Hi,
Has anybody used this woofer in a sealed configuration. The specs are decent, goes down to 50hz with a Qtc of 0.707 ?\
Anything in particular I should watch out for ?
Specs:
fs = 26
Qts = 0.37
Vas = 85
Vb = 32.06 (0.707)
Thanx,
sunil
Has anybody used this woofer in a sealed configuration. The specs are decent, goes down to 50hz with a Qtc of 0.707 ?\
Anything in particular I should watch out for ?
Specs:
fs = 26
Qts = 0.37
Vas = 85
Vb = 32.06 (0.707)
Thanx,
sunil
Used to have a sub using a pair of these in isobarik, as expected it wasnt much of a sub - got down to about 60 - 70hz ?
Am now using them in pair of TLs. Much better.
Am now using them in pair of TLs. Much better.
Ap,
Using it in a sealed config gets down to 50hz, so I'm happy about it, but how was the output, can you play it loud ? Can it keep up with the mids/tweets.
Any distortion ?
cheers,
sunil
Using it in a sealed config gets down to 50hz, so I'm happy about it, but how was the output, can you play it loud ? Can it keep up with the mids/tweets.
Any distortion ?
cheers,
sunil
I don't know where....
.... you get sealed down to 50Hz from ??
BB6 models a sealed cab with an F3 around the 80Hz mark !!
The P21 is a very good bass driver, but why waste it by going sealed??
.... you get sealed down to 50Hz from ??
BB6 models a sealed cab with an F3 around the 80Hz mark !!
The P21 is a very good bass driver, but why waste it by going sealed??
Andy,
I like the sound of a sealed sub.
Also, I have a small living, which makes the 50hz seem fine.
You mention that the P21 is a good sub, does that go for the
P21WO-39-08 as well, because I know the other, P21WO-20-08
is very well reviewed by a lot of people.
I got the 50hz mark using a Qtc of 0.707. The volume works out to
32.06 litres.
What or who is "BB6" ?
Cheers,
sunil
I like the sound of a sealed sub.
Also, I have a small living, which makes the 50hz seem fine.
You mention that the P21 is a good sub, does that go for the
P21WO-39-08 as well, because I know the other, P21WO-20-08
is very well reviewed by a lot of people.
I got the 50hz mark using a Qtc of 0.707. The volume works out to
32.06 litres.
What or who is "BB6" ?
Cheers,
sunil
BB6
Bass Box Pro 6. a nice box program IMO
even the P21WO-39 in 30L models at 65Hz, Q=.57
what program are you using??
Bass Box Pro 6. a nice box program IMO
even the P21WO-39 in 30L models at 65Hz, Q=.57
what program are you using??
Andy,
I used the formulae from the "Cookbook" & then reconfirmed it with the programs I got with "Great Sound by Weems & Koonce".
What do you think ?
Cheers,
sunil
I used the formulae from the "Cookbook" & then reconfirmed it with the programs I got with "Great Sound by Weems & Koonce".
What do you think ?
Cheers,
sunil
Andy and Sunil
I think you two (or your programs respectively) are not using the same set of TSPs.
If Sunil's TSPs were correct, then his results would be fine as well as I have checked them by calculation.
Regards
Charles
I think you two (or your programs respectively) are not using the same set of TSPs.
If Sunil's TSPs were correct, then his results would be fine as well as I have checked them by calculation.
Regards
Charles
Thanx for the input from everybody.
Can I get some info on the woofer ?
Any kind of info would be helpful.
I'm worried about ultimate power output.
It has a rated sensitivity of 88db & a power
rating of 6.3 watts.
10log 6.3=8 W
88+8=96 W
Is the 96 db on this woofer distortion free ?
Thats my worry.
Can I get some info on the woofer ?
Any kind of info would be helpful.
I'm worried about ultimate power output.
It has a rated sensitivity of 88db & a power
rating of 6.3 watts.
10log 6.3=8 W
88+8=96 W
Is the 96 db on this woofer distortion free ?
Thats my worry.
Hello sunil,
One figure I didn't see when I looked up the woofer specifications is Xmax. If you can get one with several mm each way, then you can be more sure that you can use active equalization to get flat response in the sealed box by taking of the full power capability of the woofer. I like sealed enclosures because they have smooth frequency response roll-off, which sounds better to me than other types of enclosures. Actually open baffle would probably be best for sound fidelity, but where can you dump the rear radiation unless you have a basement and can mount the enclosure with an open bottom on the floor?
The speaker design software I have shows two curves. One graphs the dB output vs. the power input assuming the cone has no excursion limit. The other one shows where the cone will actually "bottom out". Without a program like this, it is very hard to choose a woofer and design an enclosure for maximum performance.🙁
One figure I didn't see when I looked up the woofer specifications is Xmax. If you can get one with several mm each way, then you can be more sure that you can use active equalization to get flat response in the sealed box by taking of the full power capability of the woofer. I like sealed enclosures because they have smooth frequency response roll-off, which sounds better to me than other types of enclosures. Actually open baffle would probably be best for sound fidelity, but where can you dump the rear radiation unless you have a basement and can mount the enclosure with an open bottom on the floor?
