I am going to build a ported box for my sub and I'm a newbie to ported enclosures I've never dealt with them. I had mentined in an earlier topic that I got 2 Powerbass 15"s.Well my order got screwed up so I am only getting 1 now.It is 4 ohm dvc 300 wrms,400 wmax.Now as far as the amp I heard that the amp has to have a subsonic filter, is this true? How can you tell if an amp has one? Also can anyone reccomend a good one for this application? Price is not a matter. The box I will definately need help on dimensions with but I don't have the specs yet.
Replies (27)
compvr15s on 10/28/2005 22:54:06
many class d mono amps have a built in subsonic filter.. you can tell by looking at the amp, some may have a switch, other are adjustable and will will have a knob or a dial for different freqs... but its not a must have on your amp, a few companies make inline filters that will do the same thing..
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=3
(fmods is one brand, it just connects into the rca cables right at the amp, very simple to use... there is a variety of freqs to choose from, do not purchase a set until you decide what your box port tuning will be.
for amp choice a 300 watt at 2omh is very simple to find and fairly cheap....
http://www.crutchfield.com/S-JpeGoaFGWjI/cgi-bin/prodgroup.asp?g=120&avf=N&nvpair=AG%5FNumber%5Fof%5FChannels
anonymous_a on 10/29/2005 00:21:20
How do i know what to tune the port at and how is that done? Also how do I match the tunning on the port to the frequency on the amp? I want to go for maximum spl with this set up.
swez on 10/29/2005 10:17:00
Port tuning a box takes in several factors:
1. Woofer's "EBP" is above 50
2. The sub maker provides info on box size and porting recommendations
3. Using box making software can help a lot (just plug in the requested information [T/S parameters, etc.] and let the program give you the dimensions)
Here's a site that can help you: http://www.the12volt.com/default.asp?
As for Subsonic filtering, the amp used may have a selectable switch or a variable dial. It is usually marked as a SSF or USF. If your amp does not have this feature, you can use F-Mods for this application.
Finally, if you want maximum SPL from your system, consider tuning the enclosure between 45-50 Hz. That is where most subs become most efficient with SPL output. As for the amp to use, since this is a 4+4 DVC and you only have 1 sub, best to use a Class D sub amp that can deliver a solid 300 Wrms and already has a variable SSF.
Swez
anonymous_a on 10/29/2005 14:04:33
Does anyone know of any free programs to help with design of the box?
swez on 10/29/2005 14:23:04
Yep, here's a good one to work out various plans.
1. http://www.bcae1.com/carpetenclosure.htm (basic and graphics)
2. http://www.bcae1.com/spboxad2.htm (advanced w/ T/S parameters)
Swez
anonymous_a on 11/3/2005 11:25:23
Ok I just got the sub it looks like a ported enclosure can't be used at all so now what I have to do is purchase another sub.So beings that I have to go to a dual sealed enclosure can anyone walk me through building the box? The programs Swez mentioned I didn't understand. I'm guessing the volume each chamber is gonna have to be is 2.0 cubic feet if thats what gross vb means.Also width wise I wanted to have the shortest width possible due to different size trunks.I was wondering if the lost width could be made up on either height or length.
swez on 11/4/2005 08:44:55
Yes, you can vary any parameter (H, W or D) to get the desired enclosure dimensions needed. With a 15" SUB, you will need a "minimum" face panel of 17.5" H x 17.5" W per chamber. Anything smaller than that will not useful for sub mounting.
Using the bcae1 enclosure calculator: 15" woofer, 3/4" wood thickness
http://www.bcae1.com/spboxnew2.htm
The external dimensions come out to:
H = 19.0"
W = 19.0 + 19.0 + .75 = 38.75"
D = 13.5"
External volume = 5.75 cf
Net Internal volume = 4.25 cf
The net internal volume comes out to 4.25 cf. (2.125 cf per chamber) Close enough, after subtracting sub displacements. This is a pretty large enclosure, no matter how you slice it.
Will this fit your vehicles?
