Subwoofer: should we even use them at all?

Should we? Should you, should I?

Answers: No. Maybe, absolutely.

Is there any other audio subject that is so subjective and fraught with as many room, system, and media, variables as extra low frequency reproduction?

If there's ELF on the recording and you want to hear and feel it and you're using passive speakers then you might want to at least audition a properly integrated sub/s in your room. Keep in mind even the term, "properly integrated," is subjective.

I've been using subs since '98 with excellent results. I think the trick is the right low pass xover and slope. I run my mains, Revel M106 full range and use a Velodyne SMS 1 to apply the low pass slope and freq which is steep and at 60 Hz. I use a REL R305 sub, it's 10" driver is perfect for music and plenty for movies.

It's nearly impossible to locate where the sub is, it blends perfectly. I also run the SMS 1 's EQ to tame a nasty 40Hz room mode. I have a very compact 2.1 system that sounds way better than it has a right to.......it would not be the same without the sub

Elegal,

Those do exist. Duke at Audiokinesis makes a really interesting speaker system with your choice of two different subwoofer arrays, one sealed the other ported. There are four subs with four channels of amplification in either array. I think it's worth visiting his web site to check out.

There are also traditional 2.1 systems out there, tho not as many as there once were.

I love the pun! And thank you for a great answer. Perhaps they could design systems with a separate sub with suggestions on placement?

Elegal,

Ideal placement of a subwoofer is most often far from ideal placement of mid/tweeters. If you put a sub in the same cabinet as the other drivers, you'll end up with (pardon the pun) suboptimal placement of one or the other.

Rockadanny,

Totally agree!!!

My mains in my main rig are rated -3db 55Hz, while my office monitors to 44Hz. In either case, I can listen to a lot of music and be mostly satisfied without a sub for acoustic, vocals, jazz, blues, etc., even some rock. But there are times I do not want to be MOSTLY satisfied. And for those times, and when I wish to crank it, I employ a pair of 12" powered subs in my main rig.

The deep, visceral, gut-wrenching, grunt of those subs can fill in the missing parts, transporting me to musical Nirvana and change my MOSTLY satisfied experience to COMPLETELY satisfied. I'll never live without a sub (and preferrably at least two) regardless of how wonderful my mains are.

What I don't understand is why don't more mid-level to high-end speakers just design their speakers with a subwoofer built in. This, it seems, should eliminate (or at least greatly reduce) the coherency problem?

Got it. Thanks, Martykl. I am working on a few custom 'tweaks' at the moment. After these I will look further into the active crossover.

You're not the only person to mention the "expanded space" phenomenon. I'm not sure I've ever really experienced it, but it makes some sense if the sub is providing very low level bass throughout the room and that is perceived as ambient special information.

My post was focused more on your chosen x-over point and my guess is that the effect you describe is probably (I'd think) independent of that choice.

Thanks, Martykl,

Interestingly, because I can mute my Gryphon Colosseum amp, I often do so just to hear how much the Sub is working. I will say it surprises me how much it is active.

I don't hear notes per se, but the room seems tons bigger. This is on many, many recordings (live recordings) as well as deep house, electronic, soundtracks, etc.

I can mute my CJ preamp...which shuts off everything...and suddenly the 'atmospherics' disappear and I am back in our living room. But with the CJ UN-muted (but the Gryphon amp still on mute so no X1s)...those atmospherics come back again.

I believe this is part of what I like about good subs.

But your point is well taken...how much does this really alleviate from the X1s? The only thing I know is that DW himself designed the Wilson Thor/XS to be used with the big X-series speakers (cut off below 38-39hz with the Wilson Active crossover)...

guess there is only one way to find out! Thanks for your advice.

Lloyd,

The first question in my mind re: actively low cutting your main speaker at 38hz is: What's your program material?

If this is a music-centric system, I'd only point out that very few recordings in my collection have much signal below 38hz. We're talking about a couple of keys on a piano, the longest pipe on an organ, and a couple of notes on the electric bass, for the most part. It's pretty rare that these are present on a recording so the low-cut isn't really doing much to lighten the load on your X-1s 99+% of the time.

Obviously movie soundtracks are another story, but your set-up appears to be 2 channel, so I'm guessing that it's music based. I personally don't see a ton of benefit in crossing a sub in so low on a music system, but many other knowledgeable folks (including, evidently David Wilson) disagree with me on that one.

Rhyno,

I was just trying to clarify a few points that you made in a little different way, because they seemed to me to be presented in the way JL deems best to promote their (admittedly excellent) products. I hope I made clear that I wasn't really taking much issue with the main points in your post, more clarifying in a way that I feel is more even-handed. As you say, however, it's mostly six of one, a half dozen of the other.

Dear Lloydelee,

which subwoofercable do you use?