The speaker design software I have shows two curves. One graphs the dB output vs. the power input assuming the cone has no excursion limit. The other one shows where the cone will actually "bottom out". Without a program like this, it is very hard to choose a woofer and design an enclosure for maximum performance.🙁
I have a basement, and I have OB speakers..mmmm....I'm building a monopole SUB-woofer. The Illusion LM-8s are fine, but I want to bring up the REAL low-end of music information.
What box!
Hi Sunil,
Like Ap said earlier if you really want to go lower you should use a TL enclosure. With a sealed enclosure you need lots of power to drive it as a sub. In addition the Lf roll off is very high as you have already seen. You should try to get down to 40 Hz or lower where really satisfying bass lies and lots of good music - (Indian and otherwise) - contains bass notes in that region. The TL box would help you get that. You can use dacron fiber which is used for stuffing pillows. It's made by Reliance and called Racron I think.
I bought mine from a pillow maker. Altenatively you can buy the 150/- buck pillow and pull out the filling !
Are you getting your P21W from a local supplier ? If so how much is it? I wanted to get a pair of drivers.
Cheers.
Hi Sunil,
Like Ap said earlier if you really want to go lower you should use a TL enclosure. With a sealed enclosure you need lots of power to drive it as a sub. In addition the Lf roll off is very high as you have already seen. You should try to get down to 40 Hz or lower where really satisfying bass lies and lots of good music - (Indian and otherwise) - contains bass notes in that region. The TL box would help you get that. You can use dacron fiber which is used for stuffing pillows. It's made by Reliance and called Racron I think.
I bought mine from a pillow maker. Altenatively you can buy the 150/- buck pillow and pull out the filling !
Are you getting your P21W from a local supplier ? If so how much is it? I wanted to get a pair of drivers.
Cheers.
Ashok,
Thanx for that. I don't want very low bass as I have a small room.
I want clean full output at 50hz.
Another thing is, getting the cabinet done here in Bangalore is going to cost, therefore................
I got the drivers from Australia last month. Wish we had access like the rest of the world does. I need the mides & tweets now but have to wait till I can get them from there.
Do you think we can get them ordered here from abroad. Perhaps if a few of us get together & order we could work something out.
Cheers,
sunil
Thanx for that. I don't want very low bass as I have a small room.
I want clean full output at 50hz.
Another thing is, getting the cabinet done here in Bangalore is going to cost, therefore................
I got the drivers from Australia last month. Wish we had access like the rest of the world does. I need the mides & tweets now but have to wait till I can get them from there.
Do you think we can get them ordered here from abroad. Perhaps if a few of us get together & order we could work something out.
Cheers,
sunil
Sunil, aprrox. what volume is your room? I can do a few calcs. that I'm good at (found on SL's website, under THOR estimates). These are for a Sealed box however. TL's are yummy and beautiful things, I can only remember the good times I had listening to some music (indian musical-no vocals) and loved it when there were 50Hz. bursts. My TL was tuned to 50Hz. Absolutely NO port noise!
sunil said:
nope many years ago for some reason 96db /1m was considered a reference point so often u could find woofers rated at 4W menaing that the sens was 4W to get to 96db. i dont think this is the max distortion free level - that could be a bit higher.
sunil said:
I would use the technique used by KLH (Henry Kloss) in the late 70s use a EQ between the pre and power amp. these EQs usually quite steep can be built using opamps (I'd recomend OP275s) and can affect the phase of the speaker but if you keep the effects belwo 100Hz i dont think you'd notice too much.
as far as ordering drivers from abroad count me in. i got so many project ideas that I would like to get a few more drivers cheap.
The next thing i wanna try for example is a push push TL using either 2 x 6" and a 1"or 2 x 4.5" anda 3/4".
another idea i wont mind working on is a 1.5 way using 2 4" W4 657S or 654S in a push pull TL. anyone have any opinion on the 927 / 930 in such a config.
what if we used the muchused W3 871 (W3 593/594) full range and used 2 x w4 992 (PPTL) for the 0.5 way?
sorry for th hijack just got carried away at the thought of a bulk purchase of cheap drivers.
as far as the bulk purchase is concerend seeing that there are more DIYers (on this list) from Bang than any other place in India we'd have to import and clear in Bang and then re ship to others in India right?
so far DIYers i have seen on this list are from Jam'pur, B'lore, B'bay feel free to add more to this list.
what if we used the muchused W3 871 (W3 593/594) full range and used 2 x w4 992 (PPTL) for the 0.5 way?
sorry for th hijack just got carried away at the thought of a bulk purchase of cheap drivers.
as far as the bulk purchase is concerend seeing that there are more DIYers (on this list) from Bang than any other place in India we'd have to import and clear in Bang and then re ship to others in India right?
so far DIYers i have seen on this list are from Jam'pur, B'lore, B'bay feel free to add more to this list.
sunil
Seems that the 21WO-39-08 is 50Hz at -3dB in a sealed box. Yes, very nice for a small room, especially if you prefer vocal clarity over bass. In vented, it does go deeper but is pretty useless if the room is small. If anyone is interested in using this freeware, Box-Port 2 can be downloaded at:
http://www.ampslab.com/projects.htm
Seems that the 21WO-39-08 is 50Hz at -3dB in a sealed box. Yes, very nice for a small room, especially if you prefer vocal clarity over bass. In vented, it does go deeper but is pretty useless if the room is small. If anyone is interested in using this freeware, Box-Port 2 can be downloaded at:
http://www.ampslab.com/projects.htm
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