a little problem with my subs

[shadowslayer666 1]

I have 2 12" 187's from incriminator audio in a custom built 4.4 ft^3 box tuned to 31hz powered by a sundown saz-1000D and on some songs the bass just is not there on the low end. The song in question is hypnotize by jeezy. I never really noticed the problem until my friend played the song on his infinity's in a prefabed box and it sounded so much better.

Ok the problem is when the song begins there is not a lot of bass. I can feel it a bit but it is not too audible, and when the higher frequency note hits it is so loud. But that is really the only note i can hear well. My subs barely move during the parts in question.

the part i have a problem with is from :27 to :40, and it continues throughout the whole song.

I thought it could be my subsonic was too high, but i turned it all the way down to 10hz so that is not the problem. I have the bass set the 0 on headunit and the gain properly set, but the sound just isnt there. This also happens on late night tip, but i just though my subs weren't powerful enough for those lows.

I know its long, but i appreciate the help

edit: kinda looks like these subs in this video

http://www.youtube.com/watch?v=2iYlJElrtgs&feature=related

Edited October 14, 2009 by shadowslayer666

[BigCProductions99 21]

Check Your Low Pass Filter At The Amp, Subwoofer Volume On The Head Unit And All That Good Stuff.

[shadowslayer666 1]

in my post i mention i have everything set. LPF is set to 80hz subsonic is set around 25HZ. Checked the song to see where it peaks in audacity and it peaks around 34hz and 39hz

[BigCProductions99 21]

Must've Been A Touch High In The Last Post. Double Check Your Amp, And Play With The Head Unit. It Could Even Be The Version Of The Song. Wiring Could Be A Factor Here Too. Oh, And That Guy Is Definitely Not Hitting 156.2db. lol.

(Low Pass Wouldn't Have Anything To Do With This Problem.)

[lithium 358]

could be voltage drop i guess. also check the song itself, could be poor recording.

[SBranger 0]

How big is your port? How long?

[shadowslayer666 1]

port is 13.5 inches high 3.25 inches wide and 18 inches deep

[thebiggmann12 14]

try briefly turning up ur gain a bit to see if u pick up the lows better. i had the same problem when i set my gains...i set with dmm and didnt pick up the lows so i just set it by ear.

[shadowslayer666 1]

i tried that. i had the gain almost all the way up and i started to get a little worried. i didnt want to blow them, but they took all the power with no problem, but the problem still precised. It is confusing the hell out of me. Hopefully upgrading from stock headunit this month will make a difference. It could just be the stock one crapping out

[will3 2]

What kind of vehicle is it and how is the enclosure loaded ?

Where are the ports in the enclosure in relationship to the subs , are the subs right at the end of the port etc. ?

[aftershock1 0]

try turning your subsonic filter all the way off and play it at a lower volume to see if that helps.

[shadowslayer666 1]

i have pics of everything in that thread. I know there is a little cancellation because of how my port is aimed, but it should not be that extreme ( just wanted to take some of the load off of the trunk lid) I have the subs at least 4 inches away from the port. i heard that you want them to be at least a ports with from the port. They are in a 08 cobalt with stock electrical. I only get a little dimming at night when im at a light. As long as my rpm's are over 1000 there is no dimming.

I tried turning my subsonic down and it still didnt work. its confusing the hell out of me

[will3 2]

i have pics of everything in that thread. I know there is a little cancellation because of how my port is aimed, but it should not be that extreme ( just wanted to take some of the load off of the trunk lid) I have the subs at least 4 inches away from the port. i heard that you want them to be at least a ports with from the port. They are in a 08 cobalt with stock electrical. I only get a little dimming at night when im at a light. As long as my rpm's are over 1000 there is no dimming.

I tried turning my subsonic down and it still didnt work. its confusing the hell out of me

This sounds like an enclosure problem , with facing the subs forward , and the port to the rear , and with the enclosure being as large as it is for a small trunk, it sounds like your are having major cancellation problems at and around the tuning freq.

[beajay25 2]

in my post i mention i have everything set. LPF is set to 80hz subsonic is set around 25HZ. Checked the song to see where it peaks in audacity and it peaks around 34hz and 39hz

run a sweep on the port with a tl to get a real idea where your port is ... his cabis freq. is probably different from yours that would make a box respond different ...

