Bought 2 RE audio 18 SX's....... and....

[snfsh79077 10+ year member]

the fact that your box is small for theese subs is what is limiting the excursion of them. I have the same problem. my sub is in around 5 cubes net ported at 34 hzsame subs as yours only I have 1 - and I hardly get the excursion I thought it was capable of. why ? because the sub is fighting the small air space in the box. every time the sub "hits" its pushing the cone out. what this does is stretches the air inside the box - even tho the box is ported - it is still too small amount of air to stretch to allow full movment of the cone. this is why choosing the right subs is soo important. a pair of 15's in the right size box will sound better than a pair of 18's in a box too small due to the above thery.

if your subs play and sound nice - they are not damaged too badly.

the only way to check if they are going bad or not is to put that dmm meter on ohm reading ( looks like headphones on the dial for it ) and read the subs voice coils. + and - and it will tell you what the exact ohm is. when doing this have the sub facing up. do not set it upside down so the cone is resting on the table. this pushes in the cone a bit, and will throw off the ohm reading.

I have never tested a "bad sub" but I would imagine that its coils would read lower. if you had a dual 4 ohm sub, and one coil went bad, I would imagine it would read less than 2 ohms on the bad coil, and 4 ohms on the regular coil.

also - note when reading coils for ohm - it is pretty normal to see 3.7 to 4.3 ohms on the meter on a "4 ohm coil". not exactly shure why... but I get those results some times.

glad to hear you got your system bumping well.

do you have any ports leading from your trunk of the car in to the cabbin ?

or do you fold down a seat or something to allow bass to enter the drivers area?

no when a vc is damaged or fried the ohm measure will rise a little if damaged and just about infinitely if fried

 

[knowledgestick 10+ year member]

http://www.audiopulse.com/products/subwoofer-drivers/lms-ultra

18″

5000 W RMS

4th order reflex enclosure volume - 4.5 - 7.0 ft³

2nd order sealed enclosure volume - 3.8 - 6.5 ft³

thats ****ing nuts ! for a sealed enclosure 18''s that can handle that much RMS and put out that much SPL !!! i think i might need to save up for a pair of thease things they seem like they are perfect for my aplication.

"Many drivers fall short these features and relying on large box volumes to make up for low frequency efficiency, but the AXIS doesn’t need any help, with 40+ pound motor, flat-wound conductor on a triple reinforced heatsink former and all the BL product in the world, it works harder so you don’t have to give up half your car to a large subwoofer box."

i think TC sounds might be the way i am going to go, audiopulse LMS ultra drivers, i just dont know if i can afford 2 of them //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

or what types of amplifiers i could use to run them at their full potential, but those things are deffinatly my #1 target in terms of woofers now after finding out about the space requirements for them, **** !

i will be able to make those things do real well in the space that is available in my trunk. I just need to get the cash to be able to afford them, and then for now ill just get another hifonics brutus and run 2600rms to each one , then when i can afford it ill get 2 sundown 3000d's and run 1 to each.

I had no idea 18''s out there could exist like this, I wonder if FI BTL's are the same in anyway and can preform well in smaller or even sealed enclosures.

 

[knowledgestick 10+ year member]

no when a vc is damaged or fried the ohm measure will rise a little if damaged and just about infinitely if fried

rise a little as in creep up and not stop or will it fluxuate ? sorry can u elaborate a little more, thanks man //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif i might want to run a test or two on mine to make sure they are indeed 100%.

 

[snfsh79077 10+ year member]

rise a little as in creep up and not stop or will it fluxuate ? sorry can u elaborate a little more, thanks man //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif i might want to run a test or two on mine to make sure they are indeed 100%.

if its damaged it will rise to a point and stop

 

[Cameron_B 10+ year member]

http://www.audiopulse.com/products/subwoofer-drivers/lms-ultra
18″

5000 W RMS

4th order reflex enclosure volume - 4.5 - 7.0 ft³

2nd order sealed enclosure volume - 3.8 - 6.5 ft³

thats ****ing nuts ! for a sealed enclosure 18''s that can handle that much RMS and put out that much SPL !!! i think i might need to save up for a pair of thease things they seem like they are perfect for my aplication.

