New sonosub in design...some questions.. (1 Viewer)

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...
thanks!

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?
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"Once you label me, you negate me." - Soren Kierkegaard
"Those who see any difference between soul and body have neither." - Oscar Wilde

Eric, thanks for the link..

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.

Click to expand...

Click to expand...

>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?
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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 '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...
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I think you need two.
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>2)how much volume does the shiva mkII driver displace?
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I assume ~the same as the original, 0.106ft^3.
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>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?
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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
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Loud is beautiful, if it's clean

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?
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.

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.
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