helo ,
i need some help with a subwoofer driver which is 8" paper cone with foam surround, its a local unnamed driver i bought. its not a long throw driver and it must be around 40w rms and i am connecting a sony 85rms amp. so like can any one please tell me the dimensions of a vented box,the size of the vent ,and also the thickness of the mdf 4 this kind of driver.(i am using an external amplifier)
(i dont know its specs but can anyone just tell me approx. wut will work the best, i just want it to sound good)
i need some help with a subwoofer driver which is 8" paper cone with foam surround, its a local unnamed driver i bought. its not a long throw driver and it must be around 40w rms and i am connecting a sony 85rms amp. so like can any one please tell me the dimensions of a vented box,the size of the vent ,and also the thickness of the mdf 4 this kind of driver.(i am using an external amplifier)
(i dont know its specs but can anyone just tell me approx. wut will work the best, i just want it to sound good)
Nobody can tell you anything because they don't have the specs for the driver 🙂
We can't even say if it's suitable for sealed or vented as we don't know the specs.
You could try a sealed box of 30-45 litres.
It would be a very good idea to read up on how to measure the Thiele-Small parameters of this driver.
We can't even say if it's suitable for sealed or vented as we don't know the specs.
You could try a sealed box of 30-45 litres.
It would be a very good idea to read up on how to measure the Thiele-Small parameters of this driver.
thanks 4 ur reply man. its just that i am just 17yrs old and worst that i live in india so like i am not accassable to good drivers like shiva and titanic and all. so like i do my little projects with wuts available. so u think 35-40 lts will be good 4 a 8" driver? wut thickness mdf should i use?
I appreciate that it's hard for you to get good drivers. I had the same problem when I first started. You have to try and be lucky with what you buy, and measure them. Once you know what you are doing you will find it easier to judge a driver by looking at it.
Be prepared to waste money and time on drivers and cabinets that you find after are no good. It's all part of the hobby 🙂
To be honest I think you will probably build a piece of junk with what you have, but it will sound OK to you because you built it. I have been there too 😀 Don't waste your time and money on a fancy box as it will get chopped up later 😉 18mm MDF will do. Above 30 litres you will need some bracing.
Be prepared to waste money and time on drivers and cabinets that you find after are no good. It's all part of the hobby 🙂
To be honest I think you will probably build a piece of junk with what you have, but it will sound OK to you because you built it. I have been there too 😀 Don't waste your time and money on a fancy box as it will get chopped up later 😉 18mm MDF will do. Above 30 litres you will need some bracing.
hey there richi,
i have an idea wut u think of it tell me.
i have 2 i dentical 5.8 " approx. drivers. so do u think a bipolar design is good? i have also sent a picture of the driver. and as usual i dont have the specs. see if u can just tell me some approx. dimesions of a bipolar sealed box i'll be using 3/4" mdf.
please if i am wrong , in a bipolar design u place the drivers opposite to each other right? like there magnets facing each other. i am probably lookin 4 a cube.
or do u think that I should use one of the 6" drivers and use the 8" driver as a radiotor? wut u think.
if its possible tell me dimensions 4 this design also.
and thank u 4 ur replies i realy appriciate it.
do u know any site that has these basic tutorials on like wuts qts and vts and all that.
and do u think i can measure those specs manually? or do i need some equipment to measure them?
i have an idea wut u think of it tell me.
i have 2 i dentical 5.8 " approx. drivers. so do u think a bipolar design is good? i have also sent a picture of the driver. and as usual i dont have the specs. see if u can just tell me some approx. dimesions of a bipolar sealed box i'll be using 3/4" mdf.
please if i am wrong , in a bipolar design u place the drivers opposite to each other right? like there magnets facing each other. i am probably lookin 4 a cube.
or do u think that I should use one of the 6" drivers and use the 8" driver as a radiotor? wut u think.
if its possible tell me dimensions 4 this design also.
and thank u 4 ur replies i realy appriciate it.
do u know any site that has these basic tutorials on like wuts qts and vts and all that.
and do u think i can measure those specs manually? or do i need some equipment to measure them?
