[John Casler]

John, does this "push/pull" setting mean the subs are 180 degrees out of phase? Thanks. 
 
 
Cheers,
Robin

Hi Robin,

It means that the woofers in front are pushing toward you and the woofers behind you are pulling away from you.

For more clarity;

If the woofer behind you is "facing you" then you would run it "out of phase".

If the woofer behind you is facing away from you, then it is run "in phase".

The frontal woofs are always "in phase" and it is the rears that are adjusted depending on the orientation of the rear woofs.

You have to grasp that as the front woofs push at you, you want the motion of the rear woofs to be in the same direction.  The actual phasing then depends on the orientation of the rear woofer.

Since bass frequencies are somewhat hemisperical in their radiation you want the energy of the "push" action of each woofer to be in the same direction.

The concept of Anti or Reverse Phase came from the common placement, where the front woofers were on the front wall, in phase and moving at you. (pushing) and the wear woofers were on the rear wall, but to get them moving in the same direction you needed to reverse the phase.

So regular or reverse phasing will depend on the "orientation" of the rear woofs.

As my Physics Professor FL Yost used to say; "Clear?"

[satfrat]

Gotsha John,,, thanks for the explanation. 
 

[Construct]

John,   
    My intent with the review was to be as fair as possible, and provide a direct comparison to subs I have/had.  I have been recommended umpteen subs in the past, and they always fell short. I wish I had a dollar for every time I read "Zomg!!!  DUDE... this sub is wicked sick!"  Just to find out it performed sickly compared to the claims. The best bang for the buck was the 15"  dayton titanic III.  I felt the burn when I ended up with subs that the maggie crowd recommended the REL, but that sub just didn't have the cajones.  The tube-snake boogie subs didn't impact or move air, and the porthole subs all sounded boomy and undefined to me.  At that point I said I need to cut my losses and stay with the least overall compromised and that was the dayton. 
       I will not that when certain companies come out with a sub, the press reviews EVERY SINGLE MODEL.  How long has it been since there has been any VMPS sub review like the new larger, super solid or VLA?  I dunno but I see reviews for seemingly every single other company--and the resultant  hype.  The VMPS subs are a well kept secret compared to REL, SVS or the others that seem to be mainstream press darlings.         At this point, folks can buy what they want...but since I have been there and done that---the VMPS just works better than so many of them it isn't funny.  The press should be using VMPS as a reference to measure the other to see how well they (try)  to keep up. 

[BSTURGEON89]

John,       My intent with the review was to be as fair as possible, and provide a direct comparison to subs I have/had.  I have been recommended umpteen subs in the past, and they always fell short.  The best bang for the buck was the 15"  dayton titanic III.  I felt the burn when I ended up with subs that the maggie crowd recommended the REL, but that sub just didn't have the cajones.  The tube-snake boogie subs didn't impact or move air, and the porthole subs all sounded boomy and undefined to me.  At that point I said I need to cut my losses and stay with the least overall compromised and that was the dayton.         I will not that when certain companies come out with a sub, the press reviews EVERY SINGLE MODEL.  How long has it been since there has been any VMPS sub review like the new larger, super solid or VLA?  I dunno but I see reviews for seemingly every single other company--and the resultant  hype.  The VMPS subs are a well kept secret compared to REL, SVS or the others that seem to be mainstream press darlings.         At this point, folks can buy what they want...but since I have been there and done that---the VMPS just works better than so many of them it isn't funny.  The press should be using VMPS as a reference to measure the other to see how well they (try)  to keep up.

I have only had my VMPS for about a week and absolutely just love it!! I'm all ready to purchase a couple more hopefully in the near future. I haven't had countless subs but I do know that I will no longer be looking for anything else. I just can't see how there is another sub out that will sound any better than this.

[Construct]

I have only had my VMPS for about a week and absolutely just love it!! I'm all ready to purchase a couple more hopefully in the near future. I haven't had countless subs but I do know that I will no longer be looking for anything else. I just can't see how there is another sub out that will sound any better than this.

