[jermmd]

I have the ACI Maestro XL and I think it's great. I've had a Hsu and a Boston Acoustics sub that didn't compare and I've had a fair amount of experience with VMPS and Sunfire, also not as good. I'd love to hear the Fathom but really don't think I can do better than the ACI in my system.
And I agree that a sealed sub is more musical than a ported one.

[doug s.]

i am surprised no one has mentioned vmps - i still think my old upright-style larger subs are pretty hard to beat for music, especially considering the cost.  these are one of the few components that i happily bought brand-new, cuz they were such a bargain, even when compared to diy/used, imo.  and, i have heard the low-boy style, and they're not too shabby, either...     of course, the diy situation has improved a bit, since i bought my subs over ten years ago...

doug s.

VMPS hasn't been mentioned because the VMPS subs aren't in the same class as the others mentioned in this thread.   aa

George

my only performance reference was the subs of the old infinity irs reference lll's, w/six 12" servo-driven drivers per channel.  the upright vmps largers were at the same performance level.  the velodynes, rel's, etc, of about 5-10 years ago, certainly weren't competitive.  as i said, i don't have experience with the latest sub technology...  at some point, i may consider a sub upgrade, but presently, i am not hearing any deficiencies in my low-bass performance w/my old standby's...   

doug s.

[James Romeyn]

Part of a post I made a few days ago here http://www.audiocircle.com/index.php?board=135.0 

"...I’ve auditioned the larger Sound Labs several times including at Duke's, the best sounding of which was Crump’s setup at THE Show Las Vegas shortly before Bob passed away.  Speakers were placed about mid-point in the room leaving little space for seating.  Bob used the Blowtorch pre & a pair of Curl’s Parasound JC-1s (ran hot as a mutha)...list all your positive listening adjectives...In every way I can imagine the bass from the $2500 AudioKinesis STORM v2.0 subwoofer system is preferred over the stats. 

I’m 54, musician, assitant engineered & programmed synthesizer at the Sausalito Record Plant, been doing this since a teenager.  Have auditioned the following among other speakers known for great bass: Infinity IRS III ($65k late-‘80s dollars, four 7’ tall rosewood towers) properly setup in the Tiburon home of the owner of Landmark Cards & Calendars.  CES setup by the designers of many cost-no-object sub systems including humoungous stereo towers w/ four to eight drivers per side.  Linkwitz’ $15-20k commercial dipole systems.  VMPS discontinued SuperTower III SRE w/ stereo sub towers, each tower 400 lbs, 5x 12s w/ staggered resonance points.  Owned the best 2006 Sunfire Signature sub w/ automated digital EQ & owned several VMPS subs & the VMPS SuperTower/R SE (dual 15s, 10 midbass).  My last room had the equivalent of about $6k worth of acoustic soffit installed to tame bass modes.  Also heard the superb $100k YG Acoustics Anat Reference system (Yoav is a great guy, very down-to-earth, worth hearing if setup correctly).

Duke’s latest SWARM v2.0 equals or exceeds the best sub performance I know of.  You name the quality, it’s there in spades.  Slam, low bass cutoff, power, etc.  In pure musicality, pitch definition, transparency, realism, portraying differences in recording venues, this system probably sets the world standard.  I’ve played electric bass; the acoustic guitar I sold last winter was a Martin HD-28LSV (purchased from Dave “The Ghost” Caspar of the Oakland Raiders at his home in his trophy room).  There's a nice Chang grand upstairs.  The capability of v2.0 to flatten the room’s bass modes blows away the above described soffit of my last room.  I had to leave that soffit behind.  I could pickup & carry the sum total five pieces of Duke’s v2.0 in two trips in my hands from Duke’s room to my car (wish I thought of that when he wasn’t looking!)  Each of Duke’s subs is only about 1cf.  The amp is of moderate size/weight. 

