well guys i got all my stereo hooked up in my new ride but now that its in i realized that i have a blown voice coil in each of my subs. i was hoping to replace them anyways so now i'm looking for a good pair of 10" subwoofers that are about the same mounting depth as my orions which is about 5" well that is what the specs say anyways but that seems REALLY shallow because it seems as though all of the newer subs are deeper than that. i was hoping to get alpine type Rs but that is out of the question i am thinking so i'm looking at the type Ss and Es but it seems like every site i go to the mounting depth is different.
Also i need a subwoofer that would work with my box size, its about 1.1 cubic feet and has a 3" wide 10" long port. i'm not sure about the tuning frequency mostly because i really don't have a clue was the phrase "tuning frequency" means and whether it has to do with the amp or the box or what. but anyways i would prefer a 2 ohm DVC setup like my old subs. i don't really have a definate price range i have some extra money lying around i just don't know how much i'd like to spend right now. i would think that $150 or so per speaker should about do it and wouldn't really wanna spend a whole lot more than that i don't think.
suggestions?
Replies (15)
oldmazda on 02/16/2005 18:15:23
anyone?
uochronos on 02/16/2005 20:02:26
elemental designs K series are pretty shallow, alpine type E's are also, i think infinitys are pretty shallow.
Chronos
oldmazda on 02/17/2005 01:27:06
alrite well i was thinking about it a little more and has anybody ever heard of slant spacers, i have a ring made out of mdf to make the sub fit out of the box a little further but the reason i can't get anything that deep is because of the angle the face of the box is. i was thinking that if i were add or replace my ring with one that would elevate the lower end so that the subs were facing more perpendicular to the bottom of the box i would eliminate my issues with depth. does anybody know if those are made prefab because they would be a pain to make out of mdf with all the sanding and all i dont' know if i would be able to make the side that i would angle perfectly straight because i would be sanding it down so i would have to seal up any cracks with silicone or something like that so i mean it wouldn't be perfect but i think i could make it work. has anyone ever seen anything like that?
swez on 02/17/2005 09:06:02
What is the actual mounting depth in this enclosure you mentioned? If there are air vents in the back of the magnet, need an airspace equal to or larger than the diameter of the vent. (measured between magnet assy., and back wall.
Port tuning is a procuct of overall enclosure space after subtracting drivers and port displacement values. The port is measured down the center of the port or vent for overall length. The width of the port includes baffles and side end panel.
You mentioned the box is ~1.1 cf. Is that 1.1 cf/sub, minus the port or total internal airspace or something different? (please explain in more detail)
Also, what amp are you planning to use for the subs?
Swez
PS Making angled spacers can be tricky. Best way I can suggest, use 1" MDF stock here. Then cut your 1" thick donuts. Then measure the angle you desire. After that, transfer that angle to the donuts, affix donuts to a stationary jig and use a coarse belt (40-60 grit) sander to rough it to proper shape. (~90% of final shape) Finish sanding can be done with a 100-120 grit belt to obtain a clean finish for mounting and accurate angles. This will go fast with a good belt sander. Mounting both donuts on the work fixture will allow you to match thickness and angles with minimal effort. Do you see the process mentioned, in your mind's eye?
oldmazda on 02/17/2005 15:56:31
ya i know what your saying, and i have access to just about all the tools that i will need, making that jig will likely be a little tricky for me but i think that i should be able to manage. the current mounting depth is about 5" but the only reason it is that shallow is because of my box setup and the angle that my subs are at. there is more than enough airspace behind vent, it is the edge of the magnet that is getting close to the rear wall of the box. if i angle the subs there shouldn't be an issue with depth at all because if i even just get them relatively close to straight down there is about 11" to the bottom of the box. though i don't think i will be able to angle it enough so that it is perfectly straight i think that i should be able to angle it enough so that i get about 6-7" of clearance which would be plenty for the type rs that i wish to get. i will likely take off the doughnuts that i currently have on now and angle them a little bit so taht i will not only have the 1" mdf angled donut but another 3/4" one as well.
until i have money i will be using my clarion apx400.2, because my alpine MRV-T505 wouldn't be capable of powering a whole lot other than speakers which i will eventually use it for. i am aware that the clarion amplifier doesn't dish out huge amounts of power but i won't be using the subs to the extreme really either, i mean every now and then i'll crank it up but that would not be a very common occurance really i don't think. i no longer have the specs on my clarion amp but if you wish to see them they aren't that difficult to find on the net.
