Ben,
Unlike you, Markus submitted technical points which you proceeded to belittle.
Art (non-anonymous) Welter
Yes, there's a high pass on the mains and a low pass on the subs. I've found it easier to get good results for the sub/mains splice using filtering. I try to have that region as narrow as possible because a) a wide overlap can lead to localization issues and b) delay adjustments seem to offer a sweet spot and not just that "when it gets better here it gets worse there" type of situation you were describing earlier.
Yes, it would with HP and LP filters in the channels.
But I would not agree that "a wide overlap can lead to localization issues".
I know - no data either way so its just a guess by both of us. None of my customers have complained, in fact quite the opposite. They all feel the bass is the best that they have heard. Not that I know proof positive that using filters wouldn't "sound better", but I do know positively that it does not result in a smoother response and it is harder to get right.
You saw my results. There are no HP filters in them. All the subs have LP filters at different frequencies of course, but none are very steep.
I would guess that a sudden transition from the mains to the subs would "lead to localization issues."
But I would not agree that "a wide overlap can lead to localization issues".
I know - no data either way so its just a guess by both of us. None of my customers have complained, in fact quite the opposite. They all feel the bass is the best that they have heard. Not that I know proof positive that using filters wouldn't "sound better", but I do know positively that it does not result in a smoother response and it is harder to get right.
You saw my results. There are no HP filters in them. All the subs have LP filters at different frequencies of course, but none are very steep.
I would guess that a sudden transition from the mains to the subs would "lead to localization issues."
I'm currently running sub(s) in the near field and found it critical not to run them too high.
Well, I don't have any customers but I feel that the bass I have right now is the best I've ever heard
Here's a measurement taken just yesterday. The final version has a bass boost, so the response is flat to 20Hz:
Of course it's harder to do it yourself instead of having Doc Earl doing it. But this is DIY and I'm still in exploration mode.
Attachments
That is quite a bit different than what I do and I have no doubt that what you say is true in that situation. Near field subs would be quite sensitive to HFs and phase issues. I've never tried it so I can't really comment. I can't do that in my room since I have two rows of seats and the door is just behind the second row. I think that most people would want their subs located at some distance - out of the way.
Impressive results though.
Refering to the phenomena of the soundstage jumping into the room, when I last heard this I was able to locate a number of sources at various regular locations around the listening position (mostly 50cm spacing in this case). Assuming this is a high Q room mode as they seemed to build, but they sounded kind of non-linear as they did.
Fixing the mode aside, could a non-linearity be creating these sources?
Fixing the mode aside, could a non-linearity be creating these sources?
Originally Posted by bentoronto: "Time-align a big corner horn and mid-room-standing meter-square ESLs... and a giant mid-wall OB sub... hope you can hold your breath a long time... or can do the math."
I use measurement tools for time alignment, and even then, I don't try to hold my breath during the process, which can take an hour or so.
If you would like to hire me to time align your system, and hold your breath during the process, be my guest, but I'll take payment in advance
Although you can't believe everything you read on the web, here's something posted on this forum about 18 months ago:
"That said, there are many proponents using several subs all around the room without any time alignment to even out room response, things can subjectively sound good even though that type of set up is terrible when phase or group delay is considered.
In a small room, getting too picky about phase/group delay is akin to complaining about a kid with a squirtgun shooting at you in a rainstorm."
(Art... remember when you wrote that?)
I think Toole, based on testing done along with Olive, puts the various group, time, and phase screw-ups pretty far down the list of stuff that matters in a sound system.... or that can be usefully addressed when real rooms and real mic recordings are involved.... not mention big corner horns, mid-wall OBs, standing ESL panels, and so on.
If you would like to hire me to instruct you in human perception, be my guest, but you might find my consulting rates a bit steep
.Ben
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Yes Ben, I remember writing that, I'll take your word as far as when.
I have four subs in my shop, three different designs, and subjectively the combination sounds good, even though they don't phase align exactly at any point to the eight top cabinets. The aggregate sound field does not change much from the router table to the drill press.
Subjectively, my home theater system, which does align properly, sounds better, though it does not get as loud.
Art
Toole argues that it is in-principle not possible to align much except adventitiously. In other words, the ideal of sending square square waves to even one of your ears (and certainly not both) is beyond practical reach. In any case, you can't do much with subs beyond crude adjustment. And without emphasizing again big corner horns, etc.
