Stereo Integrity HT 18" Alfa-74 project - Page 2 - Home Theater Forum and Systems - HomeTheaterShack.com
Reply
 
Thread Tools
post #11 of 107 Old 09-28-13, 01:02 AM
Senior Shackster
 
vann_d's Avatar
vann_d
 
Join Date: Apr 2009
Location: Denver
Posts: 887
My System
Re: Stereo Integrity HT 18" Alfa-74 project

Quote:
vann_d wrote: View Post
The sketch does not look accurate because the 700mm triangle sides and the 750mm enclosure height look so disproportionate. In fact, if your enclosure was a right triangle with 700mm sides, the baffle width would be around 980mm. Wider than your enclosure is tall! I suggest you double check your measurements in your sketch.
Nevermind, upon closer inspection it looks like your enclosure height is 1750mm. That makes a lot more sense. Carry on. Good luck with the port configuration....
vann_d is offline  
Sponsored Links
Advertisement
 
post #12 of 107 Old 09-28-13, 10:12 AM Thread Starter
Senior Shackster
 
Join Date: Aug 2013
Posts: 192
Quote:
vann_d wrote: View Post

Nevermind, upon closer inspection it looks like your enclosure height is 1750mm. That makes a lot more sense. Carry on. Good luck with the port configuration....
You are right, as matter of fact i just increase the height to 1800mm or 180 cm.

Also you are right with the ports.I'm having some issues with the design but i finally have two options. I will post them later today.
alfa-74 is offline  
post #13 of 107 Old 09-28-13, 02:57 PM Thread Starter
Senior Shackster
 
Join Date: Aug 2013
Posts: 192
Re: Stereo Integrity HT 18" Alfa-74 project

Well, this project is a little slow because I have limited time, but its moving forward.

As I said before, now I have 2 options with more details, but I have some doubts and I would like get some feedback.

Option 1

I'm targeting for a total internal volume of 543L (19.17 ft3) so after deducting driver, ports,braces, I still get 500L (17.65).

The plan is build the enclosure with 19mm MDF (3/4") and use a double layer for the bafle and allow flush mount of the sub-woofer, so only the baffle will have 38mm (1.5") thickness.

The shape will be triangular with 700mm each side and 1800 mm (180cm) height, these are internal dimensions.will have also 2 small sides of 100 mm.

This option will have 2 flated ports of 6" by 56cm lenght, and will use elbows in order to make it fit inside the box.

I will add also 2 braces, one of them will provide support to the ports.

Adding some sketches

The first pic is complete view of the enclosure

The second is sectional view, showing the port position and braces.
Attached Thumbnails
Stereo Integrity HT 18" Alfa-74 project-enclosure-2-flare-ports-1.jpg  

Stereo Integrity HT 18" Alfa-74 project-enclosure-2-flare-ports-2.jpg  

alfa-74 is offline  
 
post #14 of 107 Old 09-28-13, 03:03 PM Thread Starter
Senior Shackster
 
Join Date: Aug 2013
Posts: 192
Re: Stereo Integrity HT 18" Alfa-74 project

Now Option 2

Everything is the same, size, volume, etc.

The only difference is the port. For this option I was trying to fit a slot port. But given the restriction of enclosure shape, I tried to placed in a vertical position along the baffle. But I have some concerns about the change of direction of 90 degress in order to put the discharge on front baffle.


Some sketches added
Attached Thumbnails
Stereo Integrity HT 18" Alfa-74 project-enclosure-slot-port-1.jpg  

Stereo Integrity HT 18" Alfa-74 project-enclosure-slot-port-2.jpg  

alfa-74 is offline  
post #15 of 107 Old 09-28-13, 03:05 PM Thread Starter
Senior Shackster
 
Join Date: Aug 2013
Posts: 192
Re: Stereo Integrity HT 18" Alfa-74 project

Any advise?

What would be the best option?

I think its option 1 with flared ports.

Also, is there something else that I need to consider regarding the enclosure design?

