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post #91 of 200 Old 07-07-2017, 03:42 PM - Thread Starter
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@ diy speaker guy I cant post it but copy and paste, add a www. Its 4 minutes and I consider to be some of the best comedy ever . Charlie Murphy True Hollywood stories, there are several witrh Rick James and Prince.

Ive read quite a bit of Ethan Winer posts, I may try a few things along that line before I tear out the header and side walls. Appreciate the sims, and showing them as well. Learned a few things in this thread which is a win for me.

http:// cc.com/video-clips/iuegla/ch...1---uncensored

John, thanks for doing the sims. I know both you and diy have the horn response wired. I pointed the question to Bill since he seamed to have a different approach, and in an effort to be enlightened some more I was hoping that he would have some reasoning why he didn't agree with the sims. Not sure why he didn't bother to look at them or elaborate on my question but no matter.
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post #92 of 200 Old 07-07-2017, 03:53 PM
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post #93 of 200 Old 07-07-2017, 03:56 PM
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Quote:
Originally Posted by Gorilla Killa View Post
I pointed the question to Bill since he seamed to have a different approach, and in an effort to be enlightened some more I was hoping that he would have some reasoning why he didn't agree with the sims. Not sure why he didn't bother to look at them or elaborate on my question but no matter.
He did see it and he can't give you any other answer than he did because he's wrong. He's just suggesting to simulate the room itself and completely ignore the 40 inch open back box, which will give you a very pretty looking sim that won't match the actual measurement AT ALL. He's said this at least 3 times through "RickJames" and his own account. He can't be any more clear because he's been backed into a corner with no escape and only a shockingly bad recommendation to defend.

My sim will match measurements, as shown in the 12 Dancing Shivas post with the sim and measurements.

If you have any more questions don't hesitate to ask.
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post #94 of 200 Old 07-07-2017, 03:58 PM
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Originally Posted by Gorilla Killa View Post
... there are several witrh Rick James ...
Really? What kind of coincidence is that, seeing as how we've been discussing "RickJames" for the last couple of days. Too funny.
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post #95 of 200 Old 07-07-2017, 04:28 PM
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Rick James: "F--- your couch!" *(Warning - has very naughty language that your grandma and your 3-year-olds probably shouldn't hear)



--------------------------------------------------------------------------------------------------------------
Subs are like pizzas: you get way more good stuff with the big ones.
https://www.avsforum.com/forum/155-di...uxl-build.html
https://www.avsforum.com/forum/155-di...-overture.html

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post #96 of 200 Old 07-07-2017, 06:10 PM
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@Gorilla Killa , I should probably apologize for contributing to the derailment of your thread. I know there's a Harry Potter joke to be had ("Master gave Dobby a sock!"), but I won't make it. Just trying to inject a little humour, sorry if I was being a goof and helping distract from your project.

If mods wind up doing a cleanup, feel free to delete all my non-IB sub-related content in this thread.

Best of luck with your project, G.K.. I'm looking forward to seeing your results and measurements. Go make some dust!

--------------------------------------------------------------------------------------------------------------
Subs are like pizzas: you get way more good stuff with the big ones.
https://www.avsforum.com/forum/155-di...uxl-build.html
https://www.avsforum.com/forum/155-di...-overture.html
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post #97 of 200 Old 07-07-2017, 07:35 PM
 
