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View Full Version : Getting more low end from 15" L7..



Captain_Ahab
07-16-2006, 04:59 PM
I have a 2005 15" L7 in aroud a 4ft^3 box tuned to around 35hz.. It gets plenty loud for me, but I would like a little more low end.. I was thinking about a 6ft^3 box tuned to around 45hz or so for competitons and then have a port plug for daily driving.. I know I would lose a db or two by going sealed for daily from my current box, but would I gain more low end?? I would gain 2ft^3... How would a sealed 6ft^3 box compare to my current 4ft^3 @ 35hz??

talon2nr7588
07-16-2006, 05:00 PM
go 6 cubes @ 32 hz

mtdewelf
07-16-2006, 05:04 PM
go 6 cubes @ 32 hz
yep, to get better lowend, tune lower :crazy:

helotaxi
07-16-2006, 05:33 PM
It all depends on how low you are looking for. Below 30hz sealed is usually the way to go. For the 30-50hz range ported will give you more. Most music doesn't have much info below 40hz. The punch in most rap music is in the is 40-60hz or higher.

Sadly most people don't know what is really low end. A bump in the 45hz range is what most people think is a good low end. With the vast majority of music this is true. This is the basis for the statement that ported boxes have better low end output. Until you are talking about the very lowest of the audible spectrum, it's true. Since most music lacks anything in the bottom audible octave, a proted setup tuned in the mid to high 30s will provide better output in the lowest region of the used spectrum.

A way to really test what you are looking for is to dial in just a bit of bass boost. If that sounds like more what you are looking for, you want more output in the mid 40hz region. That's where 95% of bass EQs are centered. If that is what you are looking for, actually raise the tuning to about 38 hz. Double bonus is that it will get the overall output louder and give you more output in the bottom octave of the used musical spectrum.

If that isn't what you want, and you are looking for the subbass that you can't really hear but makes you feel like you have to take a crap, sealed is the only to go.

SuperTrooper
07-16-2006, 06:07 PM
I just built me a sealed for my 2 L7's for the sme reason. Just finished it today. Need to do a little more sanding and then the carpeting and then I will try it out.

singlesubsetup
07-16-2006, 06:18 PM
It all depends on how low you are looking for. Below 30hz sealed is usually the way to go. For the 30-50hz range ported will give you more. Most music doesn't have much info below 40hz. The punch in most rap music is in the is 40-60hz or higher.

Sadly most people don't know what is really low end.

Sooo true! I was in an arguement with someone who tried to tell me the "boom, boom, boom" that you hear is because there box is low tuned:crap: :rolleyes:

When the reality is that is music in the 40 ish hz range like you mentioned... Love to hear I'm not the only one who knows this :D (Personally I'm not sure what the whole low tune trip is about anyway but maybe I"m just old and stupid :) )

helotaxi
07-16-2006, 07:42 PM
The whole "low tune" thing is a misconception by a lot of people that tuning a box really low will give better linearity of response. I see way too many people recommend a box tuned in the 28hz range as the "best for SQ." For most car subs, tuning that low will result in horrible sound quality and muddy response. If there was such a thing as an optimal tuning for all drivers, then getting a prefab enclosure would make sense. Alas, the same people that recommend a 28hz tuning for all subs will tell you that a prefab enclosure is crap. One size doesn't fit all for an enclosure and even less so for enclosure tuning.

Captain_Ahab
07-17-2006, 08:31 PM
Would 6 cubes @ 32hz be louder than my current setup also??

The low end I was talking about is songs like Soul Survior.. Also a Young Jock song- I know You See It.. I know there is a decent decible loss at whatever frequency those two songs hit at in my current setup.. I get lots of flexing and everything but i really dont think its over a 133-134dB..

PatFitz9
07-17-2006, 08:36 PM
make a test tone CD, and see what low really is. keep the volume constant (not too loud) and go through the different tones. see where you are lacking, and then decide what you want to do. low is when the sub is moving slower, and your ears start to hurt, rather than your chest.