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hey there,
and so u think i should use those 2 woofers in series? i have a sony 85w rms > 8ohms amp. the drivers are 6 ohms each. they must be hardly 30-40 watts.
and in case of a seal enclosure 4 an 8" driver as i told u before, does a smaller box perfom better or does a biiger box perform better?
i mean u told me that i should build a box like 30-45 lts so which is better 30 or 45?
heres a picture of the 8" sub i have. see if u get any idea from it
and so u think i should use those 2 woofers in series? i have a sony 85w rms > 8ohms amp. the drivers are 6 ohms each. they must be hardly 30-40 watts.
and in case of a seal enclosure 4 an 8" driver as i told u before, does a smaller box perfom better or does a biiger box perform better?
i mean u told me that i should build a box like 30-45 lts so which is better 30 or 45?
heres a picture of the 8" sub i have. see if u get any idea from it
Attachments
For your pair of smaller drivers you could use a cube and mount them on opposite faces. You must wire them in phase. Then you could place the speaker on the floor right up to a wall (in the middle of the wall) so that each speaker is at a right angle to the wall. This will give you an efficient method of loading the drivers and boost the bass a little. You are going to need all the help you can get with those drivers I think 😉
The 8 inch driver looks like it has a small magnet which will result in fairly high Qts. This means that it will probably be a bit boomy and uncontrolled in a vented box. I expect that the resonant frequency (Fs) of the driver will be around 45-55 Hz as it looks like cheap lightweight woofer.
None of these drive units are really any good for sub use. But if you got them free/cheap you can have a play 🙂 You will need an amp and low-pass filter to feed the sub. Have you got these?
For box sizes, making a box smaller reduces its efficiency and raises the resonant frequency (Fs) and raises the Q (peak in response). It also can protect the driver from over-excursion, but you can then melt the voicecoil.
Have a look at diy subwoofers for some tutorials and explanations of all the different parameters and box types.
The 8 inch driver looks like it has a small magnet which will result in fairly high Qts. This means that it will probably be a bit boomy and uncontrolled in a vented box. I expect that the resonant frequency (Fs) of the driver will be around 45-55 Hz as it looks like cheap lightweight woofer.
None of these drive units are really any good for sub use. But if you got them free/cheap you can have a play 🙂 You will need an amp and low-pass filter to feed the sub. Have you got these?
For box sizes, making a box smaller reduces its efficiency and raises the resonant frequency (Fs) and raises the Q (peak in response). It also can protect the driver from over-excursion, but you can then melt the voicecoil.
Have a look at diy subwoofers for some tutorials and explanations of all the different parameters and box types.
hey there,
u r terrific man. u r absolutely right abt the 8 inch driver i had put it in a vented bax before and it did sound tooo boomy. u look like a pro to me.
so wut do u think is more worth-
a) using the two 6" drivers and making a bipolar box
b) using the 8" and making a sealed box
i'd rather prefer the bipolar thing.
cuz the 6" drivers are pretty good than the cheap 8"
cuz like i have a sony hifi amplifier with 85w rms amp. and i also have the harman/kardon avr3550, so like the avr itself passes all the low frequencies to the sub out. so i dont think i'll need a low pass filter.
and one more thing i downloaded that software WinIsd i made box calculation on it with a similar lookin peerless driver. it calculated the volume as 36 lts. so i think thas fair enough.
and if i use 2 of those 6" drivers that are 6ohms each in series then it will be 12ohms right. and my amp is like 85rms which is much powerfull for one of them, so if i use two at 12ohms will that be good? cuz i dont care abt the technical thing i just want it to sound good. and best of all those 6" drivers have a rubber surround.
and can u give me the box dimensions 4 the bipolar thing using the 2 6" drivers pleasssssssssseeeeeeee?
the bipolar box will need bracing too right? cuz u know i am gonna buy the mdf (18mm) and like if u give me the box volume i'll be able to buy the mdf, cuz like the mdf is pretty expensive over here.
i'm gonna buy a 4x4 foot mdf will that be enough?
yeah and by the way wut ur name?
u r terrific man. u r absolutely right abt the 8 inch driver i had put it in a vented bax before and it did sound tooo boomy. u look like a pro to me.
so wut do u think is more worth-
a) using the two 6" drivers and making a bipolar box
b) using the 8" and making a sealed box
i'd rather prefer the bipolar thing.
cuz the 6" drivers are pretty good than the cheap 8"
cuz like i have a sony hifi amplifier with 85w rms amp. and i also have the harman/kardon avr3550, so like the avr itself passes all the low frequencies to the sub out. so i dont think i'll need a low pass filter.
and one more thing i downloaded that software WinIsd i made box calculation on it with a similar lookin peerless driver. it calculated the volume as 36 lts. so i think thas fair enough.