Duke’s subwoofer philosophy may seem strange to the uninitiated, who might view four subs as about three too many.  To them I reply: “Oh, really?”  Take a little peak over at the circle for room acoustic modifications & read the pages about people trying to control bass modes.  Duke’s philosophy, IMO, completely eliminates the need for any other contraption to flatten your modes.  The automated digital EQ of my Sunfire Signature sub was almost completely worthless (in performance) compared to Duke’s, which costs less.

One of the problems w/ acoustic absorption to flatten bass modes is that reflectivity in the bass range is a necessary ingredient for maximum realism.  To the extent acoustic absorption is employed to flatten a bass mode realism is minimized.  In other words, fixing the mode in this way replaces one problem w/ another.  Note the sense of “surround”, “elasticity” & "liquid" effect in the bass range the next time you visit a large room like a theater; w/ a good reproduction system the bass is transparently integrated into the soundfield w/ the rest of the music.  Compare the above qualities immediately on your home system upon your return.  The difference you will properly notice is that of signals below 200 Hz being reproduced in a small room (unnatural, unmusical, modal problems) vs. the natural quality of a large room.  Once you tune in to this phenomena you can not go back; this lack of realism in the bass range will become intolerable (you've been warned). 

IMO one brief listen to Duke’s mono v2.0 completely obliterates the myth of stereo subwoofer's advantage.  Listeners would immediately notice the greater power, presence & lower cutoff of the v2.0 (4x 8" drivers) vs. the earlier 6.5" drivers.   

The only thing I’ve heard previously that may rival the v2.0 is the largest stereo tower subs w/ multiple drivers, extending from the floor close to the ceiling.  Such a multiple driver array minimizes what is often the single worst mode, being the floor to ceiling (v2.0 mimics this effect but in a different way).  Such subs create their own physical acoustic, their own multiple modes, & are far more costly, heavy, physically obtrusive, & in no way desirable except for the visible “size” impact, for those needing that.
 
Cost no object subs & fullrange speakers are priced in the stratosphere.  Check the mass of the bass drivers employed in cost no object single-subs & fullrange speakers.  IMHO the v2.0 is preferable to any system w/ a smaller number of close-spaced woofers, sub or fullrange, regardless of cost, mass, size or type of driver loading.  The $100k YG Acoustics Anat Reference sounded great, & the v2.0 was far better.  (Yoav mentioned they had modal problems to work around in his CES room, something the SWARM is designed to easily solve). 

The only unknown to me is maximum output, as I didn't test that in a (large) domestic room.  Duke would almost certainly underestimate this spec if one inquired; meaning he'd be the last one to overestimate the output if a customer had specific SPL needs.  Without having discussed this w/ Duke I'd estimate one could simply add more subs & check w/ Duke for proper wiring to maintain an adequate load for the amp.  Remember the subs are only 1cf each & take up little space..."

Also, after hearing good examples of all or most of the different types of subwoofer loading (though certainly not every sub mentioned in this thread), I am convinced of Earl Geddes/Duke Lucerne's philosophy: that the loading of the sub (ported, sealed, PR, dipole, open-baffle, servo, etc, etc) makes far less difference to overall performance compared to properly employing three or four subs (if high-Q, Q must not be repeated).  Geddes recommends three subs, one located above ear level, random polarities for best mode nulling, two LP xo poles.  Duke employs four subs in a semi-cross pattern, all floor-mounted, two diagonal subs are reversed polarity, one LP xo pole.  The random & or semi-random siting & polarity inversion flattens the modes.  Having all subs in the same polarity would increase output but only at particular frequencies; dips & peaks will be larger throughout; it will also sound immensely more more lumpy, sluggish, irregular, less musical & transparent.

   

[jackman]

Hey Jack!   Do you know if the Phil sells the sub alone? Does he still offer kits? I couldn't really tell from the website.

Send me a PM or email sometime and LMK how thing are going for you and the family. 

