Lightminer,
Are you using your system for HT as well as music? Are you a pipe organ guy? If not, why worry about ultimate LF below 25hz. In my collection of >5,000 records and cds, I can only think of a few that go below 30hz. I only mention this because there are tradeoffs in choosing subs and the first one I'll give away is extension.
BTW, I can't imagine that you'll miss the difference in bass performance between EQ'd subs w/ your 3.6s and full range 3.6s. Both will "go there", but they'll sound quite different in terms of "impact". I personally have little issue with timbre (my subs are actively crossed at 74hz). I assume that this is because timbre becomes less meaningful as you descend in frequency. At 25hz, you feel it more than you hear it. I may be less sensitive to timbre issues higher in hz near the x-over than some other folks, but I don't hear the timbre change im my set up; even in the lower registers of electric bass or piano where fundamentals may fall in this critical area. However, this is a classic YMMV.
AVTalk.com and Hometheatershack.com are the two subwoofer distortion & group delay databases I know of (Thanks Shadorne and Bob Reynolds). None of the data you seek is on either site, but there are several REL model test results vailable. General rule for REL = great group delay #s, ugly distortion #s. SVS subs seem to offer a nearly unmatched balance of distortion & group delay performance (if you value both equally), and they do so at a comparatively low price.
Marty |
Firstly, I like Marty I don't understand the preoccupation with flat to 20 Hz - most rooms have 10 db SPL peaks and troughs in the bass and furthermore room boost always causes a rising output in SPL as you go lower with frequency.
Secondly, the reason for a fast bass repsonse (low group delay - no extra added cycles) is to avoid masking the transparent panel midrange with delayed or smeared bass response. A port is adding a signal delayed by 1 cycle and at 20 Hz this is 50 msecs...a lot of midrange music can occcur over 50 msecs, as that is equivalent to 50 cycles of 1000 Hz - and a loud bass sound can reduce your ability to hear the midrange details (masking) |
Shadorne,
I understand your point entirely. Now mine:
I recently heard the JL 113 Fathom (low group delay) set up with the
Maggie 1.X (don't recall the current designation) at a local dealer. After an
hour, I had the following observations:
1) The bass sounded no tighter, quicker, or less smeared than my (high
group delay) SPLRs.
2) Mid-bass and mid-range didn't sound more articulate.
3) Discontinuity between planars and subs was evident to me (I attribute this
to careless set-up).
4) The system was more dynamic sounding than mine.
5) This was a different room/different source & amplification/ different set-
up regimen than I use at home, therefore an imperfect test.
However, I concluded that the lower group delay wasn't OBVIOUSLY audible
to me in this set-up, as I expected it might be. Neither was the improved
distortion performance (The JLs produce far better distortion specs than my
SPLRs). My conclusion is that careful set-up (probably including EQ) likely
trumps specific sub performance. IOW, I suspect that the specs we use are
measuring stuff I can't hear (or, at least, hear very well). YMMV.
Marty
BTW, once I figure out which subs make the most sense (I wish I had data on
more models) , I'll probably replace the SPLRs (if only on principle alone). I
want lower GD in my system, even if the effect isn't dramatic. Same for lower
distortion. To be clear, I'm not saying better subs don't sound better. I'm just
saying that IME better set-up (including EQ if that -as is likely- proves
necessary) is more obviously beneficial to my ear.
Further, for the OP, I suspect that great subs won't fix his problem. Good
subs, properly set up, just might.