Swez
anonymous_a on 11/4/2005 10:42:47
Thank you very much Swez this size box looks like it will be compatible with different size trunks. The reason I need build it like this is because I don't know what kind of car this is going in yet and I just want to be ready for any trunk.I do have one last question though, on the sub specs it says to use 1 lb. of poly fill per sub.Should I do this?
swez on 11/4/2005 11:19:21
Since you are going to build a sealed box, no need for a sub sonic fiter network here.
As for polyfill, yes... I recommend it as virtually every box I have made or installed (made by Pro companies) all use polyfill. It dampens the rear bass waves inside the box. That gives tight, deep bass performance w/o a lot of internal cancellations that are common in non-filled enclosures. This is especially true of subs and midbass enclosures. For midrange and highs, not needed.
FYI: 1 lb per chamber seems a bit light for a 15" sub. I would suggest starting at 1 lb and be ready to bump it up to 16 ounces per chamber. It all depends on what product is used and how thick the padding is on back, sides, top & bottom.
The weight of fill used is not the key issue. It's the thickness/density of the padding that matters. You can even use carpet padding here. I'd try to go 1.0-1.5" thickness on all walls except the baffle panel. (where the sub is mounted) You can free padding from any home that just had new carpet and padding installed. Just make sure it's clean and free of dirt and pet messes.
The best padding I have used to date, is the woolen blend padding. It was free and all I had to do, was cut it to the proper dimensions, staple it into the box and then install your subs.
NOTE: Avoid padding that flakes and turns to a dusty powder over time. This can get into the sub air vents and ruin your subs.
Swez
anonymous_a on 11/4/2005 12:56:20
I think I'm gonna go with the real brand name Poly fill unless I find that carpet padding you talked about.Also I've heard some people on here talk about some dampening material that can be bought at like Lowe's and home Depot for a fraction of the price Dynomat costs.Is that true and what is is?
anonymous_a on 11/4/2005 13:01:39
Ahh I just saw someone's "sound deadening post" but is there anything cheaper?
asplundher on 11/4/2005 14:16:39
I personally prefer the polyester fiberfill that is found at Walmart in the crafts department. Only costs about $3 per 20oz bag and nets good results.
If you really need the full effect of "stuffing" a box, then you can do a thin to medium batten liner of fiberglass insulation on the sides, back, and bottom. Then a low density amount of polyfill after in the rest of the void, but not too much so as to cram it up against the sub. It is possible to overstuff a box and cause frictional losses that will act as if your decreasing the box size.
As far as sound dampening material at a lesser cost, check out www.partsexpress.com. They have several materials that I have used that are less expensive than dynamat and with good results.
Victor on 11/4/2005 15:18:14
http://www.clubknowledge.com/Car_Audio_FAQ/?g3764_2273
This is the post, if u are looking to use sound deadning material to line the inside of the sub enclosure, u can use asphalt products, they are much cheaper then butyl based ones , you can find some for like $ 2 per sq.ft.
Personally i use Foam sheets for this purpose and i am happy with it.
Victor...
swez on 11/4/2005 15:30:02
Dynamat and other such deadeners are not really needed inside a sub enclosure. They are designed for metal and plastic panel rattles.
The Wal-Mart stuff is fine and low cost. It comes in bulk like pillow/quilt stuffing. (batting) Or, you can buy it in sheet goods form too. Either way, a 1 - 1.5 inch thickness is fine.
Swez
Victor on 11/4/2005 15:33:42
Dave.... care to get on yahoo to say Hi SMILE
anonymous_a on 11/4/2005 18:52:22
Sorry guys I didn't state last paragraph right.I was talking about sound deadening materials for the trunk rattles.I was just looking for something in bulk that didn't break the bank.I know I'm gonna have to line the trunk with something because I heard a guy with 2 15"s that sounded like a huge vibrator in the trunk,there was no bass quality whatsoever.
Victor on 11/4/2005 19:56:44
you can get Fatmat at $99 for a 100sqft material.
you can get e-dead-1 at $100 for a 100sqft material
you can get B-quiet extreme at $120 for a 100sqft material.
you can get Raammat at $218 for 125sqft of material.
you can get "sounddeadening ""Aluminium"" material" at $170 for 90sqft material. from http://www.sounddeadeningmaterial.com/whatisit.html
Raammat is a butyl based product, while Fatmat , E-dead , B-quiet and "sound deadening" are purely asphalt based products, the adhesive properties and heat resistance properties of butyl are much better than asphalt.Butyl based product melts at a substantially higher temperature and stay flexible to a lower temperature.
