Bandpass design

[terra 5,000+ posts]

Doing a 4th order for 2 Cascade 18"s. I've got a total of 18 cubes to work with in my 2000 explorer. The plan is to have the sealed part at the rear of the car and the ported part towards the front with around 350 sq. in. of port firing towards the dash. This will be my first BP so I'll take any help. I've already talked to 80inches and TSGP but I just want a tad more input before I start. Box will either be trupan(if i can find it) or Birch Ply to cut down on weight. 600lbs in the trunk is definitly starting to take a toll on the Ex.

1. 4-5 cubes sealed and 8 cubes ported at 50hz. This will be a daily driver and low freq. comp car. I want power in the 25-40hz range...

Click to read more...

 

[30hrtz 10+ year member]

I'm thinkin of doin a bandpass too.But in my past experiences,they seem to only be advantages if you are limited on power.Mine have gotten loud on very low power,but very little spl change with double or triple power.Good luck with yours though.Seems like with 18s in a large ported enclosure would give you the spl and low end youre after.Keep us posted.

 

[terra 5,000+ posts]

I'm thinkin of doin a bandpass too.But in my past experiences,they seem to only be advantages if you are limited on power.Mine have gotten loud on very low power,but very little spl change with double or triple power.Good luck with yours though.Seems like with 18s in a large ported enclosure would give you the spl and low end youre after.Keep us posted.

Odd...TSGP told me that if done correctly they can be up to 300% more efficient. I've got around 6,000watts to work with so I'm good on the power front.

 

[RidnClean 5,000+ posts]

put some blue lights in it //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Skip01 5,000+ posts]

Odd...TSGP told me that if done correctly they can be up to 300% more efficient. I've got around 6,000watts to work with so I'm good on the power front.

Yehh theres a hugggggeeee gain to be had from bandpasses, but its getting them right i hear that could make or break the box

Good Luck

 

[terra 5,000+ posts]

Yehh theres a hugggggeeee gain to be had from bandpasses, but its getting them right i hear that could make or break the box

Good Luck

Thanks man..

Sorry i couldnt come through on the 500.1. I got the fusion but i was hoping to pick up the 500.1 as well but money just wasn't there.//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[Skip01 5,000+ posts]

Thanks man..Sorry i couldnt come through on the 500.1. I got the fusion but i was hoping to pick up the 500.1 as well but money just wasn't there.//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

Yehh i hear ya

No prob

 

[terra 5,000+ posts]

bump...tryin to get this design finalized...

 

[30hrtz 10+ year member]

ya they are more efficient and if done correctly as others say,it may do good for you.But like i said on mine,there was little spl gain going with over 1k watts.Sounded the same on 300 watts.So i guess mine wasnt built right,with 6k you should hit very very hard.4-5 sealed side and 8 on ported sounds good to me.good luck.

 

[dcole18 5,000+ posts]

hmmm...

 

[terra 5,000+ posts]

ya they are more efficient and if done correctly as others say,it may do good for you.But like i said on mine,there was little spl gain going with over 1k watts.Sounded the same on 300 watts.So i guess mine wasnt built right,with 6k you should hit very very hard.4-5 sealed side and 8 on ported sounds good to me.good luck.

Thanks. If I don't have any good contrary criticisms by sunday I'll go ahead and buy the wood.

Anyone have any comments on firing towards the dash right behind the back headrests?

On a side note..How much does a sheet of Birch weigh vs. MDF? Trupan?

 

[terra 5,000+ posts]

hmmm...

what you hmmming about??//content.invisioncic.com/y282845/emoticons/mad.gif.c18f003ab0ef8a0d9c27ca78d77a6392.gif

 

[bball09124 10+ year member]

EDIT: I may be getting transient response confused with group delay, please correct me if I have twisted anything.

Just know that BP's can sound a good bit different then ported boxes, transient response can be a *****. I had a BP box (not the greatest design, before I knew a heck of a lot about tuning) and there was something I just didn't like about it. Later, I read something about how BP's are notorious for poor transient response, I believe thats what it was.

An extremely dumbed example of poor transient response is the "kick" you get from a short note, it is just not there or as powerful. My understanding of transient response may be incorrect though. Or my single experience with BP boxes may have just given me a bad impression of them.

EDIT: I just did a little more research, transient response decays as you go higher up in the orders of bandpass (i.e. 4th is better then 6th is better then 8th). it shouldn't be too noticeable with a 4th order I'd imagine.

 

[terra 5,000+ posts]

good to know. I don't wanna lose the punch..

 

[terra 5,000+ posts]

ttt