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Quote:
Originally Posted by Gorilla Killa View Post
I pointed the question to Bill since he seamed to have a different approach, and in an effort to be enlightened some more I was hoping that he would have some reasoning why he didn't agree with the sims. Not sure why he didn't bother to look at them or elaborate on my question but no matter.
I thought I made it quite clear. I won't look at or comment on anything from speaker guy. That's why 'Ignore List' exists. If I wanted to subject myself to unending arguments and abuse I'd just get married again.
I told you how to sim your arrangement as I understood it. I asked you to post a picture of that arrangement in case I misunderstood it. I did see the sims posted by LTD, and if those schematics accurately reflect what you're doing then I wouldn't disagree with them. But as I understood your original post that's not how the schematic would look, and if that's not how it looks then that's not how you would model it. As I read it the red line in the schematic, which represents the driver cones, would be at the opposite end of the manifold, and that's how I would configure it, although as I already mentioned I would make that manifold no deeper than required to keep the driver frames from extending into the other room.
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post #98 of 200 Old 07-07-2017, 07:51 PM
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Quote:
Originally Posted by Bill Fitzmaurice View Post
I thought I made it quite clear. I won't look at or comment on anything from speaker guy.
Not from your main account, that much is clear. Fire up your "RickJames" account and get back in the game. I can't believe you are still perpetrating this charade. There is actual proof now, Bill. You know very well you saw my sims and everything else. Post #81 isn't going to change or go away just because you pretend you haven't seen it. Everyone has seen it. You're done here. You seem to be the only one that doesn't recognize that.

Quote:
That's why 'Ignore List' exists. If I wanted to subject myself to unending arguments and abuse I'd just get married again.
Arguments end as soon as someone has proven their point beyond any doubt. If both parties are intelligent enough to recognize the facts. If arguments don't ever end, someone is being unreasonable or not understanding facts.

As far as abuse goes, your behavior has been a poster child for abuse of all kinds. Abuse of the forum, abuse of trust, abuse of other members.

And for what? So you could bully people, litter the forum with links to your site and say stuff like this about yourself? Was it worth it? Come on man. You lost this one and everybody knows it now. Give it up. You're just making this so much worse for yourself.


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
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post #99 of 200 Old 07-07-2017, 08:01 PM
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Ask your doctor if DIY is right for you. Side effects of DIY may include anxiety, elevated blood pressure, lightheadedness, rapid heartbeat, skeletal muscle flaccidity, euphoria, psychological dependence, insomnia, confusion, blurred vision, impulsivity, uncontrolled or repeated movements.
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post #100 of 200 Old 07-07-2017, 08:05 PM
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Quote:
Originally Posted by diy speaker guy View Post
Not from your main account, that much is clear. Fire up your "RickJames" account and get back in the game.
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post #101 of 200 Old 07-07-2017, 09:58 PM
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Quote:
Originally Posted by Bill Fitzmaurice View Post
I told you how to sim your arrangement as I understood it. I asked you to post a picture of that arrangement in case I misunderstood it. I did see the sims posted by LTD, and if those schematics accurately reflect what you're doing then I wouldn't disagree with them. But as I understood your original post that's not how the schematic would look, and if that's not how it looks then that's not how you would model it. As I read it the red line in the schematic, which represents the driver cones, would be at the opposite end of the manifold, and that's how I would configure it, although as I already mentioned I would make that manifold no deeper than required to keep the driver frames from extending into the other room.
You understood it just fine, the dimensions are in post 1 and the only comments you've made about the design prove you knew it was an open back box and you understood it very well.

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.

This is exactly what was described in post 1 and you described it in detail in the italicized text I just grabbed from post 51. You also said the same thing in post 4 but didn't mention the open back box. You were equally wrong in post 4 and in post 51.

Now you saying you didn't understand the design and that's why you gave the wrong answer. This is unbelievable. Deeper and deeper. Deeper and deeper. Contradictions, backpedaling, none of this makes any sense at all.

I'm pretty much obligated to continue pointing out your errors and inconsistencies at this point. You know that, right? There's no way to fix this, stop trying.
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post #102 of 200 Old 07-08-2017, 02:14 AM
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Quote:
Originally Posted by Bill Fitzmaurice View Post
I thought I made it quite clear. I won't look at or comment on anything from speaker guy. That's why 'Ignore List' exists. If I wanted to subject myself to unending arguments and abuse I'd just get married again.
I told you how to sim your arrangement as I understood it. I asked you to post a picture of that arrangement in case I misunderstood it. I did see the sims posted by LTD, and if those schematics accurately reflect what you're doing then I wouldn't disagree with them. But as I understood your original post that's not how the schematic would look, and if that's not how it looks then that's not how you would model it. As I read it the red line in the schematic, which represents the driver cones, would be at the opposite end of the manifold, and that's how I would configure it, although as I already mentioned I would make that manifold no deeper than required to keep the driver frames from extending into the other room.

post 55 is the one that you want to look to bill.


for clarity, here is the basic model for the two sides of the i.b.


diysg's model of the U frame and then only looking at the "driver side" works as a good model for what the "listnening man" will hear.


the post that you are referring to above is where I was using different methods for modeling the horn/manifold side.


the driver side cannot be accurately modeled as just a large sealed room because of the resonance created by the manifold behind the driver(s). that is what creates the dip shown in the comparo back in post 55 and in diysg's post.