Fatmat, E-dead ,B-quiet are are 1.15mm or 45mil thick, where as Raammat and "sound deadening" are 1.5mm or 60mil thick.
Fatmat is 0.23lb /sqft , B-quiet is 0.30 lb/sqft , Sound Deadening "Alluminium" is 0.30 lb/sqft , E-dead is 0.35 lb/sqft , Raammat is 0.35lb/sqft .
The function of sound deadening mat is to immobilize a resonant, flexible surface by applying weight to it, making it less resonant and flexible. Value needs to be considered in two ways. We are trying to cover an area with sound deadener, so cost per square foot is a useful metric. Since we are trying to add mass to an area, cost per pound is another consideration. A thin mat may be cheaper per ft2, but if you need more layers than a thicker, heavier product, the second may actually be less expensive. Conversely, there may be applications where the thicker, heavier mat may be more than is needed in a single layer .
Hope this helps..
Victor..
(Some of the explanations included here are taken from http://www.sounddeadenershowdown.com/ ), just to make it a bit easier for u.
anonymous_a on 11/4/2005 20:52:22
Is there a product that has something to do with ice buildup on gutters? Can that be used?
Victor on 11/4/2005 21:34:07
I dunno.. but why wud u want to use anything and everything except the products that are actually designed and formulated for sound damping..??
compvr15s on 11/5/2005 00:44:58
they do make a shielding for ice and water, that can be used but i recommend spending the money on the other stuff.. this material is like a big roll of shingle but sticky on one side... it does not form or contour very well, and it doesn't stick vertically very well or upside down... i have tried this on a trunk that sounded horrible due to poor seals and lots of air holes in the trunk lid... final product looked horrible, it did help out but it did not last long, a few days later the temps reached 95 or higher outside and the material just fell off, leaving the stickyness behind, very hard to get off.. but this can be used just really not meant for this application
anonymous_a on 11/5/2005 02:51:28
oh ok thank you comp vr.
swez on 11/5/2005 06:22:36
Word to the wise...
Victor has done a comprehensive study on various materials available for car resonance damping. I read one of the links with lots of detailed testing and noted that asphalt based products are cheaper and do an adequate job on flat, (near flat) horizontal surfaces. (trunk and interior floors)
However, when doing vertical and inverted surfaces, (wheel wells and trunk lids) use butyl rubber based materials. The adhesion is superior and will not fall off at extreme temperatures. These compounds do cost more, but worth the extra expense.
Swez
anonymous_a on 11/7/2005 16:53:38
I was thinking about the shape of the box and was thinking about somekind of reverse wedge shape.I have a sealed box for 2 12"s and where the cutouts for the sub is it is wedge shaped with the D= 9" at the top and 18" or so inches at the bottom.I was thinking could anyone give me some kind of measurements for a box built like this but with the wedge on the OPPOSITE side of where the woofers go?I need around 2 cu.ft. of airspace per chamber.
Victor on 11/7/2005 17:01:12
Scroll down and u will see a box calculator for a wedge shaped enclosure..
http://www.the12volt.com/caraudio/boxcalcs.asp
Try it yourself, its easy and fun to play with numbers on this page.
If you still cant find the solution let us know and we can help u.
Victor.
I could have given you the dimensions , not a big issue, but since u are interested in car audio, and like to learn and easily grasp , i thought it better to show u something that can help u out as well as add to ur knowledge.
anonymous_a on 11/7/2005 17:27:26
Thank you Victor, I got exactly what I needed.Now how do I make the cuts join together on the diagonal wedge pieces
? (I'm going with Wedge Enclosure 2) Also, is the shape really gonna matter or is a traditional rectangle box better?