Hi Bo1972,

I am also a big fan of PAD cables and use their 25th Ann to Canorus across the board, with 2 exceptions: my Gryphon Colosseum was sold (2nd hand) to me with its own Gryphon Ref cable; and my Sub...after using PAD Canorus/Dominus for years...I now use Sablon Audio Quantum Gran Corona which is the only cable I have found I prefer to the mighty PADs. FWIW...I could hardly complain about the PAD with my Velodyne...so I agree with you. But I was pleasantly surprised by Mark Coles great designs with the SA QGC cable (which I thought did have some silver in it?)

martykl, appreciate your contribution and i think everyone benefits from it--too many people turn up their noses at subs, incorrectly. i can see your points and find truth in them in certain applications while not changing my mind (though mine are also incorrect in select applications too).

agreed that the port does do as you describe, but the quick rolloff in turn supports mine. 6 of one, 1/2 dozen of the other. a port is a bass bump at a given freq, and the room contributes enough of those without adding more via the port. and yes, some ported subs can sound great (wilson) without the huffing, i'm just offering a 'more likely to succeed' path, and a cheaper ported sub is less likely to succeed than a sealed sub for the same $. (further, if your mains have ports but your subs don't, you will need a darn good bass-optimization feature as you need it to address both room nodes and main-generated port nodes---the JLs ARO feature will not do this, FWIW).

if you have a preamp that can filter HP v LP or accommodate temporal shifts by delaying signal to mains / sub, great (as you describe) and its likely a benefit vs alt setups. but, if you have a pre like mine (ARC Ref 5se) and most other uber products which have no such features, you're not going to dump a great pre to move backwards to a good one in order to gain the features; furthermore, the notion of adding an outboard x-over (or using the half-assed one in the sub) is going to compromise the mids / highs---bad parts, bad results. one earlier poster mentioned his einstein preamp (great pre btw, spartan in its features), and folks w/ products like that are quite particular to transparency loss. running their mains full range and integrating a sub as i advocate is the likely best choice.

(of course, using an x-over and its resultant loss in transparency may be offset by the opp to switch amps to a lowered power, better sounding choice that doesn't have to contend w/ sub-80hz bass. YMMV).

room correction above 80hz is an entirely separate matter for room acoustics, not subwoofer bass management IMO. both are required in high end systems. (well, addressing room acoustics is ALWAYS required).

if nothing else, i hope folks realize that if their first sub integration doesn't work, think about what factors you've yet to try, as it can work exceptionally well if done right...i offered my original post as a most-likely-to-succeed route, but not the only route possible.

A source has a very big influence on a subwoofer. For example we did a test between the Olive 06HD and the Wadia 7Si. The Olive had more controle and more layers in the lowest freq. When a source is better in timing and has better dynamics a subwoofer will sound a lot different.

I have tested many powercables on subwoofers. This is the same story. With a better awg you will hear the difference. But when you use a sub from 16hz till 140hz, you even need other qualities in a powercable.

I got the best result sofar with Purist Audio powercables. Also from 80-140hz they work better than most others do.

The interconnect you use for your cable also makes a big difference. I tested many in 16 years of time. The one I own now: Audioquest Wild Dog pure silver subwoofer cable even gives you a new level in drive and integration.

All other cables I have tested don't even come close. Silver also works extreme well in speed, drive and control.

Hi Martykl,

Thanks for another very detailed post. A question for your advice:

- I have Wilson X1s and am contemplating using the Wilson Active Crossover to cut them off below 38hz (as recommended by David Wilson)...and have the Active Crossover send a properly adjusted sub-38hz signal to my Velodyne DD18.

- Currently I run the X1s full range with a 2nd IC from my preamp to the Velodyne DD18

- I'd love to get a Thor...but that is serious money for a sub! (not to mention amp, cables, etc)

- I am told to expect a very significant improvement in the effortless of the X1s even with such a seemingly subtle change

(I use a Gryphon Colosseum amp to drive the X1s).

I have found tremendous improvement thru vibration isolation of my X1s (Ultra 5s, some mass damping of the upper modules)...and have been told that Actively crossing them over may even produce a greater improvement through even further reducing distortion from thermal, mechanical and cone excursion associated with these toughest/lowest frequencies.

Assuming it is professionally set up by the Wilson dealer who carefully adjusts the Active Crossover (crossover frequency, rolloff, phase, etc) including the sub38hz-signal to send to the Velodyne...what do you think? Worth a try?

I am told it is a great bang for buck given its "only" a Wilson Crossover and one extra IC.

WHAT KINDS OF IMPROVEMENTS WOULD YOU EXPECT ME TO HEAR (IF ANY?) Thanks for your advice!

Rhyno,

While there's more than a little good info in your recap of JL's white paper, there's also some misinformation - not sure if it's yours or theirs.

Your description of port behavior may get the spirit of the design's performance more or less right, but it's not exactly correct: Ported enclosures are not merely a "trick" resulting from a port tuning phenomenon. A properly tuned ported box will drive the 3db down frequency lower from any given driver/suspension and will roll off faster below that point than the same system rolls off in a sealed box. That's more extended bass - no trick.

Bear in mind that, as you move lower from the tuning frequency, there will eventually be less bass output from the ported box, due to the more rapid roll-off below the tuning frequency. However, if the port tuning is low enough, as it is on many high-end ported subs (I believe most or all of the SVS subs can be tuned below 25hz, for example), that may not be an issue. For music, the rapid roll-off of a ported sub tuned this way will almost never be an issue.

