thoughts on tunning flat responce sa8 or man. specs

[john253a]

sa8v1.5 on 400wrms each

in trunk facing rear/pord drivers side

all in 3/4,

does in need more bracing or maybe in different places?

thinking of 3/4 round from front wall to port wall?

is it worth kerfing the port on one side between subs to port

Edited April 25, 2012 by john253a

[john253a]

i currently have them in this box, with no bracing/ no smoothed or radiused port or double front

and i'm reasonable happy,(built it as a test box for tune and port size)

just looking to optimize its performance a bit,

the above measurements may look a bit strange on new box but there a combination on metric and imperial

[john253a]

is it a bit to peeky

or should i shoot for smoething like theise

all are modled on 2 drivers

Edited April 25, 2012 by john253a

[john253a]

No ran 2 sa8 in 0.25each ported for a flat response that can comment

[Joe X]

WinISD does not factor in car cabin gain, so it would be hard to predict a true flat resopnse from those curves.

Sealed typically gives a fair flat response in cars since the rollof of sealed cancells out cabin gain, 4th orders, can be setup to give a flat response (around 1:1) up to about the tuning frequency of the ported chamber.

In ported mainly you can avoid the enclosure to peak in many ways including lowering the net volume and properly tuning BUT will loose output.

A parametric EQ is another way to tweak response.

[john253a]

The only 8"s ive ever had were sealed, used as low/mid drivers(lowpass 160/ highpass 80 on a 24db slop in conjunction with 15"s)

most of the box ive build were for 12 and 15 all around 3db peek in the mid 30's and then flatten out around 0-1db@ low 40hz

What ive been recommended for these in 1.5net @34hz, low pass the rca's at 160hz on 24db slop then set amp to 125hz/6db slop

with 14sqin port each sub

but it seem a bit peaky to me?

any thought on if that sounds right? or should i change it around a bit

Edited April 26, 2012 by john253a

[HypnotizedMind 91666]

the 0.7 / 33hz

[john253a]

each or 2

edit

if each i can just extend port to achieve that

but then ill have around 19sqin per cuft

and thoughts on port, considering ive been told 14sq each

Edited April 26, 2012 by john253a

[Noobtastic14]

If you build the box right and your panel seams are strong you will not need any bracing. You also will not need a double baffle. I suggest a nice birch ply but the classic MDF works as well. The model shows the "peaky" model still the loudest at 30hz which seems like a winner to me. You have 8s, flat means very low output unless you get it to peak where you want it to play.

[john253a]

my current box is 1.5 @33hz 27sqin of port, plane Jane box, no extras

and i was looking at 1.5 @34.5 29sqin port double brace, rounded corners, with possible flared/kerfing to port exit