John Sayers' Design Forum

John Sayers' Recording Studio Design Forum

A World of Experience
Click Here for Information on John's Services
It is currently Wed Oct 24, 2018 9:52 am

All times are UTC + 10 hours




Post new topic Reply to topic  [ 440 posts ]  Go to page Previous  1 ... 20, 21, 22, 23, 24, 25, 26 ... 30  Next
Author Message
PostPosted: Thu Aug 09, 2018 5:08 am 
Offline

Joined: Fri Aug 29, 2014 2:34 am
Posts: 261
Location: California USA
Email sent. :poke:


I'm stuck


Report this post
Top
 Profile  
 
PostPosted: Thu Aug 09, 2018 7:09 am 
Offline
Site Admin
User avatar

Joined: Thu Aug 21, 2008 10:17 am
Posts: 11269
Location: Santiago, Chile
Replied:

Unstuck now?

:)


- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.


Report this post
Top
 Profile  
 
PostPosted: Thu Aug 09, 2018 7:17 am 
Offline

Joined: Fri Aug 29, 2014 2:34 am
Posts: 261
Location: California USA
For the moment anyway. :thu:


Report this post
Top
 Profile  
 
PostPosted: Thu Aug 09, 2018 7:56 am 
Offline
Site Admin
User avatar

Joined: Thu Aug 21, 2008 10:17 am
Posts: 11269
Location: Santiago, Chile
Cool!

For anyone following the thread and not having a clue what is going on with the above cryptic conversation: Frank ran into an issue cutting the Sorbothane for isolating his speakers, as the calculator provided by the Sorbothane company is not correct: it gives you the wrong answers. When Frank cut it to the correct size, it did not compress correctly. Several of my customers have reported this to me recently, so now I would suggest that nobody should bother even trying with their faulty calculator.

So I gave Frank some tips on how to proceed anyway, ignoring what the calculator says and doing it with math instead.

- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.


Report this post
Top
 Profile  
 
PostPosted: Thu Aug 09, 2018 8:04 am 
Offline
Senior Member
User avatar

Joined: Wed Feb 01, 2017 6:03 pm
Posts: 487
Location: St. Albert, Alberta, Canada
Can you share the formulas you're using to get correct results?

Personally, I have just thought to use 1 1/2" thick chunks where possible and make sure to get 20% deflection through trial and error.

Greg

_________________
It appears that you've made the mistake most people do. You started building without consulting this forum.


Report this post
Top
 Profile  
 
PostPosted: Fri Aug 10, 2018 10:08 am 
Offline

Joined: Fri Aug 29, 2014 2:34 am
Posts: 261
Location: California USA
Hi Stuart,

Make sure to read my whole string of emails to avoid confusion. I was spitting them out as I ping ponged through my trials! :mrgreen:

To the rest of the crowd: Sorry for not being more informative guys. As soon as I get the soffit work done, I'll be back to normal levels of content!


Report this post
Top
 Profile  
 
PostPosted: Fri Aug 10, 2018 11:41 am 
Offline
Site Admin
User avatar

Joined: Thu Aug 21, 2008 10:17 am
Posts: 11269
Location: Santiago, Chile
:idea: :shock: It's all a little confusing, but I think I understood... I sent you an e-mail, to double check....

- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.


Report this post
Top
 Profile  
 
PostPosted: Fri Aug 10, 2018 12:08 pm 
Offline

Joined: Fri Aug 29, 2014 2:34 am
Posts: 261
Location: California USA
And I was starting to feel like I had a handle on things :lol: :shot:


Report this post
Top
 Profile  
 
PostPosted: Fri Aug 10, 2018 1:41 pm 
Offline
Site Admin
User avatar

Joined: Thu Aug 21, 2008 10:17 am
Posts: 11269
Location: Santiago, Chile
Quote:
Can you share the formulas you're using to get correct results
Hey Greg. Sorry I missed your post: The actual equations are on their website. You can download the engineering design guide in PDF, and they are on the first few pages, with examples and graphs on the rest of the pages. Not too complicated... just long, boring, lots of calculations...

But I'm working on a simple way to still use the calculator, by adjusting with a "correction factor". Right now it seems that you need to adjust your area to be only 92% of what it really is, and put that number in the calc. Or stated another way, divide the number that the calc gives you, by 0.92 to get the REAL area you need. So if it says you need 20 cm2, then make that (20 / 0.92) = 21.75 cm2.

Still working to confirm that this correction factor is true for all cases... Sorbothane is non-linear, so it might not work out that simple...