i don't really understand the whole port frequency tuning thing yet, how would i calculate it for my box? it is 30" long by 9.5" deep and the angled top is so that the back side of my box is 14.5" tall and the front side is 10" tall. the whole thing is made out of 3/4"mdf and already has 1 3/4" donut on so will that make the subwoofer displacement lessen? but there will be another donut on shortly.... hopefully. and my ports are 3" internal diameter and 10"long. now i think that about sums up my box if i missed out any measurements tel me and i will try to get anything i can.
i think that the system i chose would be relatively compatible though i am not sure so if anyone has some ideas or has seen an error on my behalf let me know so that i can at very least reconsider it.
swez on 02/18/2005 08:44:44
Am getting very confused by the replies here. Let's backtrack a bit, before pressing ahead.
1. The enclosure used is a ported one, 2 x10 subs yes?
2. The overall dimensions of the box are:
L= 30" (this is really called Width)
H1 = 14.5"; H2 = 10,0" (net effect is 12.250")
D = 9.5
3. The numbers in cf: 30 x 12.25 x 9.5 = 3491 in^3/1728 = 2.02 ft^3
That's the external footprint of the box. Then we have to determine the internal cf of this enclosure, sub and port displacements.
My calculations show a 1.52 internal cf for this wedge box design. If there is an internal divider board between the subs, that will make this box even smaller!
Now, the ports... Am assuming you have a pair of them, 3" dia. x 10.0" L. Is that correct? That nets about 0.03 cf/port for displacement. (net total of 2 ports = 0.006 cf
===================================================
Subs: Alpine 10" SWR displacement appears to be 0.09 cf/sub. With extention rings, will be a smaller number. (say 0.07 cf x 2 = 0.14 cf displacement.
===================================================
After crunching some numbers here, looks like you'll have ~0.69 cf/sub, if no divider board is used. If there is a divider board, that means less than .69/chamber.
===================================================
Ran some numbers on port tuning frequency from a pair of 3" x 10" ports. Looks like it will be tuned to ~49 Hz. Not bad for high SPL, but lousy for SQ bass. If the enclosure does not have an internal divider and you use only 1 port, now your PTF will be ~33 Hz. Much better SQ.
====================================================
A different option can be be used as well. Plug the ports and try it as a sealed enclosure. You get a smooth roll off of bass below 40 Hz this way and not a boomy bass sound either.
Whew... that was time consuming... That will be $25.00 in Consulting fees please. Cash or money orders are acceptable. (only half kidding)
Swez GRIN
Victor on 02/18/2005 09:02:52
hehe.. u deserve that money swez.. ( only quater kidding )..lol
oldmazda on 02/18/2005 14:55:39
woops sorry about that swez accidentally hit the "3" when i meant to hit the "4" it is actually 40" wide but other than that i think that you have it all figured out just about. i'm not sure how you calculated volume but its likely just a way i didn't think of and also they are seperated chambers. when i crunched the numbers i know i got over 1 ft^3 but i'm not 100% sure what the number was. i might not be able to reply to this post for a little while due to my going out of town but if you reply i will be sure to post as soon as i get back. thanks guys.
swez on 02/19/2005 09:45:32
OK, when you get back in town, pass me the real numbers used in this wedge enclosure design. Confirm the following:
Width = 40"
H1 = 14.5"
H2 = 10.0
D = 9.5"
Ports: 2 @ 4.0" x 10.0" long
There is a divider board (.75" thick?)
If that is correct, your internal volume net is ~ 2.05 ft^3
More math:
2.05 - 0.05 (divider) = 2.0 - 0.14 sub displacement = 1.86 ft^3
Port displacement: 4" x 10" = 0.07 x 2 = 0.14 ft^3
PTF = ~55 Hz
You have 2 primary options:
1. Change the ports for better low freq SQL
2. Eliminate the ports and run as a sealed enclosure
See ya when ya get back,
Swez
oldmazda on 02/24/2005 14:15:50
you've gotter all except for the ports swez the ports are 3" diameter not 4" hopefully that will make a little bit of a difference.
danielm87 on 02/24/2005 14:32:52
Yes, those 3" ports will take up less space in the net volume, BUT they will create a lot more port velocity, thus incurring an annoying swooshing noise every time the sub hits.
