Need sub woofer driver recommendations

... let's try to say something meaningful ...

1 - your amp looks not happy to work on 4 ohm (ideally it should double the 8 ohm power on 4 ohms, a 'strong' 150/8ohm would probably deliver 250-275 w on 4 ohms)

That does not means that your amp is bad, just that he is not designed to work on low impedances, and this is a parameter to consider in the choice of the woofer units, excluding the 4 ohm speakers and the paralleled 2-voice coils units.

2 - It is not clear if your amp and budget are for 1 sub or the stereo couple, I assume the first case, that is a 150+150 w amp and USD200 budget for the drivers

3 - Given the general format of your post, I think you're not an expert DIYer, so I would recommend to stay on simple box design, like sealed box or bass-reflex systems.

4 - For the choice of the driver, you should tell us something about what's available in Australia: I know several units that would fit your needs but their price and availability are ok in Italy, maybe they are not distributed or differently priced in your Country. Or, better, you might find there better deals.

I put here an example with a widely distributed driver.

Driver : Audax HT240 M0

VolBox : 124 litres
Filler : on box walls, 1 1/2 inch thick
Tuning Duct : Diam. 122 mm, lenght 200mm

Tuning Freq : 29 Hz
Freq -3db : 29 Hz

5 - Qtc is normally used to identify the Q factor of a closed box system, being Qts the total Q factor of a loudspeaker.
( by the way I guess that A.N. Thiele is an Aussie!)

6 - The best free software I know is WinISD. His major limitation is that is not properly considering the effect of the filler material.
Also a warning: be accurate in entering drivers parameters, winISD is a bit too much fault tolerant in that section.

bye
sandro
 

griff

Member
2001-12-27 4:01 am
Melbourne
they were a little shady b4 and im not sure where the 200 watt at 4 ohm came from, my mistake. I feel i should explain my current setup and what i want from making a subwoofer. I have a Sony str 535 amp, sony 725 dvd player, and sony cd deck, Jbl Hls 620 fronts, wharfedale valdus centre and jbl rears. I aim to attemp to make a more powerful centre channel after i complete the subbie, i need the subbie to add groundshaking ability, i listen to rock, punk, alternative, hip hop and am lacking that window shattering element.

AMP FEATURES (this is the basis for my subbie, all i need to know is a driver)
Features:
• Auto Power On/Off with signal presence
• Compact modular design
• High and Low Level Inputs
• High Level Outputs
• Volume Control
• Short Circuit Output Protection
• Active Crossover variable from 50Hz - 150Hz
• Phase Correction Switch
• Power On Indicator
• 240V Operation

Specifications:
Power Output: 150W Max @ 0.5% THD
Frequency Response(Variable): 50Hz - 150Hz
Roll Off Rate: 6dB/Octave
S/N Ratio: >64dB
Auto Turn On Sensitivity: 21mV
Auto Power Off Time: 15-20 Minutes
Input Impedance: (Line) 47k Ohm, (Speaker) 200 Ohm

Please advise on suitable 12 inch drivers, sony, jbl and other car audio drivers are easily obtainable and cheap in AUS, can one of these be used?

If not, a list of drivers would be appreciated, a website that sells them would be even better, especially and AUS one. THANKS