However, there are definitely other trade-offs with a ported box and I personally do agree that it's much easier to get a good sounding set-up with sealed subwoofers than with ported designs.

As to positioning subs in/near the same plane as the mains, many of the external bass management/digital room correction (DRC) systems will delay the electrical signal to either sub or mains to account for the delta in distance between the sub and mains. This allows more flexibility in optimizing position of both the subs and mains, which may be optimized when they are far from the same plane.

I'm not sure whether JL's own system offers this, but I'm guessing that it doesn't. Since JL's products offer in-sub room correction, it shouldn't surprise that they suggest that it's where DRC belongs (and it also explains their recommendation on room positioning). Personally, I use an external bass management DRC system and enjoy the added placement flexibility.

Running the mains full-range may offer the simplest signal path, but it also eliminates one of IMO the biggest benefits a subwoofer offers. All drivers produce more distortion as frequency drops - the longer driver excursions required for lower frequencies will reduce linearity (increase distortion). The good news is that a high quality sub (like your JL which is among the highest quality IMO) is better equipped to handle the heavy lifting at low frequency than is the woofer in virtually all main speaker systems (even including your Magico, I'd think). If you actively low cut the mains, you remove the heavy lifting from their woofer and shift the burden to the subwoofer, where it belongs. Your mains will benefit from the narrower bandwidth they're being asked to handle. So, there's a trade-off; simplicity vs optimizing bandwidth to driver. Some may prefer the full-range option (I definitely don't), but that's a matter of personal preference not system optimization.

Also, you'd need to consider the room-correction side of the issue. If your DRC is in-sub, I assume that it's functional only to the sub's high cut frequency, yes? If so, and you cross the sub out at 60ish hz, you're only room correcting to that point. In every room that I've ever measured, serious response irregularities run up to 120ish hz and significant irregularities persist above 200hz. Below about 80hz, passive treatments become increasingly cumbersome. If you limit your DRC to 60hz and below, there's a lot of room clean-up that you're foregoing.

At the end of the day, I'd say that most of JL's advice (at least as you've characterized it) is sound, but I'd also note that it's definitely slanted in favor of selling their products.

Richard Vandersteen advocates the use of powered subs. Not only does it extend the bottom, but cleans the mids and highs as well

Rhyno,

Informative post indeed.

cool post...thanks Rhyno.

here's the thing about subs. you have to put them in a position to succeed.

what do i mean by that? first off, older subs are too slow. integration issues were rightly noted. thats not the case with the new 'super-subs' that are out there (JL Audio, REL, Velodyne, etc). these newer subs are very quick and can keep up and properly augment mains in the right circumstances, leaving a drastically improved playback for those who will put them in a position to succeed.

what circumstances are those?
1) sealed subs (no ports)
2) sealed mains (no ports)
3) sub position flexibility (but close to the front plane of the mains)
4) adequate setting flexibility (namely, LP filter freq and slope, phase and volume)
and finally
5) digital room correction within the subs (JL Audio has the ARO system).

and here's why:
one of JL Audio's designers wrote a white paper in which he astutely identified that each source of bass will make the integration of a sub more challenging. ports are a source of bass, and a non-linear one at that! main channels are typically designed using ports to make the speakers A) more dynamic B) louder and C) seemingly deeper in the bass (though its really just a port-tuning phenomenon which tricks the listener. the truth is that the frequencies roll off sharply below the port tuning frequency). ---the nonlinearities of the port (whether on the mains or the sub) create a host of problems (room nodes, freq bumps) that are tough to work around. ergo, #1 and #2 above...the fewer ports, the fewer sources of bass that you have to contend with. --this is reason #1 sub integrations fail.

positioning is a function of getting the timing relationships correct. subs tucked way behind the plane of the mains means their sonic impulse has to travel further to get to the listener--and this gives rise to timing errors. plan on putting the subs close to the mains to maintain timing relationships. this is reason #2 sub integrations fail.

setting flexibility is critical to getting the most out of your subs. when you start with sealed mains, you have speakers that will have a very linear rolloff in the bass (excl room nodes, but more on this later). the subs come from the bottom up...where you have to play with settings to get the subs to roll off quickly once you reach the frequencies that the mains handle properly. if your speakers roll off 3 or 6db at 50hz, then its natural to start the subs LP filter around 40-60 (experiment) and play with the slope (12, 24 db per octave) to get the subs to drop off quickly so as not to intrude on the mains. phase should be set before anything though---check phase w/ mains and dial in for least output when both mains and subs are running, and then reverse phase of the subs. now that phase, crossover and slope are all set, play with volume to your liking. ---improperly setting phase, x-over, slope & volume (with volume the least important factor) is reason #3 sub integrations fail.

(note the mains are running full range---no parts in the signal path is best, and its preferred, given sealed mains and their natural linear rolloff).

finally, some digital room correction is in order. most high end subs have some feature to do so, and generally they're about removing room nodes (points of elevated volume)..these are far more problematic than nulls (points of reduced volume). run the sub's digital correction which will identify the nodes and shelve these frequencies down in order to reduce the node...and the beauty is, with sealed speakers / subs, you only have room-generated nulls, not port-generated! the digital correction will eliminate the node for the sub, so even if the main still aggravates the room-node, it will be counteracted by the sub's digital correction which has nulled out this freq from the sub's playback.

i've done just this, using magico S3s w/ JL F110s, and the setup is startling---the above is best bang for the buck sonics possible (as big full range speakers are expensive, for one reason---bass is expensive! so save a bunch of $$ and get the bass into a diff box and put the subs in a position to succeed).

then again, YMMV.