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post #103 of 200 Old 07-08-2017, 03:41 AM
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Quote:
Originally Posted by LTD02 View Post
post 55 is the one that you want to look to bill.


for clarity, here is the basic model for the two sides of the i.b.


diysg's model of the U frame and then only looking at the "driver side" works as a good model for what the "listnening man" will hear.


the post that you are referring to above is where I was using different methods for modeling the horn/manifold side.


the driver side cannot be accurately modeled as just a large sealed room because of the resonance created by the manifold behind the driver(s). that is what creates the dip shown in the comparo back in post 55 and in diysg's post.


Hold, stop, halt, stands!

If you are to use a manifold like that, just flus mount it.
If one where to use a manifold the driver would be on the side 9/10 times.

no one ever died from overkill
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post #104 of 200 Old 07-08-2017, 05:52 AM
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Originally Posted by Torkild View Post
Hold, stop, halt, stands!

If you are to use a manifold like that, just flus mount it.
If one where to use a manifold the driver would be on the side 9/10 times.

the o.p.'s question wasn't whether or not to build it that way, the question was what happens IF it is built that way.


the o.p. was considering a theater environment where he was asking about drivers flush with the screen wall, so there would have to be a manifold in order to connect to the room behind.


e.g. the screen wall (blue dotted line) and the behind the screen area (gray) with speakers (black)


the manifold wouldn't actually appear to be sticking out into the room.


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post #105 of 200 Old 07-08-2017, 09:39 AM
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This whole thing with Bill should have ended at post 81, in which it was said there's definitive proof that "RickJames" is Bill's sockpuppet. Actually this issue shouldn't have started in the first place if Bill could behave in an ethical manner.

But this morning "RickJames" was signed in again. I doubt Bill is going to post from that account anymore but clearly he is still trying to cast doubt on the fact that he's sockpuppeting.

There's not really anything more I can do here. I refuse to go to the moderators to tell on him. Never have, never will. Technical discussion is the only weapon I am willing to use.

So it's up the the members of the forum to let Bill know his behavior is not acceptable. If that doesn't happen it's not going to stop.

Sadly even that might not be enough, I'm afraid all Bill has learned here is how to better disguise his sockpuppets. We just gave him a college level education in how to spot a sockpuppet so if he's learned anything here, that's how to better hide his shady behavior.

Post 81 is vitally important here, there is actual proof that this is a real thing. Is this going to be ignored? It's out of my hands now, I tried.
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post #106 of 200 Old 07-08-2017, 09:44 AM
 
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Quote:
Originally Posted by LTD02 View Post
post 55 is the one that you want to look to bill.
We're pretty much in agreement there. If the manifold tube extends out from the wall, with the drivers mounted at the wall, the dominant response will be determined by that tube working as a quarter wave resonator, and you'd model it like this:



Obviously you wouldn't want that.
If the open end of that manifold tube joins to the wall then the 1/4 wavelength resonance will be heard in the room behind the speakers, but in the room the drivers are firing into the effect will be slight, and for that matter counteracted by the reflection of the wave off the wall, which merges with the initial wave 180 degrees out of phase at that same frequency. Ideally you'd want to model it with the baffle and manifold in their actual positions relative to the wall, but HornResp lacks that feature, so you have to do as sealed box like this:




That's how I understood what the OP wanted to do, and that's what I based my initial reply on. I considered mentioning the issue of the Allison Effect cancellation notch, but since it would probably have been above the pass band didn't bother, other than to say that the manifold should be as shallow as possible, to put that notch at as high a frequency s possible, as well as any resonant effects that the manifold might cause. I guess the reason why he wanted the manifold to be 40 inches deep was to put the baffle on the same vertical plane as the screen, but that would be counterproductive no matter how you look at it.






