Can you underpower a Strong amp?

After some rereading, I see you were referring to peaks, not rms.  I agree with Steve to maximize your system.My ex once told me I have a perfect face for radio.

Wow you guys are posting like crazy tonight.  Yea, I believe you both see what I was driving at.  The problem of using an amplifier with too high a power output capability is even if you have carefully set the sensitivity to maintain an average power output in the speaker's safe rating range, a dynamic peak (or using a higher than rated preamp input voltage) can still drive it to its max and exceed the thermal limits of the woofer.  This can fry voice coils even though you may think you are safe.  If one is careful with the gain setting and with the volume control, it is of course possible to use any amp with any speaker but you must always be aware of the limitations you have imposed on yourself and abide by them.  It is always the safest to use speakers with higher thermal ratings than the amplifier is capable of outputting.Support the12volt.com

(Dave, who has been reading with interest, chimes in...) Thermal rating is usually accepted as the RMS rating of the woofer. The phrase "thermal rating" really can't be quantified, 'till ya blow a voice coil... THAT'S the thermal rating... That being said, THERMAL limits can be different based on the enclosure type... Vented enclosures, simply because they have a hole to allow fresh air into the enclosure (but this should be ONLY below the tuning point) while MECHANICALLY a lower power handling system (again, below tuning point), can be a higher thermal (or electrical) power handling system. Sealed enclosures are just the opposite - higher mechanical power handling ability, with lower thermal power handling capacity.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Yep, that's correct enclosure type and woofer alignment can have a lot to do with the true limits of the system.  But in general, using the so-called "RMS" or continuous power rating of the woofer as the thermal limit is a safe bet, as it (is supposed to) indicate the max current flow the voice coil can safely handle in free air.  Or, to be more precise, I should say it is the max current flow the voice coil can dissipate as heat in free air; thus, the base-line thermal limit.Support the12volt.com

So another question. If thermal limit equates to RMS power handling is an advanced cooling system like JL's "forced air cooling" responsible for the woofer's power handling or is it voice coil, magnet, ecursion ( spell?) or in other words the mechanical limits of the woofer? Good to hear from you again "Ham Fist"There is no such thing as free installation!

tcss wrote: So another question. If thermal limit equates to RMS power handling is an advanced cooling system like JL's "forced air cooling" responsible for the woofer's power handling or is it voice coil, magnet, ecursion ( spell?) or in other words the mechanical limits of the woofer? Good to hear from you again "Ham Fist"

Thermal limit GENERALLY equates to RMS power specification. The RMS IS an electrical specification, so you can mostly take it as a gospel writing when referring to the thermal capabilities of a woofer. JL's "forced air" is a fancy term for "let's see how much MORE we can charge". However, the benefits to such a mechanism cannot be completely ruled out. As a voice coil heats up, the resistance of it goes up, reducing the power produced by the amplifier, and such a system will simply keep the voice coil temperature more stable - allowing a more consistent response curve in any given enclosure. Truthfully, (IMO) there is little added to the power handling capabilities of these drivers over any other "more conventional" driver SIMPLY because of the "forced air" mechanism. Performance "gains" are likely to be pretty minimal in respect to electrical power handling characteristics. All JL has done is opened up the port in the rear of the woofer for better air circulation around the voice coil. You can see the effect of reduced air cooling by holding a woofer still while powering it... eventually, it'll want to quit! JL has just made sure there is plenty of air around the voice coil. Power handling is almost EXCLUSIVELY determined by voice coil size. Excursion will play a small factor (longer throw woofers will cool more effectively than a shorter throw unit), and magnet will play an even smaller factor - specifically BECAUSE of magnet size. A larger magnet will generally mandate a larger overall motor structure, which will have more effective heat-sinking capabilities, and this will play more to heat removal than the magnet itself. Another design feature I am seeing in woofers of today is heat-sink ribs built into the motor structure, ala JBL GTi series of woofers - They call it "Differential Drive". (Heard 'em. Sound good... VERY linear sounding woofer. (sorry - no link - lazy today... http://www.jbl.com/car/products/series.aspx?SerId=GTI)) side note I remember Alpine did PRECISELY the same thing a few years back with a component system they had... anybody remember the name of those systems? Duo-drive or something like that... The 6 was a symmetrically driven, finned neo motor structure... end side note Oh, and thanks for the vote... Good to be back writing on a subject I understand and enjoy... Did you ever call George? I told him you'd be calling, and he did remember you!It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

A woofer system with improved air flow and higher voice coil cooling capacity could indeed increase its thermal limit (and power handling capability) beyond that normally associated with the size and gauge of the VC windings.  Engineering the best possible air flow through the motor structure is a common technique.  The mechanical limits of the woofer are just that: mechanical.  They have to do with either how far the motor can physically move before the coil is out of the magnetic flux, or before the system reaches the physical limits of the suspension (Xmax and Xmech.)Support the12volt.com

Didn't get a chance to call George, my life has got a lot more complex recently and I'm behind on almost everything. Alpine's components were called DD Drive and I still have a set in my old Benz. I was much more impressed with Alpine's new line and I think I'm going to stick with them over Eclipse ( hear Ham Fist cringe). Always love the knowledge from the "two Daves"There is no such thing as free installation!