Audyssey is not an easy system. Even when I gave the instructions to clients and friends, it was difficult.

I work at mm precision. There is no room for error. When you do not work extreme precise it will work against you.

This is a big advantage for me, but for most it is a disadvantage.

The professional microphone can measure about 1000-10.000 times as much information compared to XT32.

But you also can make more measurments. You also have a lot more options to change.

You can make your own target curves. I did read many articles about human hearing. This gave me the freedom to create a superior articulation of voices.

I can let all people hear details which the best highend pre amps of far above 15000 dollar cannot reveal.

That is why a person who is distributer of many highend brands said: you can put the highend market up side down.

I use the knowledge and thinking in highend in every price level I sell. This gives me the option to create a 3 dimensional stage for a lot less than what was possible in the past.

Lewinski,

If you need an inexpensive, sand-alone active x-over, see if you can find an NHT x-2. It's now discontinued and hard to find (probably because it's pretty widely sought after and used offers tend to get snapped up quickly), but it's a very good sounding unit, quite flexible, and a steal for the $.

Good luck with the project.

Bo:

I've thought about Audyssey Pro and looked into buying the calibration pack, but I haven't yet pulled the trigger. Knowing myself, I might get sucked into another year or two of compulsive tweaking and I'm not sure I want to do that. But, either way, thanks for the recommendation.

Marty,

You are right: after further reading about the QOL, I realized it doesn't do what I need. So that one's out.

Switching cables between the Lamm and an Onkyo doesn't sound like me. I'd rather spend the time I have for listening to music just listening to music rather than swapping cables. We are likely alike along these lines.

About the Lamm: this is not their reference preamp; it's their entry pre, in Lamm terms. So it's not a huge investment compared to the other components, and is similar to the ARC and Joule pres you replaced with the Onkyo+Audyssey. BTW, at the time I was looking for a pre I did consider that Joule pre.
The problem is I cannot listen to any of these options beforehand, so it comes down to a leap of faith.

But the two Rythmik subs I already have and I'm sold on using them.

I'm also ditching the path proposed by miniDSP. Too complex to implement and cumbersome to operate, especially the latter.

So it looks like I need a DEQX, or Onkyo 5509, or HK 990 to replace my DAC and pre, and using Dirac or another DRC software at the server, and call it a day. I can't see other practical alternatives as of now.
I might start with the DRC software and a cheap crossover between pre and amp, knowing it's a temporary setup, and finally settle on replacing the DAC and pre with a digital processor.

Hey Marty; go for Audyssey Pro with your 5509. You will go to a much higher endresult.

Lewinski,

The DEQX has always looked interesting to me, but the local dealer (possibly also the national distributor) isn't very accommodating, so - even tho I tried to stop in for a demo - I never got a chance to check it out and can't really comment. It's gotten some good press, tho.

I know zero about the QOL and never thought it was designed for this application, tho I'm not sure what it IS designed for.

If you decide to keep the Lamm, my guess is that you'd be best off passing on subs unless you want to run separate 2 systems (or dual front ends). I don't mean to spend your money, but...

The good news is that +/- $2700 buys an Onkyo 5509 with Audyssey xt32 and a pair of 12" subs from SVS. That's a set-up that I'd be happy with and it's a modest investment relative to the LAMM. It would allow you to swap the amp and sources between the pre-amps on the fly (once you've attached the subs and set-up the DRC on the Onkyo), but you have to be the type that wants to repeatedly rewire the system.

I was that guy at one time, but not anymore - and I certainly can't speak for you.

Marty,

I certainly agree with you on simplicity being preferable. Further looking into these units I came across the DEQX HDP-4, and the QOL, amongst others, but these appear to be most endorsed. What's your thought on these, as an experienced DRC user?

I think the approach proposed by miniDSP is a non starter for me. As much as I love my Lamm pre, I think I will need to decide if I'd rather keep it or do the mains/sub crossover and integration thing. Much to consider!

My Parsifal (Encore) barely makes the low 40hz range WITH the woofer cabinet - they start to quit in the mid 40s range and are well down by 40hz. The monitors start to roll off at about 55 to 60 hz in my room. There's a hump in the upper 40s thru the crossover region to the monitors that gives kick drum some extra (ahem) kick and a satisfying sense of bass with almost all music. Not exactly textbook accurate, but I love 'em with most program material, just not for the deepest bass.

I guess YMMV

I have a Rel Stadium III with my Parsifal and really enjoy the sound. The majority of the time, I listen with the monitor, woofer cabinet, and sub. The fun thing about most of the Verity speakers is that you can listen to many combinations.
I enjoy listening to them in different configurations when I have a nice stretch. Sometimes I listen to the monitor (vocals and strings). The monitors have nice speed and easily reach down into the low 40's. Sometimes I'll pull the sub out into the room and listen to the monitors and sub. Other times I turn off the sub.
I think I've integrated them to my tastes. Great speaker.

