size of subwoofer drivers vs. size of main speaker drivers

LL21 said:

basically 2 vertical stacks of 3 Magico QSubs per stack!

Click to expand...

Hi

My posts will sound like heresy to many here. I have not heard the Wilson subs but contend with certitude that for the same cash outlay of a Wilson Thor Hammer or Magico equivalent, one shall obtain much better results by using the budget for more of much less expensive subwoofers.

If one wants to have a glimpse, just turn off the main and listen to a sub .. not much going on .. right? mumble, rumbles and if the high-pass crossover cuts around 100 Hz with a any steep slope not much else ... That is what subs do.
I know the original post was about sub driver's size but allow me...

Now, Any subs from whatever manufacturers you choose, even those made of Fairy dust have to abide to the laws of physics, to the laws of small room Acoustics. A small room is any of the listening rooms that all of us here at the WBF is likely to have unless we have our own private concert hall and even then ... It has been shown by many that the best way to have a smooth bass in a room is to use multiple subs. The recommendations are not the same .. The Harman people: Devantier , Welti, etc, recommends multiple subs at specific placements namely middle of the listening room walls. Earl Geddes recommend semi random positioning. This is the idea of a "swarm" and it works for music or movies. The better the response in the room the better the bass. Furthermore, the more subs the less each individual sub has to work for a given output. If a driver works less it tends to produces less distortion. Moreover several subs tend to work in making the in-room bass frequency response more even, i-e less bumpy. This again translate into better bass.
Our hobby is dominated by several myths some of these very comfortable .. The idea of special fairy dust or manufacturer special sauce to "voice" his subs is one of these and Wilson or Magico or whoever cannot be faulted for providing uds with what we desire and to feed our imagination (insecurities?). At a budget similar to the Thor hammer + High End amp ( A Crown Class D pro amp would have been superb at the job but no one that would go for a Thor Hammer would ever consider mating it with a lowly Pro amp) A little over this budget, or at the same ... . One would buy you four (4!!) JL Audio Fathom 212 or two Gotham or 4 (!!!!) Paradigm Sub2 or to me a much better solution 5 pairs of Seaton Submersive and still find some left over money to hire a serious acoustician and have them integrate the subs in your system…
Of course subwoofers integration is not a given. It is not a plug and play affair. It requires patience and dedication to make it work. it also require an open mind. Audiophile from both side of the aisle do have the dedication, what is often missing is the willingness to accept a novel idea, to understand that the cost /price of a solution has little bearing to its effectiveness, to learn the basic physics underlying bass reproduction in a room and likely the most difficult for many to accept: that DSP in the bass does more right than wrong. In the bass the room takes over almost enirely and the best way to diminish its contribution are DSP and multiple Subs .. Preferable a combination of both.

So RonR please consider that array of multiple 15 inchers ( or the "swarm" idea you mentioned. if well executed (not a given) it has the potential to provide you with a level of reproduction you may have never experienced.

Thanks, Frantz. Yes, i think i understand your recommendations here. But for those of us with good sized rooms (15x40x11) but no place (since its living/dining) for more than 1 sub in the opposite corner of the Wilsons (which are located midway down and firing down 27 feet or so), does going from say 1 Velodyne DD18 to 1 JL Gotham or 1 Paradigm Sub 2 make a big difference?

LL21 said:

Thanks, Frantz. Yes, i think i understand your recommendations here. But for those of us with good sized rooms (15x40x11) but no place (since its living/dining) for more than 1 sub in the opposite corner of the Wilsons (which are located midway down and firing down 27 feet or so), does going from say 1 Velodyne DD18 to 1 JL Gotham or 1 Paradigm Sub 2 make a big difference?

Click to expand...

Yes. More subs is always better than less. It comes from the idea of more LF transducers tends to produce a smoother (that is less jagged ) response in the bass. So if the budget would be for one mega sub, it is always better to go for two less expensive subs... I don't know much about the Velodyne DD-18. I have heard enough the Gotham to know if it's one serious serious sub. yet I would go with two JL Fathom rather than a Gotham, if I were dedicated to Velodyne ( I am not) I would go for rwo DD-12 oe DD-15 rather than one DD-18... or IMO a better deal 2 Paradigm Sub2 ..The best deal in term of pricing remains the Seaton Submersible at around $3k each. And please do not let the modest price fool you it's a capable performer by its lone self... Drop 4 of these ... in a column array if space is a concern ... The point I am trying to drive home is not to be held captive to the idea of Subs from big-name manufacturers being better or inherently better matched to their mains ... rather to implement if possible multiple smaller subs .. This makes even more sense if the place is a living room and space is at a premium.... The smaller subs can be placed as to be almost invisible ...