Captain_Ahab
07-17-2006, 10:11 PM
My biggest dropoff seems to be once i hit about the 32hz region.. Pre 32hz it drops fast!!!

DBfan187
07-17-2006, 10:18 PM
duh!

heyman421
07-17-2006, 10:24 PM
you're really not missing out on much if you've got good output to 32hz......

30hz and below is really just a novelty, those freq's arent very audible, anything below 28hz or so with my type-x is more just a felt vibration than a sound, so you just hear the car rattling apart.......

Prob sounds great in a house, but in a car, you will notice rattles you never knew existed below that.

SQBubble
07-18-2006, 01:55 AM
soul survivor hits @ 27-30hz...

i disagree with u guys saying that most rap are only around 45-60hz, its true there is alot around that frequency.... but there is alot also that goes down low...in the 25-35hz range, and a ported box tuned @29, 30 makes it lot louder in the low end(at least seems by the ears, ) than sealed box...
ive heard my arsenal in 2.3sealed box and 3.4ported tuned @30hz, the low end are so much better and a lot more alive in the ported(meaning in the 25-40hz)....

just my 2cents!

helotaxi
07-18-2006, 12:35 PM
It depends on the sub. If you tune most subs that low they sound like trash. There is a double rolloff with a shelf to get you the lower freqs, but the [hase delay and group delay are unacceptably high most all the way across the freq range. The 15L7 you can tune down to 25 Hz without much trouble in a 6 cf box. You will lose about 4dB in the 35-50 hz region but it will be 3dB down at 23Hz. If you want low with that particular sub, that's the way to go. But that isn't the case with most subs.

SQBubble- you aren't getting real output from that sub below the tuning freq. The Arsenal can get much lower than that in a ported enclosure, BTW. With a larger enclosure you can go even lower on the tuning with that sub.

SQBubble
07-18-2006, 03:31 PM
It depends on the sub. If you tune most subs that low they sound like trash. There is a double rolloff with a shelf to get you the lower freqs, but the [hase delay and group delay are unacceptably high most all the way across the freq range. The 15L7 you can tune down to 25 Hz without much trouble in a 6 cf box. You will lose about 4dB in the 35-50 hz region but it will be 3dB down at 23Hz. If you want low with that particular sub, that's the way to go. But that isn't the case with most subs.

SQBubble- you aren't getting real output from that sub below the tuning freq. The Arsenal can get much lower than that in a ported enclosure, BTW. With a larger enclosure you can go even lower on the tuning with that sub.



hey actually u got some suggestion on a box, im gonna do a new one, i want it loud in all around frequency, mostly 30to70hz, it has to be nice and loud and cover alot of frequency, my front stage isnt that good when talking of mid-bass, I HP them @ 100hz preferably, i could do 80hz but 100hz is better, even 120hz is the best for my comp.... wut would u suggest, its a 15"arsenal im not satisfied with sealed box, its for sure i need a ported, u seem to know stuff pretty good...:D
wut do u think of 3.9cu.ft @32hz? wwould i have a good response all over the bass freqquency? its a 15"
thx



editt******sry for thread jack:crap:

helotaxi
07-18-2006, 04:14 PM
The 4 dB peak at 48hz from the current ported box is why the sealed box was not satisfying to you.

How much space do you have to work with?

SQBubble
07-18-2006, 04:19 PM
The 4 dB peak at 48hz from the current ported box is why the sealed box was not satisfying to you.

How much space do you have to work with?

max dimensions:

15"height
38"width
23"deep

SQBubble
07-18-2006, 04:19 PM
The 4 dB peak at 48hz from the current ported box is why the sealed box was not satisfying to you.

How much space do you have to work with?

so i had to make it larger?

helotaxi
07-18-2006, 04:57 PM
5.8 tuned to 30hz will give you a 5dB peak at 40hz and a 3dB down of 25hz. Loud and low. It's going to take a big box to get low. No way around it.

