blindhammer

iTrader: (5)

I'm not really concerned with making this box for spl, if i decide to venture down that path i will be making a box specifically for that, however I would like a good amount of lower freq response, so maybe the larger volume is the way to go.

With me putting an extra 100wrms into the subs, and a larger box volume, is there a chance i could dammage the subs? also is there a limit to how much box volume i can add before i start to either lose response or at least not make the gain worth the space?

I am not opposed to taking my entire trunk up if it will sound really nice, however, any saved space is a bonus.

StickyFingaz

iTrader: (4)

I think that 2ft^3 per driver will be quite sufficient for volume, as the recommended volume is 1.75 by Rockford. The flatter response will give you better sound quality, combined with the lower tuning frequency. I assumed this is what you wanted (it should still be nice and loud).

The extra wattage shouldn't be a big deal as long as you don't go ape for too long, or slam tunes below the tuning frequency without a subsonic filter.

If you were going for SPL you would jack up the tuning frequency and maybe reduce the box volume to give you a very steep response curve that would sound like , but be loud as hell at a couple frequencies.

So going above 2ft^3 per sub is probably unesscary.

blindhammer

iTrader: (5)

ok, next thing, i have a subsonic filter on my amp and no idea how to use it, please enlighten me

StickyFingaz

iTrader: (4)

Just play around and try out the different settings. I would recommend using it, but at which frequency setting is up to you.

Try around 20Hz or 14 clicks on the subsonic filter **** according to your amps manual. Basicly it will keep your amp from boosting unessesary signals which are inaudible or possibly damaging at high volumes and rob power from the amp. There is no need to set the subsonic filter above the tuning frequency.

You should also utilize your LPF if you haven't set a crossover point somewhere else (your deck for instance) to make sure your subs aren't playing signals which are above there operating range which will also rob power from the amp, and possibly damage your subs. I would suggest somewhere around 81Hz or 16 clicks on your LPF **** according to the amps manual.

One other thing, avoid using the bass boost if possible. People tend to go crazy with this and it can totally fluck up your system.

Hope that helps!

blindhammer

iTrader: (5)

ok, so Bass Boost off, subsonic i will play with, my LPF is set to 50Hz from the deck.

sound good?

also, this is basically what im looking at as far as a box, what do you think?



whoops, missed the 15.25" on the right side...

StickyFingaz

iTrader: (4)

Nice pic! Ya that looks pretty good to me. It's pretty late now but you might want to consider using a wider port, sorry I should have caught that earlier. Not totally nessecary but won't hurt, maybe 2". Try this instead. I would raise the LPF on your deck to at least 65 or 70hz though, your missing out on some beats! Sand the edges on the port entrance and exits (ie. green and purple pieces and the one red edge) to further prevent port noise. Good luck with construction, I hope it sounds good. You have some nice equipment, I doubt you will be dissapointed if you build the box right...

blindhammer

iTrader: (5)

what will increasing the port width change? It will be the same amount of air, but an easier path for it to travel right? so that will make the subs sound more lose right?

also, you were saying about rounding the edges, would it be a bad idea to imbed pieces of say 4" ABS pipe in all the internal corners of the box? I figured that it would make it easier for the air to flow out of the port. willt that help? or will it hurt? or will it even matter?

by the way, thanks so much for all the help

StickyFingaz

iTrader: (4)

No worries bout the help, that's what the website is here for! Think of the port not as a place for air to escape, but rather as adding extra subwoofer cone area. The air in the vent is trapped, and acts like a pistion moving in and out. So the more vent area the better! Check out this article for a more detailed explanation.

Many ppl use the abs pipe or angled cuts of mdf on the outside corners (where black and green meet or possibly where black meets yellow), this will help air flow and reduce the possiblitiy of port noise. This will not affect the tuning frequency either. I doubt, however, it would make a audible difference.

blindhammer

iTrader: (5)

ok cool i have a fair bit extra MDF both 1" and 3/4" so I will probably double layer and actually imbed the pipe into the mdf so it is flush as not to obstruct airflow, and you said it would not alter tuning freqency, will it effect the total volume since it is eliminating the square corners that the box had? (kinda like kicker subs, or the wendy's hamburger )

also, would i gain from making the ports even 2.5" or 3" or will they start to lose potency as same amount or air through much larger opening?

StickyFingaz

iTrader: (4)

The corners would be so small inside the box that it would hardly affect the overall volume. The one in the port won't affect the tuning frequency because it will only assist air flow, (as long as its not too big!). I would just use a 2" cut of MDF, with 45* cuts on the backside cause its easier. Like I mentioned before I doubt if this is really going to make an audible difference.

I can't really answer your other question (i don't really know enough!) a couple more inches probably won't matter, just remember that the larger the port area the longer the port will have to be. Having a huge port in a small box can have poor results but I can't give you a diffinative answer as to how much is too much, sorry!

According to the Digital Designs article, you should aim for 16"^2 of port for each cubic foot of volume. So about 32"^2 for each driver for you. So you could easily increase the port to 2.25" to achieve this number. To do this on the De:Caf box calculator we have been using, simply increase or decrease the Xmax feild (Try 17 or 18mm).