"Many drivers fall short these features and relying on large box volumes to make up for low frequency efficiency, but the AXIS doesn’t need any help, with 40+ pound motor, flat-wound conductor on a triple reinforced heatsink former and all the BL product in the world, it works harder so you don’t have to give up half your car to a large subwoofer box."

i think TC sounds might be the way i am going to go, audiopulse LMS ultra drivers, i just dont know if i can afford 2 of them //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

or what types of amplifiers i could use to run them at their full potential, but those things are deffinatly my #1 target in terms of woofers now after finding out about the space requirements for them, **** !

i will be able to make those things do real well in the space that is available in my trunk. I just need to get the cash to be able to afford them, and then for now ill just get another hifonics brutus and run 2600rms to each one , then when i can afford it ill get 2 sundown 3000d's and run 1 to each.

I had no idea 18''s out there could exist like this, I wonder if FI BTL's are the same in anyway and can preform well in smaller or even sealed enclosures.

The BTL is a ported box woofer.

 

[audioholic 5,000+ posts]

No, you are just an egotistical douche bag that needs to grow up and get over some issues. BOY

I absolutely love how you keep telling me I need to grow up while also calling me school-yard names. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

I dont care if you think i dont have a right to own this gear, I do and i have every right to learn how to use it right, so go screw yourself and get a life...

You nailed it. Your mid-grade subwoofers and entry-level amplifier are too good for you to own, and Im hella jealous. You know my motives so well.

 

[brian84corvette 10+ year member]

I think you should do this :

plan out your car build.

right now - your trunk is crazy loud, and your cabbin of the car is semi loud.

you are wasting power and sound for the end result of you not being fully satisfied

with your current system, that is more than capable of beating your car to pieces.

if I had your car, I would build a wall in it. no more back seat.

subs facing the front winshield - port also facing front winshield.

but if you feel the need to keep your back seats, do the following,.

find a way to port your trunk to the cabbin of the car.

it is essential.

either cut out a couple of big holes in the package tray, and use some large pvc pipe

or even better - get like eight 4" aero ports to use from the trunk to the cabbin and install them on your rear package tray. there is no reason to seal up all that sound in your trunk.

if your not cool with the package tray cutting, then find a way to modify your back seats to allow more sound to pass from the trunk to the cabbin.

im not calling your car junky, please dont think this, but at the same time, its not a bemer or benz here - so dont worry about messing it up. its IS going to get messed up from all the abuse you are giving it with your subs. so a fiew holes in the rear package tray isnt going to kill re sale value that much if your worried about that.

also - one question for you, about a possible box design idea I have,

what is the height of your trunk where the back seats are.

meaning - if you were to remove your back seat rest - not the bottom cussion

but the back part of the seat- and cut that area out so that it was totaly open to the trunk,

how tall and wide is the area going back there ?

my ideas are about doing your system "infinate baffle" or also making a box in your trunk that extends in to the cabbin, and becomes the back part of your back seat.

so the box is all in the trunk still, but the subs are mounted facing in the cabbin of the car

wich will allow you maximum spl in side the cabbin of the car, while increasing the size box you can turn your trunk in to.

its no good if your trunk is 150 db loud and the cabbin of your car is 135

also - audio pulse is amazing stuff. used to be "tc sounds"

but its verry costly. and in my opinion - not worth buying brand new at retail prices.