Finally, thanks again to you, Bob and Drew for pointing the way toward betetr
bass performance in my system. Your advice has been invaluable. |
My conclusion is that careful set-up (probably including EQ) likely
trumps specific sub performance. IOW, I suspect that the specs we use are
measuring stuff I can't hear (or, at least, hear very well). YMMV. You have a good point. Room modes and slow RT60 decay times of more than 1 second will also have a huge influence on the bass response. In a sense, room modal reverberation is a form of repeated/delayed bass cycles that can actually last longer than anything the subwoofer does due to a port or high group dalay. The only thing I would add is that it is all cumulative...add a slow subwoofer with large group delay into a modest highly modal reverberant space and the bass will start to dominate and sound boomy and disconnected from the panel's beautiful light midrange. So if you have a large space that has a great RT60 with very fast decay times in the bass then you might not care too much about the subwoofer group delay. BTW Large classical concert halls sound best with RT60's up around 1.4sec. Loud rock and big band in a normal sized studio monitoring room sound better with RT60's around 0.4sec. So the room as well as the genre play a big role too. |
Two more group delay observations:
First is inconsistency in test results:
If you cross check AVTalk and Hometheatershack you will see differences in the test results of the same model subwoofer (these may look smallish at a glace) which prove greater than the delta between differing makes & models. In fact, HTshack tested 2 samples of the SVS 12NSD and got significantly different GD results.
Second is Shadorne's illustration of GD's impact at 20hz:
While the GD test results really diverge at this low frequency, they tend to converge significantly as pitch rises. I wonder if the lack of really low frequency program content tends to obscure the audibility of a sub's GD capability. At least, the program material I used in my listening tests.
Marty |
Marty,
Indeed, it is fair to say that the importance of low group delay increases
significantly as you go above 40 Hz. However low distortion remains
important right down to 20Hz because an 80 Hz harmonic of a 20 Hz signal is
likely to be quite loud to your hearing even if it is of the order of a mere 1%.
(This is because hearing sensitivity increases dramatically from 20 to 80 Hz.)
So if you have high group delay and a sub which puts out say 100% THD at 20
Hz then you might be rather concerned about what this is doing to the
unwanted distortion harmonics from non-linearities in the design. |
Agreed.
I'm just finding it difficult to reconcile the published numbers I see with what I actually hear. I'll eventually order a pair of SVS 13" Ultras and use them in sealed mode - pretty low distortion from a pair and GD stays below 30 at 20hz. The cost of a pair is still below that of one JL113, so my sense is that this is a good value play. At least as far as upgraded subs can represent good value for me. I guess I'll have a better idea when I get 'em in place.
Marty |
Martykl and others - first sorry for not responding in a better amount of time. The research I set out to do was quite time consuming and while I didn't quite finish it I have enough to post. So - first of all I agree with a follow-on comment that group delay is one component of many, completely agreed and good crossover is critical, phase, placement, etc. I'm considering going bi-amping with 3.6s, well let me put it this way, I'm sure I am going to, but its a matter of what year. I really want to do it with 4 Pass 60A.5s, but that costs a car :)... So, the bryston crossover has gone up in cost, I think it used to be 2k and now its 3k, anyway it seems like what you really want to do is crossover from the active crossover, so now I need 2 3k crossovers (I'll probably get them used here), but anyway, agreed on all of that.
To answer a question, I do have some very very cool organ pieces, they aren't my goal, and I agree there is very little information below 35, even 45 Hz overall. But I'm in this to reproduce difficult sounds at the extremes. For far less cost I can not deal with the extremes from what I already have. I want the stuff in the middle and the extremes!!
However, after reading all of this info, group delay seems to make a lot of sense for critical listening of music. And lo me, I have an extra-ported sub when my sub company just came out with not only non-ported subs, but they are designed to be used in pairs, so I could have put one near each Maggie (and some say get three and put one near ceiling, don't know all the details). Anyway, the new Hsu stuff seems perfect for Maggies in some ways.
Oh - someone asked why I care strongly about it going to 20. First, not only do I want it to go to 20, I want it to go to 16! There is information you can feel. Look - there is mid fi, hi fi, and super-hi fi (alright, not a technical term). Similar to what I referred to above about going to extremes. If I already have speakers that do 35 pretty darn flat (although in my non-wall-reinforced setup I rolloff closer to 50), why spend 1 or 2k to go from 35 to 25 when hearing goes to 20 and feeling goes lower? Also on the 16 Hz, I've heard that there are harmonics from the 16hz tones that go up and change the effect. I don't know how exactly all that works.