Hey Doc!  Sorry for taking so long to get back to you, I was at the Bears game today.  I don't know if Phil formally offers kits but he's kind've a custom shop and I'm pretty sure he will be willing to help you out.  The sub stands are probably not going to work for you if you already have main speakers.  Also, I believe he has a slightly larger design that might work better as a stand-alone sub.  His new design uses a Rythmic amplifier and would be a great choice for music and HT.  I'd email the link at the site.  Phil now works with a very cool guy named Steve.  Steve is the woodworker and he always gets back to people very quickly (even if you don't need any woodworking).  If you do talk to Steve, you might want to get a quote on a finished cabinet because his workmanship is as good as I have seen.

You still playing guitar?  If you need some inspiration, it doesn't get any better than Mr. King...all the Kings are great but I find myself listening to Albert these days.  Sorry to hijack this thread.  If one person complains, I'll delete this last part, I promise.  But if you are looking to borrow some licks, you can't do better than this guy...IMO: http://www.youtube.com/watch?v=JhAya5FLw78&feature=related

There is some beautiful music coming from that UGLY guitar! Close your eyes and you can hear how much SRV lifted from Albert King.  Some people accuse Stevie of lifting his sound from Jimi Hendrix but I think he's one part Jimi and two parts Albert.  I love all three guitarists but there is a purity or simplicity to AK's playing that is amazing.  Check out his playing midway through this clip...he's playing a right handed guitar upside down, tuned to C and making massive bends.  Everything he does just works to perfection.

Cheers,

Jack

[2gumby2]

I've checked out lots of sites but I have yet to find a commercial site that provides as much detail (measurements, designer notes, etc.) than Bambergaudio.com.  Here is a link to Phil Bamberg's philosophy on subwoofers and why he feels a dual drone design is superior to sealed or ported.  For the record, I have Phil's dual drone design and it produces some of the best bass I have heard:

PR design in general:
http://www.bambergaudio.com/drones_advantage.shtml

Series 5 notes:
http://bambergaudio.com/s5-w_design_notes.shtml

SPL Graph:
http://bambergaudio.com/xls_spl.pdf


The BESL room received great feedback from people who attended RMAF.  I've yet to hear compact subs produce the kind of bass (articulate, powerful, not boomy, etc.) BESL's Series 5's produce.  These subs are flat to 18hz.

Hey jackman - Thanks for these links! Very informative and helps me narrow my choices down. The drone (passive radiator) design seems like the best solution for what I'm looking for. My current subwoofers (North Creek Music System "Thunder") is a passive radiator type and they have the best quality bass I have ever experienced. They just don't go low enough or loud enough for what I am looking for. The DIY Cable Maelstrom project looks better the more I learn about subwoofers. That Maelstrom-X is a serious looking driver.

[Mark Seaton]

Mark is a personal friend and his Submersive is absolutely mindblowing in what it can do.  A single unit can pressurize a room like no other sub I have experienced.

Thank you for the mention and praise BRM.

I don't post a lot over here, but I caught mention of this thread.

Through all this talk of 16Hz and higher levels, I might have missed it, but I haven't seen any mention of what the main speakers are and more importantly, the size and construction of the room! 

Kevin gave a pretty good comparison earlier.  I would add that the relatively tiny SubMersive can hang in the upper octave with even the 3-4x larger ED, and inside most semi-enclosed rooms extends into the 8-12Hz range.  The opposed drivers make for an entirely inert cabinet without the need of a 400 lb. enclosure.  If you were more limited to or had a desire for its reasonable size that would probably make it more interesting, but no question that larger enclosures afford more possibilities.  What I would add to the DIY option is that while there are subs on the market which are not much more sophisticated than a compact DIY sub with a nice enclosure, with a good product design, a big part of what you are paying for is the known, proven, and tested quantity.  A DIY effort still does require the execution of the design.  In general you will want to go with a DIY design having significantly more capability than a good commercial design, as details such as overload characteristics and amp clipping are things DIYers generally won't fine tune, or can't really adjust much. 

It appears size doesn't scare you. 

If you are interested in DIY, the Maelstrom or 4 would be a great way to go, especially if given enough box volume.  One thing to fix right away will be selling the HPSA-1000 amps as they have internal high pass filters at ~19Hz and won't deliver the sustained power you are looking for.  In your case, you will need a low pass and I'd recommend adding an EQ to the subs for maximum optimization.  Be sure anything you would build yourself is tuned to at least 16Hz or lower, otherwise you are likely to see some unloading issues, even with music, unless you have a high pass filter set properly.

