# Custom box buil



## Boredmods (Jun 14, 2015)

Hey all, I am looking to build a new box for my RE Audio SEXV2D4 sub. Right now I have it in ~1 ft3 sealed box. I used to have it in a 2 ft3 ported box tuned to 35hz and ported right into the cab of my old BMW, and it sounded awesome. Looking to do the same type of deal with my cruze, but use the 6x9 holes to port into the cab.

Now design is not my strong suit at all, lol. However I can build the box for sure. These are the specs right from RE Audio


Enclosure Recommendations

Model10" Compact10" Optimal12" Compact12" Optimal15" Compact15" OptimalSealed[cu.ft/liters]0.4 / 11.330.65 / 18.410.75 / 21.241 / 28.321.5 / 42.482 / 56.63Ported*[cu.ft/liters]1 / 28.32 @ 35Hz1.25 / 35.4 @ 34Hz1.5 / 42.48 @ 35Hz2 / 56.63 @ 33 Hz3 / 84.95 @ 35Hz4 / 113.27 @ 34Hz

* Need to add PD(Port Displacement) 
T/S Parameters

ModelSEX v2 10SEX v2 12SEX v2 15Thermal Power Handling [Pe], Watts750750750Nominal Impedance(dual) [Znom]2 or 42 or 42 or 4One-way, Linear Excursion [Xmax], mm192021Efficiency [SPL 1W/1m], dB88.786.984.4Volume Displacement [Vas], cu.ft/liters0.14 / 3.960.15 / 4.250.17 / 4.81








 I am also trying to retail some trunk space, I didn't have any in the BMW and that was a bit annoying. Looking for a few suggestions to tune the box to 35hz and keep the box as compact as possible 



Thanks!


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## swrocket (Oct 4, 2014)

You're missing some important T/S params, but if you can get them, try this calculator
Subwoofer Box Enclosure Design Calculator - Sealed Ported Bandpass Closed Vented
It will give you sizes and ports as well as response curves.


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## Boredmods (Jun 14, 2015)

Where can I get some of this info? I don't see anything on the MFR website.


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## swrocket (Oct 4, 2014)

Boredmods said:


> Where can I get some of this info? I don't see anything on the MFR website.


Yeah, I couldn't find it there either, but I figured you may have it if it came in the box. Try emailing the MFGR and asking for it.
If not, try on DIYMA.com and see if someone there knows.


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## hificruzer226 (Mar 27, 2013)

If you are going to build a custom box I always recommend to test and record your own T/S params since manufacturers can be inconsistent ....of course after beak in


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## Boredmods (Jun 14, 2015)

Ok, I think I have the box design that I want. Now when I am figuring out port length, lets say I get a 7.5" port at 3" diameter. Is that 7.5" the total length of the port, or the length that needs to be inside the enclosure. If that is the length that needs to be INSIDE the enclosure, does it matter how much is outside the enclosure? I have done some research and can't find a definite answer.

My goal is to port out of the top of the box, opposite side that the speaker is installed on, and up through the 6x9" mounting hole.

So far I have my dimentions as

W 24"
H 15"
D 12"
That gives me right around 1.85 ft3, with the speakers .15 displacement that is about 1.7 ft3. Using a 3" port, the calculations come out to 6.96" port, that is tuned to 35 hz. Lmk if any of this looks wrong


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## XtremeRevolution (Jan 19, 2012)

Port length depends on port area. Port area depends on vent velocity. Did you model vent velocity? 

Did you model in-cab response or are you just trying to do an SPL build? Flat raw response will not be flat in-cab.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> Port length depends on port area. Port area depends on vent velocity. Did you model vent velocity?
> 
> Did you model in-cab response or are you just trying to do an SPL build? Flat raw response will not be flat in-cab.


Honestly I just used an online port calculator that I have used in the past. I love SQ over SPL any day of the week. Right now I have my RE in a ~1 ft3 sealed box, and it sounds very delayed and shallow, I was assuming that this is because I am used to that sub in a much larger ported and tuned box that was ported directly into the cab?

Also just a little background into the wiring, I pulled the sub from the rear pass speaker, I just tied it in mono to that side, Also assuming that this is not causing the issues, could be wrong though.