Heres a useful link to use as a crutch to aid in enclosure design.
Volume and Port Length Calculator=
http://www.the12volt.com/caraudio/boxcalcs.asp#por
oldmazda on 02/25/2005 23:25:52
so my tuning frequency would be about 39Hz? would this work for the alpine type R or S? aslo would it sound half decent i am not all that sure what the tuning frequency does though i'm assuming a high tuning frequency means that it wouldn't be able to hit the low frequencies and the bass would kinda be punchier though i don't really know. comments anyone?
oldmazda on 02/28/2005 20:15:56
anybody?
danielm87 on 02/28/2005 20:27:43
Rap lows hit anywhere from 20 - 40Hz.
Rock lows or mids hit around 80-200Hz,
So on, and so on....so regardless of what you're listening to, 30-100Hz is where you're really going to rumble your chest with bass.
Which means that 39Hz is a decent tuning frequency, and when the sub plays at or a little above 39Hz, you will gain +3dB versus a sealed enclosure at the same frequency, power, etc.
Hope that helps
swez on 02/28/2005 20:48:32
OK, let's review what port tuning is about. Have you ever taken a pop bottle with pop in it and blow across the rim of the neck? Sure... we get a pitched whistle. If we drink more pop, the pitch of the whistle gets lower in frequency. Port tuning is very similar in application.
The size and shape (area) of the port(s) determine the frequency at which they begin to come into play. Are we square on that now?
Assuming you get that now, ports can add SPL to a given box design at a target frequency, determined by the box volume (Vb), the port diameter and length of the port. For high SPL applications, many will tune their ports to 50 Hz or higher. For better SQ and low end bass, tuning below 40 Hz is recommended. Many of us SQ fans target 30-38 Hz., PTF, depending on our subs and taste for bass.
One thing to note about ported subs, we need a SSF (Subsonic Filter) to block out signals below PTF. If the subs are not filtered, they unload below PTF. VERY BAD FOR A SUB. (often fries the coils)
The main benefit to a ported sub, we can set the PTF where we like it. At PTF, most audio output is from the port and little from direct cone radiation. We can pick up ~+3dB of free bass in the PTF range.
Amy more questions?
Swez
Also i need a subwoofer that would work with my box size, its about 1.1 cubic feet and has a 3" wide 10" long port. i'm not sure about the tuning frequency mostly because i really don't have a clue was the phrase "tuning frequency" means and whether it has to do with the amp or the box or what. but anyways i would prefer a 2 ohm DVC setup like my old subs. i don't really have a definate price range i have some extra money lying around i just don't know how much i'd like to spend right now. i would think that $150 or so per speaker should about do it and wouldn't really wanna spend a whole lot more than that i don't think.
suggestions?
Replies (15)
oldmazda on 02/16/2005 18:15:23
anyone?
uochronos on 02/16/2005 20:02:26
elemental designs K series are pretty shallow, alpine type E's are also, i think infinitys are pretty shallow.
Chronos
oldmazda on 02/17/2005 01:27:06
alrite well i was thinking about it a little more and has anybody ever heard of slant spacers, i have a ring made out of mdf to make the sub fit out of the box a little further but the reason i can't get anything that deep is because of the angle the face of the box is. i was thinking that if i were add or replace my ring with one that would elevate the lower end so that the subs were facing more perpendicular to the bottom of the box i would eliminate my issues with depth. does anybody know if those are made prefab because they would be a pain to make out of mdf with all the sanding and all i dont' know if i would be able to make the side that i would angle perfectly straight because i would be sanding it down so i would have to seal up any cracks with silicone or something like that so i mean it wouldn't be perfect but i think i could make it work. has anyone ever seen anything like that?
swez on 02/17/2005 09:06:02
What is the actual mounting depth in this enclosure you mentioned? If there are air vents in the back of the magnet, need an airspace equal to or larger than the diameter of the vent. (measured between magnet assy., and back wall.
Port tuning is a procuct of overall enclosure space after subtracting drivers and port displacement values. The port is measured down the center of the port or vent for overall length. The width of the port includes baffles and side end panel.
