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post #31 of 200 Old 07-05-2017, 11:46 AM
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Cute. Bill and "Rick" are now logged in at the same time, proving only that Bill has two computers.
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post #32 of 200 Old 07-05-2017, 04:03 PM - Thread Starter
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Im on on slab, have a good response with 2 sealed subs flanking the screen. I can fasten the baffle assembly to the floor and decouple from the wall with little trouble. This would be the simplest but requiring the closet to closed off.

My next question is whether or not the line array if placed inside the closet is looking for trouble. Being that its to be recessed from the edge of the opening seem like a problem. If I make the baffle 12" deep off the rear and open to the rear room does that seem like an option. That would put the front of the baffle 20 " from the edge of the closet opening. Do I need to build a false wall on either side of the arrays angling from the baffle to the front of the closet opening or am I overthinking the effect of the closet on the response
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post #33 of 200 Old 07-05-2017, 05:05 PM
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I have to ask - can you just remove the closet? It seems simple enough from your drawing - it looks like 3 partial walls spanning the width of the room. If they are not supporting walls it could be just a day job to whack em out of there.

As far as where you should put the drivers and what you should do with the closet I hesitate to give any real advice. Room acoustics are so complex - there's waves bouncing around everywhere causing peaks and dips and notches, and everything has different phase due to distances traveled after bouncing around. Everywhere you have a direct reflection you will get a notch at 1/2 wavelength, the depth of which depends on the strength of the reflection. I do know you are not happy with that closet though, so why not rip it out? It sounds like you are prepared to do some pretty significant mods to the room anyway ... Or just close off the closet completely from the theater side and open it up to the adjacent room.

A U baffle 12 inches deep shouldn't mess with your passband but I can sim it later on so you can know and see for sure. I haven't run a sim with your t/s anyway so that will give me something to do later on.
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post #34 of 200 Old 07-05-2017, 06:00 PM
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Originally Posted by RickJames View Post
You know perfectly well that Bill put you on his ignore list years ago, because you couldn't carry on a civil conversation that wasn't dominated by personal insults. For instance this.



I'm a BFM fanboy and proud of it. You're not on my ignore list, you're on my watch list, and when you insult BFM I will respond. And the idea that you, who has no body of work to be found, could ever correct someone with Bill's resume is ridiculous. DIY speaker guy? Really? Chutzpah in the extreme.

Apologies to the OP and all others with this thread derail, but some things can't be left ignored.
You know, at first I was like lulz, posting from different accounts.... but the posting style is so similar... and chutzpah, tho? Who says that...

Looking through the history is amusing. You got called out for posting nonsense years ago, and I see it hasn't stopped in the least.

Also, almost every thread this account has posted in, BFM has participated in. Definitely fishy.

I mean it makes sense, you don't want to have a public facing account bashing other companies and products or acting like a jerk on the internet when you have to worry about the reputation of your own company.

some interesting idiosyncrasies. I'm sure there are more, and these don't really prove anything, but are definitely interesting...

hidden in spoiler to keep from polluting the thread further.
Spoiler!
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post #35 of 200 Old 07-05-2017, 06:26 PM
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There's also this VERY interesting thread - http://www.diyaudio.com/forums/every...audio-com.html

And this -

Quote:
Bill Fitzmaurice is banned for repeated use of sock puppets.
http://www.diyaudio.com/forums/every...tml#post592174

Bold added by me.

And this one just takes the cake.

Quote:
In one case Bill was replying to his own posts with a sock-puppet....
I'm not makin stuff up. This is well known and repeated behavior.

I'm not the tattle tale type and I've never directly contacted a moderator but I've known "RickJames" was a BFM sockpuppet for years. I implied as much a couple of years ago but didn't come right out and accuse him at that time.

Bill doesn't hesitate to call the moderators on me but in this instance he won't because it would likely get him banned.
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post #36 of 200 Old 07-05-2017, 07:10 PM
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Originally Posted by notnyt View Post
hidden in spoiler to keep from polluting the thread further.
This isn't thread pollution, this is pretty important.

I think I have a right to strike back. Bill has been doing this for years. He's been attacking my credentials and flaunting his resume instead of making technical rebuttals, through his own account and through sockpuppet accounts since I started writing tutorials to help people design horns.

