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 sub suggestion? 
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Post Re: sub suggestion?
over powering a sub is not always a negative thing. depending on the model year of typeR you got they are a lot more power hungry then what they state. also if your box is sealed it will allow a sub to handle more then its listed RMS power. the big thing is proper tuning. i o-scope tune all the systems i install. so i know as long as the person owning the car doesn't play with the gains its set in a perameter that will not blow stuff up. i know of some guys running upwards of twice the rated RMS on stuff in sealed boxes. there is a lot more to a stereo then what the wires do and what somethings states it can handle. so all in all get your stuff done and listen to more then just the music. if something doesn't sound right its most likely not. but that is not to say the over powering is the issue.


NEUMAN

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neuman speeds and neuman drives an escort therefore i am
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14.3@ 100mph 91egt(now with "x" power) 209whp/226wtrq
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June 14 2011, 6:49 PM
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Post Re: sub suggestion?
Underpowering can sound just as bad. Clipping in the amplifier will make it sound like crap and potentially damage your sub as well (since you're sending it almost DC instead of a pulsating voltage) even when the amp is way under the rated power of the sub.

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June 15 2011, 12:32 AM
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Post Re: sub suggestion?
^ that also. hence why i o-scope tune things. you can always turn things down if your speaker is distorting from to much power. you can't always turn it up more. head room is key just like over boosting a turbo.


NEUMAN

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neuman speeds and neuman drives an escort therefore i am
Featured in SCC Readers Rides March 2005
15.592@ 88.44mph 91egt (when i was n/a)
14.3@ 100mph 91egt(now with "x" power) 209whp/226wtrq
03 - Toyota Matrix XR AWD - 07-current
93 - EGT/323 - 04-current
91 - EGT - 07-current
91 - EGT-X - 01-05
90 - 323hb - 05-07
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88 - EGT - 00-01
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June 15 2011, 12:39 AM
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Post Re: sub suggestion?
i did a bit more research and it looks like its impossible to wire a single 2/2ohm dvc sub to 2ohm. 1/4/8 ohms being the supported resistances. with that being the case my amp puts out 400w at 4ohm so should match up quite well.

now ive hit a couple of a problem with my box:

1. i had it pretty much ready for the top wood to be installed when i measured the volume with L of water then converting it to cubic feet. my problem was the box was too big so i fb'd in some cardboard boxes into the corners which brought me to the desired 1 cubic foot. that was perfect

2. i picked up my sub which was 2-3" too tall for the height of the box. i solved that problem by making a cardboard mold around the box and raising the walls.

3. my current problem is that by raising the height of the walls the box volume jumped up to 1.5 cubic feet. im really getting tired of glassing plus i dont really want to buy more supplies. would having the box .5 cubic feet (50%) bigger then the manufacturer's suggested size cause the sub to sound bad? is it possible to fill in the volume without adding to the box? i was thinking blocks of wood screwed to the wood top of the box, or maybe some bags of sand or something? ive also read somewhere about using spray foam insulation?

any tips guys? thanks for the info about the amps and everything. youve been very helpful.

progress so far Image the white crap is dust from trimming the top...


Last edited by mikeinaus on June 17 2011, 12:41 AM, edited 1 time in total.



June 17 2011, 12:26 AM
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Post Re: sub suggestion?
As far as I know, and I could be totally wrong, the volume of the box is there only to function as a hemholtz resonator to amplify or weaken certain frequencies, that the sub resonantes at, or is particularly weak at. this is why the shape of a FG box is irrelevant, as the shape of a hemholtz is irrelevant. A square box will produce resonance at similar frequencies if it has two similar dimensions, thats why every wooden box should have 3 different dimensions.

Proper volume -> most consistent bass

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Last edited by Ryan on June 17 2011, 12:47 AM, edited 1 time in total.



June 17 2011, 12:38 AM
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Post Re: sub suggestion?
any ideas on reducing volume without buying more fiberglass? ive already spent at least $120+ on just fb supplies. gone threw over a gallon of resin and like 6 bags of cloth/mat.

im leaning towards the bag of sand idea if you think it would work.


June 17 2011, 12:43 AM
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Post Re: sub suggestion?
Heh. Neat Idea. I bet sand would add an interesting oomph to it.

how did you manage to spend so much? A wooden box properly covered would be cheaper at this point.

