sub experts, need your inputs....
sub experts, need your inputs....
I've seen some enclosures where the sub is inverted, you know when the butt end is sticking out of the box. What advantage does this design has over the traditional "butt end" inside the box. How is the sound quality of the bass? Does the minimum cu.ft. of air space required by each subwoofer still applies? Thanks
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The point of an inverted sub is mostly to show off the sub more--it's usually only done for subs that have nice looking baskets and magnets. The airspace requirement should be the same. I would think the bass wouldn't have as much loudness potential due to the loss of cone area. Obviously, this installation will use more space inside the car.
Originally posted by bastard
I would think the bass wouldn't have as much loudness potential due to the loss of cone area.
I would think the bass wouldn't have as much loudness potential due to the loss of cone area.
Besides the middle area of the cone, you still displace almost the same amount of air. The only real advantage with inverted is that you present it with a larger enclosure since the sub doesn't displace air within the enclosure. It also looks good provided the sub has a massive magnet and some nice binding posts.
Plus, its relatively easy to test the speaker's ohm to determine if you fried a voice coil
Plus, its relatively easy to test the speaker's ohm to determine if you fried a voice coil
It allows you to make a smaller box for a given box design.
Since the basket and motor structure will no longer be "in" the box and taking up volume, the box is "bigger" so to speak. Also, the inversion of the cone makes for even more effective box volume.
Most people do it for show.... not all though. In my friend's FireHawk, it was our only option to get the box volume we needed as well as keeping his T-Top storage, even though the baskets on his JL W3s were ugly, it sure ended up sounding great.
Jim
Since the basket and motor structure will no longer be "in" the box and taking up volume, the box is "bigger" so to speak. Also, the inversion of the cone makes for even more effective box volume.
Most people do it for show.... not all though. In my friend's FireHawk, it was our only option to get the box volume we needed as well as keeping his T-Top storage, even though the baskets on his JL W3s were ugly, it sure ended up sounding great.
Jim
I thought I'd bring this thread back from the dead, after finding it on a search....
I have pretty much the same question as the orginator of the thread, with a slight variation. Does it matter whether the enclosure is ported or sealed, when mounting the sub inverted? I've got a Fosgate T112D4 that has a pretty nice looking magnet and I'd like to display it better. The enclosure is in the spare tire well and displaces 1.25 cuft. It's a sealed enclosure. I do not wish to lose any sound quality. Can anyone offer any input?
I have pretty much the same question as the orginator of the thread, with a slight variation. Does it matter whether the enclosure is ported or sealed, when mounting the sub inverted? I've got a Fosgate T112D4 that has a pretty nice looking magnet and I'd like to display it better. The enclosure is in the spare tire well and displaces 1.25 cuft. It's a sealed enclosure. I do not wish to lose any sound quality. Can anyone offer any input?
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From what I hear you will lose about 3 dbs by inverting the sub. I have done this with various speakers and they always sound like there is less output, especially in a sealed box.
However, the SQ will sound the same IMO
However, the SQ will sound the same IMO
If you have quality equipment that requires a sealed subwoofer box, do NOT invert the sub.
If you have a ported box and a SPL only sub and are not competing I guess it's okay. This is only done for show or when space is an issue somehow.
If you have a ported box and a SPL only sub and are not competing I guess it's okay. This is only done for show or when space is an issue somehow.
You will not lose 3dBs of output, that is complete BS.
There is no audible degradation in SQ by inverting it ... I have no idea where Fluid1 got that from. The only audible differences are that the pole vent (the hole in the magnet area) could make some audible chuffing at high volumes. The cone area difference is very small.
Look at it this way. You have a 9.25" wide effective cone area on a sub.
Pi*(9.25/2)^2 vs Pi*(2.5/2)^2 .... so thats about a ~15% cone area loss ...
then consider that you need to add an ENTIRE second 10" sub to gain 3 dB ... you surely aren't gonna lose 3 dB by losing 15% piston area.
Food for thought,
Jim
There is no audible degradation in SQ by inverting it ... I have no idea where Fluid1 got that from. The only audible differences are that the pole vent (the hole in the magnet area) could make some audible chuffing at high volumes. The cone area difference is very small.
Look at it this way. You have a 9.25" wide effective cone area on a sub.
Pi*(9.25/2)^2 vs Pi*(2.5/2)^2 .... so thats about a ~15% cone area loss ...
then consider that you need to add an ENTIRE second 10" sub to gain 3 dB ... you surely aren't gonna lose 3 dB by losing 15% piston area.
