I just acquired Cain & Cain IM-Ben fullrange speakers with a pair of matching C&C Bailey subwoofers. The Ben's are still burning in 10 hours a day, out of phase, facing each other.
But, I have been trying to figure out the best way to integrate them. The Bens are 40Hz-31kHz and run without any x-over except to attenuate/high pass the tweeter output. The 6" Fostex FE-168 Sigma fullrange driver rolls off naturally at the low end.
Terry Cain suggests starting with the subwoofers crossed in at 80Hz. As Raul has pointed out, this means that they will probably still produce some sound up to 100Hz. Which got me thinking, this is into the range of stereo reproduction, so my current Paradigm X-30 sub x-over may not be the best tool.
The X-30(like most sub XO's) takes L/R channel input and sums the channels into a mono signal for the subwoofers. This is ok for music below 60Hz(maybe even 80), but above that I don't know. Perhaps it is best to run true L/R stereo signals to the subs instead of summed mono. Though, i don't know how this affects room interactions. Mono LF signals supposedly help cancel some room nodes.
The X-30 also only accepts line-level inputs, while the X-20 uses amp/speaker level inputs. I remember reading somewhere that speaker level inputs are actually better because the subs see the exact signal the mains are from their amplifier.
Regardless, in my case, line level RCA inputs won't work because I run 40 ft. balanced cables from my preamp (S&B TVC) to my 300B SET monoblock amps which have Jensen XLR->SE input transformers. I'd have to buy 4 new line transformers to do this with the X-30. At that cost, it would be easier to simply buy two X-20 speaker levels x-overs.
Any thoughts on this guys? Is stereo subs best in my situation?
The obvious downside of running true stereo subs is cost. I have not been able to find any affordable crossovers that do true stereo output. |
Hi Raul,
Believe it or not, I actually picked up a Pass Labs XVR1 crossover for a friend, but had to ship it back to him one day later. So, I never got to use it.
The Pass X-O is built like a 200wpc amp, it must weigh 40-50lbs.
I also did some reading about the Bryston 10b a few nights ago. One just sold here on Audiogon for $500 in under 8 hours.
I was hoping to find a cheap solution, but a good crossover is going to cost money. I guess the results will be worth it. I'll let you guys know how it works out. |
Skushino, I've seen those Edgar subs at his shop which 15 minutes from my home. The Seismic is about the size of a refrigerator, but does bass in a way that I hve never heard before. Sound just eminates from all directions rather being pushed AT YOU. It can literally charge the room with acoustic waves from the nether regions.
Edgar's Titan/Seismic sub combo is a system that everyone should experience a few times whether you like horns or not. It is one of the most effortless, seamless, presentations of sound likely to be heard. No shouting, or typical "cupped hands" sound associated with most poorly designed horns. Just sound appearing out of space.
Having said that little advertisement for Edgarhorns, I've been having the same problems properly placing my dual Cain & Cain Bailey subwoofers in the proper spot to seamlessly integrate with C&C's six foot IM-Ben horns.
I'm using a Paradigm X-30 subwoofer x-over, which does summed mono outputs. Intial sub x-o point is 80Hz which seems to be a fairly transparent spot, any higher and bass tends to become boomy.
So far, placing both subs just inside the two, 8 foot apart horns overloaded the room. The Baileys are ported on the side, but I have them with the drivers facing forward and ports facing each other. Outside the horns was a little cleaner with seemingly less spl output.
A few months ago, Terry Cain set these exact speakers up in another person's home and he had the Baileys between the IM-Bens just as I have, but he had the subs angled twoards each other. That room was much smaller than mine, but I am going to try variations of that next.
I need a true subwoofer amp, though. The intermediate Denon AV receiver that I'm using to power them seems completely out of it's league, powerwise. |
Hi Raul,
I have the passive version of the Baileys, so I need an external crossover and amp(s) to use them with the fullrange Bans.
But, so far I've been really concentrating on getting proper placement for the IM-Bens. These things really put out the full 40Hz range on their own. It is more than enough for the vast majority of people and rooms whe placed right for room gain.
I'm getting a little bit of bass overload due to my room right now. I need to fine tune things and then add the subs in. |
Skushino - Dave Whiner's ModeCalc shows that I have 2 room modes at 70Hz, 3 at 141Hz, 2 at 211Hz, 3 at 282Hz, and 2 at 353Hz.
Running the IM-Bens w/o the subs is no real problem except when a sustained note(s) hit that 70Hz fundamental mode and it's harmonics(?) 211/282/353. Especially the 282Hz notes, seems like there is a 6+dB jump in output with distortion. Noticable, annoying because everything else is so pure and clean, but not ehough to destroy the music.