Victor on 11/7/2005 17:48:15
The shape aint gonna make a noticable difference
http://www.crutchfield.com/S-0BT2EoFhVbP/tech/kb15.html
rest of it, you gotta think and plan , THINK..
dont get annoyed, its good if somethings are figured out by ones self, it gives great amount of satisfaction.. but dont worry we are always here to help, so incase you cant do it then catch on us..
anonymous_a on 11/7/2005 19:12:34
thank you!
Replies (27)
compvr15s on 10/28/2005 22:54:06
many class d mono amps have a built in subsonic filter.. you can tell by looking at the amp, some may have a switch, other are adjustable and will will have a knob or a dial for different freqs... but its not a must have on your amp, a few companies make inline filters that will do the same thing..
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=3
(fmods is one brand, it just connects into the rca cables right at the amp, very simple to use... there is a variety of freqs to choose from, do not purchase a set until you decide what your box port tuning will be.
for amp choice a 300 watt at 2omh is very simple to find and fairly cheap....
http://www.crutchfield.com/S-JpeGoaFGWjI/cgi-bin/prodgroup.asp?g=120&avf=N&nvpair=AG%5FNumber%5Fof%5FChannels
anonymous_a on 10/29/2005 00:21:20
How do i know what to tune the port at and how is that done? Also how do I match the tunning on the port to the frequency on the amp? I want to go for maximum spl with this set up.
swez on 10/29/2005 10:17:00
Port tuning a box takes in several factors:
1. Woofer's "EBP" is above 50
2. The sub maker provides info on box size and porting recommendations
3. Using box making software can help a lot (just plug in the requested information [T/S parameters, etc.] and let the program give you the dimensions)
Here's a site that can help you: http://www.the12volt.com/default.asp?
As for Subsonic filtering, the amp used may have a selectable switch or a variable dial. It is usually marked as a SSF or USF. If your amp does not have this feature, you can use F-Mods for this application.
Finally, if you want maximum SPL from your system, consider tuning the enclosure between 45-50 Hz. That is where most subs become most efficient with SPL output. As for the amp to use, since this is a 4+4 DVC and you only have 1 sub, best to use a Class D sub amp that can deliver a solid 300 Wrms and already has a variable SSF.
Swez
anonymous_a on 10/29/2005 14:04:33
Does anyone know of any free programs to help with design of the box?
swez on 10/29/2005 14:23:04
Yep, here's a good one to work out various plans.
1. http://www.bcae1.com/carpetenclosure.htm (basic and graphics)
2. http://www.bcae1.com/spboxad2.htm (advanced w/ T/S parameters)
Swez
anonymous_a on 11/3/2005 11:25:23
Ok I just got the sub it looks like a ported enclosure can't be used at all so now what I have to do is purchase another sub.So beings that I have to go to a dual sealed enclosure can anyone walk me through building the box? The programs Swez mentioned I didn't understand. I'm guessing the volume each chamber is gonna have to be is 2.0 cubic feet if thats what gross vb means.Also width wise I wanted to have the shortest width possible due to different size trunks.I was wondering if the lost width could be made up on either height or length.
swez on 11/4/2005 08:44:55
Yes, you can vary any parameter (H, W or D) to get the desired enclosure dimensions needed. With a 15" SUB, you will need a "minimum" face panel of 17.5" H x 17.5" W per chamber. Anything smaller than that will not useful for sub mounting.
Using the bcae1 enclosure calculator: 15" woofer, 3/4" wood thickness
http://www.bcae1.com/spboxnew2.htm
The external dimensions come out to:
H = 19.0"
W = 19.0 + 19.0 + .75 = 38.75"
D = 13.5"
External volume = 5.75 cf
Net Internal volume = 4.25 cf
The net internal volume comes out to 4.25 cf. (2.125 cf per chamber) Close enough, after subtracting sub displacements. This is a pretty large enclosure, no matter how you slice it.
Will this fit your vehicles?
Swez
anonymous_a on 11/4/2005 10:42:47
Thank you very much Swez this size box looks like it will be compatible with different size trunks. The reason I need build it like this is because I don't know what kind of car this is going in yet and I just want to be ready for any trunk.I do have one last question though, on the sub specs it says to use 1 lb. of poly fill per sub.Should I do this?
swez on 11/4/2005 11:19:21
Since you are going to build a sealed box, no need for a sub sonic fiter network here.