Cool!.
Sadly a lot of subs don't as I pointed out in the review.  What people mistake all too often for great bass is actually boominess.  That, or just enough to fill in, but not rattle concrete.  I could get a 10"  sub to rattle wood panels, but that wasn't anything like really deep bass.
Seamless?  I know (for the billionth time)  the REL strata pairs with maggies.  People talk about musicality and fast bass.  Well the VMPS will blend with horns...and not suffer damping, definition or output.  Matching to maggies would be a breeze.  Not to mention the REL strata has less than half the power.  It's time people really knew what these subs can do.  When you listen to Rob Wasserman's bow on fingers dance on his electric bass and you get "you are there"  realism, definition and impact it's the right sub to have.  I am putting on some Anner Blysma tonight (Bach cello concertos)  and Jacqueline Du Pre  (Elgar concertos )  because they are a great test of sub integration and detail delivery.  It's about more than just SPL.

[TomS]

Just a few questions as this sub seems a little unique in configuration and I don't quite get it 
- Are the 12" and 15" drivers driven by separate amp channels or are they wired together and driven by a single channel (4 ohms?)?
- What is the thinking of having 2 different size drivers in the same sub cabinet?
- Do the 12" and 15" actives both feed into the same chamber that the PR provides the venting for or is there something else going on in there (double chambers or whatever)?

Tom

[Brian Cheney]

The idea is to stagger the resonances of the PR, 15", 12", and their combination in enclosure to have four low-Q resonances rather than two high Q resonances.  Also, the two 15" and single 12" move a lot of air; the 8 cu ft enclosure permits lower distortion and lower system Fs. When first designed in 1984 the woofer ran much higher in frequency, and the 12" had better directivity down to lower frequencies.  Nowadays everyone crosses over below 100Hz so this is not a consideration.

[Construct]

I listened for a couple hours last night...stopped in time for shark week....


Notes:
 
Blysma/cello concerto:
 Not since listening to demos of Dunlavy SC-VI or duntech sovereigns have I really heard a controlled, 1st octave like this.  The sub has it from 60hz down.  Other speakers may give you the presence of the bass and maybe the timbre.  What I got here was a well-drawn image of the cello's vibrato and hollow-bodied acoustics.  It was a goose-bumpy moment when so much of the bass's character came out at a pressure and spl like a real, full sized cello.  I was reading the paperback of the band Rush:  middletown dreams, when I could feel the book resonate in my hands at some of the draws of the bow. The resonant frequency of that book is pretty low....

Speaking of Rush I was inspired to put "Signals"  on.  I got an effect from the synth pulse that I had not gotten since attending the concert.  There is more depth and "vibrato"  to the synth pulses than is apparent with smaller subs and speakers.  It's a whole different ballgame when some speakers omit the low end, can't reproduce the energy or simply get confused when reproducing these things.  Which brought me to...

The very best of Enya I just got this from amazon.  I listened to her version of an amazing choral "Oíche Chiúin "  (Silent night)  and other tracks like orinoco flow.  Enya has a much broader scope of complexity and power than you'd expect.  There are a lot of percussive effects ranging from everything you might find in a full scale orchestra.  Just orinoco flow tends to bewilder some speakers because there is a lot going on in the bass region.  Not just sub bass---but 40-80hz that really needs control to sort out.  Too often systems reproduce this track on a simpler level  and just don't "get it."



Shark week is here!
"Ultimate air jaws"  has some amazing footage!


 

[Construct]

I just found out class d audio has an amp that will drive down to 1 ohm stable.  It has at least 250 wpc into 8 ohms.  An aluminum case can be purchased on ebay for $47--U drill it. 
This might be the ticket to high quality/high current for a very affordable price...IE under $400.

[Construct]

After much internal monologue and examination, I have decided it is counterproductive to upgrade my enclosure to the Tc sounds drivers.  My concerns are that the construction  and lack of proper bracing would result in disaster.  The hefty and powerful drivers would likely pull out, or vibrate the crap out of the box making unwanted noise and threaten structural integrity. With TC sounds drivers, the only way to go would be at least 1.5"  board or more.  That, or a VSS box.

