

[brj]

Harmon has some white papers that basically state that the best sound was by having the subs at the midpoints of the walls (both L/R and F/B).

I'll try to read those papers when I get home tonight, but one question jumps to mind immediately... assuming you only have 2 subwoofers, do the papers mention whether midwall left/right was better than midwall front/back?

(I realize that this may be room dependent.)

Thanks!

[ted_b]

Harmon has some white papers that basically state that the best sound was by having the subs at the midpoints of the walls (both L/R and F/B).

I'll try to read those papers when I get home tonight, but one question jumps to mind immediately... assuming you only have 2 subwoofers, do the papers mention whether midwall left/right was better than midwall front/back?

(I realize that this may be room dependent.)

Thanks!

Page 28 (conclusions) show 2 subs front/back, but the text reads only as opposing wall midpoints.

[John Casler]

I am a little dense.

Are you saying the jist of this concept is to have two identical subs with one on the front wall between your main speakers firing in phase and the other sub behind the listening position in the rear of the room firing out of phase?

Yesssiree Bob. that is it.

The idea is that one woofer is pushing the air "when" the other is pushing.

While I'm sure it can also introduce some problems in "some" rooms, it has a really dramatic (and positive) effect in my setup.

I have also (in a HT app) used this with "dissimilar" subs to a good effect also.  In this particular case I had the subs on the left and right "side" walls and ran them 90 degress out of phase with the fronts.

EDIT: I forgot that I should mention, I have also considered placing the rear subs "directly (as in inches) behind" my listening chair, FACING THE REAR WALL, and "in phase" with the fronts to see what that does    

[mac]

I am a little dense.

Are you saying the jist of this concept is to have two identical subs with one on the front wall between your main speakers firing in phase and the other sub behind the listening position in the rear of the room firing out of phase?

If you wish to simulate a dipole woofer, then no.  Two sealed box subs can "simulate" dipole radiation by placing them back to back (or stacked, or side-by-side).  Then flip the polarity on just the amp that feeds the rear firing woofer.  Ideally the woofers should be on the same plane as your main speakers.  Both the woofers should be fed the same signal (mono, unless you have 4 woofers).

[John Casler]

Oooops,

Seems things are getting confused since there are "THREE" seperate things being discussed here:

1) The "push/pull" set up I am using
2) Due to my incorrectly mentioning DIPOLAR radiation the dipole subs are being discussed
3) The Multiple Sub suggestions and research from Harman.

Just so all are clear that "each" of these is actually a seperate thing and some of the theory, physics and applications may crossover in the discussion.

[John Casler]

Maybe I'm the Dunce, in losing the 'vernacular'  The sub with the single front firing 12", 15" passive in the horizontal cab is the Neo Original, no?
As the Front firing active 12" and 15" w/passive 15" is the Neo Larger?
Hell...I've got 2 of the former...lemme know if I'm talking wrong.  Aside:
You don't owe me anything except your continued outstanding support/advice/and Pricing! (heh-heh)  (Cheerios for a great show!)

Aha!! Got it.  

That is the "NEW" Original Sub and "NEW" LARGER.

B, being a man of few words, (unlike others involved in VMPS ) improved both of them some years back and to "designate" the improvement, he call them the "NEW" versions.

I guess NEO means NEW?  Does it not?

Now I gotcha.

[brj]

John, do you have any feel for how much of a reduction in required power per subwoofer you need when using multiple subwoofers?  Presumably, it isn't a one-to-one relationship (2x the subs = 0.5x the power/sub), but it has to help.  I wouldn't think you need 1000 W/sub any more since each sub will be doing less work...

[zybar]

John, do you have any feel for how much of a reduction in required power per subwoofer you need when using multiple subwoofers?  Presumably, it isn't a one-to-one relationship (2x the subs = 0.5x the power/sub), but it has to help.  I wouldn't think you need 1000 W/sub any more since each sub will be doing less work...

I am actually going in the opposite direction and adding a second Crown K2 to the system.  This means a K2 for each Larger sub.

I will try the amps as mono amps (about 2500 watts each) and as stereo amps with each channel connected to a single driver.

George

[John Casler]

John, do you have any feel for how much of a reduction in required power per subwoofer you need when using multiple subwoofers?  Presumably, it isn't a one-to-one relationship (2x the subs = 0.5x the power/sub), but it has to help.  I wouldn't think you need 1000 W/sub any more since each sub will be doing less work...

Got me on that one???

I actually run all four subs off 2 channels of a 3 channel amp. (CineNova)

It has a 4Kva transformer and lists 1000wpc @ 2 ohms.

For 2 channel music the subs "lope" along and are never stressed.

Too be sure, more subs means more efficiency, but most like to have plenty of power reserves.