This thread is a perfect example. He made a HUGE mistake and in doing so also showed that he doesn't understand Hornresp, which is actually not surprising, I pointed it out and instead of letting it go he unleashes his sockpuppet. He can't provide a technical response since he's clearly wrong so he attacks me personally and reminds me of his resume. This part about the resume is actually for the benefit of those who don't quite know who's right and who's wrong. A lot of people are really impressed with resumes and, not knowing better, will believe the "more qualified" person.

Bill has been using open forums for years to market his products. Nothing wrong with that but to do so in this type of way is unconscionable. Everybody needs to be held to account for their behavior, especially when that behavior is so prevalent and reprehensible. If I get an infraction for saying so I'm fine with that, it needs to be said.
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post #37 of 200 Old 07-05-2017, 07:19 PM
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Originally Posted by diy speaker guy View Post
This isn't thread pollution, this is pretty important.

I think I have a right to strike back. Bill has been doing this for years. He's been attacking my credentials and flaunting his resume instead of making technical rebuttals, through his own account and through sockpuppet accounts since I started writing tutorials to help people design horns.

This thread is a perfect example. He made a HUGE mistake and in doing so also showed that he doesn't understand Hornresp, which is actually not surprising, I pointed it out and instead of letting it go he unleashes his sockpuppet. He can't provide a technical response since he's clearly wrong so he attacks me personally and reminds me of his resume. This part about the resume is actually for the benefit of those who don't quite know who's right and who's wrong. A lot of people are really impressed with resumes and, not knowing better, will believe the "more qualified" person.

Bill has been using open forums for years to market his products. Nothing wrong with that but to do so in this type of way is unconscionable. Everybody needs to be held to account for their behavior, especially when that behavior is so prevalent and reprehensible. If I get an infraction for saying so I'm fine with that, it needs to be said.


How about a little bit of history repeating? rofl.

https://www.avsforum.com/forum/155-di...l#post23688180

Remember the claims that THTs were flat to 1hz?

Pepperidge farm remembers...

http://web.archive.org/web/200701192...e.com/THT.html

Now it's only 10hz, still absurd.
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post #38 of 200 Old 07-05-2017, 07:27 PM
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OMG, thanks, I forgot about that. He accused ME of being a sock puppet. LOL.
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post #39 of 200 Old 07-05-2017, 08:00 PM
 
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chutzpah, tho? Who says that...
We both do. When we get together we toss about a lot of Yiddish. I picked it up when I lived in New York, and he's Jewish. When we're in the same room the inner Mel Brooks comes out of both of us. Actually, I do the better Mel Brooks, he's more of a Gene Wilder, though he looks more like Zero Mostel. He may disagree with me there.

Quote:
Also, almost every thread this account has posted in, BFM has participated in. Definitely fishy.
We follow each other. It's called being friends. The end of this month when I go to Montreal for the comedy festival we'll get together and do the Yiddish thing to the extreme consternation of waitresses and bartenders all over the city. We both wish we drove Ferraris, both have to settle for BMWs. Which of us came up with the Enzo Ferrari reference first I don't remember, probably me, that's more of a Mel Brooks thing than Gene Wilder.
Rick, see you in three weeks. Stock up on the Fin du Monde.
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post #40 of 200 Old 07-05-2017, 08:27 PM
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You're going to try to play this thing out, huh? Good luck with that.

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post #41 of 200 Old 07-05-2017, 08:42 PM
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LOL reminds me of:

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post #42 of 200 Old 07-05-2017, 09:55 PM
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Quote:
Originally Posted by Gorilla Killa View Post
Im on on slab, have a good response with 2 sealed subs flanking the screen. I can fasten the baffle assembly to the floor and decouple from the wall with little trouble. This would be the simplest but requiring the closet to closed off.

