Horn designing software

[Puggie]

To be honest I'm looking at the 15" Volt not the XXX now, basically from my playing it looks a more suitable sub (and I've found one I can 'borrow' for testing). I havn't had chance to measure up yet but the car does look smaller than I first anticipated

[Rademakers]

To be honest I'm looking at the 15" Volt not the XXX now

Good choice Luckily still the same rules apply.

I havn't had chance to measure up yet but the car does look smaller than I first anticipated

In that case let's wait till you do.

Mvg Johan

[Puggie]

Right, my friend is being pathetic and wants to keep his rear seats, so for now we have this ammount of space to play with:

Height 30" (762mm)
Width 43" (1092mm) the width at the top is the same as between the wheel arches
Depth 43" (1092mm)

Once I have finished beating the idea that loosing the back seats is a good thing, I think we should have about 20" more depth to play with.

For subs, the amp we have is happy doing 2 X 1000Watts RMS into 2Ohm, it will give about 20% more than this with the alternator running as its unregulated. because of this I'm looking at either a single Volt R3853 which is 4 ohm so bridge the amp and give it 2000w (I'm pretty confident they can take this power as a friend of mine runs this kind of power to RV3823s in his PA rig) Or use the RV3823 which is only available as an 8Ohm driver, but we could parallel 2 of them, is there room to do this, this would give more cone area and better powerhandling?

R3853
Nominal Diameter 381 mm

Power Capacity 300 watts

Sensitivity 93 dB/watt/m

Frequency Range 30-500 Hz

Impedance 4/8/16 ohms

Bl Factor 19 N/A

Voice Coil Diameter 75 mm

Voice Coil Material Copper

Maximum Excursion 28 mm (before damage)

Fs 32 Hz

Re 7 ohms

Qa 3.25

Qe 0.44

Qt 0.39

Vas 172 litres

Xmax 5.5 mm

Sd 734 cm2

Vd 600 cm3

Le 1.2 mH


R3823

Nominal Diameter 380 mm

Power Capacity 500 watts

Sensitivity 96 dB/watt/m

Frequency Range 30-500 Hz

Impedance 8/16 ohms

Bl Factor 19 N/A

Voice Coil Diameter 75 mm

Voice Coil Material Copper

Maximum Excursion 28 mm (before damage)

Fs 39 Hz

Re 5.4 ohms

Qa 3.25

Qe 0.35

Qt 0.32

Vas 133 litres

Xmax 4.5 mm

Sd 755 cm2

Vd 340 cm3

Le 0.9 mH

[CBFryman]

if you end up not doing it i am willing to take that beauty of a 18" driver off of your hands for you... make me an offer...

[mike.e]

Two 15" drivers on the horn?Very hard to fit+large rear chambers occur.

Consider two routes
-Scoop
-front loaded,rear sealed horn

with that size a horn is certainly possible.Its just a question of cutoff and sensitivity vs cutoff.

Xmax is still listed quite low...it wont matter for music at sane levels.

[Puggie]

CBFryman, postage would be a bitch from the UK

Mike.e

Right please explain in VERY BASIC TERMS what I can do with a single 15" as it looks like twin 15s will be too much. The Xmax is low but they are a lot more linear that the figures suggest, they can be run to 20-25mm excursion for extended periods, no problem and still sound very good.

Front loaded rear sealed, sounds to me like a basic sealed box with the sub firing into a horn.

Scoop, your've lost me but I'm thinking something like the PA Cabs which have a folded horn at the top and the mouth looks like a bucket scoop.

You say its a matter of Cutoff (as low as realistically possible) and sensetivity Vs Cutoff (how does this work then).

[AndrewT]

Hi,
I think your 1000w/2R amp is already bridged. You can only bridge once.
That is some alternator in the car, 3kW (1.5 times 1000w times 2) is about 4 times more powerful than normal car alternators.

[Puggie]

Nope the amp is a stereo AB, rated at 2X1000W RMS into 2Ohm, that is about what it puts out from an 10.5V supply, at 12.5V we measured 1248Watts RMS per channel, and it keeps going up almost linearly to 15.5V if you can keep the voltage up, the amp is barely 60% efficient so if you do the math you get an idea of the current draw and why keeping the voltage up is such a mission. it is rated as stable at 4Ohms bridged but will run at 2ohm bridged if you can keep it cool enough and if you can keep the voltage up near 14V then it will do 3kW bridged

It is a beast of an amp: US Amps 2000X which is the predecessor to the AX2000. www.usamps.com.

I've given up on a big enough alternator, just running with a couple of 110Ah batteries about 6" from the amp.

[mike.e]

Puggie: it takes alot of detailed writing!

You MUST read these links first

http://www.diyaudio.com/wiki/index.php?page=basshorn
http://www.volvotreter.de/ ->Downloads -> Dinsdale horn files/edgar horn files

A scoop is a horn where only one side of the cone is loaded,the rear is un enclosed. Theirs nothing too wrong about this apart from asymmetrical loading,causing 2nd harmonic distortion. Most commercial basshorns dont do this. However,if people are used to hearing reggae through scoops with this distortion,people will like the sound:d

Okay so now post the t/s specs of the woofer youl use.
What was the dimensions[max] again?
State what sort of music etc
And what is your aim

Then I can help with modeling,and CADing up the horn.

Cheers