For what its worth, here are some tricks I learned living with a Velodyne DD18:
-do as much of the setup in the analog domain as possible. Move the sub, adjust position, height etc before doing anything digital / EQ. In my ears, the less EQ the better.
- if you have a big heavy sub, consider a low trolley or similar. Positioning is not just a one-time issue. You may want to vary the sub position between "good" closer to a wall, and "optimal" more into the room, with different components in the system, room tweaks, etc.
- give it a sandbag on top (big improvement), better feet like Cerapucs (some improvement), plus a better power cable and interconnect (some).
- I have done a bit of room tuning including two Daad3 bass traps (that don't really catch much low bass, but help a bit in the 100hz or so region), but I don't believe in overinvestment at this point. It is very room-dependent. I have a fairly large 20 x 27 feet room.
-timing - better subs, materials etc may be a solution, but for now, move the sub closer to the listening position (DD18 is forward-firing). Often not so practical, but it can work.
-in some contexts the sub sounds better with the EQ and the crossover defeated. I was ridiculed for this viewpoint, in another thread, but sometimes it works, to get the best blend of sub and big speakers. The trick is to turn the sub volume REALLY LOW (like 4 of 30 steps at the DD18), so there is just a touch of deep bass. After awhile you'll notice that no more volume is needed.
- listen for the music not the bass as such. With optimal tweaking positioning you will hear more depth, more juicy treble instruments also, like flute in front of the speakers, bells sounding in the room, and similar.
- the speakers and sub should "grip" the room. Or make the room play along. I can hear this, for example, listening from a nearby room. I make better salads in our kitchen if the system plays well in the living room... But as noted above, this is a balancing act, hard to achieve perfectly.
- shifting phase 90 degrees can help cure standing modes (or a sub array).
- run the speakers full range, if they were designed for it. The sub is an add-on into the lowest frequencies. I have never had success cutting the bass to the main speakers. Even most monitors I have tried sounded best getting the full signal.

It is good to see that there are many ways to reach the same goal. I tried several subs ten years ago, before settling on the DD18. Mostly, they were too slow, lazy, or what one might call it (B&W ASW 800, REL Stratas) but I also remember a funny little over-active Sunfire that wheezed and danced on the floor when pushed. I had the Krell FPB600 / Dynaudio Consequence mk2 for ten years, and with this combo, I often liked the EQ and crossover defeat ("stealth"?) method. With my current Atma-sphere MA1s / Audiokinesis Dream Makers combo, however, it sounds best with a conventional setup, crossover at 44hz, a little EQ and 90 degrees phase. I can hear it, and it appears when I measure (using Rode mics and the REW program) also.

My problem, now, is that my new preamp (Einstein The Tube mk2) only has one set of volume-controlled outputs, going to the speakers, so if I want sub integration, I will have to use speaker level connections (or use the line out outputs on the preamp, and then adjust sub volume manually each time I adjust preamp volume - not realistic). In my experience this means worse sound (except for the REL subs, that were built for it) compared to preamp level connections. I have not tested yet, and the reason is that the new preamp sounds great and makes the whole system more muscular not least in the bass. So I am seriously thinking that perhaps the sub goes out the door. Yet I sometimes thought so, with the Krell/Dynaudio combo also, supposed to be bass leaders. So I guess the sub stays. Even if I don't use it for now, testing with / without sub is a luxury problem, compared to missing something and then pay a lot to try. And I still remember that great first impression late evening, with the DD18 in place: "hello, bass player".

Sorry, I missed the other half of your question. The configuration you describe might sound great, but it's (not to beat a dead horse) a little complex for my taste. In your shoes, I'd personally be inclined to look at something like the HK 990, which provides all the DSP (including x-over) and amplification in a single 2 channel box. As a bonus, it includes room correction, so you could A-B that against the Dirac to see which you prefer.

To be clear, that isn't a recommendation (tho I've heard and like the HK 990 quite a lot), just a simpler alternative that I'd likely pursue given my own particular priorities.

As to the required second DAC in the set-up that Dirac suggested, I can say that the Cambridge represents good value IMO.

Lewinski,

I've used several different configurations, but I'm currently taking the digital signal out of my QSonix server straight into the Onkyo via coax. The Onkyo does all DSP including x-over. The twin sub out of the Onkyo goes straight to my Rythmik subs and the main out goes to (at the moment) a pair of Cary 805s and on into a pair of OHM 100s. Sometimes, there's a different amp/main speaker combo, particularly if I'm using my Maggie MMGs, which require more grunt than the Carys can deliver.

BTW, I've previously used both of my current stand-alone DACs (Cambridge DAC Magic and Benchmark) for conversion, but - as I've noted - simplicity is important to me and I prefer the simplicity of one box. As to SQ, it's audibly different with each DAC (especially Benchmark vs Cambridge) and a matter of personal taste, but I like the sound of all three options and settled on the internal Onkyo DAC for the reasons stated above.