My next question is whether or not the line array if placed inside the closet is looking for trouble. Being that its to be recessed from the edge of the opening seem like a problem. If I make the baffle 12" deep off the rear and open to the rear room does that seem like an option. That would put the front of the baffle 20 " from the edge of the closet opening. Do I need to build a false wall on either side of the arrays angling from the baffle to the front of the closet opening or am I overthinking the effect of the closet on the response
It's still not a great feature to have a high mass vibrater coupled to the floor. If you can then remove the mechanical energy by cancellation - easy fix.

no one ever died from overkill
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post #43 of 200 Old 07-06-2017, 02:47 PM - Thread Starter
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Re: I dont care about thread derailment as long as it gets back on track. BTH threads talk about boiled ribs and boiled pizza, Im open to anything but those 2 items.

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It's still not a great feature to have a high mass vibrater coupled to the floor. If you can then remove the mechanical energy by cancellation - easy fix.
I have some time, so I may build 2. one dual opposed and one line array baffle and see which performs best in my room. Not doubting you, but like to see for my self the difference.

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I have to ask - can you just remove the closet? It seems simple enough from your drawing - it looks like 3 partial walls spanning the width of the room. If they are not supporting walls it could be just a day job to whack em out of there.

As far as where you should put the drivers and what you should do with the closet I hesitate to give any real advice. Room acoustics are so complex - there's waves bouncing around everywhere causing peaks and dips and notches, and everything has different phase due to distances traveled after bouncing around. Everywhere you have a direct reflection you will get a notch at 1/2 wavelength, the depth of which depends on the strength of the reflection. I do know you are not happy with that closet though, so why not rip it out? It sounds like you are prepared to do some pretty significant mods to the room anyway ... Or just close off the closet completely from the theater side and open it up to the adjacent room.


A U baffle 12 inches deep shouldn't mess with your passband but I can sim it later on so you can know and see for sure. I haven't run a sim with your t/s anyway so that will give me something to do later on.
I cant remove the wall in back of the closet, its load bearing. I have somewhat thought about removing the front, if I sell I can build it back easy enough. You just kicked me over the edge on that.

@Bill Fitzmaurice , are diy speaker guys sims wrong? If you feel they are, why. This isnt a troll its a straight up question. Rick is free to answer as well if he would like
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post #44 of 200 Old 07-06-2017, 03:08 PM
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Quote:
Originally Posted by Bill Fitzmaurice View Post
We both do. When we get together we toss about a lot of Yiddish. I picked it up when I lived in New York, and he's Jewish. When we're in the same room the inner Mel Brooks comes out of both of us. Actually, I do the better Mel Brooks, he's more of a Gene Wilder, though he looks more like Zero Mostel. He may disagree with me there.

We follow each other. It's called being friends. The end of this month when I go to Montreal for the comedy festival we'll get together and do the Yiddish thing to the extreme consternation of waitresses and bartenders all over the city. We both wish we drove Ferraris, both have to settle for BMWs. Which of us came up with the Enzo Ferrari reference first I don't remember, probably me, that's more of a Mel Brooks thing than Gene Wilder.
Rick, see you in three weeks. Stock up on the Fin du Monde.
So Bill, I went through "RickJames" posts. Every one of them. There's a lot of this garbage -

Bill is one of the worlds leading loudspeaker designers. If you knew anything about speakers you'd know who Bill is. Tom Danley does, Mark Seaton does, Don Keele does, Joe D'Appolito does. I doubt you know who they are too.
...
When it comes to PA Yoda is the Master. Have you looked at his site?
...
Really? You? Arguing speaker physics with Yoda? What's next, arguing aeronautics with Burt Rutan, or astrophysics with Stephen Hawking? smile.gif
...
As for Bill being an expert, his name is on the masthead of AudioXpress magazine, and before that Speakerbuilder, right along with Vance Dickason and a dozen other noted experts. Yours isn't. mad.gif
...
The only professional loudspeaker designer to post in this thread is Bill Fitzmaurice.

But not one single mention that he knows you personally, much less that you've been best friends for decades. That is like crack for fanboys, to personally know their hero. But he hasn't mentioned it once. And as far as I know you've never mentioned that you know him either, before yesterday.

What's worse is that out of the 100 or so BFM posts he's made (with no less than 75 links to your site and about 50 recommendations for people to leave this forum and go to your private forum), he never mentioned once that he might be a bit biased since he's your best friend. This is all kind of remarkable, no? With only 176 posts, most of them about you and firmly recommending your products, neither of you have ever mentioned that you are personally involved. Having a personal relationship should be mentioned by at least one of you if he's going to promote you so heavily as to talk about you in well over half of his posts and jump in to defend you dozens of times over the years. This type of hidden personal bias is unacceptable. Good thing he's not a real person, huh?