 

[knowledgestick 10+ year member]

I think you should do this :
plan out your car build.

right now - your trunk is crazy loud, and your cabbin of the car is semi loud.

you are wasting power and sound for the end result of you not being fully satisfied

with your current system, that is more than capable of beating your car to pieces.

if I had your car, I would build a wall in it. no more back seat.

subs facing the front winshield - port also facing front winshield.

but if you feel the need to keep your back seats, do the following,.

find a way to port your trunk to the cabbin of the car.

it is essential.

either cut out a couple of big holes in the package tray, and use some large pvc pipe

or even better - get like eight 4" aero ports to use from the trunk to the cabbin and install them on your rear package tray. there is no reason to seal up all that sound in your trunk.

if your not cool with the package tray cutting, then find a way to modify your back seats to allow more sound to pass from the trunk to the cabbin.

im not calling your car junky, please dont think this, but at the same time, its not a bemer or benz here - so dont worry about messing it up. its IS going to get messed up from all the abuse you are giving it with your subs. so a fiew holes in the rear package tray isnt going to kill re sale value that much if your worried about that.

also - one question for you, about a possible box design idea I have,

what is the height of your trunk where the back seats are.

meaning - if you were to remove your back seat rest - not the bottom cussion

but the back part of the seat- and cut that area out so that it was totaly open to the trunk,

how tall and wide is the area going back there ?

my ideas are about doing your system "infinate baffle" or also making a box in your trunk that extends in to the cabbin, and becomes the back part of your back seat.

so the box is all in the trunk still, but the subs are mounted facing in the cabbin of the car

wich will allow you maximum spl in side the cabbin of the car, while increasing the size box you can turn your trunk in to.

its no good if your trunk is 150 db loud and the cabbin of your car is 135

also - audio pulse is amazing stuff. used to be "tc sounds"

but its verry costly. and in my opinion - not worth buying brand new at retail prices.

Yeah the audiopulse stuff is EXTREMELY expensive, but their LMS 18'' woofers can handle being in like 4 cubic foot sealed box's aswell as big nice open ported ones.

Just was curious if the BTL's will be anything like that at all, but i guess not.

You must have been on the same wave length as me reciantly, lol. I am going to be getting a port done where the 6*9's are in the back above the back seats, and i am going to do a port where the arm-rest is in the back seats i think.

I know my cars not a beemer or a benz, it is a nice car though and that has nothing to do with porting the cabin im fine with that, because when im done with this thing its going to look like a million bucks //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif and hopefully sound like it.

I think i will still go ahead and get the BTL's and save the gear up and like you said, plan my install. I already have a pretty good idea of what i want to do once i get them in and how i want to configure them and what changes i want to make to the box.

Basicly will just have to get a new head unit that is a 8v for sure i want to be able to feed both of the amplifiers that will be back there all the current they can take to reduce the level i need to put into the amplifiers. I would go with the wall, but i like having the back-seats and being able to kick the shit out of the people in the back lol //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif this car is more or less for my own personal prefferance im not into the hole car audio scene, ill take it to a competition now and again, but when it comes down to it i am building it for me.

The width and height of the area you are speaking of is...

- the back rest is 24 inches high, from seat to top.

- The back rest is 47 inches wide from passanger side to driver side.

But inside the trunk, it is not that wide at the very back it gets smaller.

Im not quite sure if that makes any sense, but yeah. I See what you are trying to say but i dont think it would work. I am going to raise the box up 7 inches the maximum i can raise it witch will add a good amount of extra cubic feet, and i am going to put the propper sized port in the box this time.

Also, porting the cabin will be done for sure. I just have to figure out where, and how my mechanic could probably do it for dirt cheap. Anyways, Thanks for the advice man What head-units would you all recomend to use for running 2 amplifiers of this power ? I think right now the system is deffinatly nice, its deffinatly loud. But it is not where i want it to be, and i dont think any amount of tuning could get it there i want to make the switch to BTL's so i can run that extra RMS into them, aswell as the fact they are just simply more heavy duty and built to take more punishment. And the fact they preform a little better in less than optimum enclosures, After all is said and done iwth my new box i am hoping for a good 12-13 cubic feet after all displacement and bracing.

Thanks guys !

Thanks!

