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View Full Version : Box help for 2 NEW 15" Eclipse Ti's. Please check math calculations...



snb778
09-08-2005, 03:40 AM
First, Id like to say that I looked, and there arent any threads for a box on 15" Ti's since like 2004

I have 2 NEW 15" Eclipse Ti's on-the-way. Very excited, but I need some suggestions on what kind of box to make. I have heard that these can produce some nice numbers, but then again I have also heard that they like small sealed boxes?



Can I get some suggestions on either or, and some sizes? Tuning Frequencies?


I already did some calculations here, and this is what I got

For EBP, I took 22(fs)/ .39(Qes) and got 56.4. I guess anything over 50 is supposed to be ported.

THEN I calculated the F3 point with ((Vas/Vb+1)^.5)*Fs=F3....

So I did ((6.1/1.9+1)^.5)*22=45 Hz.

Whyyyy is it showing this sub wants to drop off at 45 Hz???? What did I do wrong

snb778
09-08-2005, 04:28 AM
Here is the website..... http://www.eclipse-web.com/sw9100/sw9152.html

According to this, the Fs is 22 Hz...BUT, your right on the Qts. How do I get Qes?...

I see in your info it says .42...that still comes out to 52, which is border line...but I thought this sub wants a sealed box, or at least reccomended....any experience

Thanks for the help by the way

jimmyjames1700
09-08-2005, 08:33 AM
Here is the website..... http://www.eclipse-web.com/sw9100/sw9152.html

According to this, the Fs is 22 Hz...BUT, your right on the Qts. How do I get Qes?...

I see in your info it says .42...that still comes out to 52, which is border line...but I thought this sub wants a sealed box, or at least reccomended....any experience

Thanks for the help by the way

I while back I talked to somebody at TC Sounds, the Ti build house, and had him email me the real deal T/S parameters for the Ti's because there were so many variations of them on the web. Plus Eclipse Tech support didn't know either!

So here they are:

FS 28.48 Hz
Qms 5.0
Qes .427
Qts .393
Vas 77.96 liters
Sd 720 cm^2 50% surround method
RE 5.9 ohms
Z 8 ohms
BL 27.01 Tm
PE 1000 WRMS
SPL 88.24 dB

EBP = 67

I would recommend a vented enclosure about 2-2.5 cu ft tuned around 30-35 Hz(real world), or a sealed box between around 1.5-1.75 cu ft.

At my Car Audio shop we just picked up the Eclipse sub line a while ago (always head decks and seperates) and have done a few 12's (like mine) and a few 15's. I will say that these things shine in optimized vented boxes and many of our sales team and install techs prefer these to our W7' that we also sell/install.

I personaly would go with a 2.5 cuft vented box tuned to about 41Hz. This will give you a f3 of 31 hz and a very flat response. with only +1.8 dB peak at 41Hz and good low frequency extension.

Now I know what your are thinking, way to high of a tuning freq, however in my experience with designing and building vented boxes with the W7's and now Ti's the real world tuning ends up being about 6-8 Hz lower than designed.

Go to JL's website and look at their recommended vented boxes for the W7's and lcalculate what the box is actually tuned at with BB6 or something. Believe me, you will see that they are actually tuned about 7-8 Hz higher than the recommended/real world tuning freq. All a can say is things change when a sub is actually mounted and loaded in a vehicle with real world current flowing through the VC. Static T/S parameters shift among other things.

RandyJ
09-08-2005, 08:40 AM
I have mine in a 4.3^3ft box tuned to ~24Hz. I think it would be nicer in a smaller box but I also agree that they shine in ported enclosures.

snb778
09-08-2005, 12:41 PM
iiiiiiiiiiinteresting. Thanks guys. I really have only heard one of these in my life. It was in a 1.2 cu. ft sealed box in the back of a dodge SRT-4. Powered by a bd1500.1, and wowwww. This sub has raaange. Very powerful, Very clean. I was afraid this kids back window was going to break when he was just street beatin..

snb778
09-08-2005, 01:04 PM
Ok here is my next question. When making a DUAL sealed enclosure... is it acoustically better to share the chamber, or seperate them??

squeak9798
09-08-2005, 04:59 PM
I guess anything over 50 is supposed to be ported.

Just as an FYI: The general rule of thumb is that an EBP closer to 50 means the sub is better suited towards sealed, and EBP closer to 100 is better suited for ported, and subs in the middle can go go either way.

There's no rule that says any sub with an EBP over 50 has to be ported. It just helps give you a general idea of what type of enclosure the sub may more suited for.

With an EBP of 56, the sub would really be more suited for a sealed enclosure if you followed the EBP as a guide. Though, that's not to say that you couldn't have good results with a ported enclosure aswell.

snb778
09-08-2005, 11:05 PM
Alright, very cool. Thanks a lot for the help guys. THESE THINGS ARE SUPPOSED TO BE HERE ALREADY~!~! (THE SUBS) This is kiiiiillin me!

snb778
09-09-2005, 12:32 AM
yea, gonna split the box and make seperate chambers.

snb778
09-12-2005, 01:31 AM
has anyone built a sealed box for these recently by any chance?