I use dirac and / or acourate as well as PEQ to panel beat my bass into place and to taste ..house curve etc..
So it sees my swarm of most likely this sub .. Yamaha ns-sw300 (Im going for 6 of them) and my G1's as one system.
Heres the sub im looking at and my room , you can see there is tons of space for em

I think the Paradigm Sub2's are a great design and have gotten superlative reviews.

They appear to be a sleeper in the high end.

GaryProtein said:

I think the Paradigm Sub2's are a great design and have gotten superlative reviews.

They appear to be a sleeper in the high end.

Click to expand...

Yes, i am thinking since we can only make space for 1 sub to go with a Paradigm Sub 2.

FrantzM said:

The best deal in term of pricing remains the Seaton Submersible at around $3k each. And please do not let the modest price fool you it's a capable performer by its lone self... Drop 4 of these ... in a column array if space is a concern

Click to expand...

The Seaton Submersives are terrific performers, and would be up to the quality of your mains. I had two in a smallish room, and can't imagine that three or four wouldn't provide tremendous performance.

While they're large, they're inert in operation and about the right size to put smoked or decorative glass on and turn into "tables" or display stands.

LL21 said:

With 1 corner sub, are we going to get a big jump in performance upgrading from our older Velodyne DD18 to a Paradigm Sub2? or even a DD18+? (The Sub 2 cost is about the limit of any speaker-related upgrade...so no Alex 2s or Magico QSub 15s). This will be both listening (classical but also deep house, Hans Zimmer soundtracks, etc) and watching (mainly) action flicks.

Click to expand...

A single sub in a corner is going to have high efficiency but also massive frequency response swings. Here is a fluid dynamics simulation of that for our theater. Each color represents a different pressure level (volume) at that frequency with red being the highest, and blue the lowest. Shown is just a horizontal slice at the ear level.


If you are sitting in the center line of the room, putting the sub along that axis will kill one of the modes in the middle. The trade off is that you will have less efficiency so going to a larger sub would be a good way to compensate.

By far the best thing you can do is make sure the sub has programmable EQ for at least a couple of frequencies. Without it you are guaranteed to get bloated bass. It will sound good one minute and overpower the mains the next. That is what you are seeing in the simulation above where depending on what play, i.e. what frequencies exist, you can get huge variations in level (and smearing in time domain).

RonR said:

Frantz, Do you have an opinion on 2 JL Gothams vs. 2 Paradigm Sub2s?

Click to expand...

I have heard both but in different systems and rooms. On paper the Gotham could have the upper hand but in real life it could well be a toss-up.
Price difference is substantial the Sub 2 is around 8 K while the JL Audio is almost twice the price at 14~15 K U$. So you get almost 4 Sub 2 with the price of a pair of Gotham ...
My leanings would be toward two(2) pairs of the Paradigm Sub 2 for the (almost) price of a pair of Gotham. or better several pairs of Submersive

I fail to understand how people can have an universal recipe for a subwoofer system ignoring the brand and model of the mains stereo speaker.

Most speaker designers, including those four in the TAS interview refer how critical is the integration of bass in high quality speaker systems.

Just read Amir old posts on how Arcos (short for Adaptive Room Correction and Optimization System) optimizes subs with the SDEC 4500. Do you think an inexperienced amateur can do it? You can spend a lifetime trying to adjust four multisubs with independent crossovers.

IMH opinion and small experience of subwoofers, the only really good systems I listened to with Martin Logans used Martin Logan Descent subs. When you switched the subs the whole soundstage increased significantly , there was more air and presence and bass was felt but not heard. All other systems had more bass, nothing else.

One point is mandatory for me - I would always ask for the advice of the speaker manufacturer before adding a sub.

Just my 2 pessimistic cents. YMMV.

Francisco, today we have some great Room EQs. ...And it makes for more happy combinations...I truly believe.

amirm said:

A single sub in a corner is going to have high efficiency but also massive frequency response swings. Here is a fluid dynamics simulation of that for our theater. Each color represents a different pressure level (volume) at that frequency with red being the highest, and blue the lowest. Shown is just a horizontal slice at the ear level.

If you are sitting in the center line of the room, putting the sub along that axis will kill one of the modes in the middle. The trade off is that you will have less efficiency so going to a larger sub would be a good way to compensate.

By far the best thing you can do is make sure the sub has programmable EQ for at least a couple of frequencies. Without it you are guaranteed to get bloated bass. It will sound good one minute and overpower the mains the next. That is what you are seeing in the simulation above where depending on what play, i.e. what frequencies exist, you can get huge variations in level (and smearing in time domain).

Click to expand...

