It could be seen as a reasonable set of compromises (when it isn't being abused by ignoring the effect of the short vertical dimension).
The natural progression for the ground plane is flat. An example is that wooden outdoor horn that looks like it was chopped across the middle and set down. But the exponential horn needs to expand.
The top, on the other hand goes nowhere (I mean it exits toward free space). While the curvature may result in diffraction it can also help to control it. Terminating straight walls can be kind of sudden.
Looking at the example David illustrated splitting a horn into three, this mirroring also calls for straight walls. Then, there is the opportunity to implement constant directivity, although the reasons for doing so in the bass may be few and specific, such as managing beaming if you use them up higher.
Final Comment
In any event, no matter how designed, horn size will be the dominate bass performance factor (up to some limit of diminishing returns). How the OP proportions his budget over all the elements of his system remains the most important performance determinant.
Bill
To Forum Moderators: The edit time limit is silly. You circumvent it by quoting your own post. WHG
In any event, no matter how designed, horn size will be the dominate bass performance factor (up to some limit of diminishing returns). How the OP proportions his budget over all the elements of his system remains the most important performance determinant.
Bill
To Forum Moderators: The edit time limit is silly. You circumvent it by quoting your own post. WHG
Last edited:
Zero D,1)Who needs it (stereo bass) ?
2)I thought i'd post a screenie of a section of a frequency analysis i did today of Jill Scott - A Long Walk.wav
3)The whole track didn't vary that much all the way through. As you can see, below 150Hz it's totally Mono !
4)As you're main goal is music, you won't miss aircraft/trains etc etc, being panned from L-R & R-L, i would have thought
1) No one "needs" stereo bass, but to accurately reproduce stereophonic recordings with stereo bass, two bass speakers are the minimum requirement.
2) If you took a screen shot of a section of a frequency analysis of the Art Glen "A Longer Walk" it would look quite different than "A Long Walk". If you took a screen shot of many of the early Beatles (a band from Liverpool produced by George Martin) recordings, you would notice the bass guitar is only on the left or right track.
3) Yes, a fairly high percentage of music is recorded with bass level roughly equal in both L/R channels, but that does not mean there is not stereo bass, bass guitar and bass keyboards can be hard panned left and right and "look" the same as mono bass, but "sound" markedly different.
4) In addition to stereo music tracks, the sound effects can be stunningly realistic.
I have a well-recorded stereo mic pair recording of a large diesel tractor with LF content down into the 20 Hz range starting up to the left, and driving to the right.
When I play the tractor track at a level similar to a real tractor on my three-way all horn system with a L/R spacing of around 35 feet, you can literally see nearly every member of the audience turning their heads to follow the "invisible" tractor. By the time the invisible tractor has "driven" off to the right "virtual horizon" the audience knows they were tricked, since there was no tractor seen on the road directly behind the stage.
The trick works every time, nature has genetically favored full- frequency stereo hearing both as protection from fast-running mastodons to hunting animals of all size.
Cheers,
Art
Last edited:
Bill,
There are good reasons to not allow endless editing- it can make a latter response look stupid if the OP changes his response.
By the way, you probably meant to write "dominant" rather than "dominate" ;^)
The OP is allowed to endlessly edit the first thread, for instance one will notice recent updates to the Keystone Sub thread including the location of new material and recent observations in the ensuing 6 years and 1000+ posts.
However, the OP is not allowed to change photographs in the OP, but can link threads with new photos, charts or plans.
I have made several edits to the Keystone Sub OP, some directly due to observations I noticed when responding to a troll in the "Concrete Bass Horn Design Question" thread we currently inhabit, in which I have answered literally every one of Entropy Eric's hundreds of questions. In fact, the OP has repeated questions so many times we have answered many of the questions several times, yet he seldom answers any questions placed to help him move his plans forward while failing to review most of information forum members present, much less comprehend much of it .
If this thread does not get locked first, Entropy Eric could reflect the goal change of 20 Hz to 15 Hz, and anything else he deems noteworthy.
He could even list his sonic goals if and when he decides to.
Cheers,
Art
Last edited:
Half Answer: It does not matter!