[Construct]

I ended up taking 2 more "fingernails"  of putty out.  The drivers seem to be a little more compliant now anyway.  Better articulation and depth. 

[JLM]

Construct,

Thanks for an excellent write up.  I'm so with you on the need, qualities, and requirements of foundational bass.  Most ignore the necessity of big room and separation of the amp from the sub.

Years ago I had separate bass cabinets capable of114 dB at 17 Hz (6 cu. ft. transmission lines using an 8 inch driver from I. M. Fried).  But I lacked a room big enough to allow them to sound even decent.  Finally took them to a 20,000 cu. ft. chapel and was blown away using my NAD 3020.  They were musical, graceful, and powerful.  I was so blown away that I donated them to the church.  Probably would be a category 4 sub by your scale.

How big is your room and what would you guess is the minimum for this sub?


BTW I’m a fan of big B’s style and much of the VMPS stuff.  So sad that the Michigan dealer gave up the line. 

[Construct]

Construct,

Thanks for an excellent write up.  I'm so with you on the need, qualities, and requirements of foundational bass.  Most ignore the necessity of big room and separation of the amp from the sub.

Years ago I had separate bass cabinets capable of114 dB at 17 Hz (6 cu. ft. transmission lines using an 8 inch driver from I. M. Fried).  But I lacked a room big enough to allow them to sound even decent.  Finally took them to a 20,000 cu. ft. chapel and was blown away using my NAD 3020.  They were musical, graceful, and powerful.  I was so blown away that I donated them to the church.  Probably would be a category 4 sub by your scale.

How big is your room and what would you guess is the minimum for this sub?


BTW I’m a fan of big B’s style and much of the VMPS stuff.  So sad that the Michigan dealer gave up the line.

I remember Fried, good designer!  His speakers have become kind of a collectors edition.  If you are going to use a 15"  sub, let alone something like this I'd have to do the math, and Brian Cheney has no doubt done so.  My guess is that it would work ok in a 20x12 room with an 8' ceiling as a minimum.  I am judging from varying seating position. 
IIRC, Brian isn't much of a fan of transmission lines as some can be perceived as lagging or slow.  I kind of enjoyed a few TL speakers I listened to like PMC and bug tussel.
I have some pipe organ stuff, the classics (requiem etc)  and also a disc "Cantate domino"  which has subsonic notes that are more perceived by feeling the vibration than  hearing. 
If I did this over again, I'd forgo the New larger sub, and dive into the Very Solid sub with a TC sounds driver.  That thing is bound to be many DB stronger at 14hz. 

[BobRex]

Years ago I had separate bass cabinets capable of114 dB at 17 Hz (6 cu. ft. transmission lines using an 8 inch driver from I. M. Fried).  But I lacked a room big enough to allow them to sound even decent.  Finally took them to a 20,000 cu. ft. chapel and was blown away using my NAD 3020.  They were musical, graceful, and powerful.  I was so blown away that I donated them to the church.  Probably would be a category 4 sub by your scale.

Did you have the the H bass bin or the M cabinets?  I used to sell Frieds and for the longest time the M was by reference for true bass.  Very few speakers came close for the same money.

[Brian Cheney]

I knew Bud Fried and liked his designs.  However, I have not been a TL fan since a demo I heard about 20 years back using an impulse signal as input.  One pulse in resulted in two distinct, audible pulses out.

TL delay can be pleasant on most music material, however.

[bsoko2]

The VMPS Large sub with Mega Woofers, and added a TC Sounds 15" Pr to it. This sub has the most detailed SQ that I have ever heard. I bought the one I have used and am so impressed that I'm selling my Epik Conquest. I have ordered another VMPS Large sub! Now I'll have duals in a 6000+ cu ft room open to other parts of the house.

Bill

[pocket.change]

The bug bit me (recently.)
I replaced the OE drivers in my (old) New Larger with the Dayton RSS 12" (HO) & the 15" (HF.)  After playing the combination(s) and killing a second screw gun, the above is the combo, that sounds respectable.
If for whatever reason you should decide to follow this path, be forewarned, the frame openings need to be increased (which is a real PITA.)  pc