danfortner

10-27-2003, 12:31 AM

Hey All,

I bought a 12" Eclipse Titanium back in April. I really like it and have done a few things to improve upon it. I want to keep as good of SQ as I have now and just add some more loudness. Obviously adding another sub seems perfect, but 2 of these things would be total 1500w RMS on my stock alt (about 500 too much), so I would like to see what else I can do to this one only first. But I am wondering now what would you suggest/think of my ideas to maximize the performance of this sub:

1. The first thing I am definately going to do is port this subwoofer. It has a good Fs to let it perform well in sealed or ported. I just need some help with the calculations. I used eatel.com and came up with 1.2 cuft (I am assuming before displacement, which is .19 cuft) and I used another calculator to come up with 1.5 cu ft. But I read this article Sealed, Ported, eh (http://momentum.soundillusions.net/august01/momentumtechaug2001.html) on SoundIllisions and am basing some of my background knowledge on what they are saying. One thing they say is:

For an adequate/correct tuning frequency, the equal/greater Vas should yield a flat response where the smaller Vas alignment should look similar to a sealed enclosure but with a steeper roll-off. If you don't meet or exceed the Vas of your ported driver, problems will inevitably occur."

a. I came up with 1.2 and 1.5 and thats way lower than the vas of this sub, 3.2. So this has just got me wondering if someone else could calculate a ported enclosure for this sub, geared towards SQ. The thiele small parameters are listed at the bottom of this post.

b. What is a good tuning frequency for keeping the same SQ I had when it was sealed, but adding some SPL? 30hz or should I calculate the resonant frequency of my car to find this?

2. New amplifier? The RMS of this sub is 750w. I am using a US Acoustics 1000D - 750w @ 2 ohm. People say all the time that Eclipse makes hearty woofers, and that they can take alot. But does that really mean that you should go well over the RMS to increase perfomance. I do not want to blow this sub as it was perty expensive! Would a PPI PCX-1500 be too much (1000w @ 2 ohm) or should I just stick to the 750w if I am worried about blowing it?

3. Another layer of second skin. I loved the results when I added 45 ft to my trunk, so doubling it might help to keep a little more bass inside.

Alright thats it for now. Hope you guys can shoot me some feedback.

THANKS A LOT!

Eclipse Titanium 12" Parameters:

DC-R - dual 3.1 ohm

FS - 27hz

qts - .30

vas - 3.2 ft^2

spl - 89db

qes - .32

qms - 5.0

sd - 490 cm^2

xmax - 38mm

woofer displacement - .19 ft^2

I bought a 12" Eclipse Titanium back in April. I really like it and have done a few things to improve upon it. I want to keep as good of SQ as I have now and just add some more loudness. Obviously adding another sub seems perfect, but 2 of these things would be total 1500w RMS on my stock alt (about 500 too much), so I would like to see what else I can do to this one only first. But I am wondering now what would you suggest/think of my ideas to maximize the performance of this sub:

1. The first thing I am definately going to do is port this subwoofer. It has a good Fs to let it perform well in sealed or ported. I just need some help with the calculations. I used eatel.com and came up with 1.2 cuft (I am assuming before displacement, which is .19 cuft) and I used another calculator to come up with 1.5 cu ft. But I read this article Sealed, Ported, eh (http://momentum.soundillusions.net/august01/momentumtechaug2001.html) on SoundIllisions and am basing some of my background knowledge on what they are saying. One thing they say is:

For an adequate/correct tuning frequency, the equal/greater Vas should yield a flat response where the smaller Vas alignment should look similar to a sealed enclosure but with a steeper roll-off. If you don't meet or exceed the Vas of your ported driver, problems will inevitably occur."

a. I came up with 1.2 and 1.5 and thats way lower than the vas of this sub, 3.2. So this has just got me wondering if someone else could calculate a ported enclosure for this sub, geared towards SQ. The thiele small parameters are listed at the bottom of this post.

b. What is a good tuning frequency for keeping the same SQ I had when it was sealed, but adding some SPL? 30hz or should I calculate the resonant frequency of my car to find this?

2. New amplifier? The RMS of this sub is 750w. I am using a US Acoustics 1000D - 750w @ 2 ohm. People say all the time that Eclipse makes hearty woofers, and that they can take alot. But does that really mean that you should go well over the RMS to increase perfomance. I do not want to blow this sub as it was perty expensive! Would a PPI PCX-1500 be too much (1000w @ 2 ohm) or should I just stick to the 750w if I am worried about blowing it?

3. Another layer of second skin. I loved the results when I added 45 ft to my trunk, so doubling it might help to keep a little more bass inside.

Alright thats it for now. Hope you guys can shoot me some feedback.

THANKS A LOT!

Eclipse Titanium 12" Parameters:

DC-R - dual 3.1 ohm

FS - 27hz

qts - .30

vas - 3.2 ft^2

spl - 89db

qes - .32

qms - 5.0

sd - 490 cm^2

xmax - 38mm

woofer displacement - .19 ft^2