Thanks again


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## brian v (Dec 25, 2011)

Depends upon the Amp and if you would like to hear 1 or both rear channels ..
I went with a Loc and then to a 2 channel amp that is Bridgeable for the Subs


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## Boredmods (Jun 14, 2015)

brian v said:


> Depends upon the Amp and if you would like to hear 1 or both rear channels ..
> I went with a Loc and then to a 2 channel amp that is Bridgeable for the Subs


Using a JL xd600/6. Pulled from both sides up front for the front 4 channels, and the rear pass for the sub.


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## XtremeRevolution (Jan 19, 2012)

Boredmods said:


> Honestly I just used an online port calculator that I have used in the past. I love SQ over SPL any day of the week. Right now I have my RE in a ~1 ft3 sealed box, and it sounds very delayed and shallow, I was assuming that this is because I am used to that sub in a much larger ported and tuned box that was ported directly into the cab?
> 
> Also just a little background into the wiring, I pulled the sub from the rear pass speaker, I just tied it in mono to that side, Also assuming that this is not causing the issues, could be wrong though.
> 
> Thanks again


I've been a but busy but I'll run your sub through and see what I can design for you. I've designed hundreds of enclosures. Are you planning on an aero port or are you making a slot port? 

Post up the TS specs and I'll see what I can do.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> I've been a but busy but I'll run your sub through and see what I can design for you. I've designed hundreds of enclosures. Are you planning on an aero port or are you making a slot port?
> 
> Post up the TS specs and I'll see what I can do.


The only TS specs on the MFR site are these. 
*12"*

Thermal Power Handling -Pe: 750 W
Nominal Impedance -Znom: Dual 2 or 4 ohm
One-Way, Linear Excursion -Xmax: 20 mm
Efficiency -SPL 1W/1m: 86.9 dB SPL
Volume Displacement: 0.15 cubic feet

The sub is over a year old so I don't have the original box any longer. I am looking to use an aero style port, 3" diameter PVC most likely.


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## hificruzer226 (Mar 27, 2013)

XtremeRevolution said:


> but busy


???? :dazed052::dazed002::blush:


lol just having a little but* of fun


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## XtremeRevolution (Jan 19, 2012)

We're literally wasting our time here without T/S specs and RE Audio isn't posting them on their website. I'll send them an e-mail and see if they can give them to me.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> We're literally wasting our time here without T/S specs and RE Audio isn't posting them on their website. I'll send them an e-mail and see if they can give them to me.


Sounds good. I emailed them as well, now we play the waiting game lol


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## hificruzer226 (Mar 27, 2013)

I know parts express carries those woofers might have better luck with them. RE audio went through a major change several years ago I believe now they are just importers not builders.


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## Boredmods (Jun 14, 2015)

Does this help at all?

Re: 1.756 ohms Fs: 39.03 Hz Qts: .811 Qes: .934 Qms: 6.16 Le: 1.685 mH Mms: 189.5 g Vas: 1.01 SPL: 84.49 dB 1w/1m


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## XtremeRevolution (Jan 19, 2012)

Boredmods said:


> Does this help at all?
> 
> Re: 1.756 ohms Fs: 39.03 Hz Qts: .811 Qes: .934 Qms: 6.16 Le: 1.685 mH Mms: 189.5 g Vas: 1.01 SPL: 84.49 dB 1w/1m


Are you sure those are accurate for that sub?


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## Boredmods (Jun 14, 2015)

Yes, came from parts express. Someone else was looking for the same info


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## XtremeRevolution (Jan 19, 2012)

Boredmods said:


> Yes, came from parts express. Someone else was looking for the same info


Alright I'll do some work and I'll let you know what I come up with.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> Alright I'll do some work and I'll let you know what I come up with.


Thank you, much appreciated!


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## XtremeRevolution (Jan 19, 2012)

Alright, here's what I came up with. 

1.6 cubic feet net internal volume. Two double flared 3" ports at 21" in length, which comes out to about 0.2 cubic feet. Add 0.15 cubic feet driver displacement and your gross volume is 1.95 cubic feet. Use that to build a cut sheet. You can go down to 1.9 cubic feet but don't go any larger. 

Lightly stuff the box with fiberglass insulation. I don't mean literally cram it down with as much pressure as you can, just a moderately light stuffing, like a soft pillow. Having the fiberglass in there is very important. You cannot skip this step. 

To prevent the fiberglass from blowing out of the box, cut a square of window screen and place it over the end of the tube (but before the flare) at the inside end of the box. Then, apply PVC glue, then place the coupler over the tube. I can find you some pictures of what this needs to look like if you need me to. 

