group delay?

[Vogey84]

im modeling the box ive biult to try and get ahead start on what i think ill have to do to it to fine tune it. currently it sits at roughly 18-18.5 ish with subs in has 41x5 port thats24'' long comes out the baffle 4.5'' over all the box is 48x44x25.5 sides, bottom, and port are 1.5'' and baffle is 3'' braced every corner. once the box is tuned ill be coating the inside with por15.

sorry back to the ? what should i try to keep the group delay under? box will be for 4 elite 15s in 06 navi subs up center port 41x5 up. still swaping the air susp out, havnt installed hu or ran the 2\0 power wire yet. i cant wait till it all comes together

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[THATpurpleKUSH 5,000+ posts]

Let me get this straight- you're going to coat the inside of a wooden speaker box with a rust preventative product obviously designed to work on metal?

 

[Vogey]

It's primary use is rusf prevention yes, it also has unique qualities that are useful in other ways. Anything slightly porus you want to make absolutely water/air tight and incredibly strong/hard give it a coat of por15.

 

[Vogey84]

huh i never realized my laptop and phone post umder diff accounts didnt know i had 2

 

[THATpurpleKUSH 5,000+ posts]

It's primary use is rusf prevention yes, it also has unique qualities that are useful in other ways. Anything slightly porus you want to make absolutely water/air tight and incredibly strong/hard give it a coat of por15.

You're better off using wood hardener or fiberglass or epoxy resin.

Unless you are competing and chasing every tenth of db possible, its totally unnecessary and a waste of time and money. Use 13 ply baltic birch or an equivalent ply and thats all you need.

 

[Vogey84]

if i could actually store the por15 after bein opened i prob wouldn plan on using it. as it is ive got some left over.


'

 

[Jeffdachef 5,000+ posts]

Group delay is improved with lower tuning or smaller box.

 

[Breaker]

Port's too narrow.

 

[Vogey84]

even though ive spent countless hours over the last 6 months reading n learning about box designs n playing with enclosure apps it kinda donned on me today i really have no idea how the changes in the graphs when u add or subtract air space or makr the port longer/shorter. corelate to how its gonna sound. i dont even know if im right about what looks good on the graph

is there a level of group delay that i should try to stay under?

 

[Jeffdachef 5,000+ posts]

even though ive spent countless hours over the last 6 months reading n learning about box designs n playing with enclosure apps it kinda donned on me today i really have no idea how the changes in the graphs when u add or subtract air space or makr the port longer/shorter. corelate to how its gonna sound. i dont even know if im right about what looks good on the graph

is there a level of group delay that i should try to stay under?

Your reference should be a sub in a sealed enclosure like a jl w6, theres your base reference now try to get close to that as possible with your sub in a ported. You wont get there but you can get closer and closer

 

[THATpurpleKUSH 5,000+ posts]

Buy a copy of Bass Box Pro 6, it comes with a very helpful user guide that walks you through 4 different designs with varying goals and sacrifices that box designers deal with. It teaches you how to analyze the plots and make nexessary adjustments.

 

[Vogey]

Is that fir android or PC

 

[THATpurpleKUSH 5,000+ posts]

Only on PC. Its literally the only enclosure design software worth your time. Everything else is either useless or inaccurate.

 

[Vogey]

I thought windd was supposed to be fairly decent? I'll look into bass box pro though​

 

[THATpurpleKUSH 5,000+ posts]

I thought windd was supposed to be fairly decent? I'll look into bass box pro though​

Win isd is not accurate unless you are designing a sub to play in the middle of an open field. WinIsd does not have the ability to predict the transfer function aka cabin gain and as a result will mislead you to tune far lower than necessary. The transfer function occurs around 50-70hz roughly depending on the vehicle and is a 12db/oct gain. Without the ability to figure that in, the data is incorrect below 60hz which is pretty much the entire usable bass spectrum.