Unsatisfying output from a 12" FI Q.

[CAMSHAFT 10+ year member]

If you listen to it ouside in front of your vehicle, is it loud?

 

[dB Dom 10+ year member]

I think the problem lies withing his headunit. Or the settings like someone suggested.

 

[billabongcr 5,000+ posts]

mines kinda doin the same thing. some songs it wangs..others it drags. im usin a temp amp tho so when i get my other one back and hook it up..ill let you know if it makes a different. then atleast youll be able to narrow it down from amp to box, or just the amp itself.

 

[Hundreth 10+ year member]

Why would it be the amp or the headunit? He has more than adequate power to push the Q, and adding more power would give him a 1-2 db increase at most. So what if his headunit's preouts are only 2V? Just set your gains properly. The same goes for his settings, setting the gain properly would compensate.

Either his box isn't actually tuned to 31hz, or he is just unsatisfied with the sub's low end or output.

 

[sku 10+ year member]

I have a suggestion for both the guys not satisfied with the output...

Get it metered (preferably a frequency sweep) and post the results back to us.

It is very hard for us to really know what you consider loud, since that is very subjective...

A TL or even AC numbers are very objective however....they tell us exactly how loud each frequency is/are...

If we see the numbers we can at least surmise where the issues may be...(i.e. step low end rolloff, no middle region, etc....)

Otherwise the thread will keep going with guesses.....

 

[billabongcr 5,000+ posts]

i dont think its the hu. im kindof in the same boat and my last setup was fine.

my guess is..could be the box. sucks i know, cause mines the same way. but when i get my new amp ill let you know if it helps any. im hoping its amp gains/settings.

btw: 1,000 for me:readytog: //content.invisioncic.com/y282845/emoticons/woot.gif.aaa6090e619a97b6090d16dd863c5a69.gif

//content.invisioncic.com/y282845/emoticons/beatdeadhorse5.gif.5d70132dea1eb89b73bf2fdbb6027dd6.gif never got to use that one before..

 

[LinxuS 10+ year member]

A lot of posts while I was asleep, so I'll try to cover everyones questions..

My headunit has three bass features, but only two affect the actual sub.

Bass is set at -4, but that has no effect on the sub itself. I turned the speakers, put it to +6, and it did nothing for the sub, so I'm pretty sure of that.

There is a subwoofer seeting.

The Sub out is on.

The Phase is normal (yes i've tried reversing it, but to no audible difference.)

The level is at 0. I tried experimenting, and put the output to +2, and noticed a HUGE increase, but I'm sure it was because the amp was clipping...

Bass boost on the amp is 0. Changing the phase on the amp did nothing to audible difference.

There is an EQ on the headunit, called a Parametric EQ I believe?

For the Low setting, it DOES affect the subs output. I have it set on 0, and the Q Factor set at 40 hz, on 2 wide.

Also, what does this say for me being a bass head: I used to think my Type-R 5x7s had a decent amount of bass, and I just wanted a little more. I also thought my logitech subwoofer was pretty loud on my computer.

My rearview mirror does not even move. I'm really starting to think that I might need a more powerful amp. With my stock set up, I had just about no dimming, with only the Big 3. My alt is only about 70 amps. Once I upgraded to the Yellow Top, my voltage stayed at a constant 13.8-13.9, even with the sub on full tilt on music. Does that say anything at all, or is this just a decent eletrical system? I also have a 240 amp alt on the way from Thunder.

I'm going to go measure the aero ports and see exactly what it's tuned to.

 

[Duke 10+ year member]

I've made a box that was way bigger than needed, and it destroyed my low end output. Added some wood to the inside to take up space and it improved. Could that be the case here? You should measure the ports, and give us all the dimensions of the box so we all can run our calculations on it.

 

[billabongcr 5,000+ posts]

I also thought my logitech subwoofer was pretty loud on my computer.

mine wangs //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif 50hz at 70wrms/140peak ported. bumpin yo //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[SlickCMRick 10+ year member]

wow, the rear view doesn't even move?

 

[SlickCMRick 10+ year member]

linxus are you from vegas?

we need a vegas meet, but we only have like 5 people on here LOL

 

[dB Dom 10+ year member]

Ok figured out your problem.

Turn the gain down on the amp. Set your bass level at +2. Then set the sub level to +2 or whateveris like 75 percent of the total.

Then adjust the gain to the proper voltage. And problem solved.

You need to set the sub level pretty high, even max it out to get any decent voltage out of the head unit. On my alipine I have the sub level set to +15 and just adjust the amp gain accordingly. Then if I ever want to turn down the sub I can do it from my head unit.

 

[LinxuS 10+ year member]

Yeah I live in Vegas, over in Summerlin.

Sad news boys, it looks like its tuned wrong.

The ports are about 18"-19" long, including flares.

And it APPEARS like they are 4". Just stuck my fingers inside, and measured the gap...

David told me the box was about 2.3 cuF.

That means the box is tuned around 38 hz.

http://www.psp-inc.com/psp-inc.com/cgi-bin/port_length_calculator.cgi

That's each port length right?

 

[billabongcr 5,000+ posts]

yeah but still then all the songs should hit along the same lines..no one hit rediculously loud, then another song with the same tones not hit at all? right?

 

[bk12321 10+ year member]

the sub level should definitely be higher than 0.... on the hu