You mentioned the box is ~1.1 cf. Is that 1.1 cf/sub, minus the port or total internal airspace or something different? (please explain in more detail)
Also, what amp are you planning to use for the subs?
Swez
PS Making angled spacers can be tricky. Best way I can suggest, use 1" MDF stock here. Then cut your 1" thick donuts. Then measure the angle you desire. After that, transfer that angle to the donuts, affix donuts to a stationary jig and use a coarse belt (40-60 grit) sander to rough it to proper shape. (~90% of final shape) Finish sanding can be done with a 100-120 grit belt to obtain a clean finish for mounting and accurate angles. This will go fast with a good belt sander. Mounting both donuts on the work fixture will allow you to match thickness and angles with minimal effort. Do you see the process mentioned, in your mind's eye?
oldmazda on 02/17/2005 15:56:31
ya i know what your saying, and i have access to just about all the tools that i will need, making that jig will likely be a little tricky for me but i think that i should be able to manage. the current mounting depth is about 5" but the only reason it is that shallow is because of my box setup and the angle that my subs are at. there is more than enough airspace behind vent, it is the edge of the magnet that is getting close to the rear wall of the box. if i angle the subs there shouldn't be an issue with depth at all because if i even just get them relatively close to straight down there is about 11" to the bottom of the box. though i don't think i will be able to angle it enough so that it is perfectly straight i think that i should be able to angle it enough so that i get about 6-7" of clearance which would be plenty for the type rs that i wish to get. i will likely take off the doughnuts that i currently have on now and angle them a little bit so taht i will not only have the 1" mdf angled donut but another 3/4" one as well.
until i have money i will be using my clarion apx400.2, because my alpine MRV-T505 wouldn't be capable of powering a whole lot other than speakers which i will eventually use it for. i am aware that the clarion amplifier doesn't dish out huge amounts of power but i won't be using the subs to the extreme really either, i mean every now and then i'll crank it up but that would not be a very common occurance really i don't think. i no longer have the specs on my clarion amp but if you wish to see them they aren't that difficult to find on the net.
i don't really understand the whole port frequency tuning thing yet, how would i calculate it for my box? it is 30" long by 9.5" deep and the angled top is so that the back side of my box is 14.5" tall and the front side is 10" tall. the whole thing is made out of 3/4"mdf and already has 1 3/4" donut on so will that make the subwoofer displacement lessen? but there will be another donut on shortly.... hopefully. and my ports are 3" internal diameter and 10"long. now i think that about sums up my box if i missed out any measurements tel me and i will try to get anything i can.
i think that the system i chose would be relatively compatible though i am not sure so if anyone has some ideas or has seen an error on my behalf let me know so that i can at very least reconsider it.
swez on 02/18/2005 08:44:44
Am getting very confused by the replies here. Let's backtrack a bit, before pressing ahead.
1. The enclosure used is a ported one, 2 x10 subs yes?
2. The overall dimensions of the box are:
L= 30" (this is really called Width)
H1 = 14.5"; H2 = 10,0" (net effect is 12.250")
D = 9.5
3. The numbers in cf: 30 x 12.25 x 9.5 = 3491 in^3/1728 = 2.02 ft^3
That's the external footprint of the box. Then we have to determine the internal cf of this enclosure, sub and port displacements.
My calculations show a 1.52 internal cf for this wedge box design. If there is an internal divider board between the subs, that will make this box even smaller!
Now, the ports... Am assuming you have a pair of them, 3" dia. x 10.0" L. Is that correct? That nets about 0.03 cf/port for displacement. (net total of 2 ports = 0.006 cf
===================================================
Subs: Alpine 10" SWR displacement appears to be 0.09 cf/sub. With extention rings, will be a smaller number. (say 0.07 cf x 2 = 0.14 cf displacement.
===================================================
After crunching some numbers here, looks like you'll have ~0.69 cf/sub, if no divider board is used. If there is a divider board, that means less than .69/chamber.
===================================================
Ran some numbers on port tuning frequency from a pair of 3" x 10" ports. Looks like it will be tuned to ~49 Hz. Not bad for high SPL, but lousy for SQ bass. If the enclosure does not have an internal divider and you use only 1 port, now your PTF will be ~33 Hz. Much better SQ.