If operating a bass horn from a high elevation, I would use a round one. At ground level; however, I would use just half an axisymmetric horn. Casting such a horn as a declining circular arch requires resources outside the OP's project resources. So, a rectangular section horn array will have to do. And that solution has already been explored here ad nauseam. WHG
If operating a bass horn from a high elevation, I would use a round one. At ground level; however, I would use just half an axisymmetric horn. Casting such a horn as a declining circular arch requires resources outside the OP's project resources. So, a rectangular section horn array will have to do. And that solution has already been explored here ad nauseam. WHG
Last edited:
True, but for me 30-minutes is way too short a time. As we get older the larger scope of experience replaces the speed of its recall. WHG
Last edited:
Hi Bill,
We can't allow people to change history on a whim. I feel that 10 minutes would be long enough. If you think before you post, you wouldn't need any "do overs" at all. You can always post a correction below the post in question, and that would be fine in my book, but you have 1/2 an hour right now! Surely that has to be long enough for anyone.
-Chris
We can't allow people to change history on a whim. I feel that 10 minutes would be long enough. If you think before you post, you wouldn't need any "do overs" at all. You can always post a correction below the post in question, and that would be fine in my book, but you have 1/2 an hour right now! Surely that has to be long enough for anyone.
-Chris
Yes but!
The main purpose of multiple sub-woofers is to mitigate room mode issues. The frequency domain here is ideally less than 80 Hz. Here the cues needed for sound source localization are absent and/or masked by room acoustics. To understand how the ears work in this regard, study the attached brief and then read further the references provided. WHG
The main purpose of multiple sub-woofers is to mitigate room mode issues. The frequency domain here is ideally less than 80 Hz. Here the cues needed for sound source localization are absent and/or masked by room acoustics. To understand how the ears work in this regard, study the attached brief and then read further the references provided. WHG
So Be It
I do not have the time nor inclination to compose posts off line. The bottom line here is the contributions I make are short rather than detailed because of the short edit time. That is not a loss for me. BTW I find your condescending remarks personally insulting. Your function is supposed to be to minimize such discourse that discourages contribution. WHG
I do not have the time nor inclination to compose posts off line. The bottom line here is the contributions I make are short rather than detailed because of the short edit time. That is not a loss for me. BTW I find your condescending remarks personally insulting. Your function is supposed to be to minimize such discourse that discourages contribution. WHG
Hi Bill,
No one said you ought to compose messages off-line. Just think while you're posting. If you don't think of a correction in 10 minutes, I doubt you will in 1/2 and hour.
Besides, everyone makes mistakes. No biggie if you have to correct yourself in a later post. As I said earlier - and you too, you have a full 30 minutes to make corrections before your post locks.
-Chris
No one said you ought to compose messages off-line. Just think while you're posting. If you don't think of a correction in 10 minutes, I doubt you will in 1/2 and hour.
Besides, everyone makes mistakes. No biggie if you have to correct yourself in a later post. As I said earlier - and you too, you have a full 30 minutes to make corrections before your post locks.
-Chris
Listen, I left a week ago fully intending to let you have your fun here when you threatened to start making false police reports, I didn't want to have anything to do with you anymore.
Enough is enough, you've continued to call me names and provoke me every single day even though I'm not responding. I realize that it must sting very badly to be taught things about your own field of expertise by someone that wasn't even born when you started your career but you are taking this way too far.
What exactly is your definition of "troll"?
1. You've made countless personal attacks in this thread.
2. You've made at least two political posts in this thread that the mods cleaned up.
3. You've made a threat to file false police reports.
4. You've been asked to leave this thread no less than 5 times by the OP.
5. You spent the first 700 posts giving vague and misleading answers in an attempt to get OP to pay you for "professional services".
6. Once you realized you were not going to get paid you made some really bad recommendations, so bad in fact that OP stated on at least a couple of occasions that he thought you were deliberately trying to sabotage his project in retribution for not paying you.
7. You've written so much about yourself here (and so little about anything else) that you could compile these posts and publish your autobiography. If that's not enough, you've attempted to pass off these collections of useless personal facts in lieu of actual technical answers.
8. When I left you started turning your extreme aggression on OP instead of me (but still managed to call me names at least once a day).
9. Despite the fact that you openly admitted that I taught you things in this discussion, as soon as you disagreed with me you started namecalling and personal attacks.
This is just a short list detailing your inappropriate behavior. I would recommend that you attempt to compile a similar list of my infractions and if you can't beat my list maybe think about stopping the namecalling and provocations.
I'm going to extend the offer one more time. Leave me alone and I'll leave this thread and you can have your fun. Continue to provoke me and I will come back and point out the many problems with the technical information you post. It's going to be better for everyone if you just leave me alone and stop calling me names.
