Bass is almost nonexistant

[nallav 0]

2 12" Fi Q subs in sealed separate 1.2 cu ft chambers powered by an AudioQue AQ2200 amp. On the amp I've got to turn the gain and bass boost all the way up and on the head unit the subwoofer and bass levels to the max just to hear the subs, and barely at that. Something is wrong here, and I need some help figuring out what it is.

I've double checked, redone, and double checked all the wiring, and it is correct. The subs are 1 ohm DVC, and measured at the amp, is exactly a 1 ohm load. The polarity is not reversed anywhere. Tested the DC power at both the battery and the amp to see they are the same. Tested for a ground loop to find none.

I'm at a loss as to what to look at next.

Edited November 1, 2009 by nallav

[iputon326 9]

2 12" Fi Q subs in sealed separate 1.2 cu ft chambers powered by an AudioQue AQ2200 amp. On the amp I've got to turn the gain and bass boost all the way up and on the head unit the subwoofer and bass levels to the max just to hear the subs. Something is wrong here, and I need some help figuring out what it is.

I've double checked, redone, and double checked all the wiring, and it is correct. The subs are 1 ohm DVC, and measured at the amp, is exactly a 1 ohm load. The polarity is not reversed anywhere. Tested the DC power at both the battery and the amp to see they are the same. Tested for a ground loop to find none.

I'm at a loss as to what to look at next.

it sounds like it might be bad rca's.

[bigrank916 72]

Ya it sounds like you are having trouble getting the signal. Might be the rcas. How many preouts on the h/u? Are you sure you have the rcas hooked up to the sub preout?

[mjmarovi 8]

what kind of head unit is it? and yes sounds like RCA's....or could be a xover setting problem on the deck...

[///M5 2,833]

Try a low pass instead of a high pass

[nallav 0]

The RCAs are good, not only did I use the same ones as I had for the old subs, but I swapped them out elsewhere to test them. There's no HPF inline anywhere from the HU to the sub amp. I have verified the RCAs for the subs are indeed connected to the sub out on the head unit. (3 sets of RCA outs on the HU btw, front, rear, and sub. It's an Alpine CDA-9886)

[shizzzon 461]

is the clipping light ever coming on when u got all these settings maxed out?

If it's not, u got a filter turned on somewhere.

[mjmarovi 8]

The RCAs are good, not only did I use the same ones as I had for the old subs, but I swapped them out elsewhere to test them. There's no HPF inline anywhere from the HU to the sub amp. I have verified the RCAs for the subs are indeed connected to the sub out on the head unit. (3 sets of RCA outs on the HU btw, front, rear, and sub. It's an Alpine CDA-9886)

nice deck, I run the 9887 myself but I'm not saying an inline xover, what about xover on the HU and the amp? Or you could try hooking up rca's to one of the other outputs on the deck, maybe the sub-out is having an issue. next thing to do is probably just call Audioque.

[rushnrun 14]

are you certain they're not out of phase... unhook one and see if it gets louder....

[nallav 0]

Went out this morning to work on it. After thinking about it, how it's been said that crossover and cables and whatnot could be bad, I decided to unhook everything completely from the amp and speakers, redo all the wire ends, reverify all the cables are good and run correctly, and connect everything new again. At the same time, I reset all the settings on both the HU and amp to start fresh. It's better this time, the bass boost is off and the gain isn't maxed, the HU levels are down and I'm achieving more bass. I didn't get a chance to fine tune it yet and see how it's really doing (too many people around here to turn it up) but so far it's looking better. I think the crossover point on the amp was set too low, but I'm not entirely sure that was the problem, or if it was the only problem. Or even if the problem is solved yet.

Perhaps all I needed was a fresh start on it, but we'll see when I'm able to get somewhere less populated and tune it properly.

Edited November 1, 2009 by nallav

[NDMstang65 403]

Either an RCA or a sub is wired out of phase...there's no other reason for it to be non-existant...

Regardless whatever you do NEVER max out gains/bass boost etc. That's a sure fire way to break a sub...

[thebiggmann12 14]

are the subs moving and there is no sound or are the subs just not moving?

[jcarter1885 994]

Went out this morning to work on it. After thinking about it, how it's been said that crossover and cables and whatnot could be bad, I decided to unhook everything completely from the amp and speakers, redo all the wire ends, reverify all the cables are good and run correctly, and connect everything new again. At the same time, I reset all the settings on both the HU and amp to start fresh. It's better this time, the bass boost is off and the gain isn't maxed, the HU levels are down and I'm achieving more bass. I didn't get a chance to fine tune it yet and see how it's really doing (too many people around here to turn it up) but so far it's looking better. I think the crossover point on the amp was set too low, but I'm not entirely sure that was the problem, or if it was the only problem. Or even if the problem is solved yet.

