4th order chamber size help

[Artiflex]

I have been looking around and cant seem to find any info on a good 4th order chamber size for a pair of zv5 12s.  Theres plenty of info for ported but the sealed section is where info lacks.  If the standard for a ported box is 2.5 cubes per sub then would you try 1.25 cube sealed and 2.5 ported to get a 2:1?  Do the parameters change completely for a 4th order?  Totally forget the 2.5 ported and start with a different number?   I just dont have enough experience in building 4th orders to go with a design on my own without most definitely having to start over.  Any thoughts would help.  

Edited April 20, 2019 by Artiflex

[DiBo]

1.0ft³-1.25ft³ sealed per driver. After that however big you want your ratio is on you. I'd do 2.25ft³ sealed and 4.5ft³ ported personally. 6.75ft ported max for a 2:1.0- 3:1.0 ratio. 

[Artiflex]

Thank you sir.  Would it be beneficial to the low end by increasing the sealed size per sub without raising the chance in damaging the subs because of over excursion?  

[Triticum Agricolam]

The best thing to do would probably be to model the subs in box simulation software. A larger rear chamber will get you more output below your front chamber tuning.  It also increases cone excursion though, so it’s going to depend on how much power you are running. 

[Artiflex]

I'd be running 2 zv5 12s on a ns1.  I'd like to be in a good range of 25 to 50hz if that's possible.

Edited April 21, 2019 by Artiflex

[DiBo]

3 hours ago, Artiflex said:

Thank you sir.  Would it be beneficial to the low end by increasing the sealed size per sub without raising the chance in damaging the subs because of over excursion?  

You'd be hard pressed to bottom these out in a 4th order lol. It'd take around 3000 watts per sub and some low lows to reach xmax on these. 

 

2 hours ago, Artiflex said:

I'd be running 2 zv5 12s on a ns1.  I'd like to be in a good range of 25 to 50hz if that's possible.

Tune to around 44hz on your ported side and go with 2.5 sealed 5 ported for a nice 30hz total bandwidth. Like triticum said, you should model your enclosure with some design software. 4th orders are pretty straight forward. The bigger the ratio the peakier it'll be. The smaller the ratio the flatter the response. 2:1 usually yields a pretty desirable output. Feed the beasts! Good clean power. These subs sound great in 4th and 6th orders. 

[Artiflex]

6 hours ago, DiBo said:

You'd be hard pressed to bottom these out in a 4th order lol. It'd take around 3000 watts per sub and some low lows to reach xmax on these. 

 

Tune to around 44hz on your ported side and go with 2.5 sealed 5 ported for a nice 30hz total bandwidth. Like triticum said, you should model your enclosure with some design software. 4th orders are pretty straight forward. The bigger the ratio the peakier it'll be. The smaller the ratio the flatter the response. 2:1 usually yields a pretty desirable output. Feed the beasts! Good clean power. These subs sound great in 4th and 6th orders. 

Is that 2.5 sealed per sub or total?  Going to throw this into winisd and see what I can come up with.  You guys are awesome.

[DiBo]

2.5 sealed total. 

[Artiflex]

I have been playing around with winisd and came up with a few things.  

Yellow is 4th order @ 45hz 2 sealed 5 ported.  The way the graph looks seems like I'd be losing out on a lot of bottom end unless this is just modeling the ported side? 

On a side note...

The other two colors on the graph are a orange slotted box @31hz 5 cubes and blue slotted box @28hz 5 cubes.  Do the air velocities for the two slotted box ideas seem a bit high?  If I went just slotted and went by sundown specs they want a max 40sq inches per sub so 80 for both.  How can I get that down without going over 80sq inches of port cross area?

[DiBo]

See what I mean by bigger ratio is peakier? That's a 2.5:1 ratio. If you go 2:1.0 ratio it'd be less peaky. You'll get lows with the fourth without a doubt. The orange plotted enclosure is dead nuts and I wouldn't build a box tuned any less than 31hz. You just simply don't have to with zv5 subs. They play Lows tuned at 32 and 33 Hz no problem. the upper range of the 4th order is the whole point of building a 4th order. You'll be loud and play low. A lot lower than that graph is showing. That's just a general idea and other factors come into play. For the most part tho that is a pretty good indicator of your enclosure peak. You get the Lows from the sealed side so as long as you have sufficient power they will be there.

Edited April 22, 2019 by DiBo
Lows not Lowe's haha