Alright, I haven't been to any of the audio forums in awhile. NICE job on the new forum, Mike! It looks beautiful. K, my 15" Brahma has been sitting here collecting dust since august, I finally have time to build a box! Anyone here w/ brahma experience, how does 4.5 cubes tuned to 30hz w/ 52.5 in² of port area sound? It's supposed to be a sq/spl combo enclosure, a bit more on the sq side. I have modeled this enclosure in WinISD, and it looks like it will have decent frequency response, figuring in cabin gain in my car (Isuzu Impulse RS). I would love it if someone would tell me how the transient response will be? The beast will be eating 1500w. 1500w should be safe for this enclosure, right? Does what I sugested above sound good, or could I make some changes for a dramatic difference in SQ w/o sacrificing much SPL? Dan Wiggins, I would REALLY appreciate your input here, seeing as how you are the man that designed the driver. Everyone else's input will be MUCH appreciated as well.
That box is going to give you a rather large peak in response, if you are really going for SQ that isn't desirable. Other than that there is no reason it won't sound good -- the Q numbers on the 15" Brahma make it more of a sealed box woofer (I run my 15 in 3 ft^3 sealed) but I have heard good things about them ported. - Jacob
yea.... thats a bit peaky for SQ.... I would go with 4 cubes tuned to 24 Hz If I waz you..... which Im not
I agree. This is a personal preferance. QTS values from .5-.4 are typically a "installers choice" type of an indication. .5 and up is definately a driver belonging in a sealed enclosure. .4 and lower are woofers happy in ported enclosures. The in-betweens are suited for either, dependant on YOUR personal tastes, or, dare I say, bandpass. I wouldn't stick a .47 driver in a ported app, but that is simply because I prefer sealed. If you prefer ported, it will do, although it will be happier in a sealed enclosure. The 30Hz enclosure will be a bit peaky in it's responce, but with a little EQing, it should be a good sounding box. You will need to use a subsonic quite a bit higher than I like, due to the rapid unloading of the driver just off tuning. I suggest setting the subsonic to 25Hz. Talk about killing the low end. I suggest tuning lower, and a bigger box
i have a B15 in 3.3 cuft tuned to 30hz and it sounds very good. Just got metered yesterday and hit 148.9 outlaw... not bad for an sq tune I should add i'm running it 1500 watts
So I went back into WinISD, and messed w/ the tuning a little bit. a 25hz tune gets rid of the peak w/o losing much SPL at all. Like .6db @ 30hz. And I will have to set my subsonic @ about 21hz. So is 4.5 cubes too big, small, or just right? Is 52.5 in² too much port, too little, or just enough? Can I get away w/ less area without losing SPL or SQ? It's gonna be a 15x3.5" slot.
Overkill as in it won't make a difference or overkill as in I don't need it but it will make a difference?