Further, BTW - there's an upgraded version of the Onkyo from one of the specialists (Upgrade Company?) that offers an in-home trial. At the moment, I'm kicking the idea of a trial around just to check out any potential improvements. If I pull the trigger, I'll post my impressions

When you use lighter material, you get a better response. The poweramp also has influence on the control and speed.

Ceramic woofers are very light and are a lot faster than some 'slow' material used by other brands.

In a simple stereo test you can compare the differences in integration. It is so simple!

faster subwoofers? are they midranges now.lol

New techniques and faster subwoofers has given us a much higher level of integration than what was possible in the past.

I never thought that this would be possible. Now I know it is possible!

So what is the conclusion?

The thread starter was warned against a sub due to "the lack of coherence that inheres in adding a subwoofer". I think this is system and room dependent. Bass has to be integrated anyway. There is no general rule that it is better inside a (costly) speaker than with (less costly) speakers and a sub, even if it often works out that way. So there is nothing bad that "inheres" in choosing a sub.

Marty,

Thanks for the answer. Was wondering how is your signal chain configured? From server, do you go out through USB? Straight into the Onkyo? Then the Onkyo does the crossing over, the room correction, and where is the DAC performed?

I asked the miniDSP folks about suggestions involving Dirac Live and crossovers. One option they suggested was Dirac at the server and their nanoDIGI 2x8 for a crossover in the digital domain, but also a second DAC dedicated to the subwoofers. The additional DAC I'm trying to digest...I guess any timing differences between the different DACs used would be compensated by the room correction...still not easy to digest. And I also wonder about additional jitter in the chain.

What are your thoughts on this configuration?

Audyssey Pro Is far superior in endresult compared to XT32.
The authority is a lot better. You get a different kind of sound in comparison to XT32.

It goes deeper and you have a much better timing and integration.

I, too, dislike the idea of calling bass response "slow" and prefer the term underdamped. I also like the idea of multi-sub arrays and have experimented with variations on the theme pursuant to some great posts by Duke of Audiokinesis, so I agree with a lot of this post, but....

Spkrplus wrote:

A properly installed Distributed Array has no integration issues up to about 80 Hz because it solves the bass mode before it occurs. All other solutions are band aids attempting to fix the mode after the fact, including EQ, which can't solve the timing error.

If "no integration issues" means "no room integration issues", this is an overstatement. You won't remove room effects with four (or more) subs, but you can greatly reduce their impact on direct FR and power response with careful placement. As a side note: EQ fixes the problem before it occurs, too. Once EQ filters are set by room analysis, the subsequent electrical (music) signal is adjusted prior to reaching the driver. Tho the filters are calculated "after the fact", that does not a band-aid make. If you doubt that this approach works, simply do an RTA of the direct and power response in the room (I use white and pink noise) post EQ. The benefits in both graphs are obvious, tho usually more dramatic IME on FR than power response.

The difference in power response improvement is - to me - the primary conceptual benefit of an array vs EQ, but per my own measurements, I wouldn't personally describe that delta as dramatic. My own array experiment - admittedly not ideal, two Velodyne SPL 8s and two 12" Rythmiks optimized for power response - showed power response improvement over the dual Rythmiks, but not wildly different. In fact, the power response and FR performance of that array was clearly improved by the application of Audyssey, too.

Proviso - a different subwoofer array implementation might yield different results, but my attempt was reasonably diligent. Had I gotten more dramatic results, I'd likely own an Audiokinesis array right now. To be clear, I wouldn't bet against me buying one in the future, but I'll still use Audyssey with it.

As for long wavelengths reflecting off boundaries (2 bass players), this happens with distributed subwoofer arrays as well as single subs. As a technical matter, it happens more - reflections for each sub are inevitable (4 or more bass players). Careful placement of the subs relative to the walls can smooth the response anomalies caused by each of these reflections, but they're simply smoothed in aggregation, not removed.

It's also unclear what "timing error" EQ can't solve. If you're talking about decay characteristics of the room, I don't see how a sub array would be helpful there either.

As for in-wall woofer solutions, they do effectively address the issue of reflection off the wall behind them (this is generally the worst IME) but there are still side wall, floor and ceiling issues which are certainly not trivial.

To be clear, I'm not dissing the idea of subwoofer arrays. I actually think it's a great idea. I'm just pointing out that the particular benefits of an array are overstated in this post and the objections to EQ are also overstated. Of course, the bottom line is a listening session. IME, thirty seconds with Audyssey should be adequate to demonstrate the benefits to most people (simply disable it during play). That doesn't mean it's preferable to a well implemented array, it just means that it's a very effective solution for the bulk of the problem. The best practical solution that I know of is an array with Audyssey, but, if you really want to "fix" the issue, an anechoic chamber (or room that effectively behaves as one) is the only solution that I'm aware of.

I also use the Onkyo PR-SC5509 with Audyssey Pro.

Above 99% of all people use Audyssey as Audyssey say you should use it. There is a big but......Audyssey does not think from the head of how highend is being used. And how big instruments and voices need to be in proportion.

The other limitation is the lost in dynamics. The first 2 times I did it as they tell people to use it. This was in 2010. I was not satisfied enough.