So far, I've found that lower Marimba/Xylophone/Vibraphone keys really overload the room because of their sustained resonance and decay. Cello can, but i haven't found any works that have hit that long note yet.
I've been looking at pro sound crossovers(Rane) or even some of the digital crossovers(Behringer, etc.) this last week.
But, the IM-Ben's are designed to run fullrange without any crossover at all on the 6.5" Fostex FE-168 Sigma drivers. The only components used (I think) is an adjustable 12dB/octave high-pass filter for the Fostex T-900A supertweeter >16kHz.
I'm a little leery of introducing any X-O into the mix even though all the room modes fall in teh IM-Bens range.
As for the subs, my inital experiments with both subs added into the mix have been pretty bad. I don't have a dedcated sub amp(s) yet, so I've been trying to use some solid state integrated amps/receiver that I have lying around. One's a Audio Refinement Complete(50wpc) and the other is a Harmon Kardon AVR 20 II (60 wpc).
Needless to say, it sucks - flabby, mushy, unrecognizable bass. The other problem is that the Paradigm X-30 sub x-over that I have is outputting noticable distortion/breakup.
Currently, I have the Bailey's in between the IM-Bens(10 ft. apart) facing directly forward. Terry Cain suggested starting with this position because it provides the most bass energy.But, the subs do seriously the room even at low volume - wall panels start to buzz/rattle and there is some extremely low frequency energy being generated.
I need to try positioning the subs at various angles inwards, then outwards to see whether that reduces some interactions. After that, I'll move them outside the main speakers at various angles to see how that works.
Unfortuantely, I cannot locate the subs in the corners because the living room side that the speakers are on is open and overlooks my dining room below. The rear wall is 5 feet behind the railing.
As Raul has pointed out, dialing the sub/mains intergration in perfectly could take months.
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Skushino - Fantastic article!!!!! I didn't get the concepts the first time I read it, but the next morning I went through it again using the Excel Room Mode Calculator spreadsheet with my room measurements and everything made sense. First of all, I had to re-measure my room because I realized that I was using a false length distance AND I got my room width wrong. I had been using 16'x20'x8', when in reality my room is 15'x23'10"x8'. Length-wise, I hadn't accounted for the distance that the rear wall that extends back over the dining room. Then, using the Room Mode Spreadsheet, I was able to find the proper 12' mid-length seating position at the 1st & 3rd(71Hz/24Hz) order nulls. Then, position the speakers at the 2nd order 5.75'(47Hz) null. That leaves me with the lone 4th order 94Hz length mode. Width-wise, sitting dead center of the room puts me at the nulls of the 1st & 3rd (38/113Hz) modes. I can then put the mains and subs exactly on the the 2nd & 4th nulls (75/151Hz) at 2ft & 3.75ft from the side walls. That looks to provide almost complete cancellation of the the width problems. So, by experimenting with speaker & seating placement< i should be able to do away with most of problem bands except the single 94Hz legth mode. Although, I an sure I can find a way to dampen that one, too. Unfortunately, I won't get a chance to try any of this out until next Monday because my brother and his wife are visiting with their 2 year old. Everything gets packed away from Natasha's curious fingers. |
Screenshoot of my RoomModeCalc ouput. Unfortunately, in the length mode, the closest my speakers can be to the rear wall is the 2nd order 47Hz null(5.75ft). Which makes sitting at te preferred mid-room 1st & 3rd null (12 ft) serious near field listening six feet from the speakers. That just doesn't work for me. But, it is possible to sit right in between the 3rd & 4th nulls at 19.75 ft and 20.75 ft. Both the 71Hz and 95Hz modes should be as close to their nulls as possible. On the other hand, the 24Hz mode will be at it's absolute worst. Since I don't have an amp for my subwoofers yet, and the main IM-Ben's only go to 40Hz, this shouldn't be a problem. When I do have an amp, EQ'ing that mode down should be no problem. I kind of like that solution because I didn't want to add any crossover into my main fullrange signal outside of it's stock 12dB/octave high pass filter for the super tweeter. |
What does it sound like when running strictly a subwoofer or two below 80Hz?
And what should I listen for when adjusting phase?
I finally got a decent amp for my pair of passive subs, a Samson Servo 550 (275wpc). It's a pro/live amp used in clubs/bars/etc.
Anyway, I feed my subs via a Paradigm X-30 active subwoofer crossover with line-level inputs.
I am currently feeding the X-30 directly from my cd player's "fixed" outputs and my monoblock tube amps from it's "variable" outs while rebuilding my passive transformer volume control.
Anyway, last night while playing assorted jazz, classical, and rock I would intermittently turn the volume down on my main speakers to listen strictly to the subs output.