A 6cf sealed box will play flat to nothing and will give a 3dB down of 30hz.

Either box will fit in the space you have to work with.

SQBubble
07-18-2006, 05:21 PM
5.8 tuned to 30hz will give you a 5dB peak at 40hz and a 3dB down of 25hz. Loud and low. It's going to take a big box to get low. No way around it.

A 6cf sealed box will play flat to nothing and will give a 3dB down of 30hz.

Either box will fit in the space you have to work with.



:eek: 5.8!!!!!!!!!!!! wut about the high end with that big of a box...??

wouldnt it sound muddy and weird above 50-60hz?

heyman421
07-18-2006, 05:23 PM
ya, l7 15's sound muddy and wierd above that anyways

CJL
07-18-2006, 05:56 PM
I got my 12" L7s tuned to ~30hz and songs like Young Jeezy's Soul Survivor, Lil Scrappy's No Problems gets hella loud for me and the song Bass I Love You the lowest note shakes my whole sterring wheel.

helotaxi
07-18-2006, 06:05 PM
:eek: 5.8!!!!!!!!!!!! wut about the high end with that big of a box...??

wouldnt it sound muddy and weird above 50-60hz?
Regardless of what you want it to do, it's still a SUB woofer. It isn't meant to play that high in the first place. That said, the higher frequency response isn't affected as much by the enclosure. It's more a factor of cone breakup and attenuation due to voicecoil inductance.

If you want low and loud, you have to make a trade. The trade is box size.

SQBubble
07-18-2006, 06:19 PM
alright so till wut freqquency u think itll play good in this box>?

helotaxi
07-18-2006, 07:24 PM
Above 80hz the sound starts to become directionalized and you will realize that it is coming from behind you. If you don't care about that, you can get up to 150hz with MOST (not all) subs without problems. Some will let you get a lot higher, but these are usually sound reinforcement/monitor type woofers pressed into car sub woofer duty.

The inductance of the voicecoil will cause the sub to begin to roll off at about 700hz with the coils wired in parallel (I'm assuming coils wired in series for the Le value given on the AA website). Cone breakup might cause some distortion issues at a freq lower than that.

singlesubsetup
07-21-2006, 03:07 PM
:eek: 5.8!!!!!!!!!!!! wut about the high end


Huh?:eyebrow: :crazy: :rolleyes:

bikinpunk
07-21-2006, 03:45 PM
I have a 12w7 ported and tuned to 28hz in a 2 cubic feet box. Songs like Soul Survivor get REALLY loud, but sound very good in the SQ department. I had a tough time deciding on what to tune to, but knowing I wanted a little more "boom" to the bass was the deciding factor. My previous sealed box sounded great quality-wise and had very precise punch, but it just didn't achieve the boom, so I went ported, tuned low to keep that sq, but get the boominess I was looking for. My box sounds GREAT. It's dead-on accurate, and if it were "louder" it would be pointless, but was my logic wrong?

There are a couple songs (literally like 2 or 3) that don't play right, and I'm not sure what it could be. Mainly becasue I don't know the frequency of the bass sections. One in particular is "hood rich" by the big tymers. For some reason that song always sounds like I've lowered my bass setting to 0 and the bass is barely audible, and doesn't make much of a wake in the sound pressure department either. Can you offer some advice on what this could be?

I'll be building a new box soon to go in my new car, so this topic saved me from making one of my own similar to this.

helotaxi
07-21-2006, 07:37 PM
Does the sub move on those particular songs? If it is really moving, the bass notes are lower than the tuning of the box and the port is working against the sub and cancelling the output. If it is barely moving, it is a higher freq than the Le of the sub wants to let it play.

Some other possibilities are that your crossover or subsonic filter got messed up. You also might have miscalculated and mistuned your enclosure resulting in a higher tuning and thus a higher low end rolloff. It could also be that that particular is right at the maximum point of impedance rise for the enclosure resulting in the amp's inability to really drive the sub at that particular freq.