Okay, but, if the newer 3.6s are 5.5k and the 20.1s are in the 11k range, and I spend 3k on a sub, I'm halfway to 20.1s! If I had 20.1s I would spend less time on sub forums :)... (Of course, given the right actively bi-amped solution).
Okay, so all that said, here is what I gathered:
Martin Logan Depth
http://www.avtalk.co.uk/showthread.php?t=15239
Group Delay
20 HZ 28 ms
25 HZ 30 ms
30 HZ 20 ms
Decent numbers, but very significant roll-off in output from 40 to 20 HZ......
VTF-3 MK3 w/Turbo (very similar to HO w/Turbo, which is what I have, but not as powerful. I would assume as port distance is the same, that the group delay should suffice for comparison.)
http://www.hometheatershack.com/forums/subwoofer-tests/5763-hsu-vtf-3-mk3-turbocharger.html
Group Delay
20 HZ 40 ms
25 HZ 15 ms
30 HZ 12 ms
REL Storm 5 (all I could find for REL)
Group Delay
20 HZ 9 ms
25 HZ 4 ms
30 HZ 2 ms
(So definitely faster that HSU w/turbo - but note not flat at all to 20! Using the Frequency Response Magnitude chart, Peaks at 40, and goes down quite strongly. At 40 it is 92 db, at 30 88 db, at 20 84 db, at 16 81 db. The HSU is within 2 db flat to 16 HZ!.)
JL Fathom - not in my list but many talk about it.
Couldn't hack it flat to 20 HZ, let alone 16!!
But here are its Group Delay numbers anyway:
Group Delay
20 HZ 33 ms
25 HZ 24 ms
30 HZ 10 ms
There was a velodyne SPL-1200 MK2, but it was so fallen off by 20 it didn't interest me, and the group delay was high (60 ms at 20 HZ) so forget it...
Martin Logan Depth
Group Delay
20 HZ 28 ms
25 HZ 30 ms
30 HZ 20 ms
Decent numbers, but very significant roll-off from 40 to 20 HZ......
So my comments on that based on preconceived notions is that I'm very dissapointed in the Martin Logan solution as I would have thought they would have focused more than anyone on Group Delay, I expected bad numbers for Hsu/Turbo models which came through - though not bad as you get away from 20, its really the super low bass that is slow, and REL is indeed king of this issue. I'd like to get this number for the new ULS-15 Hsu, but can't find it. Several people say it is 'low' but no testing and numbers I can find. I really think that might be the one to have.
The only thing with the REL - and maybe just get next model up is it doesn't go as low as it could. People are saying on another forum that 2 ULS-15s are flat to 5 Hz. Woo hoo! Now that is something. |
Lightminer,
For your goals, I suspect that a pair of SVS Ultras in sealed (or maybe 16hz tuned) mode would be hard to beat. Remember that the additional sub provides 3db (more like 5db in my room) output, so read the distortion/clean output graphs at lower output to maintain "apples to apples" comparisons.
Also, bear in mind that the output at, say, 50hz from your Maggies will NOT sound the same as the 50hz output from a sub. I can't say for sure which you'll prefer, but I'm confident that you'll hear a difference. If you EQ the subs, I'm nearly 100% sure you'll hear quite a significant difference.
Good Luck
Marty |
I know this isn't music, but the movie 'Push' has some of the best bass I've ever heard integrated into a movie. And I mean really low bass. I think flat response is a bit low, raise the level of the woofer (assuming you're crossing over at 60 Hz or below, mine is at 50 Hz), just move it up a tad.