As for polyfill, yes... I recommend it as virtually every box I have made or installed (made by Pro companies) all use polyfill. It dampens the rear bass waves inside the box. That gives tight, deep bass performance w/o a lot of internal cancellations that are common in non-filled enclosures. This is especially true of subs and midbass enclosures. For midrange and highs, not needed.
FYI: 1 lb per chamber seems a bit light for a 15" sub. I would suggest starting at 1 lb and be ready to bump it up to 16 ounces per chamber. It all depends on what product is used and how thick the padding is on back, sides, top & bottom.
The weight of fill used is not the key issue. It's the thickness/density of the padding that matters. You can even use carpet padding here. I'd try to go 1.0-1.5" thickness on all walls except the baffle panel. (where the sub is mounted) You can free padding from any home that just had new carpet and padding installed. Just make sure it's clean and free of dirt and pet messes.
The best padding I have used to date, is the woolen blend padding. It was free and all I had to do, was cut it to the proper dimensions, staple it into the box and then install your subs.
NOTE: Avoid padding that flakes and turns to a dusty powder over time. This can get into the sub air vents and ruin your subs.
Swez
anonymous_a on 11/4/2005 12:56:20
I think I'm gonna go with the real brand name Poly fill unless I find that carpet padding you talked about.Also I've heard some people on here talk about some dampening material that can be bought at like Lowe's and home Depot for a fraction of the price Dynomat costs.Is that true and what is is?
anonymous_a on 11/4/2005 13:01:39
Ahh I just saw someone's "sound deadening post" but is there anything cheaper?
asplundher on 11/4/2005 14:16:39
I personally prefer the polyester fiberfill that is found at Walmart in the crafts department. Only costs about $3 per 20oz bag and nets good results.
If you really need the full effect of "stuffing" a box, then you can do a thin to medium batten liner of fiberglass insulation on the sides, back, and bottom. Then a low density amount of polyfill after in the rest of the void, but not too much so as to cram it up against the sub. It is possible to overstuff a box and cause frictional losses that will act as if your decreasing the box size.
As far as sound dampening material at a lesser cost, check out www.partsexpress.com. They have several materials that I have used that are less expensive than dynamat and with good results.
Victor on 11/4/2005 15:18:14
http://www.clubknowledge.com/Car_Audio_FAQ/?g3764_2273
This is the post, if u are looking to use sound deadning material to line the inside of the sub enclosure, u can use asphalt products, they are much cheaper then butyl based ones , you can find some for like $ 2 per sq.ft.
Personally i use Foam sheets for this purpose and i am happy with it.
Victor...
swez on 11/4/2005 15:30:02
Dynamat and other such deadeners are not really needed inside a sub enclosure. They are designed for metal and plastic panel rattles.
The Wal-Mart stuff is fine and low cost. It comes in bulk like pillow/quilt stuffing. (batting) Or, you can buy it in sheet goods form too. Either way, a 1 - 1.5 inch thickness is fine.
Swez
Victor on 11/4/2005 15:33:42
Dave.... care to get on yahoo to say Hi SMILE
anonymous_a on 11/4/2005 18:52:22
Sorry guys I didn't state last paragraph right.I was talking about sound deadening materials for the trunk rattles.I was just looking for something in bulk that didn't break the bank.I know I'm gonna have to line the trunk with something because I heard a guy with 2 15"s that sounded like a huge vibrator in the trunk,there was no bass quality whatsoever.
Victor on 11/4/2005 19:56:44
you can get Fatmat at $99 for a 100sqft material.
you can get e-dead-1 at $100 for a 100sqft material
you can get B-quiet extreme at $120 for a 100sqft material.
you can get Raammat at $218 for 125sqft of material.
you can get "sounddeadening ""Aluminium"" material" at $170 for 90sqft material. from http://www.sounddeadeningmaterial.com/whatisit.html
Raammat is a butyl based product, while Fatmat , E-dead , B-quiet and "sound deadening" are purely asphalt based products, the adhesive properties and heat resistance properties of butyl are much better than asphalt.Butyl based product melts at a substantially higher temperature and stay flexible to a lower temperature.