-andrew

 

[knowledgestick 10+ year member]

oh and here is a link to a walled out mini cooper, i bet this box is less cubic feet than mine.

http://www.stevemeadedesigns.com/board/index.php?showtopic=19084

" His box is around 12Ft cubed net at 31hz with 2 re audio mt 18' and hes suppose to be powering them with 2 saz-3000ds but cant seem to get his *** in gear to finish some lousy door panels. "

So there you go, 12 cubic foot box for 2 RE audio 18'' MT's.

The port looks to be much larger though, So i will deffinatly be taking care of getting my port extended and made to the propper size to obtian the freqency that i am looking for.

i know 35-40hz is good for SPL competitons but for daily driving/competitions i want this box to be a mixture of SPL and personal preferance, So i think i am going to go for the low 30's like i have said already. I love that bass you can just feel shake your hole car apart //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I will probably port it at 31hz like that mini cooper in the above post.

It is funny that i am using hifonics amplifiers with RE audio gear, RE audio's subwoofer tech said that hifonics are some of their best competition in bassraces and other more serious competitions. I am glad to be using 2 deciant brands, At first i thought thease SX's where a little wimpy, But once i learned it was my fault for not adjusting the gain propperly i found new respect for them. They slam hard, But they are just not quite what i am looking for I dont think.

We will see once the new BTL's arrive, Because before those go in i still have to get another amplifier, another battery , my new head-unit and my box re-done, the last 2 will be done first so that i can get an improvement out of my current setup/install.

Then once my new head-unit is in, my new box is made with the new port, I will get the 3rd battery installed, along with my 2nd alternator and have my 2nd hifonics brutus dropped in along with the FI BTL's to top it off.

I hear what you are saying though about most of the noise being trapped in my trunk. I am trying to figure out a way to perhaps make the back of the box, the back-rest of the seats, and to have the port in the middle of the two seats or somthing, I dont know. ALOT of air preasure comes up through where the speakers sit, I wish it wasnt all metal there so i could just remove that cover and allow ALOT ALOT more air to flow through that would be very nice.

Thanks for the help and input guys ! i knew the box wasnt causing the thermal over-heating, look at how small that mini coopers box is for 2 SX 18''s !

stupid me with being stubborn and not adjusting the gain right

Thanks to those who nailed that one through my thick skull //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

BTW guys, can you get higher quality decibal meters than the one i have that is hand-held and cant read over 130db ?

-andrew

 

[mazdakid 5,000+ posts]

that guy with the mini cooper is on this forum, and its for mt 18's like you said the first time, not sx18's.

do you have speakers in the back deck?

 

[snfsh79077 10+ year member]

that guy with the mini cooper is on this forum, and its for mt 18's like you said the first time, not sx18's.do you have speakers in the back deck?

x2 you can't compare two different setups. Your SX's require more airspace. As for him not getting his "shit" together for those panels, hes doing all the work himself in what was his daily driver for a long time so its not something he can just park and do. The work he did is way more than you could ever.

 

[knowledgestick 10+ year member]

x2 you can't compare two different setups. Your SX's require more airspace. As for him not getting his "shit" together for those panels, hes doing all the work himself in what was his daily driver for a long time so its not something he can just park and do. The work he did is way more than you could ever.

ahahahahahha man, i never said anything about him dragging his ***, and yea the guy has mad skills and is seriously good at what he does, do you want to point out to me where i said any otherwise ?

there was no reason for you to say that i could never do that, even though i probably couldnt but its just another one of those times when somebody trys to say somthing to stir up crap.

its strange how SX's require more airspace than the MT's witch are the 70 pound SPL version's of the SX's.

But yeah, the guy did a great job on his install. And im sure like everybody else, he had to start someware.

