Fi Q15... not much excursion, why? (videos and pics)

[themerc 0]

My enclosure is strangely shaped because of my spare tire, but it's 4 cubes @ 32 Hz with 58.5 sq. inches of port area. My Q15 has the BP power option and I'm powering it with a Sundown Audio SAE-1000D. My headunit has 2V pre-outs and the 1000D has a 0.2v - 6v adjustable input sensitivity, so my gain is about 3/4 of the way up. I have an Excessive Amperage 250A alternator, big three with 1/0, 1 group 65 Duralast Gold battery and 2 Kinetik HC1800 batteries wired in parallel with 1/0 gauge...

Does it seem like I'm not getting a lot of excursion?

"white girl" by U.S.D.A.

vid 1

"hood nigga" by Gorilla Zoe

vid 2

"choppin' blades" by UGK

Vid 3

Vid 4

Vid 5

Edited February 2, 2008 by themerc

[///M5 2,833]

3/4 of the way up is NOT a valid gain setting. Go ahead and set by ear, but do measure with a test tone and see what you are giving it. On the same note, if you are really looking for excursion perhaps using those same test tones will give you a known quantity instead of some arbitrary music.

--one last thing, excursion while related to output isn't what you should be shooting for.

[themerc 0]

3/4 of the way up is NOT a valid gain setting. Go ahead and set by ear, but do measure with a test tone and see what you are giving it. On the same note, if you are really looking for excursion perhaps using those same test tones will give you a known quantity instead of some arbitrary music.

--one last thing, excursion while related to output isn't what you should be shooting for.

Yeah I set the gain playing a 35 Hz tone and measured the voltage at the amp's speaker terminals. I turned up the gain until I reached around 31.5 volts (sq. root of 1000 watts x 1 ohm is 31.6 volts), which just happened to be about 3/4 of the way up. I didn't hear any distortion, I just thought that I shouldn't be turning the gain past 3/4 of the way up, so I didn't keep turning it up.

About the excursion, I've never had anything this powerful before. My last setup was 2 Kicker CVR12's ported with 2 Kicker 400.1's powering them, so I don't know if my setup is as loud as it should be. I posted those first 2 videos on a forum and everyone said something didn't look right and my sub should be slamming playing those songs.

Edited February 2, 2008 by themerc

[JimJ 11]

If you want excursion, go with a sealed enclosure...

[Jpm4536 0]

Could it be possible you wired your voice coils to work against eachother? IDK what that would do tho, it might just mess it up instantly...

[themerc 0]

If you want excursion, go with a sealed enclosure...

I don't want excursion, I just want the loudest possible daily setup, and people said from my videos something didn't look right. They said it was probably my enclosure.

[JimJ 11]

Comparing output by looking at a video is, in a word, stupid.

Don't listen to them, if you're concerned about output go by what you do on a sensor, and nothing else.

[jonbearsmt 919]

from what i have seen fi's dont travel that much.. i have bl's my travel some.. but compared to other brand of subs, that hardly move compared to JL's but my bls have more output with less travel

[JimJ 11]

The BLs, for example, have a listed Xmax of 21mm...which is right in line with other 12-spokes out there.

[muddybass 13]

and q's have 27mm of xmax

[loudcav 1]

why did you set your gains with such a low frequency test tone?

[JimJ 11]

If it's a decent DMM, it should be relatively linear at that frequency.

[lee 2]

my Q18 has insane excursion, but its in a sealed arangement

[shizzzon 461]

you shouldnt set an amp's gain via voltage only because you do not know what resistance it is currently at.

Yea sure it might be 0.7 at rest, but what if you measured the amps at being 15a?, that's a 2ohm resistance.

Properly set an amp up via oscilloscope. You can buy em at www.partsexpress.com

I watched your vids, i do not recognize any of those songs but i would play some lower frequency test tones and see if it moves more.

Also, what is your subsonic filter and LPF set at?

[subwoofery 0]

I was about to ask about the subsonic filter also...

Not questionning your knowledge, just happen to be one thing we forget about... sometimes...

[themerc 0]

I have a craftsman DMM with DC clamp. I set the gain with the 35hz tone after me and my friend listened to different tones at low volume and decided 35hz sounded the loudest. I set my LPF to around 80hz I believe. I need to check that subsonic though.

[themerc 0]

My subsonic is set at 1/4 turn up, what Jacob Fuller told me to set it to.

[themerc 0]

If it's a decent DMM, it should be relatively linear at that frequency.

What do you mean?

[ANeonRider 3]

Like Jimbo said, if you want excursion, go sealed.

A subwoofer excursion will be decreased the closer to you get to the enclosure's tuned frequency in a ported enclosure to nearly nothing right at the Fb.