Perhaps all I needed was a fresh start on it, but we'll see when I'm able to get somewhere less populated and tune it properly.

Head Unit Settings

Bass Boost/Exend = Off

Loud/Loundness = Off

Sub Level: + whatever yours goes up to minus a few whatever your preference

Bass = 0 or lower, whatever your preference

LPF = 100Hz or lower, whatever your preference

Amp Settings

Gain = Set with DMM, no more than 50-60% if you dont have one.

LPF = 100Hz or lower whatever your preference

Bass Boost = Off

SSF = 1-5 Hz lower than box tuning, or until subs start to reach its excursion level.

[mjmarovi 8]

pretty much right Jay-cee, but you really only want to use one LPF. so you would want to turn either the one on the HU or the amp all the way up or off. of course you would want to go with which either one is of higher quality. or perhaps if they are different db/slope

[nallav 0]

Head Unit Settings

Bass Boost/Exend = Off

Loud/Loundness = Off

Sub Level: + whatever yours goes up to minus a few whatever your preference

Bass = 0 or lower, whatever your preference

LPF = 100Hz or lower, whatever your preference

Amp Settings

Gain = Set with DMM, no more than 50-60% if you dont have one.

LPF = 100Hz or lower whatever your preference

Bass Boost = Off

SSF = 1-5 Hz lower than box tuning, or until subs start to reach its excursion level.

Done. I knew this multi meter would come in handy for something. Finally I got it to where it sounds good and isn't clipping. Thanks.

However, this is still pretty damn quiet. I've heard a single 12" Rockford P1 powered by a 200W amp (sorry can't remember the make/model) louder than this, in my same truck. Surely my setup should be louder. Could the box be limiting it? Would a ported box make that much difference? Will the sub get that much louder as it breaks in? I've heard people talk about how loud these subs can be, but I'm just not seeing it at this point. But it definitely does sound good.

[sqjeep 9]

Are you using the bass knob with the audioque?

[jcarter1885 994]

Yeah a ported enclosure usually does sound louder than a sealed enclosure (more output with ported enclosures) and once they continue to break in the will be louder and lower.

[thebiggmann12 14]

what kind of car are these in?

[mjmarovi 8]

are you sure you have it wired to 1 ohm? you have them wired in a series/parallel combination correct? each sub in series, then the two together in parallel to the amp?

would it be possible to take a video? I know it's not the best, but would def. give a general idea of what kind of output you're getting.

a ported box would be much louder, but really something's wrong if it's that quiet

[KU40 173]

Does your head unit have a high pass filter? Are you using a subwoofer RCA output on the deck or just a front or rear output?

[///M5 2,833]

I think it is time to start over and describe everything you have and everything that you have done.

[nallav 0]

but I'm just not seeing it

Correction. Hearing it.

[nallav 0]

Starting over. Here's my setup:

Vehicle: 1999 Chevy Tahoe

Head unit: Alping CDA-9886

Door speakers: 2 pairs Boston SL60

Speaker amp: Soundstream TRX4.640

Subs: 2 12" Fi Q (with BP Power option)

Sub amp: AudioQue AQ2200D

Door speaker and amp are fine. Absolutely no issues there. Sound awesome, even when they play loud. Exactly what I wanted, and better than my expectations.

Head unit has 3 RCA outs: Front/Rear/Sub (Front and Rear go to 4 channel amp, Sub goes to bass amp)

No LPF on the HU, and HPF is off.

Subs are wired to 1 ohm, and verified 1 ohm on the DMM.

Set gains with DMM, almost 47VAC (can't remember exact number) and clipping happens at full volume, but is rare. Gains were set with sub level on HU at max, bass knob at max, volume at slightly above 3/4, with a 50Hz tone.

LPF on amp is a 90-95Hz (approx)

Subsonic filter at 25Hz (approx)

With 47VAC and 1ohm, ohms law gives me 2209W. I'm just under 47VAC on the DMM, so by calculations I'm definitely within 50W of that Ohms Law Calculator @ the12volt.com

Approx 20 feet 1/0 gauge power wire with 200 amp circuit breaker (which has yet to trip). Ground cable is about 1 foot, same 1/0 wire (is it right to call it wire when it's that damn big?!?) Battery and alternator not yet upgraded, but will be soon, and it seems to provide plenty of power for what's in use currently.