I had thoughts how it could be better. I developed my own way of measuring. These days we measure at totally different places and Heights.

We also measure the subwoofer differently than they do.

They endresuls are way superior to their quality in endresult. I never will share this information with another person. Even not for money. With this I have an extreme advantage over all my competitors. I never had such a big and convincing advantage in audio before.

The differences are: superior dynamics, speed, blacks integration, sharper focus, resolution and atriculation of voices.

The subwoofer is also a lot more dynamic and controlled than you can achieve with the Audyssey way of Pro.

We modified the microphone stand. The Audyssey stand is fully useless. We measure at mm precision.

The new outcomming Onkyo PR-SC5533 in September will not have Audyssey anymore. I will test it for Onkyo when it comes out. For me it will be far inferior in endresult. I still can sell the old one, The new one is good enough for me to sell. The level is not good enough to be used for myself.

Lewinski,

I've used several active x-overs and I divide them into 2 groups. The analog models included a tubed Marchand, an NHT x-2, and the internal active x-over in my Theta Casablanca. The Marchand was too noisy for me, but that might be unique to that piece, rather than the model, since I've been told that others had more success. The NHT is an excellent piece (and IMHO a great value), but I ended up pairing it with a Velodyne SMS-1. The resulting performance was excellent, but the set-up was a giant PITA (thanks to the Velodyne) and the multi box/cable arrangement was inelegant. The Theta is a really flexible and good sounding unit, too - and a one box solution.

I moved to an Onkyo 5509 pre-pro after I heard Audyssey xt-32. A lot of A/B testing at a couple of local places led to a loan of an Integra pre-pro which I felt was (much, to my taste) superior to the Theta. The crossover in the Onkyo (like most modern pre-pros) is effected in the digital domain. I ended up buying the Onkyo version because I couldn't hear a difference in sound between it and the Integra version, it was significantly cheaper, and I preferred its appearance.

To the x-over question: It's hard to separate the performance of the digital x-over (vs the analog x-overs) because they were integral (pardon the Onkyo Integra pun) parts of two very different pre-amps/pre-pros. In the end, I like the Audyssey powered one-box solution of a pre-pro for my main 2 channel system and that means a digital x-over comes as part of the deal. Whether it's the digital cross, the room correction, the balance of the preamp circuitry, or any combination of the above, the bottom line is that I found it to be a better mousetrap. Since I had already effectively stopped listening to LPs in favor of a server (and consequently didn't really have to deal with the cognitive dissonance presented by ADC and DAC for my analog LPs) I retired my ARC LS-25 and Joule LA-150 without much indecision. As always, YMMV.

Hope that helps. BTW, I've never heard the Dirac correction package, but I've done a bunch of research on it: There's definitely some interesting software there. If you do pull the trigger on Dirac, I'd be grateful if you posted your take on its performance.

Above 80hz low freq. become touchable. That is why when you use your subwoofer a lot further ( 120-140hz) you become what I call stealth low freq.

That is the main reason why you need an extreme fast subwoofer in response to use easilly to higher freq.

Using till max 80Hz, is like using subwoofer during the 80's!! That was the past, it is about now.

Shameless tangent!

Marty: I'm interested in your experience with room correction. I also use Rythmiks (two 12" very heavy DIY boxes) in a stereo setup. I'm looking into Dirac for room correction (as my only source is a highly optimized computer), plus an active crossover to high-pass the tube amp and send the bass to the subs. Was wondering what your experience was with active crossovers?

Now, more relevant to the original post: I have small floorstanders (B&W 804S), and adding a sub was a good improvement. I started with a REL Storm III as reinforcement to the low end. Using measurement software/mic and a lot of time, I achieved good integration and I was much happier than without the sub. That REL has one 10" driver.
Then I replaced the REL with two 12" Rythmik subs. Much better! Initially they were also used as reinforcement in the lowest bass. I used Earl Geddes approach: both subs running a summed-up-bass signal, both set up with different crossover pounts, different phase, volume, etc (and different adjustments in the PEQ section) to get a smoother room response. And indeed it was a lot better!

Lately I tried an experiment: high-pass the tube amp (and hence the speakers) thru the crossover built into the plate amp of the Rythmiks, that crosses over at 80 Hz. Subs were kept in the same location (for now), but are now used as stereo and with different settings from before. This gave me a better sound. Better soundstage, imaging. I think the explanation is my speakers, while they can reproduce below 80 Hz, do so with higher distortion. Plus the tube amp must not be too happy to go down there either.
So in my experience subs are a very good thing for music. They do take significant effort and time to get right. And the reasons why they are a good thing aren't only about reaching down deep in the bass, but in some cases relieving the amp and speaker from playing where they are not most comfortable doing.

Cheers!

I have heard the DD18 several times. Not the DD18+

I never heard the DD18 reach the stealth speed I have at home. This is my Reference level of timing. So I compare everything with this quality. When it is less, it is fully useless in my world.

A know a few person which I sold cables who own JL subwoofers. You don't see them here a lot in the Netherlands.

I never liked any Krell speaker. It is better just focus on one thing....for them it is amps.

Magico subwoofer is of an extreme price. When there is a demo here in Holland, I will go for a listen.