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June 17 2011, 12:48 AM
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Post Re: sub suggestion?
gallon of resin was like $30+, cloth/mat were $6 a bag, gloves, brushes, mixing cups, tape +++


June 17 2011, 1:00 AM
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Post Re: sub suggestion?
throw a port in it! i would knock out those corner peices you put in to reduce the size. that should bring it back to about 2 cubes. then put in a nice 3" port roughly 10" in over all length. that will give you a tune of about 38hz IIRC. it will sound great. you could run a 4" port at about 13 inches. i could work the math for you later tonight if you want me too.


NEUMAN

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neuman speeds and neuman drives an escort therefore i am
Featured in SCC Readers Rides March 2005
15.592@ 88.44mph 91egt (when i was n/a)
14.3@ 100mph 91egt(now with "x" power) 209whp/226wtrq
03 - Toyota Matrix XR AWD - 07-current
93 - EGT/323 - 04-current
91 - EGT - 07-current
91 - EGT-X - 01-05
90 - 323hb - 05-07
89 - ELX - 98-00
88 - EGT - 00-01
neuspeedescort - neuman audio car stereo fabrication

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June 17 2011, 12:05 PM
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Post Re: sub suggestion?
i was kinda planning on a sealed box but if you think a port would be better im open to the idea. i was in a new cherokee lorado a couple weeks back and the stock stereo was amazing and is kind of my inspiration. i want a well balanced high quality sound more then loud bass.

does the location/direction of the port matter? my box isn't very tall. the back of it where the sub is going to be is the deepest and is maybe 11" the front side is at the top of the hump in the spare tire well and is maybe 6". the only place i think it would work is if i had it horizontal on the front wall of the box near those boxes i added. im planning on having a little storage spare there under a false floor for oil and such. i also dont know how it would affect the sound having the port going into a mostly enclosed area. i know almost nothing about ports but i was under the impression they needed to be in a specific spot and distance from the rear wall of the box?

where do i buy tubes for ports? would pvc work? your pretty much the audio guy around here from what ive been reading Neuman. ill go with whatever you think would be best...

also those boxes i threw in took up roughly 4L of volume or .141 cubic feet. if i removed them id have a volume close to 1.65 cubic feet if my maths right.

just read this about my sub from crutchfield
Quote:
Recommended Vented Box Volume: The vented box sizes recommended by Alpine range from 0.75 cu/ft to 2.0 cu/ft. Within this range, the ideal size recommended by Alpine is 1.7 cu/ft, so this is the enclosure recommended by Crutchfield. A slot port with the following dimensions should be used with the 1.7 cu/ft enclosure: W = 12", H = 1.25", L = 21". If you cannot use a slot port in your enclosure, you will need a port tube with the following dimensions: Diameter = 3", L = 9.9".


looks like my box's volume would be perfect for a port. if the location doesnt matter ill probably pop those boxes out and be done with it.


June 17 2011, 8:45 PM
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Post Re: sub suggestion?
i'm glad to see you did some research. that is something i can't say for a lot of people. going off the alpine specs it looks like that port (3" tube) is going to be tuned at roughly 29hz. this will make your box very musically friendly. granted it will get loud when you want it too. port location is subject to opinion. as long as your port is 9.9" or 10 to make it easy and has a free opening to breath you should be ok. if you port it under the false floor you may have an issue. i suggest porting it up at the back of the box if your concerned about stuff falling in there. find a small speaker grill to retro fit on it but at the same time make it sit flush and look clean. i know that is a lot to accomplish. just think tho this is the final touch to the mission you have already started.


NEUMAN

_________________
neuman speeds and neuman drives an escort therefore i am
Featured in SCC Readers Rides March 2005
15.592@ 88.44mph 91egt (when i was n/a)
14.3@ 100mph 91egt(now with "x" power) 209whp/226wtrq
03 - Toyota Matrix XR AWD - 07-current
93 - EGT/323 - 04-current
91 - EGT - 07-current
91 - EGT-X - 01-05
90 - 323hb - 05-07
89 - ELX - 98-00
88 - EGT - 00-01
neuspeedescort - neuman audio car stereo fabrication

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June 18 2011, 10:01 PM
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Post Re: sub suggestion?
the problem with a vertical port is the box is only 9" deep at the back wall. the deepest part (where the sub sits) is 10" deep. any problems with using an L shaped or curved port? or a shorter, skinnier/ fatter port? when the length of the port is measured does it include the thickness of the top board (3/4")? or is it supposed to be 10" below the wood?

after i install the top i would have on average height of 8.25" with the center of the box being maybe 4" deep at its lowest point.