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post #107 of 200 Old 07-08-2017, 09:52 AM
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Quote:
Originally Posted by Bill Fitzmaurice View Post
That's how I understood what the OP wanted to do, and that's what I based my initial reply on.
This is a flat out lie. This is what you said in post 51. You described exactly what OP was saying in post 1. Exactly.

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.

You understood just fine. You still recommended modeling it as a simple sealed box and ignoring the open back U frame.

Now that it's been confirmed that this is the wrong way to do it, now you change your tune and say you didn't understand the question.

Every time you lie Bill, I'll be right here to feed your own words back to you.

BTW your first picture doesn't show up and the second one shows what NOT to do to simulate it accurately.
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post #108 of 200 Old 07-08-2017, 11:21 AM
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Here's another likely BFM sockpuppet. http://techtalk.parts-express.com/member/4743-sounder
Not sure if that link will work if you are not signed in, but it's forum member "Sounder" on the PE techtalk forum.
It's easy to search all his posts, there aren't many.

This account has only 21 posts, if my count is right -

- 17 of them directly mention Bill Fitzmaurice and/or his products and private forum (a couple of them mention leaving the forum and joining Bill's private forum)
- 14 links posted to Bill's site and private forum
- a few links posted to other sites highlighting BFM products, these are links that Bill regularly posts from his own account
- tone, phrasing, wording and overall message seems to line up with Bill's posting style

And of course there's more of this type of "Bill's resume vs your resume" stuff, which is probably most telling of all. Every time Bill encounters someone smart this is always the answer.

I'm familiar with Bill's professional credits. Daryl, what are yours, if any?

And of course he got called out on it in this thread. http://techtalk.parts-express.com/fo...-12-horn-combo

And this stuff - you can't do it yourself, it's too hard, you need Bill's plans -

I think your asking way too many elementery questions to be designing your own cab.

At least in the case of this likely sockpuppet, he was smart enough to quit soon after being called out on it. But the account has been active as recently as today. Bill is likely checking up on all his sockpuppet accounts now to see how damning they are.

Just in case anyone is wondering, I got tipped off on this account by PM, I'm not searching all the forums all day tracking down Bill's sockpuppet accounts. If anyone else has anything to add PM me.

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post #109 of 200 Old 07-08-2017, 11:31 AM
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shout out to Bill's VPN provider, privateinternetaccess dot com.

rofl.
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post #110 of 200 Old 07-08-2017, 01:21 PM
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Quote:
Originally Posted by Bill Fitzmaurice View Post
...
If the open end of that manifold tube joins to the wall then the 1/4 wavelength resonance will be heard in the room behind the speakers, but in the room the drivers are firing into the effect will be slight, and for that matter counteracted by the reflection of the wave off the wall, which merges with the initial wave 180 degrees out of phase at that same frequency. Ideally you'd want to model it with the baffle and manifold in their actual positions relative to the wall, but HornResp lacks that feature, so you have to do as sealed box like this:




That's how I understood what the OP wanted to do, and that's what I based my initial reply on. I considered mentioning the issue of the Allison Effect cancellation notch, but since it would probably have been above the pass band didn't bother, other than to say that the manifold should be as shallow as possible, to put that notch at as high a frequency s possible, as well as any resonant effects that the manifold might cause. I guess the reason why he wanted the manifold to be 40 inches deep was to put the baffle on the same vertical plane as the screen, but that would be counterproductive no matter how you look at it.


this isn't accurate and is the whole point of the whole thread.


the impact from the manifold will create a cancellation dip in the frequency response which is what diysg showed in model and with his correlation of model to measurements.


i confirmed his approach of modeling a u-frame and looking at only one side of the driver, so the driver side can be modeled in hornresp.


playing around with the room size and distance to the rear wall in order to get the room resonances to line up with the issue being discussed only confuses the issue.


the allison effect (aka sbir or rear wall 1/4 wavelength cancellation) will be minimal to zero if a baffle wall is constructed on the same plane as the drivers, but the cancellation resonance from the manifold will remain.

