# Help me design an enclosure RFA-104



## Buickmike (Aug 10, 2012)

So I have a pair of RFA-104's that I plan on putting in the back of my Buick Grand National. RF originally specified these as needing .66 ft sealed enclosures, but apparently recanted and stated that they need to go into larger ported boxes. I've heard everything from 1.0-1.4 ft on these. The only thing that remains consistent is porting them at 35hz. The caraudio.com ported calculator came back with just under .70ft ported at 35hz. Anyone want to put in their 2 cents? Here are the specs:

http://www.rockfordfosgate.com/rftech/library/1994/5_Subwoofers/RFA-104_108-TS.pdf

Thanks!


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## Buickmike (Aug 10, 2012)

Nobody? 

I pulled out my old Radio Shack "Building Speaker Systems" book and cam up with .68 ft ported at 45hz. That just seemed too far off from what I have seen floating around on the Internet in the past. Plus, I slapped one in a 1.5 ft box ported at 35hz and it sounded really good. 

So I called Rockford Fosgate's customer support line to see what they tell me. To my surprise the guy brought it up and told me what they recommended from the factory.

.75ft sealed or 1.50ft ported at 35hz.

I had a friend with these sealed and they were pretty amazing. Very tight, clean, and hit damn hard. I do remember people saying to stay away from sealed enclosures on these though. 1.5ft per sub is a little bigger than I want because I only plan on using up 2.5ft total with the box I planned. That gives me roughly 1.2ft per sub. Can I make up for this with fiber fill?

Thoughts?


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## Buickmike (Aug 10, 2012)

Alrighty then, here is an update. I have a .75ft sealed box for my JL 10W0 and I swapped it out for one of my Audiopliles to see how it would perform sealed. It seems constrained until you put some good power to it and then it wakes up. This setup would be awesome if all you listened to was Pantera because deep rock bass hits hard. I seriously felt like I was getting beat in the chest with a baseball bat. Other than that it totally sucks in a sealed box. It had no real SQ value to it whatsoever. Although clean and accurate, it was very mechanical sounding. These things are so smooth, natural and musical when ported. Now I know which way I will go. Hopefully a 1.25ft box is not going to hamper the quality too much.


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## SUX 2BU (Oct 27, 2008)

Nice subs. Always like the RFA line. I would give it at least 1 cube, ported or sealed. I like old school subs and use them but they need airspace. They don't have the ridiculously heavy cones and super-stiff suspsensions like most of the current subs too these days in order to get small boxes and crazy power handling at the expense of efficiency.

That said, I ran a 1 cubic foot ported box for the last while, tuned to about 35 Hz. Ran an old Alpine 6013EX 10, Blues BL-10 and a gold-letter Kicker C10-4 in it. It was decent but I figured it needed more air. So I've built a 1.95 cubic foot ported box tuned to 35. I'm hoping for quite a bit more output now


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## chad1376 (Dec 27, 2012)

Buickmike said:


> ..I pulled out my old Radio Shack "Building Speaker Systems" book ...


Wow, it _is_ the "Old School" forum. You should get an old TRS-80 and program it with the code in the back of the book. Actually, I made a pretty cool spreadsheet (circa 1989), using the formulas in that book. It would calculate box responce at different frequencies and graphed a fairly usable responce plot. I wish I still had the book and file to look at just for kicks.


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## Buickmike (Aug 10, 2012)

SUX 2BU said:


> Nice subs. Always like the RFA line. I would give it at least 1 cube, ported or sealed. I like old school subs and use them but they need airspace. They don't have the ridiculously heavy cones and super-stiff suspsensions like most of the current subs too these days in order to get small boxes and crazy power handling at the expense of efficiency.
> 
> That said, I ran a 1 cubic foot ported box for the last while, tuned to about 35 Hz. Ran an old Alpine 6013EX 10, Blues BL-10 and a gold-letter Kicker C10-4 in it. It was decent but I figured it needed more air. So I've built a 1.95 cubic foot ported box tuned to 35. I'm hoping for quite a bit more output now


Yeah, its nuts how much power modern subs need to really pound. I remember back in the day how you could hear a car for blocks with nothing more than a Kicker C series sub and 100 watts. 

I had 2 Lanzar Pro Plus 12's in sealed boxes running off a single Optidrive Plus 100 bridged at 2 ohms. :surprised: It was stupid loud. I couldn't even swallow a soda with the volume way up. I think I hit 151db with that setup. It was in the hatch of a Porsche 924S.


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