Best DIY sub for 18" driver

[davygrvy]

I examined the cross-section view of the EL36C just to check some dimensions with hornresp. It looks like the compression ratio is whooping 0.81:1. This not a front loaded horn. It's all back loaded. The horn appears to be only a conversation piece to get the sensitivity numbers up at 100Hz.

Hornresp info that I estimate:
Ver=23.40
Ang=0.5 x Pi
Eg=2.83
Rg=0.00
Fta=6.38
S1=1182.00
S2=1436.60
Con=40.00
F12=0.00
S2=1436.60
S3=2304.00
Con=63.20
F23=0.00
S3=2304.00
S4=4276.30
Con=87.76
Sd=962.00
Vtc=41522.00
Atc=962.00
Com=Cerwin Vega EL-36C

[littlemike]

Originally Posted by juxta

I think I should work with what I've got so I'll try to find something to utilise my 400w Qsc...

400 W is PLENTY to start with, especially considering you'd have to go all the way to 4000W of power (if your subs could take it) to gain 10 more dB through power alone. Jim ran all 4 of his off 1/2 a EP2500 if I recall correctly, and makes plenty of noise.

[juxta]

Originally Posted by davygrvy

What's the max SPL you're after? Normal rock levels of 107 average 25 feet out?

I was told by littlemike:
According to the manufacturer, your KP-362's make 102 dB with 1 Watt and are -4 dB @ 55 Hz. Looks like you want efficient subs that would reach an octave lower, so you'd want something that played a bit deeper than Jim's design. The KP-362 will each make 126 dB at full power, ideally you want the subs to produce a bit more than that. You may need multiple subs to get there (2 per main)

Some of the electronic/dubstep I've played with has content way down low (20 to 25 Hz.), so no matter what you do for a sub - it would be wise to run a strong (48 dB/oct) highpass filter to save your drivers and use the amp power where it matters.

After all this -

Answer #1 = From 30 Hz to 100 Hz.
Answer #2 = Greater than 100 dB 1W/1M

[juxta]

Originally Posted by littlemike

400 W is PLENTY to start with, especially considering you'd have to go all the way to 4000W of power (if your subs could take it) to gain 10 more dB through power alone. Jim ran all 4 of his off 1/2 a EP2500 if I recall correctly, and makes plenty of noise.

Thanks mike,
How does he run 1/2 a EP2500?
Connection wise?

[juxta]

Originally Posted by davygrvy

I examined the cross-section view of the EL36C just to check some dimensions with hornresp. It looks like the compression ratio is whooping 0.81:1. This not a front loaded horn. It's all back loaded. The horn appears to be only a conversation piece to get the sensitivity numbers up at 100Hz.

So this is why they can use a 18".....

[davygrvy]

Originally Posted by juxta

So this is why they can use a 18".....

Or put another way... this is why an 18 in a horn is not an efficient horn. pressure = good.

[jbell]

Originally Posted by juxta

Thanks mike,
How does he run 1/2 a EP2500?
Connection wise?

I ran one ep2500 for subs (2 per channel for 4 ohm load) and another ep2500 for tops with tops in series/parallel for 5.3 ohm per channel.

[juxta]

Originally Posted by jbell

I ran one ep2500 for subs (2 per channel for 4 ohm load) and another ep2500 for tops with tops in series/parallel for 5.3 ohm per channel.

Thanks jbell

[littlemike]

Originally Posted by jbell

I ran one ep2500 for subs (2 per channel for 4 ohm load) and another ep2500 for tops with tops in series/parallel for 5.3 ohm per channel.

Sorry - Knew you had EP's running it, could not remember if it was one or two

[littlemike]

Originally Posted by juxta

Thanks mike,
How does he run 1/2 a EP2500?
Connection wise?

Well - I had to - I'd run the subs on one side series-parallel wired, and the tops wired series-parallel on the other side.

As long as the impedance is within the range the amp can handle, it will be fine.