Edit:

just did some more research. from what ive found the shape of the port isnt that important. its more important to have smooth curves and maximum airflow then it does shape. is this correct?

now whats the best material for a port? pvc? are flared ends important?


June 18 2011, 10:51 PM
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Post Re: sub suggestion?
angled port will play no factor.

hit up the home repair shop. lowes, home depot, ace, etc.etc. find a 3" ABS (black plastic) sweeping 90 and the shortest piece of 3" possible. the 90 will be about 7-8 inches of your port length needed. when figuring your port length measure the center line of the curve. it will help keep you the most accurate. then the flared bell sections glue stubs of pipe in them. the little ridge inside will not effect the sound. on one end the one you choose to be the one exiting the box cut it so the piep is at the bell or the stub extends 3/4" to clear the top plate. before you warry the top plate to the glass bowl i suggest glassing the pipe to the wood. if you want you can apply a little bondo in the seem and sand it out to make it smooth. if you want. so to answer you yes pvc will work. i use it all the time. so does any body else.

if you want to flare it after all this and the port is installed like i said with it glassed. get a router with a 1/2" round over bit and put a small flare to it.


NEUMAN

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neuman speeds and neuman drives an escort therefore i am
Featured in SCC Readers Rides March 2005
15.592@ 88.44mph 91egt (when i was n/a)
14.3@ 100mph 91egt(now with "x" power) 209whp/226wtrq
03 - Toyota Matrix XR AWD - 07-current
93 - EGT/323 - 04-current
91 - EGT - 07-current
91 - EGT-X - 01-05
90 - 323hb - 05-07
89 - ELX - 98-00
88 - EGT - 00-01
neuspeedescort - neuman audio car stereo fabrication

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June 18 2011, 11:29 PM
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Post Re: sub suggestion?
Quote:
then the flared bell sections glue stubs of pipe in them. the little ridge inside will not effect the sound.


what do you mean by this? im assuming you mean to just put a tiny section of pipe after the curve to reduce the connector diameter back to 3" like the rest of the pipe?

as for attaching it to the top ill find a way to make it work. the false floor is going to be covered in carpet so it doesnt matter that much if the top of the box is fugly...

one last question. i plan on having my false floor sit ontop of the box with 3/4" wood. it will have sections cut out for the sub face and the port opening. do i include the 3/4" thickness of the 2nd piece of wood in the length of the port? or does the port length matter more for inside the box?

and do you know of any type of filter or fabric i could cover the top of the port with to stop debris from entering? i plan on putting a grill ontop but itd be nice to have something to keep out any crumbs...


June 18 2011, 11:47 PM
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Post Re: sub suggestion?
mikeinaus wrote:
Quote:
then the flared bell sections glue stubs of pipe in them. the little ridge inside will not effect the sound.


what do you mean by this? im assuming you mean to just put a tiny section of pipe after the curve to reduce the connector diameter back to 3" like the rest of the pipe?

as for attaching it to the top ill find a way to make it work. the false floor is going to be covered in carpet so it doesnt matter that much if the top of the box is fugly...

one last question. i plan on having my false floor sit ontop of the box with 3/4" wood. it will have sections cut out for the sub face and the port opening. do i include the 3/4" thickness of the 2nd piece of wood in the length of the port? or does the port length matter more for inside the box?

and do you know of any type of filter or fabric i could cover the top of the port with to stop debris from entering? i plan on putting a grill ontop but itd be nice to have something to keep out any crumbs...



1. yes you understand perfectly.

2. attach the port to the top section on the inside to not hinder any air flow.

3. that 3/4" of false floor wood will not change the port tune by much. if anything it will lower it. lower is generally better 9 out of 10 times.

4. honestly i would find a grill from a 6" speaker and attach just the metal art to the false floor section. it shouldn't suffocate the port flow.


NEUMAN

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neuman speeds and neuman drives an escort therefore i am
Featured in SCC Readers Rides March 2005
15.592@ 88.44mph 91egt (when i was n/a)
14.3@ 100mph 91egt(now with "x" power) 209whp/226wtrq
03 - Toyota Matrix XR AWD - 07-current
93 - EGT/323 - 04-current
91 - EGT - 07-current
91 - EGT-X - 01-05
90 - 323hb - 05-07
89 - ELX - 98-00
88 - EGT - 00-01
neuspeedescort - neuman audio car stereo fabrication

facebook fan page


June 19 2011, 12:44 AM
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