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/
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/
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..
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
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..
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
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
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
Is this the one you are using?sachi said:
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.
I am afraid, I do not have a defenitive answer.
I 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
Hi,
...well, last week I put a whispy "pad" of fiber fill on the back inerior wall behind the driver (which is half obscured by the tube wall where I have no absorbsion material). Then I packed (pretty tightly) fiber fill iin the top end (closed end) of the tube, about half way to the speaker. This resulted in a more thuddy and less defined sound and I also felt the the already weak mid range suffered even more, although it is hard for me to tell (some hearing loss from loud concerts in my youth). Then I tried a very fluffy lighter stuffing technique in the top end of the tube, coming up closer to the driver. Remember that this is a folded tub so the stuffing is resting in the top end of the tube and rises towards the driver. This resulted in a less thuddy bass.
Now I am wondering if the bloody things sounded best without any stuffing at all. They seemed to have better bass definition before I started messing with this stuffing.
What do you think?
Stuart
...well, last week I put a whispy "pad" of fiber fill on the back inerior wall behind the driver (which is half obscured by the tube wall where I have no absorbsion material). Then I packed (pretty tightly) fiber fill iin the top end (closed end) of the tube, about half way to the speaker. This resulted in a more thuddy and less defined sound and I also felt the the already weak mid range suffered even more, although it is hard for me to tell (some hearing loss from loud concerts in my youth). Then I tried a very fluffy lighter stuffing technique in the top end of the tube, coming up closer to the driver. Remember that this is a folded tub so the stuffing is resting in the top end of the tube and rises towards the driver. This resulted in a less thuddy bass.
Now I am wondering if the bloody things sounded best without any stuffing at all. They seemed to have better bass definition before I started messing with this stuffing.
What do you think?
Stuart
Good afternoon Stuart,
Yes the stuffing does tend to muddy the sound especially if the stuffing is too dense...
Try lining the walls alone with the material...!! another important factor here is, if your stuffing is too dense
and less porous that will tend to reduce the internal volume...Law of dimnishing returns. If you have used MJK's math cad sheets, as you increase the stuffing you would see better and better responses...
but we should also consider how practical those densities we specify are...!!
If its a TL, the best use of stuffing would be to reduce ringings etc caused in the tube... you would hear a charecteristic tube like (cave like) sound
when you put your ear close to the open end of the tube...after stuffing these tend to go away. Midrange frequencies should actaully ge a better defenition after stuffing..!!
One experiment you can do is try feeding some impuleses, or chirps to the speaker and notice if you can pick up any ringing...
a good comparisson would be to listen to these first on headphones.. (be cuations to reduce the level before using headphones..)
If you wouldnt have accees to these chirps try these...
Play some music on your CD player...
Forward while the track is playing...at a good speed (may be 4x or 8x)
pause and listen to the speaker...
generally on an unstuffed line...you will hear a charectersitic..."guingggg..." imeediatley after the pause..
Repeat the same after stuffing...the "guing..." should go off or be reduced significantly..!
As a rule of thumb, I would give more importance to vocals than any other band of frequencies..
Stuffing reduces the relaunch of internal reflections through the cone, which I feel is much more important especially while working with smaller drivers...
many thanks
ajju
Yes the stuffing does tend to muddy the sound especially if the stuffing is too dense...
Try lining the walls alone with the material...!! another important factor here is, if your stuffing is too dense
and less porous that will tend to reduce the internal volume...Law of dimnishing returns. If you have used MJK's math cad sheets, as you increase the stuffing you would see better and better responses...
but we should also consider how practical those densities we specify are...!!
If its a TL, the best use of stuffing would be to reduce ringings etc caused in the tube... you would hear a charecteristic tube like (cave like) sound
when you put your ear close to the open end of the tube...after stuffing these tend to go away. Midrange frequencies should actaully ge a better defenition after stuffing..!!
One experiment you can do is try feeding some impuleses, or chirps to the speaker and notice if you can pick up any ringing...
a good comparisson would be to listen to these first on headphones.. (be cuations to reduce the level before using headphones..)
If you wouldnt have accees to these chirps try these...
Play some music on your CD player...
Forward while the track is playing...at a good speed (may be 4x or 8x)
pause and listen to the speaker...
generally on an unstuffed line...you will hear a charectersitic..."guingggg..." imeediatley after the pause..
Repeat the same after stuffing...the "guing..." should go off or be reduced significantly..!
As a rule of thumb, I would give more importance to vocals than any other band of frequencies..
Stuffing reduces the relaunch of internal reflections through the cone, which I feel is much more important especially while working with smaller drivers...
many thanks
ajju
Hi Folks
I revisited this page today and see that things have evolved a bit. FYI, I have used felt as well as Black Hole for wall lining of my ported enclosures, and fibreglass(messy stuff which I wont use again) as fill, as well as Reliance's dacron for both two ways and subs.
The felt wasnt thick enough so I folded it. Black Hole is very expensive and I suspect we have cheaper options available here.
George
I revisited this page today and see that things have evolved a bit. FYI, I have used felt as well as Black Hole for wall lining of my ported enclosures, and fibreglass(messy stuff which I wont use again) as fill, as well as Reliance's dacron for both two ways and subs.
The felt wasnt thick enough so I folded it. Black Hole is very expensive and I suspect we have cheaper options available here.
George
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.