-

Jump to content



Sign up for a free account!

Signing up for an account is fast and free. As a member you can join in the conversation, enter contests and you won't get the popup ads that guests get. Click here to create your free account.

Photo

New sonosub in design...some questions..


This topic has been archived. This means that you cannot reply to this topic.
6 replies to this topic

#1 of 7 Seungsoo Hwang

Seungsoo Hwang

    Stunt Coordinator

  • 209 posts
  • Join Date: Aug 06 1999

Posted February 08 2001 - 05:41 PM

I am starting my new sub project, which is actually for school as well as for my own fun. It looks something like:

3.5 cu ft Shiva MkII tuned to 25hz via a 12.25" long 4" wide vent.

I went with a higher tuning than most since I want the mid-bass punch I did not experience from my larger previous sonosub, a EBS design. This one is geared mostly towards techno and hiphop music with a smidge of HT use, so stop me if I am doing somthing wrong.

I need to know:
1)how is the tuning for the application? Note that I am ordering a PNR aeroport from Parts express which is 16" total length including flares, so I need one that is smaller than that obviously...
2)how much volume does the shiva mkII driver displace?
3)has anyone felt the need to stuff/line a vented enclosure such as? Dan mentioned that in the 95L design of the white papers, 32oz of polyfill was good for the design. Why, and how?
4)can someone tell me where to find the link to the scratch n dent section of the adire website? I cant seem to find it...Posted Image
thanks!

#2 of 7 Eric M L

Eric M L

    Extra

  • 18 posts
  • Join Date: Nov 12 2000

Posted February 09 2001 - 01:42 AM

Scratch-N-Dent

#3 of 7 Aaron D

Aaron D

    Stunt Coordinator

  • 81 posts
  • Join Date: Jan 31 2000

Posted February 09 2001 - 02:48 AM

Sorry to break in on the conversation, Seungsoo, but I, too, am interested in the usefulness of this tuning frequency. I know that most DIY's prefer to tune to ~16-20 hz, but is the sub still good for music (metal, jazz, classical, etc.)?

I know you lose a few db ~40-80, but how critical is this?

------------------
"Once you label me, you negate me." - Soren Kierkegaard

"Those who see any difference between soul and body have neither." - Oscar Wilde
"The same forces that operate in the birth and temporal existence of man also operate in his destruction and death."- Maimonides

#4 of 7 Seungsoo Hwang

Seungsoo Hwang

    Stunt Coordinator

  • 209 posts
  • Join Date: Aug 06 1999

Posted February 09 2001 - 06:30 PM

Eric, thanks for the link..

Quote:
Sorry to break in on the conversation, Seungsoo, but I, too, am interested in the usefulness of this tuning frequency. I know that most DIY's prefer to tune to ~16-20 hz, but is the sub still good for music (metal, jazz, classical, etc.)?

Aaron, I'm not completely sure on this, but should be after Im done building the sub. Most commercial offerings are tuned higher than we are used to in the sonosub world, and they do have the "punch" in the midbass that seems lacking in the 16~20hz tunings. It seems most people are building them down low to cover all/most of the LFE material for HT. A music-dominant sub, depending on the type, would most likely benefit a lot from a higher tuning than the lower ones for HT and HT/Music. (this all assuming you are not trying to recreate pipe-organ tones etc..) I guess I'll post up something of my impression after Im done.

#5 of 7 Greg Monfort

Greg Monfort

    Supporting Actor

  • 884 posts
  • Join Date: May 30 2000

Posted February 10 2001 - 03:51 AM

>It looks something like:
3.5 cu ft Shiva MkII tuned to 25hz via a 12.25" long 4" wide vent.

>I went with a higher tuning than most since I want the mid-bass punch I did not experience from my larger previous sonosub, a EBS design. This one is geared mostly towards techno and hiphop music with a smidge of HT use, so stop me if I am doing somthing wrong.

>I need to know:
1)how is the tuning for the application?
====
It's a little low IMO. ~4.6ft^3/27Hz is about right as an acceptable tradeoff between 'punch' and extension. This should give you the needed punch in the <50Hz BW, and use EQ to tailor the >50Hz 'punch' as required.

Of course with this high an Fb, using EQ to attenuate the BW ====
> Note that I am ordering a PNR aeroport from Parts express which is 16" total length including flares, so I need one that is smaller than that obviously...
====
I think you need two.
====
>2)how much volume does the shiva mkII driver displace?
====
I assume ~the same as the original, 0.106ft^3.
====
>3)has anyone felt the need to stuff/line a vented enclosure such as? Dan mentioned that in the 95L design of the white papers, 32oz of polyfill was good for the design. Why, and how?
====
Stuffing lowers box Q, not what you want in this application IMO. You should line one wall, bottom, and back with some absorbant for any minor mids/HF resonances.

GM

------------------
Loud is beautiful, if it's clean
Loud Is Beautiful, If It's Clean

#6 of 7 Seungsoo Hwang

Seungsoo Hwang

    Stunt Coordinator

  • 209 posts
  • Join Date: Aug 06 1999

Posted February 10 2001 - 07:01 AM

Thanks for the reply. I was wondering is 25hz was still too low, since i thought the original sbb4 22~23hz definitely was.. I was originally going to make a traditional box, but since I'm going sono, I can make the extra volume work.
So Im seeing this:
4.6 ft^3 @ 27hz via (2) 4"D x 16.87"L ports (flared, guess that'll throw it off a bit).
WinISD numbers look pretty good for app..
Think I can fit a shiva(11"), (2) flared ports(5 9/16") and a input cup (4 1/8" x 4 1/8") on a 20"D tube? Posted Image
Hmm 16.87" long ports, I guess I'll just have to buy flared ends from Madisound instead of the Aeroports. Can you refresh my memory of how to calculate the flared ends into the total port length?
thanks again.

#7 of 7 Patrick Sun

Patrick Sun

    Studio Mogul

  • 37,665 posts
  • Join Date: Jun 30 1999

Posted February 10 2001 - 07:06 AM

Seungsoo, just add 1" to the final end-to-end flared port. For example, if your design required a 16" long, 4" wide port, you have to cut the flared port's middle port section so that when you put the flared ends on each end of the middle port section, it winds up being 17" long from end to end.


------------------
PatCave ; HT Pix ; Gear ; Sunosub I + III ; DVDs ; LDs
"Jee-sus, it's like Iwo Jima out there" - Roger Sterling on "Mad Men"
Patcave | 2006 Films | 2007 Films | Flickr | Comic-Con 2012 | Dragon*Con 2012