Of course if the ED A7-900 isn't too big, you might want to wait about a month when a larger, dual driver version of my Terraform finds its way into someone's home.   For music use the 12Hz tuning isn't really required, although it does have some benefit, where I've been considering a less huge version with higher tuning, power and output as there are cases where that is useful.  I will warn that if you crave instant gratification, the SubMersive is my only such offering, as the Terraform is a built-to-order design, also being more expensive than the others you have mentioned above.

Enjoy the hunt!

[James Romeyn]

Kevin's info was very pertinent.  A source that measures flat anechoic below 100 Hz will sound bloated in the average domestic environment. 

Toward avoiding this problem Duke engineered v2.0 to rolloff below 100 Hz at the inverse rate of the average room boundary gain, producing music that sounds as "flat" in the bass range (flat being a good word used here) as I know of.

From my experience it would be a huge mistake to purchase based on anechoic test tone specs because the average room is going to skew listening results far more than the sub's anechoic output.  Carver, Geddes & many other independent sources have shown that human sensitivity to THD in the bass range is extremely low; meaning the ear doesn't detect high THD in the bass range.  We're talking really high figures in the double digits.  It's the midrange, where localizing takes place based on the horizontal placement of our two ears, where acuity is highest.     

I didn't state this earlier but few or no domestic rooms can properly accomodate a 16 Hz tone.  Large organs are installed in commercial environments designed for the purpose.  The average home is going to have an unlistenable S/N ratio w/ all the buzzing, rattling, shaking & modal problems.  That's more an interesting exercise & less an enjoyable musical experience.

It is highly recommended to input your room dimensions into Whiner's Real Traps room calculator to confirm modal effects.  The worse the modes the greater the advantage of Duke's subs & the lower (by comparison) would be the performance in your room of any system lacking Duke's mode-cancelling technology & any system lacking his inverse room-gain design. 

It's my experience that EQ (Duke's amp has 1-band parametric EQ but it was unemployed when last auditioned) is a one-dimensional fix for a three-d phenomena; EQ is of little use, no use or may potentially make modes worse by shifting their effect to a different range, compared to v2.0 technology.

Apologies for repeating this but I think it's worth it.  Duke's v2.0 puts to rest, IMO, the entire argument that one type of subwoofer loading is better than another.  The deeper you explore competing sub loading technology the more impossible it is to analyze the data.  Everyone's a PhD doing the work & they all come to the mutually exlusive conclusion there's is superior. 

The only known caveat is that apparently, Duke's technology would NOT work if all four subs had identical high Q because the high Q would dominate & the mode-cancelling quality would suffer.  In Duke's case the Q is low to moderate, & again, engineered w/ a FR that tapers downward below 100 Hz to cancel the average domestic boundary gain.

 

[2gumby2]

Just when I thought I was getting closer to making my final decision, you guys give me some more great information to consider. Thanks Mark Seaton and ro739! I would be using the low level inputs on the HPSA1000-R amps. Would the 19Hz high pass filters in the amps affect this low level input configuration? I was leaning toward building using the Maelstrom-X drivers and passive radiators, but now I'm going to take another look at Audiokinesis and Mark Seaton's designs.

[2gumby2]

Forgot to mention my speakers and room. I ordered a pair of the new Kismet speakers from Odyssey Audio. Klaus decribes them as "Loreleis on steroids", essentially new bases and crossovers. The room is 16' by 26' with 8' ceilings opening into a kitchen and hallway on one side.

[James Romeyn]

Gumby
Your room dimensions are very close to mine: 7.6 x 16.6 x 25.8'  You may be surprised (maybe depressed) after inputting your dimensions into Ethan Winer's Real Traps room calculator here http://www.realtraps.com/modecalc.htm  The importance of doing this can not be overstated.  IMO, unless your room's modes are specifically accounted for, the modes will contribute more to the overall sound & performance than the difference between any & every subwoofer mentioned in this entire thread.   