The thing I did really notice is that "RickJames" uses the same tone, wording and phrasing as you do Bill. You didn't even bother to hide your sockpuppet identity well. Sure, friends can talk the same sometimes but not friends that only meet up once a year and live so far apart in vastly different cultures. He likes all your favorite phrasing (sow's ear, silk purse) and well as your favorite strawman argument "my wife can have a say in my speakers when I can tell her what to do with her shoes".

Those are fairly popular phrases and ideas but what's more fascinating is stuff like this that you've been saying for years.

Don't try to design your own horn, it takes years of experience. From what you say the Table Tuba Long Style should do just what you want.
...
To see what it can do in a horn using Hornresp use the system design tool, which will calculate an ideal horn. Then you can make the length shorter, the throat larger and the mouth smaller until you get the box size down to where you're comfortable with the size.

How many times have you posted these exact same things, Bill? Dozens?

The Hornresp system design tool is the kicker here. NOBODY else in the free world advises ANYONE to design like that. It's absurd, it's a recipe for failure. It's the easiest way to make a beginner quit.

And surprise, surprise. "Rick" doesn't like diyaudio either. I wonder why.
That explains a lot. I've lurked there (diyaudio) maybe three or four times, and all they do there is argue. Places like that give the internet a bad name.

There are way to many coincidences here Bill. I think it's been proven beyond any reasonable doubt that "RickJames" is your sockpuppet account. And you use it to good effect, promoting yourself, your website, your resume ("Rick" even suggested that you know more than the people arguing with you because you had more "likes", as if that's an even remotely accurate way to assess knowledge or proficiency, and besides you are bound to get a lot of "likes" when you post all day every day on multiple different forums).

I'm not going to tell on you but sooner or later someone is going to flag this thread for the moderators. You could just walk away with whatever dignity you have left, at this point this issue is going to be investigated. It will be pretty funny if you continue to try to play it out until the very bitter end.
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post #45 of 200 Old 07-06-2017, 03:16 PM
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Re: I dont care about thread derailment as long as it gets back on track
I'm willing to give you all the help you want. In the thread, by PM, email, even phone or skype. Believe me, this small side topic won't affect your level of support in any way. If you have any questions let me know.

IF you have already listened to the system and you feel the closet is a problem THEN I would remove it. Not before.
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post #46 of 200 Old 07-06-2017, 03:16 PM
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I saw that about the wife's shoes too rofl. I knew it sounded familiar but didn't have the time to find the source. I like that he "follows Bill", yet shows up in posts that Bill has only liked posts in, or where Bill's name is mentioned. It' definitely a shill.
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post #47 of 200 Old 07-06-2017, 03:38 PM
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I have some time, so I may build 2. one dual opposed and one line array baffle and see which performs best in my room. Not doubting you, but like to see for my self the difference.
If you bolt it to a sold concrete slab and have the baffle well braced and decoupled from the wall it's not going to transfer much energy to the structure.

But symmetrical manifolds avoid this issue almost completely due to force cancellation, which they do very well.

Either way will be fine but they will sound audibly different without eq. The manifold WILL have a resonance and even if it's outside the passband and steeply crossed over it will still be at least vaguely audible. Eq will fix that to some extent but it still won't make the sound on each side of the wall equal. The only thing you can do is make the manifold as shallow as possible and cross over low and steep.

Either option could work very well for you (because you have a concrete slab to bolt to). When I see resistance to manifolds it's usually an issue of the builder wanting to be able to see the drivers, and I get that. They are a beautiful thing to look at. Is this a factor in your design decisions?
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post #48 of 200 Old 07-06-2017, 04:26 PM - Thread Starter
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All this is behind the screen so I dont care about looks, all about end performance. Would the line array benefit from 2 facing out and 2 facing in for cancellation.