and if i use 2 of those 6" drivers that are 6ohms each in series then it will be 12ohms right. and my amp is like 85rms which is much powerfull for one of them, so if i use two at 12ohms will that be good? cuz i dont care abt the technical thing i just want it to sound good. and best of all those 6" drivers have a rubber surround.
and can u give me the box dimensions 4 the bipolar thing using the 2 6" drivers pleasssssssssseeeeeeee?
the bipolar box will need bracing too right? cuz u know i am gonna buy the mdf (18mm) and like if u give me the box volume i'll be able to buy the mdf, cuz like the mdf is pretty expensive over here.
i'm gonna buy a 4x4 foot mdf will that be enough?
yeah and by the way wut ur name?
If you want to go with the bipolar one then try a box 300 x 300 x 300 mm internal. To keep things simple (and because you will probably move on from this anyway, so save your money and effort) don't bother with any bracing. The box is fairly small and using 18 mm wood will make it rigid enough given the displacement it's going to see.
Connect your drivers in series and in phase, i.e. +ve of driver to -ve of other driver, then one connection from each driver to amp.
4 ft x 4 ft sheet should be enough I think, but just check by seeing how big each panel you need is and how you can get them out of a sheet. If MDF is expensive try plywood. MDF dust is bad for you, try not to breathe it in and wear a mask.
Don't expect too much 🙂
Connect your drivers in series and in phase, i.e. +ve of driver to -ve of other driver, then one connection from each driver to amp.
4 ft x 4 ft sheet should be enough I think, but just check by seeing how big each panel you need is and how you can get them out of a sheet. If MDF is expensive try plywood. MDF dust is bad for you, try not to breathe it in and wear a mask.
Don't expect too much 🙂
thanks a lot 4 ur help,
i wanted to ask u that how would i know which driver is good and which is bad. u know i wont get any technical specs over here. so wut sort of good features should i look 4 in the driver?
tommorrow i'll buy the mdf board, the whole design does fit on the 4x4 board. do u think i should put any stuffing?if yes wut sort of stuffing? will bracing help? because i'll have some leftover mdf after i cut out the main cube.
and do u think i could make any modification to the sub with the left over mdf to make it go deep?(i am using an external amp incase u wanna know, will that change the dimensions?)
i wanted to ask u that how would i know which driver is good and which is bad. u know i wont get any technical specs over here. so wut sort of good features should i look 4 in the driver?
tommorrow i'll buy the mdf board, the whole design does fit on the 4x4 board. do u think i should put any stuffing?if yes wut sort of stuffing? will bracing help? because i'll have some leftover mdf after i cut out the main cube.
and do u think i could make any modification to the sub with the left over mdf to make it go deep?(i am using an external amp incase u wanna know, will that change the dimensions?)
You can't really go on looks as to how a driver will perform. You can see if it's well engineered and built for a start, but you also need knowledge of what kinds of characteristics suit which applications. One driver may be good for one thing but rubbish for another.
One thing I will say is that the normal advertised specs of power handling, magnet weight and frequency response are next to useless.
It takes a lot of playing with different drivers and measuring them and trying different designs before you can do a good first stab on viewing.
If you don't have any specs for your local drivers then you will simply have to equip yourself to measure them. You can set yourself up with the basics for not much more than pocket money.
I will say from experience though that restricting yourself to local drivers you will end up wasting a lot of time and money and still probably be missing the performance you desire. However, I would not have the knowledge I have today if I had not done that, and it means I can design a better system now that I do go and buy top of the line drivers.
Stuffing the box will not make much difference. Unless you use the right stuff you can even make things worse. Forget about it for now. I don't think bracing will make much difference either in this instance. The dimensions I gave you are just a guide but I was expecting no amp etc to be mounted inside.
There's really not that much you can do with those drivers (box wise or electronically) to make them go proper deep. You could make the box a little bigger (say extra 5-7 litres, take up the spare volume with blocks if you want) and maybe add a vent later on to see how that changes the sound.
Just have fun building your first speaker and don't expect too much. 🙂
One thing I will say is that the normal advertised specs of power handling, magnet weight and frequency response are next to useless.
It takes a lot of playing with different drivers and measuring them and trying different designs before you can do a good first stab on viewing.
If you don't have any specs for your local drivers then you will simply have to equip yourself to measure them. You can set yourself up with the basics for not much more than pocket money.
I will say from experience though that restricting yourself to local drivers you will end up wasting a lot of time and money and still probably be missing the performance you desire. However, I would not have the knowledge I have today if I had not done that, and it means I can design a better system now that I do go and buy top of the line drivers.