Hi Bo1972, as an owner of Velodyne DD18 (original), I think I know where you are coming from. How is the DD18+ by comparison?

Have you ever heard JL Audio, Krell Master Ref Sub or the new Magico QSub? Just curious since it would be fun to hear from someone who has. I certainly have read many good things about JL, but curious if you've heard them how you would compare them with my trust old DD18. Thank you!!

Dynamics is something totally different than response. This is what is the weakest part of Velodyne.

I like the drive and eq system of the DD18 when I heard it the first time. But still I didn't like the integration.

I have showed this to some Velodyne owners at my home. Then it is easy to understand what a faster resonse does.

This makes a subwoofer go to a different level.

Then you get stealth low freq. I am Always looking for the best. This search never stops. People often ask to me if life is not more difficult to be so demanding. In my view it is not. It is who I am. Doesn't cost a lot of energy, it works just natural.

In audio it needs to be the best, the rest I don't F...care!
That is why people can feel offended. I want the best for my clients as well. I want for them they same level as I want for myself. There is not difference, that is why I think and work for my clients as I do for my self.

In October 2011 Jeff Hedback (Hd Acoustics) and Nyal Mellor (Acoustic Frontiers LLC) published "Acoustical Measurement Standards For Stereo Listening Rooms." Hd Acoustics clients include Ozzy Osbourne, Lifehouse, and Trevor Horn. Page 19: “To obtain the best possible LF response boundary interference issues can be tougher to address. Varying the fixed distances from ‘speaker to boundary’ and ‘listener to boundary’ will reduce strong cancellations. It is a balancing act as one location that may offer a smoother LF response may not provide the optimal midrange and treble response ” (emphasis added) Page 20, paragraph 2: “ everyone desires a ‘flat’ LF response and no modal ringing. Simply, this is a tough achievement. The absurdly large collection of interrelated variables between two fullrange speakers and the room (speaker design, speaker/listener location, room size/construction and acoustical control within) makes this so. It is up to the individual to determine what their limits are as regards placement and acoustical treatments ” (some emphasis original, some added note the qualifying phrase “absurdly large“)

Let us narrow the discussion to bass reproduction systems (subs or full range speakers) properly tuned with appropriate system Q. Audiophiles wrongly describe such systems as having "fast" or "slow" bass, and such descriptions are misleading or worse. Would you want a low E string on a 6-string guitar to be "faster" than the high E? No, of course not. Low E is 82 Hz, high E is 328 Hz. Obviously, the Low E must be "slower"...two octaves "slower" to be exact.

Guess what? Bass is a slower wavelength vs. mid/treble. Of course it must be slower. Double basses are larger than violins by design.

"Slow" bass more accurately describes a bass mode effect unrelated to the speaker itself. Even though modal effects often result in Frequency Response windows of 15 dB or worse, that is not their worst and most audible effect. The worst and most audible effect is that the mode wavelength is completely outside the diatonic scale and unrelated to the original bass note pitch. After the bass note ends on the program, the modal effect continues bouncing between boundaries. Imagine two bass players, one of them plays perfectly, while the other bass is tuned a quarter tone off (sometimes plus, sometimes minus, depending on the mode), and he holds bass notes about a 32nd note too long. This is the inherent effect modes cause, which results in audiophiles wrongly using terms like "slow." Yes, the note didn't end, but the speaker is not reproducing the note, the boundaries make the note. We're talking about the equivalent of over 100% THD. We're talking about bass notes not on the music program.

There are really only two ideal solutions, neither of which require any EQ nor acoustic treatment for small 3 to 6 dB FR windows, and virtually no timing errors as described above. One is a Distributed Sub Array, the other is a Dual Bass Array. The latter might perform even better than the former, but the latter also costs about twice as much and ideally requires subs built into both front and rear walls.

A properly installed Distributed Array has no integration issues up to about 80 Hz because it solves the bass mode before it occurs. All other solutions are band aids attempting to fix the mode after the fact, including EQ, which can't solve the timing error.

Initially, three or four subs seems like 2 or 3 too many. When you hear the performance level, you'll wish you found out about it earlier and never look back. Even 1cf subs can reach -3 dB @ 20 Hz with enough power for HT or music. That's another benefit: ideal bass works just as well for music as it does for HT.

Hi all.
Bo1972 - dynamics is no problem wherever the dd18 is placed. It is a very forceful sub. The trouble is integration, as I am sure everyone here is aware of. If you think the sub is too slow, do the obvious thing, move it up front, closer to the listening position. Works quite well with the DD18. For space reasons this is not so easy for me. James Romeyn (associated with Audiokinesis) suggested, if you have to line it up more towards the wall, turn it to 90 degrees phase. This has worked well in my context, using big bipole speakers.

I agree with Martykl...a good combination is tough to beat in my opinion.

I cannot say if my own X1/Grand Slamms plus Velodyne DD18 would work for others...but it works for me. And I know more owners of the big Wilsons who DO use Subs with them (in parallel...not cutting off the Wilsons) than those who do NOT use them.

At below 40hz, I honestly find the solidity of foundation is wonderful, and I find the 'blending' to be quite good after months and months of fine tuning every few weeks.