Use PSP double flared ports. You can find them on madisoundspeakerstore.com. 

You'll need 2 of these:
https://www.madisoundspeakerstore.com/flares/ports/vents/3flare-complete-kit/

One of these:
https://www.madisoundspeakerstore.com/flares/ports/vents/3flare-psp-3tb/

Two of these:
https://www.madisoundspeakerstore.com/flares/ports/vents/3flare-psp-3rg/

Cut the extension port in half and use the two extra couplers to achieve the 21" length. You will need to side fire these ports, mounted toward the rear upper and lower corners of the box. Be sure to calculate how much clearance the sub will need to the ports inside when making your box dimension calculations.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> Cut the extension port in half and use the two extra couplers to achieve the 21" length. You will need to side fire these ports, mounted toward the rear upper and lower corners of the box. Be sure to calculate how much clearance the sub will need to the ports inside when making your box dimension calculations.


Ok now with this, is that 21" length to be fully inside the box? Or can the port stick out a little? Trying to get as much inside the cab as possible.

Thank you so much for all of the help. Trying to get a cut plan set up now


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## XtremeRevolution (Jan 19, 2012)

Boredmods said:


> Ok now with this, is that 21" length to be fully inside the box? Or can the port stick out a little? Trying to get as much inside the cab as possible.
> 
> Thank you so much for all of the help. Trying to get a cut plan set up now


Have you worked with these ports before? I'm having a hard time figuring out how you're going to mount them and seal them in order for the ports to fire into the cabin. It just won't work. 

Side fire the ports and have one of the back seats folded down when you want to get some extra output. It's not feasible to try to fire them through the rear deck.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> Have you worked with these ports before? I'm having a hard time figuring out how you're going to mount them and seal them in order for the ports to fire into the cabin. It just won't work.
> 
> Side fire the ports and have one of the back seats folded down when you want to get some extra output. It's not feasible to try to fire them through the rear deck.


I have not. Any of the boxes that I have had made usually they end up using PVC pipe for ports, and they fire through the rear. This is a total new world to me lol


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## XtremeRevolution (Jan 19, 2012)

Boredmods said:


> I have not. Any of the boxes that I have had made usually they end up using PVC pipe for ports, and they fire through the rear. This is a total new world to me lol


Look at the picture of the ports. They have to be mounted and sealed at the end of the outer flare. There's no way you're going to make that work. Just side fire the ports and keep it a totally contained enclosure.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> Look at the picture of the ports. They have to be mounted and sealed at the end of the outer flare. There's no way you're going to make that work. Just side fire the ports and keep it a totally contained enclosure.


Ok cool, going to get cracking on the build tomorrow. Thank you for the help. On a side note, do you happen to have any pics of the MiniDSP install? I am trying to find a good place/way to mount it, let alone that dc/dc board that is not enclosed in anything lol.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> Look at the picture of the ports. They have to be mounted and sealed at the end of the outer flare. There's no way you're going to make that work. Just side fire the ports and keep it a totally contained enclosure.


Alright awesome. If I do 2 2" ports does that shorten the overall length of the ports? Also I just received this email form RE Audio, I found it rather amusing.

'We currently do not have accurate specs. We sourced the testing to an outside company and they did a terrible job. Then we purchased all the test equipment to do the tests in-house and the guy that did the testing either had fat fingers, or did the test near significant ambient noise. Either way the numbers are inaccurate. I tries putting the numbers into my programs to develop correct enclosures, and came up with totally bogus numbers. I will update you when the latest tests have been completed and accurate box dimensions are available.

-- 
Thank you,Russell Anthon
RE AUDIO TECH



626-733-7009'


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## hificruzer226 (Mar 27, 2013)

Boredmods said:


> Alright awesome. If I do 2 2" ports does that shorten the overall length of the ports? Also I just received this email form RE Audio, I found it rather amusing.
> 
> 'We currently do not have accurate specs. We sourced the testing to an outside company and they did a terrible job. Then we purchased all the test equipment to do the tests in-house and the guy that did the testing either had fat fingers, or did the test near significant ambient noise. Either way the numbers are inaccurate. I tries putting the numbers into my programs to develop correct enclosures, and came up with totally bogus numbers. I will update you when the latest tests have been completed and accurate box dimensions are available.
> 
> ...