Also, this only applies to their V2 calc: the V1 is also wrong, but in a different way.... Right now I have them both open with the exact same data in each, v1 says the deflection is 23.75% and the frequency is 16.8 Hz, V2 says the deflection is 19.3% and the frequency is 12.9 Hz So there's MAJOR differences here! Don't trust the calculators. I'll be talking to them probably tomorrow, to see what they say. Frank already made contact.

Quote:
Personally, I have just thought to use 1 1/2" thick chunks where possible and make sure to get 20% deflection through trial and error.
That's one way to do it, but you need a very accurate method for measuring, and it takes a while to do that! And you need to account for the fact that a lot of the vibration in a speaker is in the front-to-back direction, not so much up-and-down.... Plus you have to account for the fact that speakers are not weight balanced: the center of gravity is not over the center of the bottom panel with most speakers, so it will tilt one way or the other if you don't compensate.... And for pads that don't have weight on them, only pressure, or a combination of weight and pressure, you can force them to have 20% deflection WITHOUT having the correct pressure... and you can also force them to have the correct pressure WITHOUT having the correct deflection! :) - in both cases the frequency will be wrong, and it won't isolate properly... (Don't ask... too complex to explain here, and I'd be giving away too much proprietary stuff anyway...)

- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.


Report this post
Top
 Profile  
 
PostPosted: Sat Aug 11, 2018 5:11 am 
Offline

Joined: Fri Aug 29, 2014 2:34 am
Posts: 261
Location: California USA
Back to you sir! :jammin:


Report this post
Top
 Profile  
 
PostPosted: Sat Aug 11, 2018 6:59 am 
Offline
Site Admin
User avatar

Joined: Thu Aug 21, 2008 10:17 am
Posts: 11269
Location: Santiago, Chile
Ping----pong! Check your email. Time to get out your pet octopus, and start assembling that sucker!

- Stuart -

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.


Report this post
Top
 Profile  
 
PostPosted: Sat Aug 11, 2018 7:22 am 
Offline

Joined: Fri Aug 29, 2014 2:34 am
Posts: 261
Location: California USA
I have a bit of a problem. lets see what we can do about it....email sent. :?


Report this post
Top
 Profile  
 
PostPosted: Sun Aug 12, 2018 4:34 am 
Offline

Joined: Fri Aug 29, 2014 2:34 am
Posts: 261
Location: California USA
Ready for the next Phase! :yahoo: Email sent!


Report this post
Top
 Profile  
 
PostPosted: Sun Aug 12, 2018 7:17 am 
Offline

Joined: Fri Aug 29, 2014 2:34 am
Posts: 261
Location: California USA
We have a winner! :thu:


Report this post
Top
 Profile  
 
PostPosted: Sun Aug 12, 2018 12:35 pm 
Offline
Site Admin
User avatar

Joined: Thu Aug 21, 2008 10:17 am
Posts: 11269
Location: Santiago, Chile
Update! Frank has assembled his speaker enclosure boxes with the speakers inside them, and they worked out great! We had to adjust some of the mounting process, because of the error in the Sorbothane calculator (as mentioned a few posts back), but with the correction factor that we figured out, it all came together nicely.

Photos of the assembly process, and the final outcome:

Attachment:
FRKUS--Speaker-enclosure-assy-1.jpg


Attachment:
FRKUS--Speaker-enclosure-assy-2.jpg


Attachment:
FRKUS--Speaker-enclosure-assy-5.jpg


Note that some things are hidden in those photos on purpose, as there's some parts of how I do this that I'm not prepared to reveal in public yet. Maybe one day. Those folks who take the time and think it through carefully might be able to figure it out for themselves. One reason I don't want to reveal it, is because it is complex to get right: Frank can testify to that! :) What you don't see here is the ten pages of instructions that I wrote for him, on how to put it all together, and you also can't see the headaches he went through to make it happen. You really can't see it in the photos, but that's precision carpentry and assembly, right there. It is all accurate to 1/64"...

But happen it did, and the effort will be well worthwhile!

Nice work, Frank! :thu:

Next up: mount them in the soffits, and put baffles on them...

- Stuart -


You do not have the required permissions to view the files attached to this post.

_________________
I want this studio to amaze people. "That'll do" doesn't amaze people.


Report this post
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 440 posts ]  Go to page Previous  1 ... 20, 21, 22, 23, 24, 25, 26 ... 30  Next

All times are UTC + 10 hours


Who is online

Users browsing this forum: No registered users and 15 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group