Food for thought,
Jim
Originally Posted by JimRHIT
The only audible differences are that the pole vent (the hole in the magnet area) could make some audible chuffing at high volumes.
He doesn't need to .. he was just letting us know of what he heard. He may have been incorrect ... but he never really tried to push it on us, so lets not grill him
Either way, the truth has been revealed above
Either way, the truth has been revealed above
You could mount a second woofer inside to form a trapped volume of air which is sent back and forth using one speaker to push and the other to pull. This sort of set up is call isobaric and is pretty rare (at least I ain't seen one!). The second internal speaker might be a way to "cheat" and get another 3dB worth of power into/out of the same size box.
There are some disadvantages of inverse mounting of the subwoofer. At lower sound levels you possibly can hear the motor noise and the spider isn't always treated to take the UV rays of the sun like the "top" side components of the speaker.
One of the advantages is that speaker magnet will be that it will be cooler as the woofer can vent to the free air of the car interior.
Here's a pretty good subwoofer forum.
http://www.diysubwoofers.org/
Another enclosure design that you may hear of is isobaric. Isobaric is not actually an enclosure type but a woofer loading method. Isobaric loading can be used in conjunction with any of the enclosure types, except perhaps infinite baffle. Isobaric loading consists of two woofers coupled together by a short enclosure which is only long enough to prevent the two woofers from striking one another. The woofers may be mounted face to face, back to back or front to back. It is important however to have the woofers firing in phase with one another. In order to accomplish this with the woofers firing front to front or back to back one of the woofers speaker leads must be reversed with respect to the other woofer.
Isobaric loading is usually used when space is at a minimum or a maximum number of woofers wish to be used in a certain volume of space. By isobarically loading the woofers, a box of only half the size of a one woofer box is needed. For example, if a 12" woofer requires a two cubic foot box, the same 12" woofer isobarically loaded only requires a one cubic foot box. The cost of this design, other than doubling the woofer cost, is a reduction in the subwoofer system efficiency by three decibels (if both woofers are given the same power as a single woofer), which is equivalent to halving the amplifier power. New, small box subwoofer designs have all but negated the need for isobaric loading in car audio and it has fallen out of popularity.
Advantages of this design are increased linearity in the speaker movement, lower space requirements, and increased power handling.
Disadvantages are increased cost, increased design and assembly complexity, and decreased efficiency.
Isobaric loading is usually used when space is at a minimum or a maximum number of woofers wish to be used in a certain volume of space. By isobarically loading the woofers, a box of only half the size of a one woofer box is needed. For example, if a 12" woofer requires a two cubic foot box, the same 12" woofer isobarically loaded only requires a one cubic foot box. The cost of this design, other than doubling the woofer cost, is a reduction in the subwoofer system efficiency by three decibels (if both woofers are given the same power as a single woofer), which is equivalent to halving the amplifier power. New, small box subwoofer designs have all but negated the need for isobaric loading in car audio and it has fallen out of popularity.
Advantages of this design are increased linearity in the speaker movement, lower space requirements, and increased power handling.
Disadvantages are increased cost, increased design and assembly complexity, and decreased efficiency.
One of the advantages is that speaker magnet will be that it will be cooler as the woofer can vent to the free air of the car interior.
Here's a pretty good subwoofer forum.
http://www.diysubwoofers.org/
Originally Posted by Paul350Z
You could mount a second woofer inside to form a trapped volume of air which is sent back and forth using one speaker to push and the other to pull. This sort of set up is call isobaric and is pretty rare (at least I ain't seen one!). The second internal speaker might be a way to "cheat" and get another 3dB worth of power into/out of the same size box.
There are some disadvantages of inverse mounting of the subwoofer. At lower sound levels you possibly can hear the motor noise and the spider isn't always treated to take the UV rays of the sun like the "top" side components of the speaker.
One of the advantages is that speaker magnet will be that it will be cooler as the woofer can vent to the free air of the car interior.
Here's a pretty good subwoofer forum.
http://www.diysubwoofers.org/
There are some disadvantages of inverse mounting of the subwoofer. At lower sound levels you possibly can hear the motor noise and the spider isn't always treated to take the UV rays of the sun like the "top" side components of the speaker.
One of the advantages is that speaker magnet will be that it will be cooler as the woofer can vent to the free air of the car interior.
Here's a pretty good subwoofer forum.
http://www.diysubwoofers.org/
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