Play a frequency lower than Fb, and watch out (excursion-wise)... at lower than Fb, you can unload the subwoofer since the enclosure cannot control the driver.

[themerc 0]

Like Jimbo said, if you want excursion, go sealed.

A subwoofer excursion will be decreased the closer to you get to the enclosure's tuned frequency in a ported enclosure to nearly nothing right at the Fb.

Play a frequency lower than Fb, and watch out (excursion-wise)... at lower than Fb, you can unload the subwoofer since the enclosure cannot control the driver.

Yeah today I tried playing bass I love you and at a certain point the sub bottomed out. Back when I first put the sub in I accidentally played a 25hz tone instead of a 35hz tone and the sub bottomed out and I blew a fuse in my power distribution block lol. I guess I'm not worried about the excursion anymore... I'll try to make it to a competition this month and get it metered.

[nick_19 1]

Have you checked the math of your enclosure...

You could have it tuned way too low...

Where it bottomed out was at about 6-10 htz... Those are the super short low notes in "Bass I Love You"

[shizzzon 461]

6-10 hz?

I have never heard of any song going that low, that's purely inaudible as well.

The lowest bass track i have goes down to 10hz and WAY before it even get's to that point, all you can do is feel the bass, not hear it. Anything below 26hz, in my opinion, is a waste of energy, hehe. In other words, i never let the SSF start below 26hz. regardless of how low tuning is. IT just doesn't sound decent... because there is hardly any sound, lol

[themerc 0]

Have you checked the math of your enclosure...

You could have it tuned way too low...

Where it bottomed out was at about 6-10 htz... Those are the super short low notes in "Bass I Love You"

It's 4 cubes tuned to 31-32Hz and it definitely bottom outs at 25Hz. I blew a fuse when I played 25Hz and it bottomed out and I don't want to try 30Hz and blow another fuse.

[shizzzon 461]

if you are blowing fuses on your power line and not your amp.... then the fuse on your power line is not large enough.

Also, playing right around your tuning frequency exhibits high impedance rise so playing 30hz would be a lot less stressful than 25hz.

Playing anything below your tuning frequency usually causes lots of cone movement and playing notes approx 12-15hz above tuning as well.

IF all those vids u made were playing right around tuning, then nothing to worry.

See, think of it this way, how do competitors get over 20KW of power to each sub?

There are lots of ways and tips such as-

burping at tuning frequency causes the least cone movement, meaning you can push more power at that note as long as you know how to control the sub from overheating.

Using an amp such as a JBL with crown technology will have the least potential of the speaker leads from catching on fire due to too much amperage... why? Because these amps, with the help of crown's tech, can output consistent power between 3-8 ohms, i believe is the range and if you hookup an ammeter and DMM to the amp, it shows a constant 8 ohm output regardless of real resistance. Short burps also have less potential of causing damage than longer burps.

Trust me, it's normal if it doesn't move a lot around tuning. Your movement becomes greater below tuning and about 12-15 hz above it. Above tuning may differ from how the box is tuned but i usually tune ported boxes where u got yours tuned at and that's what i notice.

[themerc 0]

if you are blowing fuses on your power line and not your amp.... then the fuse on your power line is not large enough.

Also, playing right around your tuning frequency exhibits high impedance rise so playing 30hz would be a lot less stressful than 25hz.

Playing anything below your tuning frequency usually causes lots of cone movement and playing notes approx 12-15hz above tuning as well.

IF all those vids u made were playing right around tuning, then nothing to worry.

See, think of it this way, how do competitors get over 20KW of power to each sub?

There are lots of ways and tips such as-

burping at tuning frequency causes the least cone movement, meaning you can push more power at that note as long as you know how to control the sub from overheating.

Using an amp such as a JBL with crown technology will have the least potential of the speaker leads from catching on fire due to too much amperage... why? Because these amps, with the help of crown's tech, can output consistent power between 3-8 ohms, i believe is the range and if you hookup an ammeter and DMM to the amp, it shows a constant 8 ohm output regardless of real resistance. Short burps also have less potential of causing damage than longer burps.

Trust me, it's normal if it doesn't move a lot around tuning. Your movement becomes greater below tuning and about 12-15 hz above it. Above tuning may differ from how the box is tuned but i usually tune ported boxes where u got yours tuned at and that's what i notice.

Okay sweet. As for the fuse, I guess it doesn't really bother me that it'll blow if I play 25Hz at 32/40 volume and not 35Hz... it blew like 2 seconds after playing the 25Hz tone, which was faster than I could have gotten back to the front of the car and turned it off. I didn't mean to play 25Hz and it could've hurt the sub, so I'm glad it blew as fast as it did. And yes, it was the fuse in my power distribution block, it's a 40A mini ANL.

Edited February 5, 2008 by themerc