Scary....


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## Boredmods (Jun 14, 2015)

hificruzer226 said:


> Scary....


pretty much my thought....I may retire that sub if that is truly the case and if those numbers that I got off of the other site are just made up....


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## hificruzer226 (Mar 27, 2013)

More than likely those are the bad numbers PE had received from RE.


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## Boredmods (Jun 14, 2015)

Well looks like I'm going to scrap the re audio. Looking into one of these http://www.daytonaudio.com/index.ph...ss315ho-44-12-reference-ho-dvc-subwoofer.html

Anyone have any experience with this sub?


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## hificruzer226 (Mar 27, 2013)

Its funny I told you this would happen on post #6


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## XtremeRevolution (Jan 19, 2012)

Boredmods said:


> Well looks like I'm going to scrap the re audio. Looking into one of these Dayton Audio RSS315HO-44 12" Reference HO DVC Subwoofer 2 Ohm - Reference Series - Loudspeaker Drivers By Series - Loudspeaker Components
> 
> Anyone have any experience with this sub?


I got the same reply from RE about the TS specs I requested. Yeah, sell it. 

That's a great sub. I've built two enclosures recently for that sub. Works great sealed in pairs.


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## XtremeRevolution (Jan 19, 2012)

Boredmods said:


> Alright awesome. If I do 2 2" ports does that shorten the overall length of the ports? Also I just received this email form RE Audio, I found it rather amusing.
> 
> 'We currently do not have accurate specs. We sourced the testing to an outside company and they did a terrible job. Then we purchased all the test equipment to do the tests in-house and the guy that did the testing either had fat fingers, or did the test near significant ambient noise. Either way the numbers are inaccurate. I tries putting the numbers into my programs to develop correct enclosures, and came up with totally bogus numbers. I will update you when the latest tests have been completed and accurate box dimensions are available.
> 
> ...


Just for future knowledge, I used two 3" ports for a reason. Vent velocity at peak RMS was getting too high for comfort on anything smaller. Two 2" ports sure would be shorter, but your vent velocity would be far too high and you'd start chuffing and de-tuning. Most vented enclosures are severely compromised because nobody wants to make ports as long and large as they need to be. It's too expensive and usually too difficult. It's the right way to do it though.


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## Boredmods (Jun 14, 2015)

XtremeRevolution said:


> Just for future knowledge, I used two 3" ports for a reason. Vent velocity at peak RMS was getting too high for comfort on anything smaller. Two 2" ports sure would be shorter, but your vent velocity would be far too high and you'd start chuffing and de-tuning. Most vented enclosures are severely compromised because nobody wants to make ports as long and large as they need to be. It's too expensive and usually too difficult. It's the right way to do it though.


Thank you for the info. I have an old loudspeaker guide that I am going to have to study a bit it seems. These are the specs from the Dayton

Impedance2 ohms

[HR][/HR]Re6.5 ohms

[HR][/HR]Le3.17 mH @ 1 kHz

[HR][/HR]Fs21.5 Hz

[HR][/HR]Qms3.70

[HR][/HR]Qes0.41

[HR][/HR]Qts0.37

[HR][/HR]Mms327.7

[HR][/HR]Cms0.17 mm/N

[HR][/HR]Sd514.7 cm²

[HR][/HR]Vd720.6 cm³

[HR][/HR]BL26.5 Tm

[HR][/HR]Vas61.3 liters

[HR][/HR]Xmax14.0 mm

[HR][/HR]VC Diameter65.5 mm

[HR][/HR]SPL84.6 dB @ 2.83V/1m

[HR][/HR]RMS Power Handling700 watts

[HR][/HR]Usable Frequency Range (Hz)
20 - 500 Hz

Now I ran them through a calculator and came up with a ported box at

Box volume - 1.32 ft3 
(plus speaker and port displacement)
(1) 3" port at 13.8"
Box Frequency - 30Hz

Does that sound a little more accurate than the RE Audio sub?


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## Boredmods (Jun 14, 2015)

Alright. I fished the box for the Dayton. Installed it and wired it up. Seems like it is really lacking in punch. Sounds accurate, just no power. 

The box specs are
Ported box
1.36 ft3
3" port
14.24" long

I covered all of the sides in insulation and left some loose in the box. The port however comes within a inch and a half from the wall. That should t matter though right? Maybe too much insulation in the box?


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