Why big amps

Srsly?

If so, model a Mal-X in a 6.5 cu. ft box and see just how many watts you need to get the full x-max.

Then consider many are going to apply 12 dB LT and just how many watts 12 dB is. :P

I'll be running 4000 watts through 2 mal-xs. They'll be about 2mm over xmax at peak.

Go ported if Watts matter, they need HUGE watts for those sealed designs


Actually build an IB, no need for huge watts at all, one EP2500 can driver 4 18" driver to sick SPL

It could be because I don't buy power sponge subwoofers (LMS) but I feel the top end that anyone should use with subs is around 1000w - 1200w at the most. After that you are just dumping power onto the VC with little to add. Now, I don't say that as a 'fact' that you can't or shouldn't use more power than that, just that I won't.

Now if you look at it as 1000w max RMS power per sub, the need for amps that do TWICE that is recommended. And that's just me...many other users here want to use upward of 2000w per driver meaning they might want to get a 3000-4000w amp.

I think a lot of us should start looking into per household nuclear reactors for cheap, plentiful electricity.

You have a tradeoff between efficiency and low frequency capability. Most people here give up a good amount of the former to get the latter. If you want a more efficient setup then get that 95dB B&C 21" or something. It'll be awesome overall, but you won't be hitting as low as the Mal-X stuff here.

You are forgetting bandwidth and the intended use. For instance you wouldn't use a prosound driver for a 'SUB' woofer, as it would not have the throw. It has higher sensitivity yes, but it will be mechanically limited.

If your goal is loud, but not low, grab some high efficiency pro drivers with short throw, and tune high. Output galore, and you don't need a lot of wattage. Box size will be a downfall though.

On the other hand <20 hz requires an aweful lot of cone area, throw and power applied.

Horn loading. The maximum output of a driver is limited by the driver and box relationship. A 7 mm throw 15" driver on 400 watts can do pretty amazing things when you have it in a 9 foot path length horn with a large enough mouth area.

1. While the Peerless XLS drivers sound wonderful, especially when used at higher frequencies (as in a bass-driver for a 3-way) other drivers have double the xmax which would take 4X the power to get there with the same suspension stiffness. Those with stiffer suspensions so they work well in smaller boxes take more.

2. Power required to reach xmax at low frequencies is dependant on the force needed to overcome the box air spring and suspension stiffness. It goes up in smaller spouse-friendly boxes; so although 60W will drive the Peerless XLS drivers to xmax in free-air you might hit the 300W pmax first in a small box.

My direct answer to your question, "why big amps", is why not?

Small sealed boxes put a lot of extra stiffness in the total suspension of the system causing them to require a lot of power to reach Xmax. The trend these days however is to make the resonance low enough that capacitive reactance in the coil makes the actual power requirement much lower. The high impedance however makes the voltage requirement very high. So, many compact subs will have an amplifier that claims to be 1000 watts or more but in reality it probably isn't. It has the voltage capacity to be 1000 watts if it is driving 4 ohms but near the resonance it may actually be driving 20, 30 or more ohms so the actual power is far less. If not for this, most of these would just smoke their voice coils.

mk

You really need to model these subs that you don't believe can take this power. Before port tuning my 19ov.2 can take a bit over 1000 watts before reaching xmax. I still have room left before its mechanical limits, but run the numbers on a tc sounds or xxx will take a lot of power to reach xmax. Thousands of watts.

What will be the SPL levels?

TC2000 15" drivers in a 12cuft ported box tuned to 15hz I believe only need 800 Watts to hit XMax

Take it from me, the Maelstrom does just fine with 2KW on tap. It isn't overkill, especially in sealed alignments that use some EQ.

lol, its all about headroom Have you seen "TheEar"'s wall of sound? Do a search

Yes. One-way.

So what would loose if you used a Ep2500 in single channel mode vs bridged mode? Is it SPL levels?

+1

I am lazy tonight.

Bridging two amplifier cahnnels together nets double the voltage, for a 6dB gain in output over a single channel provided you're not current limited (that has to double with voltage).

LMS 5400, 38mm xmax, 44 mm xmech. TC3000, 30mm xmax, 46mm xmech. I am not sure on the Soundsplinter RL-S 15, but it looks like a TC3k based motor with more magnet volume, I bet the xmech is closer to 55mm. That would put it over 100mm P-P . 4"

Here's a pic of the SS RL-S 15"..

This is probably a better topic for another thread. My current 6.5", the EX-6.5 does pretty good compared to some of the bigger name drivers. If you want to see a measured distortion comparison you can look at the SoundStage Review. They measured it in the NRC and they use that same measurement set-up for all their speaker review measurements. That is pretty cool because it allowed us to look and compare just the raw THD numbers vs. a lot of other big-name drivers. I think if you spend some time looking at the measured distortion, compared to the Ushers, SS, Seas etc... you will see that the EX-6.5 spanks virtually all drivers of comparable size/format.

Here is the Exodus EX-6.5 in a 0.5 ft^3 cabinet with roughly a 38Hz tune

http://www.soundstagenetwork.com/mea...exodus_kepler/

Compare that with the Usher used in the Be-718. Looks like about a 40Hz tune (which would favor the Usher driver for the >50Hz distortion measurement).

http://www.soundstagenetwork.com/mea...eraudio_be718/


Here you have the Wilson Duette ($12,500/pr) with a larger 8" driver. I'm not sure if this is the SS driver or not. It does pretty good but it has roughly 40-45% more cone area than the EX-6.5. The Wilson dedicated stands cost more than a pair of Exodus Keplers, and I think the Kepler measures better both on/off axis.

http://www.soundstagenetwork.com/mea...wilson_duette/

Lmao....

Spinal Tap, these go to Eleven....
http://www.youtube.com/watch?v=d54UU-fPIsY

I never thought about squirrels on my 18" drivers