I dont know what the acceptable time for ringing is below 30 hz is. I know 300 ms or below is considered good. Im running at 600ms below 30, not sure if its the closet or the new room, little of both.
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post #49 of 200 Old 07-06-2017, 04:41 PM
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All this is behind the screen so I dont care about looks, all about end performance. Would the line array benefit from 2 facing out and 2 facing in for cancellation.
I wouldn't call it a line array. It isn't nearly long enough to function as a line array inside a sub's passband.

2 facing in and 2 facing out for cancellation of what? You will get some minor even order distortion reduction but it will be very minor and even order distortion is not unpleasant anyway. You won't get any force cancellation because all the drivers cones have to be moving in the same direction at the same time or they will cancel each other (assuming they are all on the same flat baffle).

I don't really want to get into what's acceptable as far as ringing times. Different frequencies will ring for different amounts of time. If you listen to it, will it be acceptable? That I cannot say. Room acoustics are very complex.
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post #50 of 200 Old 07-06-2017, 04:48 PM
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There's always the treatment option as well - in the room, in the closet, wherever you want. If you use enough it can be quite effective. Here's some testing, a nice article, quick read, pretty pictures.

http://ethanwiner.com/density.html
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post #51 of 200 Old 07-06-2017, 08:12 PM
 
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@Bill Fitzmaurice , are diy speaker guys sims wrong?
I haven't looked at them.
If what you're doing is basically an open back box containing the drivers, attached to the wall, with the front wave aiming into the primary listening area and the rear wave coming out of the back of the box, firing through that wall into the room behind it, making it a true IB situation, then it would model as a sealed cab, with the volume of the room the rear wave fires into being entered as the Vrc, the depth of that room the Lrc. If that's not what you're doing I'd need to see a diagram of what your intent is.
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post #52 of 200 Old 07-06-2017, 08:20 PM
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I haven't looked at them.
If what you're doing is basically an open back box containing the drivers, attached to the wall, with the front wave aiming into the primary listening area and the rear wave coming out of the back of the box, firing through that wall into the room behind it, making it a true IB situation, then it would model as a sealed cab, with the volume of the room the rear wave fires into being entered as the Vrc, the depth of that room the Lrc. If that's not what you're doing I'd need to see a diagram of what your intent is.
Really Bill? If you've got me on ignore on your main account use your "RickJames" sockpuppet account to check my sim. Oh yeah, you already did and didn't understand it.

The 40 inch deep U baffle has been mentioned at least a dozen times here, including in post #1 . I admit, I didn't quite understand the design myself after post #1 but it's been talked about quite a bit since then and it's extremely clear that it's a 40 inch deep U baffle in between two very large rooms that I simulated. Don't backpedal and try to pretend you don't know there's a 40 inch deep manifold being discussed and simulated.

The saddest (or is it the funniest?) part of all this is not your sockpuppet account, it's not that you didn't understand my Hornresp sim, it's that you don't intuitively know what a 40 inch deep U baffle will do, what with the massive resonances and all. Someone with your years in the game should know these things like the back of your hand. This is beginner level audio theory, Bill.

Keep posting though, keep digging your hole deeper and deeper. I'll keep pointing out your mistakes, the things you pretend you haven't read, and the things you don't understand.
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post #53 of 200 Old 07-06-2017, 09:08 PM
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$15 a knock til its over. 15 years of this have left my brain numb...only recently called out on another forum for similar account behavior.
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post #54 of 200 Old 07-07-2017, 01:25 AM
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If you bolt it to a sold concrete slab and have the baffle well braced and decoupled from the wall it's not going to transfer much energy to the structure.
It will transfer the same amount of energy in all cases.
But the high mass concrete slab will absorb it better then a wall. So less rattling, and that's what we want.

If by structure you only means walls and likes, I agree.