====================================================
A different option can be be used as well. Plug the ports and try it as a sealed enclosure. You get a smooth roll off of bass below 40 Hz this way and not a boomy bass sound either.
Whew... that was time consuming... That will be $25.00 in Consulting fees please. Cash or money orders are acceptable. (only half kidding)
Swez GRIN
Victor on 02/18/2005 09:02:52
hehe.. u deserve that money swez.. ( only quater kidding )..lol
oldmazda on 02/18/2005 14:55:39
woops sorry about that swez accidentally hit the "3" when i meant to hit the "4" it is actually 40" wide but other than that i think that you have it all figured out just about. i'm not sure how you calculated volume but its likely just a way i didn't think of and also they are seperated chambers. when i crunched the numbers i know i got over 1 ft^3 but i'm not 100% sure what the number was. i might not be able to reply to this post for a little while due to my going out of town but if you reply i will be sure to post as soon as i get back. thanks guys.
swez on 02/19/2005 09:45:32
OK, when you get back in town, pass me the real numbers used in this wedge enclosure design. Confirm the following:
Width = 40"
H1 = 14.5"
H2 = 10.0
D = 9.5"
Ports: 2 @ 4.0" x 10.0" long
There is a divider board (.75" thick?)
If that is correct, your internal volume net is ~ 2.05 ft^3
More math:
2.05 - 0.05 (divider) = 2.0 - 0.14 sub displacement = 1.86 ft^3
Port displacement: 4" x 10" = 0.07 x 2 = 0.14 ft^3
PTF = ~55 Hz
You have 2 primary options:
1. Change the ports for better low freq SQL
2. Eliminate the ports and run as a sealed enclosure
See ya when ya get back,
Swez
oldmazda on 02/24/2005 14:15:50
you've gotter all except for the ports swez the ports are 3" diameter not 4" hopefully that will make a little bit of a difference.
danielm87 on 02/24/2005 14:32:52
Yes, those 3" ports will take up less space in the net volume, BUT they will create a lot more port velocity, thus incurring an annoying swooshing noise every time the sub hits.
Heres a useful link to use as a crutch to aid in enclosure design.
Volume and Port Length Calculator=
http://www.the12volt.com/caraudio/boxcalcs.asp#por
oldmazda on 02/25/2005 23:25:52
so my tuning frequency would be about 39Hz? would this work for the alpine type R or S? aslo would it sound half decent i am not all that sure what the tuning frequency does though i'm assuming a high tuning frequency means that it wouldn't be able to hit the low frequencies and the bass would kinda be punchier though i don't really know. comments anyone?
oldmazda on 02/28/2005 20:15:56
anybody?
danielm87 on 02/28/2005 20:27:43
Rap lows hit anywhere from 20 - 40Hz.
Rock lows or mids hit around 80-200Hz,
So on, and so on....so regardless of what you're listening to, 30-100Hz is where you're really going to rumble your chest with bass.
Which means that 39Hz is a decent tuning frequency, and when the sub plays at or a little above 39Hz, you will gain +3dB versus a sealed enclosure at the same frequency, power, etc.
Hope that helps
swez on 02/28/2005 20:48:32
OK, let's review what port tuning is about. Have you ever taken a pop bottle with pop in it and blow across the rim of the neck? Sure... we get a pitched whistle. If we drink more pop, the pitch of the whistle gets lower in frequency. Port tuning is very similar in application.
The size and shape (area) of the port(s) determine the frequency at which they begin to come into play. Are we square on that now?
Assuming you get that now, ports can add SPL to a given box design at a target frequency, determined by the box volume (Vb), the port diameter and length of the port. For high SPL applications, many will tune their ports to 50 Hz or higher. For better SQ and low end bass, tuning below 40 Hz is recommended. Many of us SQ fans target 30-38 Hz., PTF, depending on our subs and taste for bass.
One thing to note about ported subs, we need a SSF (Subsonic Filter) to block out signals below PTF. If the subs are not filtered, they unload below PTF. VERY BAD FOR A SUB. (often fries the coils)
The main benefit to a ported sub, we can set the PTF where we like it. At PTF, most audio output is from the port and little from direct cone radiation. We can pick up ~+3dB of free bass in the PTF range.
Amy more questions?
Swez
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