PEQ cut at 30Hz

[kryptonitewhite 1]

So over the last 2 years I pre-planned my van build making it clear that I don't want 30Hz-60Hz. That I must have as much 30Hz on down output as possible, but 60Hz on up would be nice as well. With only 1 HO alt, I was able to sort of get by by having my subs LPed at 31.5Hz. Less information to re-create, more power for the narrower band... and that narrower band is very high excursion (low frequency) for more cone motion to keep things cool with a clipped signal.

Well I'll be getting 2 more HO alts, so I can bring the LP up to 100Hz where it should be, as I finally moved my 6.5's HP up to 100Hz. But my excursion problem, as predicted, is 25Hz-45Hz, and I want to take out 30-60 anyway. So I am playing with WinISD and for fun took out 30Hz at -6dB.

[///M5 2,833]

How did you model the cabin in WinISD?

[ssh 924]

How did you model the cabin in WinISD?

say what

Edited August 12, 2010 by stefanhinote

[kryptonitewhite 1]

How did you model the cabin in WinISD?

you got me. Im not advanced, but at least I do a little plotting, no? I dont know how to include boundary/room/cabin gain. Im willing to learn though....

[kirill007 52]

How did you model the cabin in WinISD?

you got me. Im not advanced, but at least I do a little plotting, no? I dont know how to include boundary/room/cabin gain. Im willing to learn though....

He is just saying (in his way ) that you can't do that.

[kryptonitewhite 1]

lol alright, alright. here's the other kicker... with my cabin gain included, my rear enclosure is 60 cubic feet. My front cabin is 70 cubic feet. My rear enclosure is tuned to 21Hz. Windows up, my cabin is tund to 19Hz. So if I burp windows up, am I doble tuned to 19Hz and 21Hz? Shoot for the middle? Windows down, am I 6th order BP?

[kirill007 52]

It's sort of a 6th order BP, but no need to account for that.

How did you figure out cabin tuning?

And you can't really measure cabin gain with equipment that costs under thousends of dollars.

You can easily find cabin resonance, but that's not really important for you're goals.

[kryptonitewhite 1]

I aproximated cabin airspace... same portmy goal was just to buildit as big and tune it as low as I could, so goals met. Just need to PEQ out 30-60 as originally planned, but Ive never used EQing before so iw as scared Ive got the crossover thing mastered (well, changing them anyway) so time to tackle EQing (gulp)

[kryptonitewhite 1]

I had a thread about it when i was still designing it, someone made up this pic for me and I added a little to it

[Impious 1,476]

I guess I really don't understand what this thread is about? Are you asking a question or just making random statements?

[kryptonitewhite 1]

same as most my threads, random statements in hopes somethin will come up. ive never EQed before, so when I get stuck, ill post it here where ive laid a little base line of my intentions i guess

Edited August 12, 2010 by kryptonitewhite

[///M5 2,833]

I guess I really don't understand what this thread is about? Are you asking a question or just making random statements?

It obviously has nothing to do with a PEQ cut at 30Hz

[kryptonitewhite 1]

I guess I really don't understand what this thread is about? Are you asking a question or just making random statements?

It obviously has nothing to do with a PEQ cut at 30Hz

they rarely ever have anything to do with the title, do they? lol

[cobra93 47]

So this is a bait-n-switch?

[kryptonitewhite 1]

So this is a bait-n-switch?

yes sir! So here's the switch:

can it be loosely said, as a general statement, that often the peak SPL is sometimes about 5Hz above tuning? ( completely ignoring vehicle resonance)

I am 60 cubes tuned to 21Hz, my peak from 30Hz down was 25Hz and 26Hz. I'm sure I would have peaked much higher above 30Hz, but i purposely did not go above 30. I am considering possibly maybe shortening my port as much as I can... my wall is 10" thick, so 10" port, reulting in a 24Hz tune. If I do this, will "put on" actually lose dBs on the 25Hz tone? Will my peak no longer be 25-26Hz, but maybe 29-30Hz?

[///M5 2,833]

No, making general statements does not apply to specific situations.

[kryptonitewhite 1]

If I cut my port down, will i lose dB at 25hz?

[///M5 2,833]

Considering you avoid and disdain all recommendations that are given to you, I seriously doubt anyone is going to take the time to model and figure out what nonsense you are attempting to create in your box in the first place which basically means you'll just have to try it....or you could start by actually listening for once.

[kryptonitewhite 1]

sounds good, and on that note, how about mor copy/pasting that has nothing to do with the title?

If I win the lotto, I'm going to pay scott for a full run of Parthenons. Whatever I dont use Ill give away.

My van is 47" tall by 61" wide

I'd either have 1 built with a 40" square cone and have a 20" port next to it to cover 15Hz-100Hz, or put it in 8th order and have it fart 15Hz-30Hz and have 2 18's LMS ULTRA 5400s behind the seats for 30Hz-100Hz. Or I could have 6 Parthenon motors put on 6 22" cones, get the tooling figured out for the surrounds, spyders, and baskets, and run 6 in a sealed wall. 2 high, 3 wide. 3Hz-100Hz

If I ran into $100,000 Id redo the van built very close to what i have now, having learned quite a lot what to do a bit different, and run 4 RE AUDIO XXX 18's.

Id I could get 4 LMS 5400's right now to swap, I would. If SS RL-ps or Maelstrom-X 18's were only $100 more per sub, Id have them in there right now. If I could get AA Avalanches for the same price, I would. Mayhems. Havocs.

I got 3.5" p-p for $200. I get the same 30Hz down with these IB3s as I could with SS RL-ps or Maelstrom-X 18's AA Avalanches Mayhems. Havocs. None of these subs can move any further, therefore none of these gain gain any output from 30Hz on down. Yes they all have much better motors, much better FR curves, built for this application, but the fact is... if the IB3s can bottom out from 30hz down, and they move just as far, then there is nothing to be gained.

I got 30mm Xmax for $200. You cant beat it. If someone offered me a trade for LMS ULTRAs (which have 50mm Xmech, 38MM Xmax) there would be a little to gain from 30Hz down. If someone offered me MX18's, AA Avas, RL-ps, Mayhems, or HAVOCS for 4100 more, Id have them. Paying double to tripple for no 30Hz down gain? not this guy.

My home theater towers are 49"x98" faces. I'd do 2 22" Parthenon wide by 4 tall sealed, or 1 40" square each tuned to 7Hz

[johnecon2001 82]

I think this thread has run its course..