Folded Horn

[TheBassChild]

Hey all,
I have recently purchased the Behringer EP4000 Amplifier. Intend to use this amplifier to power a new pair of subwoofers im getting. The question is...what to buy? I've got 2400WRMS into 4 ohms, and would prefer large subwoofers. My original thought was to buy 2 18" and make a folded horn for them. Is this the right way to go? My aim for my system is as loud as possible. SQ I dont mind for as much, but the dBs. My budget for subwoofers and box is around $1000.

Thanks

Sam

[chris661]

How low do you want to go?

Or, to put it another way, what sort of music will this system be playing?

[doug20]

what sort of music will this system be playing?

and what sort of movie content do you want to reproduce?

[18Hurts]

As Chris asked, you want loud but how low do you require?

Loud an low are at odds with each other--unless you build a giant box. The dual 18's, is that two subs or just one? Depending how low you want to go, for example Dubstep around 20 to 30 Hz or car audio woofer cooker stuff such as Bass, I love you 16 Hz and lower.

You will find very, very quickly that below 30 Hz and above 125dB lives the giants of the subwoofer world--those stacked concert subs that are taller than you are not for looks.

Where will this be used? Outside, clubs, in a house or ???? I would bet it will be used in a house, a garage or outdoor parties sort of thing with any form of music or "other" plugged in from cell phones, iPods or Youtube videos? If so, I would build two boxes with two 12" woofers each in a tapped horn configuration. Point being 12 inch subs are the most common on the planet and that will drive the costs way down and allow anything you want.

The issue with plugging in ??? MP3s is they may contain very low frequencies at high levels. Go at least for 30 Hz or lower, use a high pass filter to cut out all bass below the tuning frequency and use two boxes. You'll find two boxes much easier to move, they couple together at the mouth to give a boost to SPLs and put out more lows.

If you want the maximum "slam" and SPLs possible, use the 35 to 40 Hz tuned horns with high pass filter set at that frequency. You'll lose the generally electronic tones from Drum and Bass dance music and the dropped D tuned guitars. Write off all the car audio boomer "test" stuff.

JBell has a design for a single 15" that is tuned to around 40 Hz, puts out incredible SPLs and for your budget--you could build four of them to blow the windows out of your house.

How low is low, how loud is loud? At least you don't want 125dB at 30Hz from a $80 woofer.

[jbell]

Originally Posted by 18Hurts

At least you don't want 125dB at 30Hz from a $80 woofer.

[doug20]

Originally Posted by 18Hurts

How low is low, how loud is loud? At least you don't want 125dB at 30Hz from a $80 woofer.

How about almost 120dB clean @ 30Hz from a $80 woofer?

[jbell]

Originally Posted by doug20

How about almost 120dB clean @ 30Hz from a $80 woofer?

How about 130db flat to 30hz in a corner with a pair of $30 drivers in about a 300 liter cabinet size? That work?

[doug20]

That will work

What is the THD at 130dB and what drivers/build is that one?

[18Hurts]

Originally Posted by jbell

How about 130db flat to 30hz in a corner with a pair of $30 drivers in about a 300 liter cabinet size? That work?

I love the smell of a freshly baked JBell MCM TH in the afternoon... it smells like sawdust! Burned voice coils stay crunchy in milk. Those are the MCM 8" aluminum cone subs from what I understand--can I get 125dB at 30Hz if I hang them up in a tree?

[jbell]

Originally Posted by 18Hurts

I love the smell of a freshly baked JBell MCM TH in the afternoon...

FLH.... I like the mcm in FLH, not TH. And that's only 100 watts per driver.... not enough to cook anything...

Just had to toss that out for the OP to try to find out what his intentions really are....