Sidefiring vs Downfiring with diy sub (my findings)

michael_w

I was bored so, once again, I decided to rearrange my room. I moved the 2ch gear rack off to the side and brought the sub out from behind it and put it directly in the middle (it was in the middle before but now it's front and center). I had that running for a while and then tried something different. I took my diy atlas 15 with a 360 watt css plate amp that is built to downfire and flipped it on it's side.

Once I spun a couple cds and fiddled with the crossover, gain and phase I had it where I liked it. It sounded okay but just didn't have the sound it had before. I was pretty suprised it changed so much by a small change like that. I had to crank the gain knob to get the same response as well as set the phase to 0 instead of 180 as I had it before to get it to sound anything like it was before. The major thing I noticed was that the sub didn't dig as deep as it was before. It was almost as if it were not even there unless I really cranked it. It wasn't adding anything useful into the music, except annoying upper bass that my lsi7's were already covering just fine.

The only things I really liked about having it sidefiring was that it provided a better stand for my monitor and keyboard being a bit lower and that I finally got to show off the giant Atlas with it's cool carbon fibre dustcap. Other than asthetics, it sucked when placed sidefiring.

All in all it was an interesting experiment and a nice workout for my back lifting a sub that weighs more than me. Maybe the moral of the story here is that you should really fiddle with things if you can. If you have a sidefiring sub and you can try it downfiring or vice versa, give it a shot. You might have the opposite results and actually like it that way.

Some pics of both setups. Those little 3" audax pipes look pretty tiny when put next to an atlas 15

Early B.

Interesting observation. Awesome sub, BTW.

I noticed you have wheels on your sub. Do they rattle when the sub is firing? I had wheels on mine but took them off because the ball bearings rattled. Your wheels may not have ball bearings, so you might be OK.

BullShifter

If you don't mind me asking, what are the dimensions of that sub? Where have I seen those speakers before?

michael_w

No problems with the casters. I'm quite glad I put them on after having to move the thing myself a few times. It's far easier rolling the thing on carpet than it would be to lift it into a tight spot I might have a problem if I ever have to move to hardwood floors, but I don't see that happening for a little while.

The sub is 23" high, 23½" wide, 25½" deep and sits 4" off the ground from the 2½" casters and little double stacks of ¾" mdf for legs, although probably more like 3½" from it sinking into my carpet.

Which speakers are you talking about? The ones on the far sides are polk LSi7's on 20" semi-diy stands, then the tall skinny ones are my diy voigt pipes using a 3" audax full range driver (# HT080M0). The sub is an ascendant audio atlas 15 in a 6.5 cubic foot box ported with two flared 4" ports, each about 18" long with a flare that goes out to about 7".


A drawing of what it looks like... as you can tell from the pic the amp was a very tight fit between the two ports. I got lucky and only had to cut a small section out of the middle brace to get it to fit in. (section not shown in the drawing)

BullShifter

michael_w wrote:

Which speakers are you talking about? The ones on the far sides are polk LSi7's on 20" semi-diy stands, then the tall skinny ones are my diy voigt pipes using a 3" audax full range driver (# HT080M0). The sub is an ascendant audio atlas 15 in a 6.5 cubic foot box ported with two flared 4" ports, each about 18" long with a flare that goes out to about 7".

The tall skinny ones. Are they posted on another site?

michael_w

Diyaudio.com

scornful

What program did you model the sub with? I've used SolidWorks almost exclusively for several years now.

Steve

michael_w

I drew the box up with autocad r14 but I simulated the box with winISD and unibox. I used those to try and give me a general idea as to how it'd sound and how I should build it. I mainly drew the autocad one because I was bored having to wait over 2 months to have the sub shipped here and to give a little perspective as to if things would actually fit the way I had planned. With a to scale drawing I found out that the amp would bearly clear the ports and that I'd have to compensate for that.

I just quickly took a look at the solidworks website and it's pretty intriguing. It looks like a good program to design things with. I'm not really into modeling or autocad much, but I've fiddled around a bit at home with r14 and at school with an architural version.