I can only assume your room has major modal effects.  My modes were exacerbated by the fact that two surfaces are concrete, the front wall & floor.  Concrete doesn't flex like wood/sheetrock does, which softens the mode effects.  If/when the modes are flattened, the harder/non-flexing concrete surfaces are an advantage.   

The worse the room's modal problems, the more valuable is Duke's technology/philosophy, for the simple reason that it flattens mode effects more effectively than any other technique I know of, & I've owned some of the most expensive types such as a professional acoustic soffit. 

I've read nothing but good things about Klaus' gear including the speakers.  If you can, when subs are installed, performance would almost certianly improve if w/ a high-pass crossover on the main speakers, 80-125 Hz depending on the rolloff rate.  If a tube amp is employed the input coupling cap value can be altered to achieve the HP crossover on the main speakers.  PM me for another method. 

I'm auditioning Duke's AudioKinesis subs at home when his demos return (please return ASAP!); would be surprised if I don't purchase.   

In mid-'07 I happened to purchase the same Dayton sub amp Duke employs.  Since about 1990 I've had four 10s sub drivers laying 'round, waiting for sealed enclosures (only need 1cf each for 40 Hz anechoic f3, 30 Hz w/ average room gain).  I finally built enclosures a few months ago & (shamefully) replicated Duke's overall setup/layout.  I was generally quite happy w/ the results, until...     

I auditioned Duke's v2.0 about a week ago.  v2.0 blows away my rip-off even after trying every possible setup variable.  An educated guess is that the finer points in the v2.0 architecture, such as the low-Q & inverse room gain rolloff below 100 Hz, elevate performace far above my (again, shameful) rip-off.  Good for DUKE!

[2gumby2]

No concrete in my room. Only drywall and carpeted floors with curtains on the rear wall.

I looked at the Audiokinesis site and I don't think those subs have the depth and output I'm looking for. I already have some outstanding subwoofers for bass quality (North Creek Music Systems "Thunder" subs), but they give out at about 25Hz. The pipe organ music that I listen to will reach down to about 16Hz and I don't want to miss anything.

I'm still seriously considering the Maelstrom and Mark Seaton designs. I'm also looking at the Velodyne SMS-1 system to help in fine tuning. Any opinions on the SMS-1 or other recommendations?

[Big Red Machine]

QSC  DSP-30 is more sophisticated than the SMS.  Check it out:

http://www.qscaudio.com/products/dsp/dsp30/dsp30.htm

Run your sweeps, get your data into Excel and RoomEQ, decide on your adjustments, then at your computer load them into the DSP and you're done!

[rydenfan]

The SMS-1 is an invaluable tool. It will make a nice addition to your system and should help for a flatter FR.

[Joe_K]

Check out the ACI Maestro XL.  It does everything you want.  Quick enough for music, nice and clean and tight, response below 20hz, etc.

Mike is a circle owner here on AC and a great guy to work with.

Bryan

I have the ACI Maestro XL and I think it's great. I've had a Hsu and a Boston Acoustics sub that didn't compare and I've had a fair amount of experience with VMPS and Sunfire, also not as good. I'd love to hear the Fathom but really don't think I can do better than the ACI in my system.
And I agree that a sealed sub is more musical than a ported one.

I second and third the recommendations for ACI’s Maestro. I also agree with the comments that sealed enclosures are better for music. I’ve had a Maestro for two years now and love it. It does everything so well; fast, tight, clean, very articulating, whether playing softly or cranking it up for serious listening. You owe it to yourself to check one out, there’s a thirty day trial period too. I recently ordered another one for a second system! Like you I was all over the web reading reviews and user comments and I kept coming back to ACI. I’m glad I did! I wanted a sub of this caliber for years, now I wonder how I lived without it.  The Maestro integrated seamlessly with my mains!