Reading the literature (rather than experimenting myself), it looks to me like the jury is still out on alignment or maybe just how important it is relative to other speaker issues (for example is it more important to have multiple subs which can't be much aligned, as this thread and much discussion these days addresses). Great in theory.
There are published just-noticeable-difference kind of tables for alignment detection at different frequencies. Interestingly, the best discrimination is at mid-way up the scale. Whether those tables are any more useful for setting up a system than say, Fletcher-Munson tables*, is something you know much more about than I do.
A bit odd to compare the shop sound to your no doubt well-evolved music room because there are likely other differences. On the other hand, my hero Briggs (Wharfdale) used to say his speakers sounded wonderful when covered with saw dust.
Ben
*that aren't useful
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The later is far more important than the former. Anyone can just have a discussion - winning is what its all about!
Ben,
As an individual, I get to be the jury, and like Marcus, I have found that LF alignment makes an audible, measurable, preferable, difference.
If you experiment yourself, rather than just read about others opinions, you may find the difference to your liking also.
Just think how good it would feel when you add "DSP" to the rest of your 1956 system
.By the way, nothing against 1956, I was born then, and '56 T Birds are one of my favorite cars.
Art
Individuals differ in the qualities they favour in their sound systems. Alignment, despite what compromises that come along with attaining it, may enhance certain qualities that some people have high on their list. But different for others who might regret the compromises.Ben,
As an individual, I get to be the jury, and like Marcus, I have found that LF alignment makes an audible, measurable, preferable, difference.
If you experiment yourself, rather than just read about others opinions, you may find the difference to your liking also.
Just think how good it would feel when you add "DSP" to the rest of your 1956 system
By the way, nothing against 1956, I was born then, and '56 T Birds are one of my favorite cars.
Art
Multi-sub users can, I guess, live well enough without alignment because they have other sound benefits such as being better able to combat the nasty resonances of every music room. ESL folks accept various compromises so long as we have the breath-taking clarity of an ESL to listen to a guitar.
As far as age goes: no argument. On the other hand, folks who shake heavy cardboard cones to make sound are a few decades behind folks (like me) who have/had high-voltage direct-drive amplified ESLs. Not to mention the motional feedback subs people (like me) have been running since the late 1960's.
Who seems old fashioned now?
Ben
Because of the early war effort (that's WWII), Paul Klipsch had to be careful how much wood he used in the woofer. My unit is from early 1950's, I think. Love it.
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bentoronto wildely mixes topics just to be right. I'm more interested in what is right (and how to get there), not who.
Maybe we should go back and be more specific what we're talking about. I was talking about the sub/satellite splice.
I believe that we can't localize sound sources below about 80Hz but I also believe that this is no longer true for frequencies above about 80Hz. There are studies that strongly support that belief (Martens, W.L., Braasch, J., and Woszczyk, W. (2004). “Identification and Discrimination of Listener Percepts Associated with Multiple Low-Frequency Signals in Multichannel Sound Reproduction,” 117th Convention, Audio Eng. Soc., Preprint 6229).
Below 80Hz multiple sources spread out randomly in the room can smoothen the frequency response. They can also reduce modal ringing. Both is very desirable. In that scenario delay can be used to achieve those goals (probably the best example is a double bass array, though here the source locations are anything but random). Of course there are limits to how much delay is useful. Time alignment in that context means applying delay to each sub individually. It's not that subs need to be time aligned to a fixed marker - other than the marker that results in best performance (flat frequency response and low modal ringing).
Above 80Hz our hearing is able to extract localization cues from the sound field. We're dealing with signals from sub+l, sub+r, sub+l+r and anything in between. I've found that matching the frequency response of these 3 as close as possible improves reproduction a lot. This is probably due to stereo's interchannel level to interaural time conversion (see Blumlein's "Stereo" patent or Lipshitz "Stereo Microphone Techniques: Are the Purists Wrong?"). EQ and delay can be used to achieve that goal. I'm not sure how important time-alignment of sub to mains here really is but more often than not I've found that the necessary delay for best frequency response was close to the physical distance. The latter is of course somewhat irrelevant in the context of multiple delayed subs.
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