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post #111 of 200 Old 07-08-2017, 01:38 PM
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shout out to Bill's VPN provider, privateinternetaccess dot com.

rofl.


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post #112 of 200 Old 07-08-2017, 01:49 PM
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Yeah, this is as real as it gets. There really isn't any doubt at all about what Bill is doing.
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post #113 of 200 Old 07-08-2017, 02:53 PM - Thread Starter
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Originally Posted by notnyt View Post
shout out to Bill's VPN provider, privateinternetaccess dot com.

rofl.
um, wow. not much more to say about that
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post #114 of 200 Old 07-08-2017, 02:59 PM - Thread Starter
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Is the amount of resonance because of the driver? If you took the 40" u baffle and put a back on it, and made it either sealed or ported, why is it not subject to the same issues or am I not understanding the cause of the resonance
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post #115 of 200 Old 07-08-2017, 03:58 PM
 
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Quote:
Originally Posted by LTD02 View Post
the driver side can be modeled in hornresp.
It is modeled in HornResp, exactly as I showed. Since neither model has any rear wave contribution the only output shown on the charts is the driver side. You had it right with your posted charts, one showing the result of the rear wave, a peaked response, one showing the result of the front wave, a normal response. The difference between those and what I posted is is slight, and would be explained by the schematics.
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post #116 of 200 Old 07-08-2017, 04:09 PM
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It's not the driver, it's the open back box. Any cavity (box with a hole) will have a resonance. In a ported box that resonance is a benefit, it's tuned to where you need it to boost up the bass. But in a bad design (like a deep open back box) that resonance is right smack where you don't want it.

If you closed the box to make it sealed, the box would still have a resonance but it fits in and doesn't stick out like a sore thumb for a few different reasons, one of them being that the back wave is contained in the box.

Just think transmission line. Everyone knows those have a series of really strong resonances if unstuffed. That's the same thing that happens in an open back box because it IS a short transmission line. The box shape and depth determines where the resonance will be, and in this case, at 40 inches deep it puts the resonance at about 55 hz, and it's a STRONG resonance.
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post #117 of 200 Old 07-08-2017, 05:00 PM
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post #118 of 200 Old 07-08-2017, 05:44 PM
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@diy speaker guy or anybody else


how would this be modeled? same driver side as before. same length manifold, but drivers half way recessed. i'm aware the frequency of the peak and the cancellation will be higher, but in this case the listener is getting both effects. or is that just a simple horn with a throat chamber?


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post #119 of 200 Old 07-08-2017, 06:03 PM - Thread Starter
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Quote:
Originally Posted by diy speaker guy View Post
It's not the driver, it's the open back box. Any cavity (box with a hole) will have a resonance. In a ported box that resonance is a benefit, it's tuned to where you need it to boost up the bass. But in a bad design (like a deep open back box) that resonance is right smack where you don't want it.

If you closed the box to make it sealed, the box would still have a resonance but it fits in and doesn't stick out like a sore thumb for a few different reasons, one of them being that the back wave is contained in the box.

Just think transmission line. Everyone knows those have a series of really strong resonances if unstuffed. That's the same thing that happens in an open back box because it IS a short transmission line. The box shape and depth determines where the resonance will be, and in this case, at 40 inches deep it puts the resonance at about 55 hz, and it's a STRONG resonance.
ok, now i got it.

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Originally Posted by corradizo View Post
Sounds like a ported IB is the answer! ;-)
^^ This is where I was headed I know @MKtheater has one and it was discussed briefly in another thread.
Is modeling this the same as a run of the mill 6cft box except the box is 400 cft as an example and where in relation to the driver would the port go. Is there optimal placement or anywhere on the wall floor to ceiling. Does depth of the box still have the same bad influence if its been ported
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post #120 of 200 Old 07-08-2017, 06:14 PM
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Pretty sure you'd still have the same issue. The port resonance will come into play at a lower frequency.
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