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post #55 of 200 Old 07-07-2017, 01:35 AM
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@Gorilla Killa
i know that you didn't ask me in post 43, but i'm fairly sure that dsg's model is accurate (or at least it is to the extent that it highlights the resonance issue).


in hornresp there are a couple of ways to model i.b. (the traditional approach is to model the manifold as a horn loaded onto a sealed chamber the size of the back room, whereas dsg's approach looks to the driver response only using one side of the driver).


as viewed from the manifold side of the horn, the manifold would act like a horn creating a big increase in output at a frequency based on its length.


that resonance can be seen here. the light gray line is the output of the manifold side while the solid line is the output of a sealed sub (or in this case flush mounted on the wall in between the two rooms).





then when you walk around to the other room, aka the "driver side" which is what you asked about in your o.p., that resonance creates a cancellation--the dip in the gray line.





as a check to see if the two modeling methods translate, here is a comparo of the horn side sub vs. just looking at one side of the driver as dsg modeled. this would be the response in the room the manifold was firing into (aka your rear room).


the match is close enough to say both methods are the same.







i'm not sure if there is a way other than what dsg did to model the driver side of a manifold in hornresp.
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post #56 of 200 Old 07-07-2017, 05:51 AM
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$15 a knock til its over. 15 years of this have left my brain numb...only recently called out on another forum for similar account behavior.
Which forum? Can I get a link, please?
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post #57 of 200 Old 07-07-2017, 06:12 AM
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All you need to do to see if my sim is accurate is look at something I've simulated before that was actually measured. If you are not familiar with the 12 Dancing Shivas, it's a 12 driver IB on a very long manifold. The sims I did of that project matched the measurements performed by the guy that built it very well, at least up to 200 hz. I did sim it from both sides but I guess I didn't show or post the measurements from the other side since the side I showed was dramatic enough evidence that the sim was correct. Here's an old post I wrote about that showing the sim vs measurement. Note the high degree of accuracy in the sim up to 200 hz. Even the the measurement is very low res you can clearly see the dip and spike in the sim and measurement. Yes, I know what I'm doing. Yes my sims match reality. Bill's won't of course because he seems content to completely ignore the 40 inch deep open back box. If you sim the Shivas project as Bill suggested you would get a sim that was nice and smooth - and would not match the measurements.


So I looked for the original 12 Dancing Shivas webpage with all the measurements, it's gone now.

But back in 2013 I simulated the 12 Dancing Shivas just for fun because I was told it couldn't be done. And at the time I grabbed a couple of images of the measurement from the webpage.

The first image (with my sim overlaid) shows the measurement written out in text form at a bunch of frequencies between 6.2 and 49.59 hz.
The second image is a near field pink noise measurement with 1/3 octave smoothing.

My sim shows a remarkable correlation with the measurements, especially below about 200 hz. Above 200 hz the curve shape is still the same in the sim and the measurement but the frequencies in the sim are off, as there's no perfectly accurate way to sim this with Hornresp (Hornresp considers all 12 drivers as a single composite driver located at the midpoint of the 12 physical drivers).

The huge dip at 55 hz in the sim doesn't show in the measurement because the sim assumes infinitely rigid construction and because there's 1/3 octave smoothing in the measurement. 1/3 octave smoothing hides a lot of really bad stuff.

There was also a measurement from the other side of the IB which was dramatically different than the side shown, and my sim for that side of the IB was also equally accurate. Unfortunately I didn't grab the measurement at the time and I didn't show the sim for the other side of the baffle wall.

While this rocky response is not the end of the world, the measurements and the sim show pretty clearly why you don't want deep cavity resonances well inside the subwoofer's passband.





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post #58 of 200 Old 07-07-2017, 07:51 AM
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Sock puppets?!?

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Subs are like pizzas: you get way more good stuff with the big ones.
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post #59 of 200 Old 07-07-2017, 08:21 AM
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One thing that hasn't been mentioned yet is that if you absolutely stuff the entire 40 inch deep open back box with dense stuffing, it would at least somewhat counter the issue with the resonance. Probably not completely because it's an extremely strong and very wide resonance, but at least partially. Still, it isn't good design to build stuff that requires vast amounts of dense stuffing to work properly. So no matter what is chosen (flat baffle, flat baffle with open back box or symmetrical manifold with drivers mounted on the sides) any cavities in the design should be as shallow as possible to push the resonance as far above the passband as possible. Even then a bit of stuffing may be required to calm the resonance down.
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post #60 of 200 Old 07-07-2017, 08:36 AM
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Sock puppets?!?

Rofl.

I think the crux of it is you're not supposed to be advertising your site if you're a vendor on here without paying. The way around that is to create a separate 'fanboy' account and just spam it that way.
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