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SUPPORT FORUMS FOR DECWARE SPEAKER PLANS >> Wicked One Support Forum >> Pass band?
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Message started by Hellion on 12/29/05 at 20:20:10

Title: Pass band?
Post by Hellion on 12/29/05 at 20:20:10

Okay I am thinking of building a wiked one box. I have a great ammount of curiosity and love trying new things. I would like to know if it would be a good idea to try introducing a vent in the sealed volume. Suppose I were to vent the box as if it were a 6th order bandpass with a pass band around 40 hz on one side, and a pass band of about 60 hz on the other. This is assuming that the volume in front of the driver before the opening into the horn acts like the front volume of a bandpass enclosure. (Please correct me if I'm wrong I do not understand how this box works at all.) I have had good results with a 6th order bandpass, though choosing the right cutoff frequency is crucial to powerhandling characteristics and overall efficiency. (Not a good idea for ultra low frequency high volume boxes.) Just adding a bit of lining goes a long way with this kind of box, and I was curious if a bit of lining wouldn't hurt. It always seems to clean up the 6th order boxes and get rid of noise outside the pass band.

Perhaps the transient performance of 6th order band pass systems is worse than sealed? If so, Please advize! I do not want to make a sub standard WO my first time around. ;D

Title: Re: Pass band?
Post by jj420 on 12/29/05 at 21:19:47

somebody here did port a WO, with interesting results. Im not certain excactly, but the final report was that while SPL went up, SQ went down in a big way, so i guess it depends on what you are trying to make.

Title: Re: Pass band?
Post by Adrian D. on 12/31/05 at 15:57:57

as far as i know, the wo is said to be a fast design.
i'd say don't port it. people say it's loud enough the way it is.
i don't know about lining the inside. i guess a VERY small amount won't hurt. you'll find the answer to some of your questions here
imo, the wo is a bp4 which fires in a folded horn (please correct me too if i'm wrong, i'm here to learn). i'm also very curious, but i haven't got any space inside for a wo :(. maybe i'll do a garden sub

Title: Re: Pass band?
Post by bnew63 on 12/31/05 at 17:47:12

As said many times by many people on this site,Build a stock one first its easy enough to scale up or down.You,ll love it as it is.Then if you get the hankering to modify,go crazy.I think you should experience what Steve intented this design to sound like.I've built four of them over the past two years all of different sizes and after a few tweeks they all performed beyond my expectation.
Just my two cents
Brian

Title: Re: Pass band?
Post by gexter on 01/01/06 at 05:41:33

bnew63 wrote on 12/31/05 at 17:47:12:

I second that, while stating that the only reason you may see hacks for me is only because of lack of funds and a wonderful supply of used junk.

Title: Re: Pass band?
Post by Jet-Lee on 01/03/06 at 14:31:43

gexter wrote on 01/01/06 at 05:41:33:

I second that, while stating that the only reason you may see hacks for me is only because of lack of funds and a wonderful supply of used junk.

haha, me and gex are on the same page.

Build the original first.

Disregard what I build. It's just a bunch of junk I throw together for the simple joy of building, and lack of funds.

Title: Re: Pass band?
Post by vivio on 01/08/06 at 10:10:18

I.am right now modifing the wo to 6th :)
just build a 1/2 wo : and trying to get it loud for spl.
trying to make it a One note wonder . @ 65 hz

Title: Re: Pass band?
Post by Jet-Lee on 01/09/06 at 14:35:23

65hz? Isn't that kind of high for SPL comp?

Most systems I've heard play best around 40-50hz. What's the resonant frequency of your car? (I'm assuming this is for a car, since it's being made for SPL).

Title: Re: Pass band?
Post by Hellion on 01/11/06 at 07:23:00

uhh how do I know what my car's RF is?

Sorry, but I haven't posted here because I am making the origional wo like some people suggested, though I am wondering about making one that would be an eighth order triple reflex bandpass. Which definately would NOT be a one note wonder! He he try that one on for size!

Title: Re: Pass band?
Post by Jet-Lee on 01/11/06 at 21:25:22

Isn't the general rule of thumb that the higher the order the less the range? So an 8th order is more of a one note wonder than a 6th?

Title: Re: Pass band?
Post by Hellion on 01/12/06 at 03:34:28

To be honest, I don't know. I do not know for sure if the origional wo is a bandpass. If it is then I would be making an 8th order triple bandpass. if not then it would be a sixth order dual reflex. You can tune one side of a sixth order dual reflex to one frequency, and the other side to another by changing the volume of the chambers, and the length of the ports. definately not a one note wonder.

I don't really understand the wo anyway.

Title: Re: Pass band?
Post by Hellion on 01/12/06 at 03:36:05

oh by the way check this out...
http://www.the12volt.com/caraudio/boxes6.asp

Title: Re: Pass band?
Post by J_Rock on 01/12/06 at 04:21:06

The WO isn't a kind of box. The closest you get to it as far as design is a 4th order BP with exponential ports, yet still it doesn't work out so well.

If you port the sealed chamber you could call it a 6th order and many would believe it.

If you port the sealed chamber twice, once out to the trunk the other into the compression chamber, it would become an 8th order.

I have no idea how you could hope to model the Box since there really is no way to model the horn type port thing(Rubber throat or Impedance Transformer).

Building a spec'd out 8th order is going to be easier, but not easy.

Its all pretty much guess and check above 4th order, although winISD pro calculates 6th order.

If you are looking for serious bass with no musicality Higher order BPs are definetly your ticket, they are just a pain in the ass.

Title: Re: Pass band?
Post by J_Rock on 01/12/06 at 04:26:06

Also like to add that the higher you go in order of BP the smaller frequency response that the box can handle.

And on 12 volt the guy talks about unloading the woofer. That can happen below the box's ported frequency, but not above it. Above the tuning frequency the port no longer resonates acting like a sealed enclosure. Thats why ported enclosure can still go up in frequency fine, but they need a XO below the tuning frequency.

Also, when tuning ports in an enclosure they must be off of each other's frequencies or else you get serious cancelation. I.E. one port must be 60 hz, the other 65hz.

Title: Re: Pass band?
Post by DirtDawg on 01/12/06 at 04:56:02

Even if you try to deal with the narrow passband by building more boxes, like 1 well tuned "one-note box" for each note, you will still have poor transient response. Without good transients your system won't be very musical. :'(

Title: Re: Pass band?
Post by Adrian D. on 01/13/06 at 19:14:55

well, spl comp sistems don't 'care' about sq ?
anyway, the risks are big. imho, it's not worth the pain, unless there are large prizes for winning spl comps. but the time & effort put into building a decware box is well and truely worth it.

Title: Re: Pass band?
Post by db_audio on 03/01/06 at 13:36:55

talking about spl comps - i love to compete but you know its funny how someone will spend thousands of dollars and hundreds of hours of time building an award winning system, just to win a 20 dollar trophy and get 10 minutes of "fame". while when the bikini girls win (wearing a 50 dollar thong) they win hundreds of dollars...dont make since sometime. I wish that there would be someway that larger prizes (like cash) given out when you win one of the comps. sorry for rambling but i wanted to get that off my chest. -dan-