In a bit of a pickle...maybe?

[hayes55987 0]

Approximetely 1-2 weeks ago, I decided to I needed a new sub. There was a big upcoming sound competition in my town and I needed something to beat a rival of mine that had more money, and more time,haha So I knew Fi was a good place to go. At this point, i was extremely focused on beating my rival and so I decided to go all out with my power options (JBL BP1200.1) and get an 18" BL fully loaded. This worked pretty good for the competition. Didn't do as well as expected, but we tuned the box way to high in a poor guess on our part of the cars freq. it was around 41 and we were tuned for 47-49hz. still, we managed to hit 141.6 at the headrest with 1400 watts of power, stock electrical system, and a 30 second run which really drained the car. After the competition though...it hit me. I have a 1995 Honda Accord and I realized I had to fit an 18" BL into the trunk. I finished the box up yesterday and it...sorta fits in. I had to take out spare tire and everything and angle it in. My question is, what do you guys think of the set-up? Is it cutting things to close? Here are the specs:

its a 5.00 cu ft box exactly tuned to 37hz. The port dimensions are 2 in high, 22 inches long, and 30.5 inches wide. Vent Velocity is around...17m/s at max I think.

Here are the problems with the box though...I have no subsonic on my amp and the box excursion exceeds the subs at 24Hz.

although i am playing mainly music, usually not very loud even, is this that big of a concern? I am not really that worried now because most music never even gets that low and I will avoid playing the classic songs such as Late Night Tip and what not.

What do you guys think about the situation I got myself into? haha

Thanks!

[JimJ 11]

It's a problem with an enclosure tuned that high.

Harrison Labs makes inline subsonic filters that you plug into the amp interconnects, PE sells them.

[tejcurrent 13]

^^x2.

And as far as having things jammed in there, if it sounds good and meets your goals then I'd say don't worry about it, or make the box to fit the car better.

[hayes55987 0]

as far as jamming it in there. i'm not really that happy with the way it is. I ripped out the bottom and took out the spare tire. I forgot to mention in my first post I think that the box was tight enough that there was no possible way to put any of it back in. So far my plan is to take my router and then on my double baffle, cut out the outside diameter of the sub and flush mount it to give me the extra room to have my spare tire and the carpet floor back in my trunk.

Secondly, i can re-tune the box pretty easily by filling up part of the ports and siliconing them in or something like that to tune it lower, but I was worried about vent velocity when I made the box. It peaks at like 18 m/s. but if I tune the box down to say...31Hz, the vent velocity jumps up to 20m/s. is this going to really be noticable?

If someone wants to help me out anymore like in live talk, i have AIM and Windows Live. I can send you the BBP file or dimensions or something like that. I will also post the dimensions on here.

Current Box:

15" High

32" Wide

27" Deep

Port: tuned to 37Hz (the port actually has two braces position every third of the way. so techincally I guess it would be 3 ports of around 9.5" wide each)

2" High

22" Long

30.5" Wide

The New Design Maybe?

15" High (but the BL would be flush mounted in one of the baffles and then i'd have clearance to get it in the trunk)

32" Wide

27" Deep

Port: Tuned to 28.8Hz ( I have my ports broken up into three technically with the braces, so I would just fill in one of them leaving me with two ports each 9.6" wide, or 19.32" total)

2" High

22" Long

19.32" Wide

lemme know what you think!

AIM: hayes55987

MSN: [email protected]

[hayes55987 0]

Ok...so i figure i'd keep you updated and I have another question if its worth it or not.

Here's the deal...I took my box back home earlier today, took it back out, took out my router, and then routed out 1/4 of an inch of the mounting circle. now I am able to fit the sub semi-flush mounted into the trunk with the carpet bottom and everything.

the only thing I have left after listening to it for a few days is if its worth it for me to seal up one of the ports? I'm tuned to 37 now and if i plug up one of the ports, i'd be down to around...29hz

my only concern with this is vent velocity...it goes from 15m/s to 20.5m/s i think if i lower the tuning. I could flare the ports a tiny tiny bit to help. Also, it increases the group delay around 3ms

the offsets are obviously a lower tuning and that my excursion goes down to like 19hz before over excursion.

let me know if i'll even notice the negatives of the changes or how you think that will work!