3 15 l7s box build please help

[j.castro]

ok thanks becus ive heard some pretty ****** reviews about the hifonics amps they say they do ther rated power but the singal is very clipped and distorted? i dont no much about the mbq amps would they be able top power the l7 good overall? do they do there rated power?

 

[abladeafficionado]

ok thanks becus ive heard some pretty ****** reviews about the hifonics amps they say they do ther rated power but the singal is very clipped and distorted? i dont no much about the mbq amps would they be able top power the l7 good overall? do they do there rated power?

I haven't used any of the Onyx stuff from MBQ, but their Discus amps that came out a few years ago were awesome. MBQ has made a decent comeback in the amp market. For clean power on your budget, they're your best option.

 

[j.castro]

yea i think these are the ones ill be going with i read that these new onyx line is the remake of the discus line and thes amp arew suppose to do anound 150ish more han there rated power.havent seen bad reviews on these thanks its a great help saved some money and got a solid amp

 

[BeaverGod]

40Hz will sound like absolute shit IMO. It'll be very peaky and loud, but have no low end extension. 32Hz is about the sweet spot IMO. Then again, I care about SQ/SQL, not SPL... 32Hz doesn't defeat the purpose, it is the purpose. The purpose of porting is to gain volume and low end extension at the expensive of steep rolloff below tuning frequency. A steep rolloff below 40Hz is not what you want.

A lot of the rap I listen to has heavy bass lines in the 30Hz-34Hz range. I have some stuff that's recorded at -2db at 33Hz. If I had my box ported to 40Hz, the subs would unload on those bass lines and potentially damaged themselves. Go model up those subs at 40Hz with WINisd and tell me what happens. It'll be peaky, and the power handling will drop significantly below about 34Hz.

Set your SSF an octave below your tuning frequency also to protect the sub.

32 hz is too low for a couple reasons pal
a. if you tune this low unless youre making a wall with 20 cubic feet your port surface area is going to be too small for 3 15's whose cone area is more similar to 18" round subwoofers
b. if the port surface area is too small and in this case it would be for 3 15's the air is slowed and the waves are no longer in sync and it sounds like shit
c. just because you tune the box at 40 hz doesnt mean you lose woofer control below that frequency. its typically 5-10 hz below the tuning frequency that this occurs
d. even in sealed boxes playing source material at ultra low hz extends the woofer beyond its normal range (watch a sub playing at 20 hz and one playing at 60). so if anyone plays music this low it doesnt really matter what box youre using if you have any awareness of what your equipment is doing
e. if youre wanting 3 15's to have any kind of sound quality appeal youre retarded especially L7s. sure they can still be tight but i havent seen any SQ cars with 3 15's. odds are you will get more performance out of 2 15's than you will 3 because assuming you have an amp capable of driving all 3 properly, your roof and windows will flex so much that it wont be any louder. not to mention you have more cubic footage to make an appropriate box for 2 subs instead of compromising for 3.
f. the point of a ported box is to get the "boost" from the port into the heart of the optimal subwoofer range ie 35 to 80 hz. picture a bell curve. if you tune the box at 30 hz you will barely hear anything above 50hz. especially with the L7s




hifonics is legit, look for any bench tested review of their products, they always hit rated power.




edit: just looked at kicker website. the tuning frequency for their 15l7 is right at.............40 hz

internal airspace is 2.55 cubic feet with .45 cubes of port each of dimensions 2.5 by 16.25 by 19.5.
if you go to their website they pretty much tell you exactly what you need to build to make their sub sound as good as theyre going to get.

 

[abladeafficionado]

32 hz is too low for a couple reasons pal
a. if you tune this low unless youre making a wall with 20 cubic feet your port surface area is going to be too small for 3 15's whose cone area is more similar to 18" round subwoofers
b. if the port surface area is too small and in this case it would be for 3 15's the air is slowed and the waves are no longer in sync and it sounds like shit
c. just because you tune the box at 40 hz doesnt mean you lose woofer control below that frequency. its typically 5-10 hz below the tuning frequency that this occurs
d. even in sealed boxes playing source material at ultra low hz extends the woofer beyond its normal range (watch a sub playing at 20 hz and one playing at 60). so if anyone plays music this low it doesnt really matter what box youre using if you have any awareness of what your equipment is doing
e. if youre wanting 3 15's to have any kind of sound quality appeal youre retarded especially L7s. sure they can still be tight but i havent seen any SQ cars with 3 15's. odds are you will get more performance out of 2 15's than you will 3 because assuming you have an amp capable of driving all 3 properly, your roof and windows will flex so much that it wont be any louder. not to mention you have more cubic footage to make an appropriate box for 2 subs instead of compromising for 3.
f. the point of a ported box is to get the "boost" from the port into the heart of the optimal subwoofer range ie 35 to 80 hz. picture a bell curve. if you tune the box at 30 hz you will barely hear anything above 50hz. especially with the L7s




hifonics is legit, look for any bench tested review of their products, they always hit rated power.




edit: just looked at kicker website. the tuning frequency for their 15l7 is right at.............40 hz

internal airspace is 2.55 cubic feet with .45 cubes of port each of dimensions 2.5 by 16.25 by 19.5.
if you go to their website they pretty much tell you exactly what you need to build to make their sub sound as good as theyre going to get.

Manufacturers do NOT recommendat the optimal enclosure for SQ or SQL. They recommend a box that is small and loud. They sacrifice low end extension for boomy bass in the 50Hz region. 2.5 ft^3 for a square 15"? That's not near enough airspace. Go over onto DIYMA and start reading around, there's a lot of information out there, you just have to start reading. You can get SQL out of an L7, not a lot, but you can get more low end extension by porting lower. Deep low end extension is one of the most impressive aspects of having a ported box.

Hifonics are mediocre amps at best. The new MBQ is a far better line.

 

[j.castro]

so i hooked up two mbq amp to two of the l7s in a box wired them dwn to 2 ohms and it wasnt very loud? it not even louder than my frends two cvr 15s hooked up to the same mbq? am i doing somthing wrong here?

 

[TnTahoe]

fyi Hifonics and MBQuartz are the same company all under the name MaxxSonics

 

[Pachanga02]

3 l7s should sound nice. I have 1 in my xl and am very happy with how it sounds. Good luck with ur project and post some pics of the finished product

 

[j.castro]

with 1000rms these subs should be pounding pretty well rite?i just dont no why the two cvrs sound louder than the two l7s

 

[abladeafficionado]

with 1000rms these subs should be pounding pretty well rite?i just dont no why the two cvrs sound louder than the two l7s

What boxes are they in? The box makes all of the difference, if yours are in a small sealed box and his are in a properly built ported enclosure, his will be much louder.

---------- Post added at 07:32 AM ---------- Previous post was at 07:29 AM ----------

fyi Hifonics and MBQuartz are the same company all under the name MaxxSonics

The MBQ Discus were benched and put out more power than rated, with a lower THD, and a higher efficiency than the Hifonics line. I haven't seen anything on the new Onyx line, but if they're anything like the Discus line, they're far superior to the Hifonics line.

The MBQ Formula amps were a great run too, underrated, and clean power.