Bass knob has a clipping light, no idea how accurate it is though. But it rarely goes off now that gain has been set with DMM.

Bass boost is off.

Set gains with DMM with bass setting (not sub level) on HU at 0, 2, and 5 (out of 7) with no audible difference when played at the levels it was set with.

No ground loop from amp chassis to vehicle. Tested and verified with DMM. Although, can someone verify that the RCA should be grounded to the vehicle? I didn't wire any ground in, but DMM shows continuity from outer ring of RCA to vehicle ground. Just want to verify if this is correct.

Subs wires as per this diagram http://akamaipix.crutchfield.com/ca/learningcenter/car/subwoofer_wiring/2DVC_2-ohm_mono.jpg

12 guage speaker wire from the amp to the speaker box. I only was able to get 6 feet of 12 guage, which I put in yesterday. At the same time, I also rewired the box with the 16 guage I had. This included cutting and stripping all ends as new, and inside the box where it's 16 guage I ran 2 wires for each connection to ensure there's enough wire for the signal to get through. This did seem to help slightly.

What more info do you need? I'll be happy to provide it.

I know a ported box will be louder (+3db compared to -3db if I recall correctly, but I might not be recalling correctly, and I'm not sure how that applies when the subs are in separate chambers), but how much louder would that actually be? It's not much issue for me to build another box, it'll just take time before I can get the material and a work space.

Current box is made from 3/4" MDF, 2 layers on top where speakers mount, silicone applied at all joints and areas where it might leak, with sperate 1.2 cu ft chambers. Divider is also 2 layers. This box is extra sturdy. Tested by parking a wheel on it. My truck weighs damn near 5500 pounds when last weighed.

I'd be happy to provide video and pictures, just let me know more specifically what this video needs to include and I'll get right on it.

Another thought. There's LOTS of space inside a Tahoe. Should I go with 4 subs total? I had 3 before, but I didn't like weird numbers like 1.33ohms. Not much a problem for me to get 2 more subs and another amp. The harder part will be the electrical.

I'm sure someone will ask, so my goal is sound quality (though I'm not an audiophile) at ALL volume levels, including loud. I listen to a lot of rock and metal, so control over the woofer is a must. But from time to time I also listen to a select bit of hip-hop, where the bass is crucial.

Trying to be as informative and helpful as I can be so we can figure this out. If any more info is needed, or if I'm missing anything or doing something retarded, I'll be happy to correct it or provide the info. It's gonna help me out in the end so there's no point for me to be an arseho about it.

Like I said, I have no issue with building a new box if that's what I need to do. I have a fully equipped woodshop (somewhat) readily available to me to make very accurate boxes. Also, if I do need a new box, I'll be looking into better wood than MDF, so feel free to suggest something if that's the case.

I don't have access to any other amps anymore, at least not easily. I do however still have my 3 Boston G2 subs if I need them for testing purposes. However, they won't be able to handle the power from this amp.

Instead of building a new box, if this is what's needed, could stuffing the box do the trick?

There's no carpet on the box yet. Before I put the carpet on, I planned on spraying the box with the spray on truck bed liner, I figure this will not only help it to stay sealed, but help keep it rigid and keep it together (though I really don't have any fear of the box coming apart). Then put the carpet over that. Any thoughts on that?

I have a feeling the RCA cables to the bass amp might not be as good as they should be, but I really can't say for certain. Any way to test this? I swapped them out with other sets of cables with no audible (at least on my level) improvement, however.

Thank you all for the help that has been given so far, and for the help I'll surely receive in the future. This forum has so far been the most knowledgeable, informative, and ready to assist place that I've found. I only wish there was a better way to repay you all other than a simple thanks.

Edited November 3, 2009 by nallav

[RE XXXv3 31]

Maybe your amp or hearing is crappy. 2 sealed 12's in a really large space could be the problem but I've heard 2 ported 10's in a Jimmy on maybe 2000 watts and I couldn't breathe.

[NDMstang65 403]

speakers are stupid..they do exactly what you are telling them to do..in the environment in which they are in...it is not the speaker...there is a gremlin elsewhere

i'm not reading through the entire thread..but did you do a 'pop' test on the speakers with a battery to ensure that you have them wired correctly and there is not a terminal band backwards? If you have the speaker hooked up 'properly' then it will move forward..if it is backwards then it will move backwards...