Indian equivalents of the following DIY items.

[ajju]

you are welcome.."boss"...!!
All, inspired by you..!!

btw...
in the formula, I doubt if there was also a "gamma" the adiabatic coefficient in the numerator..I'll check and confirm...

For some elementry equations and a wealth of information check out this place...http://www.diysubwoofers.org/

[ajju]

Guys can you giveme your views on this stuffing that i have done...

Sachi..!
In my opinion the stuffing is good enough...!!
but i caution you, be extremely careful with that yellow stuff...!
If you have a port make sure that the fibres are well packed and doesn't escape through the ports..
Further...
I would have dampened the braces by sticking tar sheets on to them... Why because after the cutouts, there are relatively thin sections which could rattle...!!

Many thanks
ajju..

[Vivek]

If I remember correctly, Vivek from bangalore, had once procured sheets of Racron for his MTM.

I did not buy the Recron pillows. I went to JC road and found polyfibre rolls in a bedding store. Great stuff.

[sachi]

Sachi..!
In my opinion the stuffing is good enough...!!
but i caution you, be extremely careful with that yellow stuff...!
If you have a port make sure that the fibres are well packed and doesn't escape through the ports..
Further...
I would have dampened the braces by sticking tar sheets on to them... Why because after the cutouts, there are relatively thin sections which could rattle...!!

Many thanks
ajju.. [/B]

Thanks for that Ajju.
BTW, the ports are blocked from the inside by speaker grill cloth to ensure that glass wool fibres don't come out.

In addition to the damping that you see, the back panel too would be damped with 1 inch thick glass wool.

Where do i get tar sheets and T-nuts in Bangalore?
starnge that u should mention that the baffle would rattle..in fact it did make a ratting sound , but it was because only 4 screw holes are prvided for the woofer and it was rattling against the baffle board..
solved it by using caulking material bought from corrson.

Regards,
Sachi

[ajju]

Where do i get tar sheets and T-nuts in Bangalore?

Try SP road for T nuts...!! take a drawing or picture with you...
best and efficient communication..!!

Tar sheets -> can be found at most hardware stores. These are used for water proofing roofs...else corrson provides it...but mightbe at a slightly higher price...when searching locally see if you can get hold of the impergnated veriety...they would be thin 2-3 mm thick sheets with plastic sheets on either sides...I generally get rid of the plastic sheet on one side and make the tar stick to the baffle surface...(is a difficult and messy process...makes you look as if you have got a part time job with PWD)...you can even uses a hammer or a batten to beat the sheets in... use mild heat...put it in the sun for a while or use hot water bags... tar is a sticky highly viscous material...so it would settle down..

in fact it did make a rattling sound , but it was because only 4 screw holes are provided for the woofer and it was rattling against the baffle board..

What woofer are you using...??
when you mount the woofer...line the edges of the baffle cutout or the back of the woofer with double sided tape..or some kind of foam strip..!! tighten all screws evenly.
The problem is accentuated if you have a stamped frame woofer with 4 holes or so...if its a stamped frame woofer...you can even consider drilling a few additional holes to make it 8 or so..!!

Many thanks
ajju

[sachi]

Hey Ajju,
What are the actual effects of putting those tar sheets on the braces?
Will it add to the damping of the enclosure?


Btw, the driver that i am using is the Dayton 10 inch classic.

Cheers,
Sachi

[s_zimble]

Hi.
I have finally read all the past few days of posts...very interesting diversions...

Vivek and Ajju,
I wanted to clarify a couple things with stuffing a TL or TQWT (I assume a folded tube behaves the same). From all that has been said, it appears that I would do well by only lining all interior surfaces of my folded TQWT. This said, why do I always see tappered tubes stuffed only from the top to the driver?? Also, would you recommend I use the polyfill sheets, or some flat carpeting, or pieces of Army wool blankets, or....

In addition, does anyone know what type or style of stuffing would be required in a BLH enclosure??

Thanks for the feed back.

PS: did anyone read the Brentworth info page I posted? What do you think they mean by "valved" enclosure interior. Could something open and close in there?, or could they be using a fancy (wrong) term for a taper?

Stuart

[tcpip]

Originally posted by sachi
Btw, the driver that i am using is the Dayton 10 inch classic.

Is this the one you are using?

Now decent woofers are available in India too, at least compared to what we used to get before.

I am wondering how the Dayton you're using would compare with the Peerless 10" I can get in Bombay. The specs look very similar. Magnets in both cases are about the same in size. Both have stamped baskets. Both have Fs of 25 Hz. The Peerless driver is rated for about 150W RMS power (which is twice that of the Dayton), and has a price about twice that of the Dayton (at Rs.2500 or a little less). Peerless has a lower-priced 10" too, with a smaller magnet and a lower power rating. That one costs about 20% less than the big one. I'd go for the big one any day, just for the bigger magnet and slightly heavier basket. Otherwise, the construction is similar.

The Dayton Reference Series woofer seems to be in a different league. In price, it sort of matches what I'd pay for the Peerless India woofer here, but in construction it seems to be in a much better class. Luvvly.

[ajju]

In post no 297, I had incorrectly mentioned that adding stuffing makes the process adiabatic.. This is not true...
Adding stuffing has the effect of changing the process from adiabatic to Isothermal.
appologies for the wrong info...

Ajju

[ajju]

This said, why do I always see tappered tubes stuffed only from the top to the driver?? Also, would you recommend I use the polyfill sheets, or some flat carpeting, or pieces of Army wool blankets, or....

I am afraid, I do not have a defenitive answer.

I [b]guess[\b], in the case of tapered tubes, it can be assumed to be a open and a closed tube coupled back to back with the driver mounted at the join. The tapered closed section, I guess is placed in an attempt to nullify the harmonics introduced by the open pipe. And if absorption is the primary requirement at resonance, the sound energy has to be converted into some form of heat...and hence more stuffing on the tapered end..!


As far as the materials you have listed go, I reccomend, try using all of them in layers with the densest closest to the enclosure walls, and check if it does make any difference... Do share the results..

ajju