The scene where he walks into the restaurant and moves the salt (water? can't remember) pouring out from the waitress to the person's food/drink with his hand - that should be very audible. If you adjust the woofer up a bit (not too far!) so that you can clearly hear that as loud bass, then the movie will have a ton of really really really really low bass that is well done - not overdone. I'm pretty sure we're talking 20 - 35 Hz bass, that is some serious soundwork they did. If your system doesn't go to 20, you'll be missing out! :) |
Stereo subs are the best and crossing them over where the mains leave off is a must. Having them in the same plane as the midrange driver panel and facing forward will also increase the seemlessness. Placing the subs on a support platform also improves the definition. |
Has anyone experimented with horn subs?
I have recently acquired some Soundlab M1's and still have a long way to go to get the total system working properly. One aspect is the bass weight. Soundlabs are reviewed as having very good realistic bass, so a sub should not be necessary.
However before I got the Soundlabs I was going to try out a Klipschorn bass unit that I managed to get hold of - my theory is that it would make the ideal sub. Only a horn has the transient speed and "air" to keep up with a panel????
Any responses? |
Only a horn has the transient speed and "air" to keep up with a panel????
Any responses? A horn subwoofer would need a huge chamber. If it were folded and made of concrete (so the walls did not introduce distortion) then it might work but we are talking dimensions of 30 feet or so. If you are thinking ported or TL design then the transient response will not be as good as a sealed box. |
What about the Wilson Benesch Torus "infrasonic generator?"
I have yet to hear them, but from what I understand the push pull design and extremely low mass (half an ounce) of the 18" driver supposedly makes it extremely fast, and would seem like a perfect match for stats.
Can anyone comment on them? |
You would need a massive BLH sub. Or 2 stay clear of klipsch w bin yuck. Or maybe consider a 31.5 in super woofer in ported cabinet. The Fostex 31.5 in was amazing transient reponce very low excursions massive cone area so matchs up great with planars or stats. |
Somewhat further OT here:
NHT's lifestyle "woofer" system is being closed out at Audio Advisor (I get their mailers) @ $300 per. This isn't really a "subwoofer", but it puts two 10" drivers in a very slim sealed box (app 6" deep) with IIRC a 200 watt amplifier. Max extension is something like 38hz @ unspecified spl/unspecified THD.
Observation: Since the narrow cabinet puts the front of the woofer 6" from the wall, cancellation effects should be minimal.
Observation 2: Max excursion of the drivers is unspecified, but can (presumably) be limited by employing multiple units in the room.
Question: If you scatter 4 - 6 of these units in your room ($1200 to $1800) how do you suppose performance would compare with conventional subs in the price range?
I'm not in the market, but the question crossed my mind and I wonder what you guys think.
Marty |
Soundlabs are reviewed as having very good realistic bass, so a sub should not be necessary.
However before I got the Soundlabs I was going to try out a Klipschorn bass unit that I managed to get hold of - my theory is that it would make the ideal sub I agree with Johnk - stay away from bass bins - far away. Gordon Holt used Soundlabs (very fast) for many years before switching to ATC speakers (fast with panel-like mids and more dynamics). An 0.1/15 ATC sub will probably integrate with panels as good as if not better than most anything else - only problem is they are $7K which is like twice what a good JL subwoofer costs. If budget constrains you then check out a JL F112 first and see how that sounds (it is great value for a tight/fast sub). On another point - how would you stop the bass from a poweful sub (like a JL or ATC) from interfering with the panels - surely the giant panel surfaces will be influenced by the air vibrations in the room. What I mean is this - when I play music loud then I can feel all the surfaces vibrating as they respond to airborne LF vibrations. Obviously a woofer with a huge magnet will be tightly controlled and remain unaffected - this is unlikley to be th case for a huge surface area of a panel in a relatively weak force field. |
Hey guys, I ran across some interesting developments here and thought they might bear out on what we are discussing.
Hsu has a new subwoofer (not so new now, but newer than the latest post above) and it might help us with panel integration. It is called the VTF-15H and while it is a bit bigger than my VTF3-HO (11.5 inch woofer vs 15) that is not in particular what I care about.
