twotonetrack

I recently had boston components/coaxials, clarion head unit, JL 300/4 amp with a 10w3v2 in a custom box in the stock sub location. Two channels are bridged to power the sub and the other two on the front speakers. There is distortion when I crank up the sub so I ordered a JL 500/1 that should arrive shortly. This should help the distortion but the bass does not fill the car like I am used to even at low volume (L7 15" w/1000watt in G20) and my driver door rattles. Is the location to blame? Finally would Nazaar's box or similar under-strut sound better than a rear corner custom box with a 10w7?

chaparro78

iTrader: (2)

The Sub behind the driver's seat is a bad location and you are not geting the best quality sound from your sub from there. Take advantage that you have a hatch and mount your Sub/s in the trunk. There are many differentways of doing this where it takes up litte space or in ways you take up the entire trunk depending on what you want.

twotonetrack

Which then would be better for sound:

an under-strut 10w7 box like Nazaar's
or
a rear-corner custom sub box built thick
or
a custom built under-strut box built extra thick and reinforced?

chaparro78

iTrader: (2)

Both of my systems have been in the spare tire compartment facing up. And both sound incredible. i have heard a few that have the subs under the strut bar, the sound pretty good as well but then you have a sub facing back and there is rattle in the rear licence plate. Here are my previous and current setup

stu46

out of the 3, go with #1.

twotonetrack

Speaking strictly sound quality, Would Nazar's box perform as good or better than as custom built under-strut box? I understand thickness ranges from only 1/8 inch to 3/4 inch in Nazar's box. It is also said to need to be filled with sound foam for extra airspace for the 10w7. This makes it sound that it was not built for the 10w7. The w7 needs an extremely thick box to function correctly and 1/8 inch might not cut it.

VO...

iTrader: (25)

X2 on location to blame for the sub not sounded as deep/clear as you probably expect.. I also agree with chaparro78 on the spare tire well install. Mine sounds good in the tire well also. Think of the hatchback as a giant mega phone.

VO...

iTrader: (25)

3/4 MFD is what you wanna go with. It resonnates less and will hold better under harsh conditions being produced by the sub.
Foam is used to trick the sub into thinking there is more air space in the enclosure. It manipulates the speed at which the sound waves travel on the inside of the box. You will have to do trial and error when using foam to see which application is better. People generally use foam when : example- they need 1.50 cu ft of enclosure space, but only have enough room to build a 1.25 cu ft enclosure.

MacRayZ

iTrader: (-1)

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Paul350Z

iTrader: (1)

There is some science involved. Subwoofer installation is only parcial black magic.

If you have the internal volume of the speaker you can actually run the speaker's Thiel-Small parameters though an on-line java calculator to give you what the speaker is likely to sound like.

Distortion ... could be that you're clipping your amplifier by over driving it out of the headend. Every amplifier - even a 500 watt one is going to have a linear portion of it's response and a non-linear one where typically the output transistors either run out of power supply or run outside their linear response and start to clip or distort. This signal will then be sent to your subwoofer which will do it's best to reproduce it.

Music is made up of sine waves - you've seen them I'm sure - nice smooth round waves. Overlay the right sine waves together and you get music. Clipping is where the sine wave turns into a square wave where the tops and bottoms of the previously smooth wave turn flat - they turn into a DC voltage!

Speakers take the sine waves of music and oscillate back and forth smoothly (if your singer is in tune!) to produce music. They disapate most of the wattage sent to them as heat but a small amount is made to move the voice coil in and out producing music. When amplifiers clip they send DC voltages to the speaker - a DC voltage causes a speaker to stop moving - it stops disapating the energy as music and starts producing more heat. Not only does the music sound like fingers on a chalkboard but it also burns your voice coils destroying the speaker's motor.

I have lots of expensive test equipment - RTA's, SPL meters, O'scopes - but the best piece of equipment is my ears. You can hear a clipping amplifier. You can hear a subwoofer being driven beyond it's abilities.

Actually corner loading a subwoofer is an old practice which actually creates gain - pointing the speakers into the back of the Z loads that area up.

It's going to be real hard for any two 10" speakers to make the base of a 15" - pie are square ya' know!

dannichols

x3 on the chaparro78 design. Mine is facing up in the tire well and sounds great. I had a Nazar box before and had way more rattle then. There is only 1.5" of space above the strut bar, when you blcok the strut off, air flow is limited and you create an isolated air-space.

LS350Z

Best way to build pressure in the Z is having the sub facing upwards toward the rear hatch. Firing backwards from the strut brace is better then the touring model location behind the seat but still isn't as good as firing upwards. Get the sub as far back as possible for best results.