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2ndGenTeg · 08-17-2002, 02:50 AM

Image Dynamics says to run a good, clean 1000 watts RMS to the 12" iDMax. JL says a good, clean 750 watts RMS to the W7.

The best prices I have found are $450 for the 12" iDMax, and $575 for the 12W7.

Today I found out that JL does not warranty the W7s, period. That probably rules out the W7. I'm not interested in paying $575 for a woofer that if it blows, I'm SOL.

Here's the chart I referenced when comparing Image Dynamics and JL woofers (all models are 12"), and the setups I'm considering:

Model Cost Power #Drivers FinalCost FinalPower
iDMax 450 1000 1 450 1000
IDQ 200 350 3 600 1050
ID 120 200 5 600 1000
W7 570 750 1 570 750
W3v2 180 300 3 540 900
W0 110 125 5 550 625

In addition, most manufacturers do not manufacture woofers with impedences designed to work with an odd number of drivers. Image Dynamics happens to be one of them. Their woofers only come in dual 2 or 4 ohm voice coil configurations. This makes making a power efficient setup with an odd number of drivers difficult. The closest I could get with 3 IDQs would be a 2.66 ohm or 1.33 ohm load by wiring the voice coils from each woofer in series, and then running the woofers in parallel. In my mind, this is wasting 25% of my power efficiency to the inability to get the desired impedence- 2.66 ohm instead of 2 ohm, 1.33 ohm instead of 1 ohm (remember power production is the inverse of impedence- you produce twice as much power at 2 ohms as you do at 4) ( I'm not trying to start a debate- I'm well aware a higher impedence translates to cleaner sound). As for the IDs, they only come in a dual 2 or dual 4 ohm configuration as well. With 5, About the only thing I could do would be to once again wire the voice coils from each woofer in series, then run wire the woofers in parallel. This would yield a 1.6 ohm load- 37.5% loss in efficiency.

JL happens to make dual 6 ohm voice coil W3v2s. So I could wire all six voice coils in parallel to 1 ohm stable amp and get the most out of it (0% loss). With the 5 W0s, I sould get the 12 ohm models, and wire them in parallel to get a 2.4 ohm load, and run them with a 2 ohm stable amp (only a 20% loss in efficiency).

And the reason that's a big deal to me is this: If I have a 0% loss in power efficiency, and I need a 1000 watt amp, I go buy a 1000 watt amp. If I have a 33% loss in efficiency and need a 1000 watt amp, I have to buy a 1500 watt amp- 500 watts I didn't have to pay for if I had just planned my system a little better. In addition, I don't have to power that 33%, i.e. I have a 40 amp draw on my battery rather than a 60 amp draw.

Long winded, I know, but now you know why I'm leaning toward the 3 W3v2s.

08-17-2002, 02:50 AM	#8
2ndGenTeg 4th Gear Join Date: Aug 2001 Location: Boulder, CO Age: 45 Posts: 830	Image Dynamics says to run a good, clean 1000 watts RMS to the 12" iDMax. JL says a good, clean 750 watts RMS to the W7. The best prices I have found are $450 for the 12" iDMax, and $575 for the 12W7. Today I found out that JL does not warranty the W7s, period. That probably rules out the W7. I'm not interested in paying $575 for a woofer that if it blows, I'm SOL. Here's the chart I referenced when comparing Image Dynamics and JL woofers (all models are 12"), and the setups I'm considering: Model Cost Power #Drivers FinalCost FinalPower iDMax 450 1000 1 450 1000 IDQ 200 350 3 600 1050 ID 120 200 5 600 1000 W7 570 750 1 570 750 W3v2 180 300 3 540 900 W0 110 125 5 550 625 In addition, most manufacturers do not manufacture woofers with impedences designed to work with an odd number of drivers. Image Dynamics happens to be one of them. Their woofers only come in dual 2 or 4 ohm voice coil configurations. This makes making a power efficient setup with an odd number of drivers difficult. The closest I could get with 3 IDQs would be a 2.66 ohm or 1.33 ohm load by wiring the voice coils from each woofer in series, and then running the woofers in parallel. In my mind, this is wasting 25% of my power efficiency to the inability to get the desired impedence- 2.66 ohm instead of 2 ohm, 1.33 ohm instead of 1 ohm (remember power production is the inverse of impedence- you produce twice as much power at 2 ohms as you do at 4) ( I'm not trying to start a debate- I'm well aware a higher impedence translates to cleaner sound). As for the IDs, they only come in a dual 2 or dual 4 ohm configuration as well. With 5, About the only thing I could do would be to once again wire the voice coils from each woofer in series, then run wire the woofers in parallel. This would yield a 1.6 ohm load- 37.5% loss in efficiency. JL happens to make dual 6 ohm voice coil W3v2s. So I could wire all six voice coils in parallel to 1 ohm stable amp and get the most out of it (0% loss). With the 5 W0s, I sould get the 12 ohm models, and wire them in parallel to get a 2.4 ohm load, and run them with a 2 ohm stable amp (only a 20% loss in efficiency). And the reason that's a big deal to me is this: If I have a 0% loss in power efficiency, and I need a 1000 watt amp, I go buy a 1000 watt amp. If I have a 33% loss in efficiency and need a 1000 watt amp, I have to buy a 1500 watt amp- 500 watts I didn't have to pay for if I had just planned my system a little better. In addition, I don't have to power that 33%, i.e. I have a 40 amp draw on my battery rather than a 60 amp draw. Long winded, I know, but now you know why I'm leaning toward the 3 W3v2s.