It has a 'sealed mode' (meaning --> quick/fast) *and* it has extensive tunability features that may make it so we can tune it to a more panel-friendly state. I will not be acquiring one anytime soon :), so someone else who owns one or who can somehow borrow one and who has 1.7/3.6/etc. will have to test if they feel so inclined, but this looks very promising.
It has an alterable Q Factor, as well as an alterable EQ. Well, anyhow, I'll just let this owner explain it:
http://forum.hsuresearch.com/showpost.php?p=78790&postcount=88
(Please do read that - that is the point of this post.)
And here is a professional review:
http://www.hometheater.com/content/hsu-vtf-15h-subwoofer
So, will this help? It very well could be!!
I'd love it if someone who really knows subs could read all the literature on the tune-ability of it and comment - maybe it is all just eq, or maybe it can change other properties of the sound to make it blend with panels better. And the sealed mode will help, someone mentioned that above - the VTF-3HO that I have doesn't do that, but this new one does.
And - I think we are a funny group, crossing over at 45 Hz (at least for 3.6/3.7 owners), so our sub needs are different than most. I think what this newer sub can do if you are crossing over at 70 or 80 will definitely be very very significant (1.6/1.7, other lower-bass e-stat owners)! |
11-21-11: Lightminer
Hsu has a new subwoofer ... called the VTF-15H ... [which] ... has a 'sealed mode' (meaning --> quick/fast) *and* it has extensive tunability features that may make it so we can tune it to a more panel-friendly state.
SVS also offers this feature in their top line box sub, the PB13-Ultra. It has three ports and three plugs, making for four lower extent rolloff profiles. The 13" driver itself is massive and built for very long throw--reminds me of the JL driver. Follow the live link to see the description, the pic of the driver, and the four frequency response curves from sealed, one, two, or three open ports. It's been five years since this thread was started. In the last few years, I think several sub contenders have come out with more configurability, speed, and power to mesh with panel speakers. Candidates include JL, the Velodyne DD+ series, the top line Hsu's, and the SVS's. I've heard a pair of JL Fathom F212s mated to a pair of Magnepan 20.1s and it was seamless. I heard it for a couple hours with a professional setup driven by Ayre electronics and Transparent cable throughout. |
I'd believe that - a pair of F212's seems to be the current state of the art from what I've read, never heard them. The fun part of the Hsu 15H is they are 850 each! Basically free compared to the JLs :).
I still think its crazy that we are doing this for 16 - 45 Hz, but on those few tracks, it sure does make a gigantic difference! |
The problem with matching subs to panels is poor transient response in many subwoofers, excessive driver excursions and the problem of the sub sounding best in placements that doesn't mate best to loudspeaker in the position sub sounds best in. With panels 2 or more large cone limited excursion drivers match best. Multiple sub bass sources again are the better match. |
11-23-11: Lightminer
I'd believe that - a pair of F212's seems to be the current state of the art from what I've read, never heard them....
I still think its crazy that we are doing this for 16 - 45 Hz, but on those few tracks, it sure does make a gigantic difference! According to the review of twin JL Gotham G213s in Issue 26 of ToneAudio, the infrasonic information conveyed by the subwoofers that go lower than 20 Hz is relevant to any kind of music, and recreates the room ambience that so often distinguishes the sound of live music from reproduced. The review says in part:
Two subwoofers does not mean that Im shaking the rafters with the Gothams. Quite the contrary. It allows me to run them at lower levels and to produce a more refulgent, satisfying sound. But that sound can be hard to pin down because, as I tried to suggest above, the Gothams are often out of the picture when no real deep bass frequencies are present. But they are producing ambience all the time. Turn the two subs off and it sounds as though the mains shrank in size and volume even on a Bach solo guitar piece. Weird? Definitely. But impossible to refute. There is apparently information in the subsonic region that fills out the sound of a concert hall. Once youve heard it, you cant go back.
Now I'm dying to get a pair of sealed subs that'll put that sensation in *my* listening room. |