 I recently read a couple of reviews for two well respected subs with comments like “cabinet doesn’t shake much at high volumes” and “sub tends to walk around with loud, deep bass” My Maestro has none of those characteristics, the enclosure is absolutely dead quiet and stable! Just the best sub I’ve heard and it blends well with the décor, ie high WAF factor!
http://www.audioc.com/speakers1/maestroxl/maestroxl.htm

JK

[2gumby2]

Joe - You're right about ACI making some very nice gear. I've had the opportunity to visit the ACI room at RMAF the last three years and those Saphire XLs are VERY good speakers. Wish I could have heard the Maestros. I've learned a lot since I made my initial post and the recommendations and information from the members here has been great. Still educating myself and I hope to have a pick by the end of next week.

[James Romeyn]

This post is only for members w/ experience testing in their own rooms digital EQ & extensive bass traps to solve the audible performance problems caused by bass mode effects in listening rooms.  I fit this description; owned a $2800 modern sub w/ digital EQ & my last room had about $7k worth of acoustic soffit (cost for equivalent soffit from ASC).   

Do members w/ the above qualifications agree or disagree w/ the following?

...unless your room's modes are specifically accounted for, the modes will contribute more to the overall sound & performance than the differences between any & every subwoofer mentioned in this entire thread...

Also: Digital EQ is easily affordable & very compact (built in to many if not most modern subs, outboard EQ small & affordable).  If digital EQ solves bass mode effects , why does there exist a huge & growing market for acoustic solutions based on mechanical damping for bass modes?  (Look at RealTraps' website; they grew in a few short years from two principals to eight full time employees IIRC). 

Further, why does anyone even care, when designing & building a professional soundroom, to methodically insure only the most ideal room proportions are employed?  Why on earth does anyone even care about anything relative to room modes if it can be efficiently solved so easily w/ EQ?

IMO both EQ & acoustic mechanical damping of modes via bass traps are band-aid approaches to the single worst problem in achieving state of the art reproduction.  Any & all money spent to achieve a specific desired goal such as "16 Hz" performance in a subwoofer is money tossed down the drain till the issue of bass modes in the room are addressed & solved.

Ask someone who records music w/ content at 16 Hz for their opinion (you can find them at shows), but preferably NOT someone who sells subs, EQ products, bass traps, etc.

Also, again, take a look at the size & design of spaces housing organs w/ 16 Hz pipes.  The only similarity to your soundroom is that both have walls.  The two rooms respond very differently to 70.6' long wavelengths. 

If all one cared about was 16 Hz reproduction & did not care at all that many/most of the frequencies above that tone were horribly skewed out of proportion (in other words music sounds bad) then you might be able to get that 16 Hz tone in your room for a few grand or maybe less.  (The room's S/N ratio from rattling is a separate issue.)  If you want 16 Hz & the rest of the musical spectrum to be correctly proportioned, & you think this can be done for a couple grand or less...no way.  Reminds me of 1979, the dawn of Red Book CD & Philips' CDP101: "perfect sound forever".  There are myriad (& always will be) sellers of products promising the world for a song, & equal numbers of buyers (self included) desiring & willing to believe it's possible. 

Another way to put this is: the goal of properly proportioned music reproduction & 16 Hz capability is not easily solved even if money was absolutely of no consequence.  Even cost no object (literally), you will not find universal agreement on the most efficient means to the above described end by even PhD acoustic teachers in universties.  I would predict that if you simply asked a PhD in acoustics if there is universal agreement for this solution among his peers, he'd tell you no, absolutely not.  He would not apologize for that.  If this doesn't prove the approaching water is way over one's head I doubt anything will.   

[2gumby2]

ro7939 - Good comments and you've brought out some points that I hadn't given much thought to. That is, at what frequencies do I listen to most? Well... it's not 16Hz and your comments made me realize that I should look for a more balanced sound since there will always be compromises. Still considering the Submersive subs, ACI Maestro, DefTech Trinitys, and DIY Cable Maelstrom project. I'll need to find some good amps if I go with the Maelstrom as I don't think my current PE amps will be up to the task.

[James Romeyn]

Glad to help.  Keep us posted on your purchase/progress.