[shadowslayer666 1]

i could run sweeps using my computer through the aux port with winISD, or i just downloaded some test tones, i think shizzon put them up. I dont have a tl though so i would just have to do it by sight i guess. Any other ideas?

[KU40 173]

Cancellation, that's probably it. A little cancellation goes a long way. There's a reason you don't see anybody with their subs and ports 180* from each other, and why people on here would advise you not to do it.

BTW, this contrasts to your review in your build thread of "hit really hard in the 30 to 60 hz range."

[shadowslayer666 1]

Well when i first played them i was listening to lost by gorilla zoe and in audacity it says that song peaks at 32 and 34hz, and that song is so loud on the subs.

Listening to some test tones, they peak around 40 hz so that would suggest the box is tuned around the low 30's. As far as cancellation, would that cause the subs to not move? Im going to try to borrow a friends camera to record it, but the subs hardly move, thats why i dont think its all cancellation. Also if it was 100% cancellation the peak and the trough would have to hit my ears at the same exact time, and a 30 hz wave is 24 feet long so i would have to be 12 feet away from my subs and i am about 5-6 feet away, also wouldn't i hear the subs as being louder a different distances then, depending on where i am in relation to my car?

[shizzzon 461]

your box and port specs don't add up.

Give me your dimensions of your box and port placement...

is your 4.4cubes GROSS or NET?

Either way... it's not 31hz... so i need to know specifics... It's possible you are tuned lot higher than u think.

[shadowslayer666 1]

The box is 34x15x21 (lxhxd) and the port is 3.25x13.5x18

just plugged it into re box creator and it says 4.34 ft^3 tuned to 30.57. So it will be a littler higher after the .2 from woofer displacement

[KU40 173]

Subs don't move that much around the tuning frequency unless you have extra power. Download winISD alpha and take a look at the excursion chart. Within about 10 hz of the tuning frequency most of the air movement comes from the port.

Also, that wave length thing doesn't matter. Easy tests- roll down your windows or move your box forward/backward in the trunk. Your system gets louder with the windows down because it removes some reflections and cancellation, and so does moving the box more toward the back of your trunk instead of near the rear seats.

But if the subs aren't moving much on any frequencies, it's likely just a lack of power problem.

[BigCProductions99 21]

After Looking At Your Build Log, I See A Definite Reason, I Guess You Already Know What It Is By Now. Your Stock Headunit Could Play A Small Factor Here As Well. Instead Of Scrapping Your Box, You Could Plug The Port And Add Aero's To The Front. (Try To Cut Out The Side Piece Of The Port When You Do This.)

[shadowslayer666 1]

wow i was actually thinking of asking if i could do that. what do you recommend to plug the port? This will probably have to wait till spring though...its almost freezing in ohio...global warming my ass

[shizzzon 461]

your tuning is still off by your specs and your port is weird...

I am getting 4.4cubes after port displacement and 4.2 after sub displacement tuned to 35hz...

Your box depth is 19.5" but your port depth is 18"????

That only leaves 2.25" of space before it hits the back wall so tuning will be off and choked.

I think you need a new box built properly.

[KU40 173]

Oh I didn't see you have a stock head unit. Many stock head units have bass limiters to protect the interior speakers. As the volume goes up, they keep the bass level about the same. Have you had any sub setups in this vehicle before? If this is your first one, it's possible. Check with another source, as has been said. But if you've had other sub setups with the same head unit and they seemed fine, it's likely the box issue with this one.

[rushnrun 14]

Oh I didn't see you have a stock head unit. Many stock head units have bass limiters to protect the interior speakers. As the volume goes up, they keep the bass level about the same. Have you had any sub setups in this vehicle before? If this is your first one, it's possible. Check with another source, as has been said. But if you've had other sub setups with the same head unit and they seemed fine, it's likely the box issue with this one.

The stock chevy units really cut off the bass when you turn up the volume. I tried running the stock one in my suburban... it was only loud at low volumes with the gain way up on the amp.. turn the volume up on the deck and the bass went away...

I'm with shizzon.... your specs don't add up... I noticed in your other thread that you said you cut the port to get it further away from the face... how much did you cut off?? so how long is the port now?