Next time you try and insult somebody make sure i am the one who actually put him down, that was his GF i think who said that in the post when she responded to me when i asked my question about how much RMS he is putting into them and how much cubic feet his box is. I never once put down his craftsmanship or said i could do any better, So that was completely uncalled for and a waste of everybodys time.

do thease posts in this forum constantly turn into gutter crap ? i am a member on steve maede's site and many others and id have to say this place has the biggest collection of immature douche-bag's who try and get off by putting people down than any other internet forum i have ever seen, and thats saying alot.

I thought http://www.abovetopsecret.com was bad, some members here make that place look like happy-get-along-hold hands land.

Owell atleast i have plenty of other forums where the members are much nicer and open to helping not just arogent and stuck up //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif BTW if i set my mind to it and opened a shop and made it my goal to do custom installs im sure i could, so no he did not do somthing i could never do. I just dont have the tools, or the facilitys to get into doing my own work or i would.

 

[knowledgestick 10+ year member]

that guy with the mini cooper is on this forum, and its for mt 18's like you said the first time, not sx18's.do you have speakers in the back deck?

MT 18''s are much larger than SX's they are for pure SPL and you would think would put out alot more preasure than the SX's.

Also they are like 80 pounds, so how could that woofer require less space than the SX's ?

 

[brian84corvette 10+ year member]

because that woof is more about trying to be louder than clean.

a good clean sounding 18 = FI Q

a loud as F sub = FI btl.

both are totaly opposite of eachother.

if you listen to any kind of music daily for pleasure while driving, id say Q

but if your only goal is to produce loud tones of bass for a meter = BTL.

something about how they design the motor to work is how it requires the air space needed

for the box, and tuning. but yes, it seems weird that one sub can be ok in 4 cubes and the same size sub from another brand or even diffrent line up needs 7 cubes

it is my personal belief that the re sx series is suposed to have some kind of sound quality engineering done,

as mine sounds good up to about 70% of its playing capability. pounds nice and hard, almost clean.

but when going for the gold, and giving it all it can take - it just sounds like pure spl tones.

im not even shure if there is any sub that can play that loud and sound clean and musical if you will.

anything above 140db is basicly pushing to pure spl range for me I believe.

fourm member snoodpan has 2 re sx 18's walled in his jeep - and I believe he hit 152 on a tl recently at a show.

thats quite a good number I believe and I would be verry proud of that result in my car.

 

[snfsh79077 10+ year member]

ahahahahahha man, i never said anything about him dragging his ***, and yea the guy has mad skills and is seriously good at what he does, do you want to point out to me where i said any otherwise ?
there was no reason for you to say that i could never do that, even though i probably couldnt but its just another one of those times when somebody trys to say somthing to stir up crap.

its strange how SX's require more airspace than the MT's witch are the 70 pound SPL version's of the SX's.

But yeah, the guy did a great job on his install. And im sure like everybody else, he had to start someware.

Next time you try and insult somebody make sure i am the one who actually put him down, that was his GF i think who said that in the post when she responded to me when i asked my question about how much RMS he is putting into them and how much cubic feet his box is. I never once put down his craftsmanship or said i could do any better, So that was completely uncalled for and a waste of everybodys time.

do thease posts in this forum constantly turn into gutter crap ? i am a member on steve maede's site and many others and id have to say this place has the biggest collection of immature douche-bag's who try and get off by putting people down than any other internet forum i have ever seen, and thats saying alot.

I thought http://www.abovetopsecret.com was bad, some members here make that place look like happy-get-along-hold hands land.

Owell atleast i have plenty of other forums where the members are much nicer and open to helping not just arogent and stuck up //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif BTW if i set my mind to it and opened a shop and made it my goal to do custom installs im sure i could, so no he did not do somthing i could never do. I just dont have the tools, or the facilitys to get into doing my own work or i would.

I didn't click the link I just knew who you were talking about. Also you made it sound like you were the one criticizing so slow your roll buddy.

Also, I believe the MT's are more of a groundpounder woofer that can take large amounts of power for an extended amount of time. Well when you want to send a woofer a lot of power you don't always want a giant enclosure. The sx's have lower power handling capabilities but require a bigger box.