I expected to hear distinct, clear-cut, drum strikes or the clean resonance of standup bass strings, but that isn't what I got. Everything was rather muted in a undefined way. It certainly fleshed things out when mixed in with the mains speakers, but I expected more attack, I guess.
The best description would be a line that an audio reviewer once used - the subs recreate the trailing edge of a note rather than the leading edge. More resonsce and decay than strike.
I've tried varying the x-o frequency from ~60Hz-120Hz.
Does this seem right? |
Thanks for clearing that up Raul, I was just a little worried that I somehow burned up my subwoofer crossover. Everything sounded great when both the subs and main speakers were playing, but when I turned down the mains, the subs sounded muted and out of focus.
Amazing what an influence such a bad sound can have. I thought instruments and voices sounded pretty damn good before, but now after hearing things with the subs, mains-only sounds thin and one dimensional.
The subs added depth and flesh to everything. Amazing because it does so with very little output. It really doesn't take very much volume wise. Although, what little it does, pushes my 275 wpc sub amp to it's limits on organ music and other sustained low frequencies. |
Good idea Sstark,
I'm going to get a decent SPL meter this week to help check my room problems with some test tone cd's, anyway.
It's reassuring to hear that you are actually corssing in the subs that high(as compared to standard 80Hz) because my intial tests over the last week or so, seem to indicate that the 100-120Hz range works best in my room. It's hard to ell where in that range it falls because Paradigm doesn't provide precise numbering along the dial, nor would that matter because I understand that the pot can be up to 20% off.
Anyway, I've been using two or three cello works for tuning the crossover frequency - Kronos Quarter "Gnarly Buttons" & "Pieces Of Africa", and Roger Kellaway's "Cello Quartet". There are also some excellent blues/jazz bartone works that I've noticed get "fleshed out" with the higher setting.
80Hz seems to be a "cleaner" setting, but 100+Hz tends to help out cello, piano, organ, etc.
BTW, Terry Cain suggests using push-pull tube amps with the passive subs. And he said they don't have to be monster amps to get great sound, so I'm considering some vintage PP organ amps. I figure they had to be able to push some current in order handle sustained organ notes in cathedrals/churches. |
Hi Raul, I just burned RealTraps Test Tone CD onto a blank cd and have been playing with it for an hour or so. It's amazing how much output jumps on in the frequencies where there are room modes. Fells like 5x the volume or more. |
You're right, Doug....
I don't own an equipment rack or isolation system yet, so I actually have to place my turntable down below in the dining room and use long IC's to get it away from LF energy right now. When notes hit those room mode frequencies, the panel in my fire place starts to buzz and the windows vibrate.
So, it's not really worth it(using TT) for me until I get a good rack and room treatments. Getting up to run downstairs every 20 minutes or less is beyond silly.
But, having said all that, the difference a sub (or subs) make in the texture of bass and midrange is astounding. My main speakers are similar to yours in FR(~40-36kHz). Though, in reality, I'd bet you've got a lot more 40-60Hz output than mine.
Anyway, everything is much more fleshed out. There's just so much more "body" to instruments and vocals it is surprising. Not in a "slam" or "punch" style, but the actual resonance of the instrument. Tonality and texture have jumped into the next league.
I can't speak to spatial information yet because of my room problems, so others will have to jump in for that. But, suffice it to say, I cannot stand to listen to my mains anymore without the subs. They sound weak and anemic in comparison.
Pretty surprising considering two weeks ago I thought they did a terrifc job of producing deep, tight, bass for horns. I still do, though nothing close to what I've got now.
But, since you've already said in your system description that the Salamander Synergy Triple 20 is "Too resonant for a serious audiophile, but looks nice in the LR", it's a safe bet that you'd have to get a new equipment stand or a lot of isolation platforms, blocks, rollers, pads, etc. Then, there's the inevitable room issues to keep you occupied for a good long while, especially with only on spot for sub placement.
Aaaw, screw it - go for broke! That's what this silly hobby is all about - spending money and chasing that last 5% of performance. You'll never know what your system is truly capable of until then(just joking). |
Don't worry Skushino,
I have to wait until my girlfriend goes to bed before I can watch SciFi Channel or play computer games. And I'm 40 years old! Talk about a dork.
I tried a listening session tonight of one sub versus two(summed mono). Same songs, same passages, seconds apart. Out of that rudimentary test, it seems to me that one sub gets you 80% or more of tonal benefits. But, the second sub adds depth and texture to what's there.
As for energy or room mode cancellation, I kinda got the feeling that I have less problems with one sub than two. How's that for weird? One of my subs must be slightly out of position because it is supposed to cancel a lot energy.