Fantastic Amir! Thank you!!! A few questions:

1. While the speakers are 15' into the room (firing a further 25' down to the far end), the seating position is at that far end...and the only position in the room that does not intrude on living/dining space is the corner directly to the left of the listening position. Are we in for a load of trouble if the sub will be shut above 40hz?

2. There is a very very slim change we could do a 2nd sub in the corner on the right of the listening position (doubt it due to built-ins). Big improvement possible?

3. Assuming 2 above is out...so only 1 sub...when you say the sub has some EQ, have you ever played with the big Velodynes or their software? Just curious as to whether you feel that is 'sufficient' EQ. i understand some people simply buy the Velodyne crossovers/software to use with other subs so hopefully this is a good sign.

In a nutshell, once we get past a certain level of power, mass...it seems set up (both physical and electronic) seem to matter quite a lot in subs by the reading here as well as the demo above you show where the sound gets wildly out of control at certain frequencies...fair takeaway from your post?

Thanks again...very helpful...

Ron, I just auditioned a Datasat 12.4!!! mch dsp system, w/4 subs positioned around the room, 2 in front, 2 rear. The system was optimised for room curves etc, and the 4 subs in effect had the same signal, so spoke as one. I have to say despite small aspects of the sound that didn't work for me, it was a total triumph of sub bass integration, w/no seeming consciously perceivable source of sub 40Hz frequencies. I do believe if you're going to go down the dedicated subs route, this would be the way to do it most seamlessly.

RonR said:

Amir, thank you for the amazing (and scary) video. (That video should be enough to give high-strung audiophiles with single subwoofers agita for a week. : )

Click to expand...

This video is really great - it shows that most of us are still in the stone age of bass setting. The proper way of doing it is using the power of simulation crossed with measurements. Simulation is a great tool for speaker (and many other things) development now-a-days.

Fortunately no one I know about puts subs in the corner! Please note this is the same argument some people use against the absolute need to use golden rule or similar criteria for room dimensions - audiophiles will not place their speakers in the corners.

Can you imagine how scary would be a video of four subs incorrectly adjusted?

RonR said:

(...) That theory suggests that no subwoofer would work with Wilson speakers as well as the Thor's Hammer, but, in the case of the Thor's Hammer, which is in some ways a dated design, that theory quite possibly, if not quite likely, does not apply. And two Thor's Hammers, no matter how you look at it, has a severe cost/benefit problem. (But I have to believe the phenolic composite Thor's Hammer cabinet is more inert and resonance-free than any of the other subwoofers which use MDF construction.)

All else being equal I agree it would make sense to deploy Martin-Logan subwoofers with Martin-Logan panels. But when you compare, for example, the ML BalancedForce 212 with the REL Gibraltar 1 they seem pretty similar (same size driver, same specs, same size and weight enclosure) except that the ML uses two 12" woofers back-to-back and has built-in EQ, and the REL uses a smaller, but Class AB, amplifier.

But, microstrip, do you really think you would be able to hear any material difference between a pair of ML 212s or REL G1s on the same system? I really do not think so. I do not see why, with so many similar design parameters, the ML 212 would sound better with, say, the CLX than would the REL G1.

What do you think would be the ideal subwoofer system for ML Neoliths? Four BalancedForce 212 subwoofers (eight 12" drivers in total, but only 22" tall) spread around the listening room or two tall subwoofer towers each composed of two, vertically stacked modules of pairs of dual-opposed 15" Seaton drivers (eight 15" drivers in total)?

Click to expand...

At some time I had the Wilson Watchdog subwoofer with the Wislon Watt /Puppy 7. It was a particularly good match - the electronics were designed by Richard Marsh. Although fully analog, the integrated crossover included an equalizer with variable Q, f and amplitude. Unfortunately the color of the subwoofer was very different from the main speakers, there was a lot of negative bias on this aspect!

I have no experience with the new 212 subwoofers, although some people who heard it with the CLX in our distributor large room told me it is significantly better against the Descent. But it could be the adjustment.

I have now one Descent i with the Soundlabs. I tried multisubs in a Gueddes approach with three subs with the help of REW and it was a complete subjective disaster - it measured very good, but sounded artificial. Probably my lack of experience or my very long room is not adequate for such system.

Corner placement for multiple subs are not that bad.. you get a ton of spl and depth out of them, leading to major cuts with DSP which in turn increases amp overhead and thus they work a lot less for the same bass ... the same swarm approach with speakers smoothing room nodes will still work.
Lots of target curve based DSP out there that can see the system as a whole and make for easy setup and integration..their results are nothing short of amazing these days..

A while back I ran a set of Meridian dsp6000's .. with 8 x8" woofers and a set of SVS sb 13 utra subs and had amazing integration using a Dspeaker antimode 2.0.. it was so easy to do..