Thanks a lot
alfa-74 is offline  
post #16 of 107 Old 09-30-13, 01:37 PM
Senior Shackster
 
vann_d's Avatar
vann_d
 
Join Date: Apr 2009
Location: Denver
Posts: 887
My System
Re: Stereo Integrity HT 18" Alfa-74 project

I like option 1 better because I think the round ports give more predictable results than slot ports. I also like your bracing scheme better with that design. I would try to add a couple more braces with dowel rods to the middle of the bigger unsupported section.

Also, have you thought about stuffing the enclosure with fiberglass insulation or polyfill?
vann_d is offline  
post #17 of 107 Old 09-30-13, 09:06 PM Thread Starter
Senior Shackster
 
Join Date: Aug 2013
Posts: 192
Re: Stereo Integrity HT 18" Alfa-74 project

Thanks Vann D

Yes, I think I will go with the 2 flared ports option.

Regarding braces, how many would be ok? 4?

I was planning to use this shape for the braces. Is it ok? Should I go with a different shape? for example window?

About stuffing, that was going to be my next question or questions.

Is it necessary?

How much? Where?

I was thinking about using Delcron, covering the 2 surface behind the driver, is it ok?

Regards
Attachments
alfa-74 is offline  
post #18 of 107 Old 09-30-13, 11:02 PM
Senior Shackster
 
gorb's Avatar
 
Join Date: Sep 2010
Location: Fort Worth, TX
Posts: 658
Re: Stereo Integrity HT 18" Alfa-74 project

Nice. Most of the projects I've seen involving that driver have just been multiple sealed boxes (which are of course very nice), but it's nice to see a big ported one being done. I also like the shape you're going for, so I'm looking forward to seeing the photos throughout the build process and of course the finished product.
gorb is offline  
post #19 of 107 Old 10-01-13, 02:31 AM
Senior Shackster
 
▀art West-VL.'s Avatar
Bart
 
Join Date: Sep 2011
Location: Belgium, West Vlaander
Posts: 403
Re: Stereo Integrity HT 18" Alfa-74 project

connect the front center of the brace also with the middle of the sides
Attachments

Break in your loudspeakers at 35% RMS power:
Right-click → 'save as...'


To view links or images in signatures your post count must be 10 or greater. You currently have 0 signatures.
(hit "repeat")

Last edited by ▀art West-VL.; 10-01-13 at 02:36 AM. Reason: added drawing adjustment
▀art West-VL. is offline  
post #20 of 107 Old 10-01-13, 08:19 AM Thread Starter
Senior Shackster
 
Join Date: Aug 2013
Posts: 192
Quote:
▀art West-VL. wrote: View Post
connect the front center of the brace also with the middle of the sides
Great!!

I will do that, looks better

Thanks
alfa-74 is offline  
Reply

Bookmarks

Tags
alfa74 , project , stereo integrity ht 18

Quick Reply
Message:
Options

Register Now




PLEASE COMPLETE ALL REQUIRED FIELDS BELOW... THANKS!

REQUIRED FIELDS ON THIS PAGE
YOU MUST COMPLETE ALL OF THESE

Username
Password
Confirm Password
Email Address
Confirm Email Address
Random Question
Random Question #2




User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
PLEASE READ BELOW PRIOR TO ENTERING AN EMAIL ADDRESS!

ATTENTION!

YOU MUST ACTIVATE YOUR ACCOUNT!

Activation requires you reply to an email we will send you after you register... if you do not reply to this email, you will not be able to view certain areas of the forum or certain images... nor will you be able download software.

AN INVALID EMAIL ADDRESS WILL CAUSE YOUR ACCOUNT TO BE DELETED!

See our banned email list here: Banned Email List

We DO NOT respond to spamcop, boxtrapper and spamblocker emails... please add @hometheatershack DOT com to your whitelist prior to registering or you will get nowhere on your registration.


Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML is not allowed!
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


For the best viewing experience please update your browser to Google Chrome