18" BTL enclosure type

[bigrank916 72]

Ok here is the email I sent to Fi. Just thought Id post it here while I wait for their reply cause they r so busy.

I bought an 18" BTL a while ago and need some recommendations on the type of enclosure I should use.

First I went to my local shop to see what kind of designs they could offer me and what they thought would work best for my application. I talked to the guy that specializes in enclosures and unfortunately he hasn't heard of Fi before. So I gave him the web addy to get the parameters of the sub so he could plug the numbers into the enclosure software they have. But, the bad thing was, it couldn't calculate the specs for whatever reason.

At that point we started bouncing ideas back and forth but ultimately he wanted me to contact you guys. Who better to get ideas and info from then the people who made the sub! Some of the things we discussed were doing a down firing box or maybe even a bandpass. We also talked about a blow-thru because I have a truck. It sounds real nice cause I can have my back seat again and ridiculous bass.

I do believe in his skills to make this happen. All the ideas he has given are things he has done before in the same vehicle with success. He has been in spl competition many times. Hell, the guy has even built a few 8th order bandpass enclosures. If you can do that with success, you have got my vote! Now I'm not saying I want to build a wall behind my seat (not that one driver will constitute a wall) but I did buy a BTL so I do like to go really loud.

With all that being said, here is what I have to work with. My truck is a 1991 Chevy Silverado c/k ext cab 2500. I have taken out the back seat for maximum area. The max dimensions of the back is 58"W x 24"H x 24"D. The sub will be powered by a Sundown Audio SAZ-4500d so there will be plenty of headroom. I know the sub doesn't need that much power but the amp was pre-ordered so its too late to turn back now. Plus I can always throw that 18 in my other car and grab 2 more to size it up right...someday.

Right now Im building a simple 5-6 cuft. slot ported box tuned to 32hz after sub disp and int bracing. Mainly to make sure its not DOA but, also to get a reference point of how it sounds on the small end. So what do you bassheads think?

And no, not the baking soda bassheads!!

[Duran 387]

Only 5-6 cubic feet? You realize that you have 19 cubic feet available? I say about 8 cubic feet with 120 square inches of port area tuned between 30-35 hz.

[bigrank916 72]

Only 5-6 cubic feet? You realize that you have 19 cubic feet available? I say about 8 cubic feet with 120 square inches of port area tuned between 30-35 hz.

Yes, I know that. I want to build a small one to make sure the driver is ok and as a reference point like I wrote in my post. How will I know if I dont like the box if I dont make it?

I know the general 5-10 cuft. ported @ 30-35hz with 12-16sqin of port area per cubic foot.

The final box will be bigger...trust me. This is my mock draft box 1.0 in March. There will always be changes until draft day.

I am looking for more input on what type of enclosure for my vehicle. Im really intrigued with a blow-thru setup but Ive never tryed it before. Down firing sounds good also but I can imagine the bracing and bracketing will be extensive to hold that driver up. The bandpass is pretty straightforward depending on what order it is.

If there is any other configuration that works well, by all means, put it on me. Id love to hear all opinions.

[bigrank916 72]

bump

[NDMstang65 403]

Not much we can do to help..if you want to know what is "Loudest" you have to figure that one out on your own..as every single vehicle is different.

It's sort of asking John Force how to run the fastest quarter mile time...there are 2 million variables...he simply can't tell you how to do it. That is why we have the ranges to stay within..if you stay there, you are fine.

-Nick

[SpeakerBoy 64]

I smell a build log

[bigrank916 72]

I smell a build log

yes. Very soon. Dig cam is on the way.

[bigrank916 72]

Not much we can do to help..if you want to know what is "Loudest" you have to figure that one out on your own..as every single vehicle is different.

It's sort of asking John Force how to run the fastest quarter mile time...there are 2 million variables...he simply can't tell you how to do it. That is why we have the ranges to stay within..if you stay there, you are fine.

-Nick

no it's not one of those questions. Just looking to see if anyone has tried or seen a setup like the options I talked about. Just lookin for some feedback Thats all. Like if I did a blow-thru will there be so much vibration noise from the bed that I'll wish I tried somethin else. This topic is not about how big I should build the box. I pretty much know what size and tuning I will do.