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Discussion Starter · #1 ·
I am building a DIY subwoofer project.

I would like some opinions of my ideas.

Non powered remote amp.

The subs I am using are car audio subs. I know I know not the greatest idea but they are a great SQ subwoofer. Model is Soundstream R-12SQ with an xmaxx of 16mm. Rated 25hz to 1500khz 120oz magnet, dual 4ohm 4in VC in series showing a 4ohm load to amp. 600 watt RMS. I plan to cross it over at 20 hz high pass and 120hz low pass.

I post more info if needed.

I want SQ for music and movie capability (50/50 movie and music)

I am putting 2 of them per cabinet (building 2 subs).

My idea is one down firing and the other front firing.

I am not sure if I want to use a sealed or ported box.

1 inch MDF then covered in cabinet grade ½ inch Cocobolo wood with a custom DIY front grill. I have to make it look like furniture to appease her. No real size restrictions though if it they look good


Room is 20Lx14Wx9H.

Amp is QSC GX5 rated at 700 per channel @ 4ohms

Crossover is Behringer DCX2496 Pro

[email protected] 12 gauge connectors and cable.

1. If I go sealed can I put both in one chamber or should I use 2 chambers. Sealed volume is 1.3 cu ft. per speaker. So box should be 2.6 cu. Ft. I assume then adjusted for bracing and sub volume.

2. If I go ported box volume is 2.0 cu. ft. per speaker or 4.0 total again adjusted for bracing and sub volume, should I use a slot port or round tube? Can I use one chamber. What should I tune to? Recommended is 29hz. 2x 4in x 16.75 tubes, will it play to 25hz if ported to 29hz?

3. If sealed I will fill to half with poly fill, but if ported should I line it and with what if so?

4. How much floor clearance would I need for the down firing speaker if I can build it that way?

5. Will using the DCX2496 after the line out from my receiver also boost the voltage so that I get full wattage from the amp?

6. Can I put one driver on each side of the box if I do a sealed box without a middle divider?


Thanks in advance for any ideas or even criticisms.


Bop
 

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Sounds like you know whats going on. Why does one need to be front facing and the other downfiring? Its not going to matter there nothing to be lost or gained either way other than aesthetics. And they can share the same air space. I would build 4 seperate enclosures if i were you to help with room modes and flatten your frequency response. Do you have any of the drivers T/S parameters? It would be best for you to model them using Winisd. You can DL it from here http://www.linearteam.dk/ . Once you get the drivers info loaded in there you can find the optimal enclosure size, port volume, tuning point, how much power they can be fed before over excursion, etc.... Its an invaluable tool to have when building your own sub. Its tough to say whether to go sealed or ported without modeling it. Since its 50/50 music and HT Id go sealed and use an EQ to boost the lower end to get you closer to your desired extension.
 

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Discussion Starter · #3 ·
I downloaded and tried to use that program but I must be stupid because I didnt understand it.


Here are the speaker specs I have:


Max 1200 watt

RMS 600 watt

Mag. Wgt. (oz) 120

V.C. Size (in.) 2.5

V.C. Imp 4Wx2

Fs (Hz) 29

Vas (Cu. Ft.) 2.075

Qms 4.397

Qes 0.52

Qts 0.465

Xmax (in.) 0.65 (16.5 mm)

SPL 86

Tune Freq. (Hz) 29

FREQ. RESPONSE (Hz) 25Hz-2k

Hole Dia. (in.) 11.25

Depth (in.) 8.125


Thank you
 

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No your not stupid it can be confusing at first. Did you open the help section and follow the instructions on loading your own driver? From the specs i see you posted you may be missing a few key specs to be able to load the driver in Winisd. I cant spout them off the top of my head ATM im drawing a blank. Open the help section in the program and it should have a section on loading your own driver parameters. Follow that exactly and you should be well on your way. Maybe a call to the sub manufacturer can get you the rest of the specs if anymore are needed.
 

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WinISD is confusing for the first time using it. If you did not get instructions like I did, go here, http://www.hometheatershack.com/foru...inisd-pro.html , and read up on it. The parameters have to be entered in a certain order. After that its all about playing with the parameters to obatin what you want. Just take your time and play around with the program and the base list of drivers. I had a hard time too at first but after a few times it becomes easy.
 

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Discussion Starter · #6 ·
I got ahold of the manufacturer and that was all the specs I could get.

The drivers were last produced in 2003 when the drivers were built in the US.

The company was sold and everything is made overseas now so the missing info is not available. They have no more info on the drivers built pre the company selling


What to do now?


Bop
 

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It looks like you have enough to model it. The program will automatically set parameters for what you do not have. Take a look at the page I pointed you to and give it a shot.
 

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Discussion Starter · #8 ·
I still cannot get it to work.

I followed the instructions on that page to the letter, sigh

I get it all loaded then when I try to use the newly created driver I get the floating point error. Then followed by some long extension error which locks up the program.


????
 

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Discussion Starter · #10 ·
No I am dual booting XP Pro and W7 Ultimate 64Bit.


It was happening in either until I got the order right to put in the parameters.
 
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