I played a few deep bass laden tracks (Bach organ, Bjork, Pink Floyd) and then walked up to the master bedroom which is on the floor above and behind the living room (tri-level house). There seemed to be more energy in that room with two subs than one. Although, one was still enough to annoy someone in bed.
I think absorption/basstraps are the only real answer to your(and my) problem. Since I have two subs pointing directly forward, I really don't need the added room gain. So, I am going to experiment with DIY absorptive panels on the wall behind the speakers and bass traps in the corners. The same behind the listening position to drain energy away from the wall 2-3 behind my head. I'm also going to put panels at the 1st reflection points. |
"Too much Bass", an addiction! You are dead right, SirSpeedy.
I just started weening myself down off heavy bass out of my subs this weekend. For the last couple of weeks I've been listening to an artificially high level just because I could and it felt GOOD.
But, over the last several days I kept getting the feeling that it was too much. No matter how much I turned up my main speakers, the bass was just too prominent.
So, little by little, I've been turning them down. Not intentionally or conciously, just every once in a while I'd get up and turn it back a little.
It's still too much, but a lot less than I had. I figure by mid next month, I ought to somewhere near reality.
On a side note, yesterday I moved all the furniture out of my living room and moved my system to the other side of the room. Someone just tipped me off to the fact that I was losing a tremendous amount of midrange due to the open wall behind the speakers which looked down onto my dining room.
I also moved the subs in between my mains instead of outside them.
Good God, was he ever right! And my low frequencies are much more even now according to a test disc I've been using. I've only got two problem areas now - a massive 24-34Hz boost and a nearly complete suckout 54-64Hz.
This 24Hz bump is huge, but so little music strays into that I area I haven't noticed it as of yet, except for the test tone notes. Which is why I kind of like to think of it as a free sub amp EQ boost.
The 60Hz suckout is a different matter, altogether. |
SirSpeedy, addictions are tough to kick...
You've got to ween yourself down a little at a time - cold turkey can kill ya'.
I've been slowly walking myself down the crossover point and volume range steadily. Surprisingly, the difference is increadibly subtle for such a large output difference.
But, as you suggest, lower levels allow more detail to sneak through. I also moved my subs to the corners(obvious, but I never tried it) behind my mains and moved the mains further out from the wall.
The corner loading actually reduced bass output from the between-the-mains position substantially. But, it also cleaned things up nicely. The lows aren't as obvious as before and blend well with the rest of the frequency range.
Corner ubs and mains farther from the wall created what my system has been lacking since I upgraded a few months ago - DEPTH!
Before, it was wide but flat. Now, I am beginning to get a sense of the distance between performers on stage with good recordings. And I get touches of that 3-D effect at times.
I tried the Cardas Golden setup, but that really wasn't any better than other positions and essentially rendered my living room useless with the speakers almost 7 feet from the front wall and my seating position 6 feet away. That's way too close for 6 foot tall speakers.
I hope to get a couple of other fanatics over to my house this weekend to help with positioning. It is just too hard to do alone with speakers this big. Get up, slide them a few inches, measure, re-measure, slide them again, sit down, listen some music, get up again and again and again.
After a while, it becomes impossible to tell the diference between positions. Yet, I slug on in the spirit of this crazy hobby. |
Skushino, I tried the subs in-line w/ mains....
I made sure they were both exactly the same distance from the front wall, then tried them outside and inside of the mains - near wall, away from wall.
Between the mains, things started to open up and deepen at about 4.5 ft from the back wall out to ~8 ft at the Cardas Golden Ratio for setup. The difference in depth of soundstage between those two distances didn't seem to be too great. But, I got a marked difference when I angled the subs almost 45 degrees towards each other (the middle). That added a lot of air and space.
Unfortunately, that was 2am and the differences could have been from fatigue. Like an idiot, the next day I started moving things around and cannot find that exact spot again.
But, when I moved the subs to the corners there was a noticable difference in depth. The only problem was that it seemd like the bass frequencies were slightly disconnected, lagging, or behind(time-wise) the rest of the music.(This was with the speakers 7 ft out and subs in corner) Nothing obvious, just a subtle feeling that kind of threw off the cohesiveness of everything.
As I moved the mains back toward the wall (and subs) the timing began to integrate again. Right now, at 4 ft. from the wall, the timing issue isn't readily noticable yet.
SirSpeedy's:
I'm going to try mocing the subs out of the corner more to see how that works. Oddly, I also have my mains 39" from th side wall. This places them at the null of 84Hz width mode(though sitting in the center-width of the room already deos this). So far, that seems to the best spot for maximizing soundstage width while maintaining imaging. |
Skushino - Audio Physics advises against subs in-line w/ mains. (see bottom of page) "If you encounter any problems with this set-up, you may consider adding a subwoofer, which should not be placed in line with the speakers." |