Stuffing the box will not make much difference. Unless you use the right stuff you can even make things worse. Forget about it for now. I don't think bracing will make much difference either in this instance. The dimensions I gave you are just a guide but I was expecting no amp etc to be mounted inside.
There's really not that much you can do with those drivers (box wise or electronically) to make them go proper deep. You could make the box a little bigger (say extra 5-7 litres, take up the spare volume with blocks if you want) and maybe add a vent later on to see how that changes the sound.
Just have fun building your first speaker and don't expect too much. 🙂
helo,
u still have'nt told me ur name.
my name is siddharth
ok so i have made a box approx. 32 lts (inner volume).
with 18mm mdf. i have pasted and screwed the boards together. i used small steel L-shape braces inside at corners and one mdf piller to support the walls ( cuz they were bending inside because of the steel braces.
tell me again do u think i should stuff the box?and do u think i should make a vent?
tell u wut, i'll make a bipolar sealed enclosure if it sounds good i'll keep it or i'll make a vent hows that sound?
u still have'nt told me ur name.
my name is siddharth
ok so i have made a box approx. 32 lts (inner volume).
with 18mm mdf. i have pasted and screwed the boards together. i used small steel L-shape braces inside at corners and one mdf piller to support the walls ( cuz they were bending inside because of the steel braces.
tell me again do u think i should stuff the box?and do u think i should make a vent?
tell u wut, i'll make a bipolar sealed enclosure if it sounds good i'll keep it or i'll make a vent hows that sound?
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sidd_raj2002 said:
I'm surprised that you could bend a bit of MDF that thick.
sidd_raj2002 said:
As I said before, don't bother with stuffing.
sidd_raj2002 said:
Yes, that's what I was saying.
hey there,
i already built the sub. guess wut it sounds terrific !!! seriously.
it first sounded a bit boomy so i put some foam cubes in. now it sounds a lot tighter.and its not distorting at real high volumes either(may thas because of the sealed enclosure). wut u think should i put more stuffing to make it sound tighter?cuz it is a bit boomy right now too. wut stuffing do u suggest?
but beleive me i could not ahve done this without ur help man. excellent. this baby sounds way better than many other (costly) subwoofers I saw, they were ofcourse smaller but the cost was like more than 80 or 90 $ but i buit this one in hardy 30$ including drivers.
heres the picture of the finished sub. wut u think should i give it a cherry polish? wut u think?
i already built the sub. guess wut it sounds terrific !!! seriously.
it first sounded a bit boomy so i put some foam cubes in. now it sounds a lot tighter.and its not distorting at real high volumes either(may thas because of the sealed enclosure). wut u think should i put more stuffing to make it sound tighter?cuz it is a bit boomy right now too. wut stuffing do u suggest?
but beleive me i could not ahve done this without ur help man. excellent. this baby sounds way better than many other (costly) subwoofers I saw, they were ofcourse smaller but the cost was like more than 80 or 90 $ but i buit this one in hardy 30$ including drivers.
heres the picture of the finished sub. wut u think should i give it a cherry polish? wut u think?
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I'm glad you are happy 🙂
What is the stuffing you used like? How dense is it? I'm surprised it made such a difference to the sound.
It's usually the case with speakers (especially cheap ones) that bigger boxes sound better.
What is the stuffing you used like? How dense is it? I'm surprised it made such a difference to the sound.
It's usually the case with speakers (especially cheap ones) that bigger boxes sound better.
Did you glue all the panels together? If yes, it's well done because not noticeable hehe.
A coat of paint will look good.
A coat of paint will look good.
helo,
i used some foam i dunno wut density it hs but its not too dense like the foam we use in mattresses . is much like a sponge. and i also put in a woolen cap. it sounds extreme 4 the cost. it can easily beat any other entry level ht subwoofers .
yea and simon i have first pasted the panels with rubber adhesive and then screwed them together i have also used L-shaped angles braceing inside at the edges. and one wooden beam to support the walls.
i used some foam i dunno wut density it hs but its not too dense like the foam we use in mattresses . is much like a sponge. and i also put in a woolen cap. it sounds extreme 4 the cost. it can easily beat any other entry level ht subwoofers .
yea and simon i have first pasted the panels with rubber adhesive and then screwed them together i have also used L-shaped angles braceing inside at the edges. and one wooden beam to support the walls.
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