QFP
The edit requirement for me in regards to presenting long informative posts is implied. The quest for perfection is ingrained in me by over 50-years of consulting practice success. Here I am just doing some "pay forward"; but never the less, it will come with an "automotive finish" most of the time. So I will keep the posts brief. WHG
The edit requirement for me in regards to presenting long informative posts is implied. The quest for perfection is ingrained in me by over 50-years of consulting practice success. Here I am just doing some "pay forward"; but never the less, it will come with an "automotive finish" most of the time. So I will keep the posts brief. WHG
Last edited:
I do know the Beatles were from Liverpool & were produced by George Martin
Sure lots of, especially but not exclusively, 60's records had hard panned bass. Tamla Motown as just one example of Many, used to do that often. I & lots of others, once we got over the novelty, found/find it annoying though. Each to their own though. I mentioned about sound effects in my Post # 1098 but the OP wants the system for music.
Hi Bill,
"pay forward" is a concept instilled in a few of us. It is the professional norm in fact.
If you have a long post that you find an error in, just contact the moderating team and we'll help you fix the issue. There are others around that would use a longer posting window to corrupt the past, changing the implications of some posts that were very clear. This is why there are edit limits. When you go back to some very old posts, or any in the past, you can be certain it is as was written. If for any reason the team intervenes to help someone correct something, we leave a note to be clear about it. We can see these notes, I don't know if members can to be honest with you. The moderating team has to act responsibly, so there are safeguards for us as well. We treat posts as high value information in as much as it isn't something to be played with. Every thread ever posted is searchable, and does exist here.
I hope you can appreciate our position on this. We can help if the situation warrants it.
-Chris
"pay forward" is a concept instilled in a few of us. It is the professional norm in fact.
If you have a long post that you find an error in, just contact the moderating team and we'll help you fix the issue. There are others around that would use a longer posting window to corrupt the past, changing the implications of some posts that were very clear. This is why there are edit limits. When you go back to some very old posts, or any in the past, you can be certain it is as was written. If for any reason the team intervenes to help someone correct something, we leave a note to be clear about it. We can see these notes, I don't know if members can to be honest with you. The moderating team has to act responsibly, so there are safeguards for us as well. We treat posts as high value information in as much as it isn't something to be played with. Every thread ever posted is searchable, and does exist here.
I hope you can appreciate our position on this. We can help if the situation warrants it.
-Chris
Hi Art,
Bill's proposed system has three horns expanding "conically" in the horizontal plane. Entropy455 appeared to be interested in this concept as a possible alternative to his own design because it would be easier to construct. Bill had previously suggested limiting the upper frequency to about 80Hz in Post #1020, but I got the sense that Entropy455 was still aiming for closer to 300Hz. I was trying to show that directivity could become an issue if he adopted Bill's design but then attempted to run it significantly above Bill's recommended upper limit.
Kind regards,
David
Most of the time I see and correct within ten minutes. But there have been times I have posted a part reply and while compiling the remainder of the reply, the edit times out and I have lost the whole of the extra content and any corrections if that had been necessary.
There is a way around this. One sends the corrected post to the Moderators and asks them to substitute the corrected for the incorrect.
lots of work for the Moderators, especially if the edit time limit were reduced from the existing 30minutes.
ps
am I allowed by the Forum Rules to use the "Moderator" word in this post, or do I need to edit the post before I get binned?
Hi Andrew,
Of course you can. Why wouldn't you be?
Yes, if the case warrants it, we can correct or add the missing text, but it must not reverse or change was the original post said. Often if someone posts something silly, we won't remove it. The same goes if that post had a number of replies and changes would change what the replies would be.
We aren't here to be your nanny. Information that isn't important to actually be in a specific post, but rather in a new one would be expected to be in a new post. That, you can do on your own. It's always been this way. The moderating team is mostly here to help you out and isn't a group of scary monsters unless someone deserves a heart to heart.
So the universal moderator was just used to warn against bad behaviour. Please heed the warning.
-Chris
Of course you can. Why wouldn't you be?
Yes, if the case warrants it, we can correct or add the missing text, but it must not reverse or change was the original post said. Often if someone posts something silly, we won't remove it. The same goes if that post had a number of replies and changes would change what the replies would be.
We aren't here to be your nanny. Information that isn't important to actually be in a specific post, but rather in a new one would be expected to be in a new post. That, you can do on your own. It's always been this way. The moderating team is mostly here to help you out and isn't a group of scary monsters unless someone deserves a heart to heart.
So the universal moderator was just used to warn against bad behaviour. Please heed the warning.
-Chris