Fatmat, E-dead ,B-quiet are are 1.15mm or 45mil thick, where as Raammat and "sound deadening" are 1.5mm or 60mil thick.
Fatmat is 0.23lb /sqft , B-quiet is 0.30 lb/sqft , Sound Deadening "Alluminium" is 0.30 lb/sqft , E-dead is 0.35 lb/sqft , Raammat is 0.35lb/sqft .
The function of sound deadening mat is to immobilize a resonant, flexible surface by applying weight to it, making it less resonant and flexible. Value needs to be considered in two ways. We are trying to cover an area with sound deadener, so cost per square foot is a useful metric. Since we are trying to add mass to an area, cost per pound is another consideration. A thin mat may be cheaper per ft2, but if you need more layers than a thicker, heavier product, the second may actually be less expensive. Conversely, there may be applications where the thicker, heavier mat may be more than is needed in a single layer .
Hope this helps..
Victor..
(Some of the explanations included here are taken from http://www.sounddeadenershowdown.com/ ), just to make it a bit easier for u.
anonymous_a on 11/4/2005 20:52:22
Is there a product that has something to do with ice buildup on gutters? Can that be used?
Victor on 11/4/2005 21:34:07
I dunno.. but why wud u want to use anything and everything except the products that are actually designed and formulated for sound damping..??
compvr15s on 11/5/2005 00:44:58
they do make a shielding for ice and water, that can be used but i recommend spending the money on the other stuff.. this material is like a big roll of shingle but sticky on one side... it does not form or contour very well, and it doesn't stick vertically very well or upside down... i have tried this on a trunk that sounded horrible due to poor seals and lots of air holes in the trunk lid... final product looked horrible, it did help out but it did not last long, a few days later the temps reached 95 or higher outside and the material just fell off, leaving the stickyness behind, very hard to get off.. but this can be used just really not meant for this application
anonymous_a on 11/5/2005 02:51:28
oh ok thank you comp vr.
swez on 11/5/2005 06:22:36
Word to the wise...
Victor has done a comprehensive study on various materials available for car resonance damping. I read one of the links with lots of detailed testing and noted that asphalt based products are cheaper and do an adequate job on flat, (near flat) horizontal surfaces. (trunk and interior floors)
However, when doing vertical and inverted surfaces, (wheel wells and trunk lids) use butyl rubber based materials. The adhesion is superior and will not fall off at extreme temperatures. These compounds do cost more, but worth the extra expense.
Swez
anonymous_a on 11/7/2005 16:53:38
I was thinking about the shape of the box and was thinking about somekind of reverse wedge shape.I have a sealed box for 2 12"s and where the cutouts for the sub is it is wedge shaped with the D= 9" at the top and 18" or so inches at the bottom.I was thinking could anyone give me some kind of measurements for a box built like this but with the wedge on the OPPOSITE side of where the woofers go?I need around 2 cu.ft. of airspace per chamber.
Victor on 11/7/2005 17:01:12
Scroll down and u will see a box calculator for a wedge shaped enclosure..
http://www.the12volt.com/caraudio/boxcalcs.asp
Try it yourself, its easy and fun to play with numbers on this page.
If you still cant find the solution let us know and we can help u.
Victor.
I could have given you the dimensions , not a big issue, but since u are interested in car audio, and like to learn and easily grasp , i thought it better to show u something that can help u out as well as add to ur knowledge.
anonymous_a on 11/7/2005 17:27:26
Thank you Victor, I got exactly what I needed.Now how do I make the cuts join together on the diagonal wedge pieces
? (I'm going with Wedge Enclosure 2) Also, is the shape really gonna matter or is a traditional rectangle box better?
Victor on 11/7/2005 17:48:15
The shape aint gonna make a noticable difference
http://www.crutchfield.com/S-0BT2EoFhVbP/tech/kb15.html
rest of it, you gotta think and plan , THINK..
dont get annoyed, its good if somethings are figured out by ones self, it gives great amount of satisfaction.. but dont worry we are always here to help, so incase you cant do it then catch on us..
anonymous_a on 11/7/2005 19:12:34
thank you!
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