2 questions: enclosure / est. price

[BreakingBad]

first question: i had an enclosure built, designed by immacomputer for a re xxx 18", 07 ver. anyway, on some notes i notice (which it seems to be) the box making a weird noise, almost like the box resonating. to describe it better, its a high-pitched noise that seems to come from the sub playing a note the box isnt either responding to, or something. very hard to explain, but it is -very- noticable.

for example, if i run a 100hz to 20hz test song, from 50-35hz (around there) its booming... but right around 30-20 it makes a high pitched resonating noise, which you can obviously hear over the bass, then obviously at 20hz everything is shaking you just can't feel or hear it really.

now is this due to bad bracing in the box? could a non-stable box make those noises on certain notes?

second question: at some point i'll be selling my XXX 18 (2007). retails for 2,000+. given i find a true, honest buyer - AROUND what should i get for a used XXX 18, great cosmetic and performance condition?

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[DBDRAGGUY 10+ year member]

first question: i had an enclosure built, designed by immacomputer for a re xxx 18", 07 ver. anyway, on some notes i notice (which it seems to be) the box making a weird noise, almost like the box resonating. to describe it better, its a high-pitched noise that seems to come from the sub playing a note the box isnt either responding to, or something. very hard to explain, but it is -very- noticable.
for example, if i run a 100hz to 20hz test song, from 50-35hz (around there) its booming... but right around 30-20 it makes a high pitched resonating noise, which you can obviously hear over the bass, then obviously at 20hz everything is shaking you just can't feel or hear it really.

now is this due to bad bracing in the box? could a non-stable box make those noises on certain notes?

second question: at some point i'll be selling my XXX 18 (2007). retails for 2,000+. given i find a true, honest buyer - AROUND what should i get for a used XXX 18, great cosmetic and performance condition?

It is hard to tell, my first guess is turbulence (port noise) at that frequency. Tell us more about the box and maybe someone will know for sure.

 

[BreakingBad]

It is hard to tell, my first guess is turbulence (port noise) at that frequency. Tell us more about the box and maybe someone will know for sure.

~5.35 cu. ft sealed...

built strong, but i'm thinking not enough bracing for the XXX...he has 2x4's bracing it as he didn't have dowel rods.. i can always take it back and have them redesign it / re-do it if needed as i told him what i wanted, and they guarantee their work/warranty it.

 

[mdillon 10+ year member]

well if its not port noise, could it be mechanical noise? maybe its the way the box is interacting with your vehicle. try filling it with poly fill to see if you can get the whining noise to change or go away. it could just be a volume issue.

 

[BreakingBad]

no idea, it occurs randomly.

what would happen if a sub that large wasn't properly fitted in the box (ie, loose screws or not screwed in tightly)?

 

[mdillon 10+ year member]

noise from around the basket escaping. buy weatherstripping and bolts to make sure its good and sealed. if you push the cone down, it should return to rest very slowly.

 

[60ndown 10+ year member]

air leak somewhere, proly round the sub somewhere, sealed box shold have nothing but bass, def no squeaking?

take sub out, check hole size cutout, get some weather stripping/rubber matt or something about 1/2 inch thick and rubbery, glue strip of rubbery material around sub hole and re-insert sub making sure there is no space/leak/anywhere for air to escape easily, screw sub down tightly.

but an 18 with lots of powerina sealed box will create lots of pressure and any holes will force air out and make weird noises.

ANY HOLES AT ALL

 

[azimuth 5,000+ posts]

make sure you silicone all the corners on the inside.

 

[60ndown 10+ year member]

$2000 RETAIL = $600 used, imo.

not many people buy a sub like that and treat it gently, so we can assume any sub like that has been 'wanged' pretty hard.

= $600 + or -

 

[Immacomputer 10+ year member]

Do some checking and see if it is really coming from the enclosure or if it is coming from the vehicle somewhere.

I have a nasty rattle around 15hz that is very loud. It is coming from my car but it's hard to locate. See if it is something of that sort; those very low frequencies can really get things resonating and with a driver of that size, there's bound to be some panels clanking.

If the enclosure was causing issues, you would see it from the joints or hear it coming from a joint.

 

[BreakingBad]

air leak somewhere, proly round the sub somewhere, sealed box shold have nothing but bass, def no squeaking?
take sub out, check hole size cutout, get some weather stripping/rubber matt or something about 1/2 inch thick and rubbery, glue strip of rubbery material around sub hole and re-insert sub making sure there is no space/leak/anywhere for air to escape easily, screw sub down tightly.

but an 18 with lots of powerina sealed box will create lots of pressure and any holes will force air out and make weird noises.

ANY HOLES AT ALL

I will double check the seals, but i may be leaning towards immacomputer as this thing will def. hit some low freq's..

$2000 RETAIL = $600 used, imo.
not many people buy a sub like that and treat it gently, so we can assume any sub like that has been 'wanged' pretty hard.

= $600 + or -

Dude i see 04-05 XXX's going for 3-500 plus shipping which were less than 1000 retail...double the price...and only 100 more? ha. i wouldn't let this thing go for any less than 800, unless it was over 2-3 years old...

and it hasn't been "wanged" HARD. it's only on 1500w right now, i'm saving up for a 3kw amp + batteries.

Do some checking and see if it is really coming from the enclosure or if it is coming from the vehicle somewhere.
I have a nasty rattle around 15hz that is very loud. It is coming from my car but it's hard to locate. See if it is something of that sort; those very low frequencies can really get things resonating and with a driver of that size, there's bound to be some panels clanking.

If the enclosure was causing issues, you would see it from the joints or hear it coming from a joint.

i appreciate it man, more than likely you're right as it's only on certain frequencies at certain volume levels at certain songs...

but i can say this, in my exp. with this box/sub combo... it will POUND on these songs:

- yung joc - hell yeah

- unk - comin down the street

- gucci mane - re up

but on songs like:

- dolla/akon - who the fk is that

- big kuntry - ol skool

or higher frequency songs, it hits, but not that "pounding" type of hit. im just assuming that this is due to the size of the driver + enclosure + wattage?

would say, 2 15"s in a ported enclosure tuned to 32hz sound better in any way?

don't get me wrong, the sub def. has potential, i just need the power to back it up...i'm running stock alt + stock hood battery + 1 deka intim. battery in rear, on 1500 watts - HALF the recommended power. i'm thinking yellow top under the hood, another deka or 2 in the rear along with a sundown 3kw amp... that should def change some stuff up a bit as far as output..