agedhorse

If they were of any decent quality, they should be good for another 20-30 years. What about where preamps (and in some cases power amps) generate more harmonics than you consider "low distortion" yet sound big and clean. I'm talking about more common tube amp topologies that are considered clean but don't measure as such. Actually, it's a great speaker when properly designed around and used within the limits of the design. I have a lot of experience with custom variants of this driver that I designed, tens of thousands, and experienced very few issues. Correct, but some cabinet manufacturers didn't truly understand the limits and thus placed ridiculous claims of power handling when playing the spec. game. Then, players incorrectly believing what they were told (marketed to) unintentionally beat the hell out of them. It's all about providing an accurate presentation of the speaker's capabilities.

Good question. Spec sheets are simplistic guides for what an average designer might expect to achieve when designing around it, but there are a lot of specs that are not on the spec sheet because they become more application specific and depend on the skill and experience of the designer in order to exploit more performance. For example, one of ICEPower's older module families did not specify 4 ohm BTL operation and in fact warned against it, yet in spite of all the other manufacturers who had no first hand experience with the platform (and end users with even less knowledge and experience) expressing their doubt and prognosticating that it couldn't possibly work, that the amps would blow up by the thousands, I developed a pair of simultaneous technique that we at Genz Benz/KMC received a patent for that allowed this module family to work without any issues (performance or reliability) into 4 ohms BTL. I worked with the engineers at ICEPower to validate the design (so that our contract could include ICEPower's warranty of an off sheet application), and we built close to 10,000 amplifiers using this technique and have had way LESS issues than other manufacturers attempting do do this their own way once they ran into the patent. These amps are now approaching 18-20 years old, and through my factory service program I replace maybe one or two power modules a year (less than 2% of amps serviced under this program need new module). This IP transferred over to Fender when we were acquired, around the same time that Fender introduced the Rumble V3 series. This is similar to how we obtain a 2 ohm rating on all of the Subway 800 models, 2 ohms was an off-sheet application that required design validation in order for the modules to be covered. Again, well over 10,000 amps with no problems. This is not accidental success, it's the result of understanding to a very deep level the underlying technology. Making a mistake in this sort of application can be very costly, in fact it can ruin a company, that's why we analyze and test and test and test... I typically use the 10% THD threshold in most of my bass amp models because there are elements and techniques that I use in both the preamp and power amp circuits to emulate various aspects of pre and power tube performance. Since tube circuit performance generally includes the addition of harmonic components (the particular harmonic series that's generated varies depending on what's being emulated, the pre and power tube emulation is different too), these added harmonics show up in the output measurement as THD. Most players seem to prefer somewhere between 5 and 20%THD when driving their amps hard (towards rated power), so I chose a mid-point value that represents the average player's sweet spot. This agrees with the experimentation we did when using a Bass 400+ and allowing a group of players to drive the amp where they felt it was in their sweet spot, and it was all in the same 5%-20% range. This is exactly why there is a notation in the specifications that the THD number in the rated power spec includes preamp AND power amp, the rated power is with full context, it can't be separated out.

Not as straight forward as you think. Sure you can generate numbers, but how accurate and also how useful is more difficult. The more you measure, the more difficult you realize the task becomes. Agreed, there are lots of holes in your good intensions. It’s in part equating the numbers to real world performance is much more difficult than it appears.

It depends on the manufacturer, the design and intent of the design, and the execution. In many ways, the power supplies used in class D amps are MORE robust not less, but there are many more factors in how an amp performs. Sone manufacturer’s marketing folks are more creative in their presentation of the specifications, that’s a choice that they have determined their customers are ok with.

It depends on the manufacturer, the brand and the product category. Some are misleading (intentionally or otherwise) but not all.

Correct, what I said earlier is that there is no approved component level repairs for the ICEPower modules. Your problem is with the amp manufacturer not offering out of warranty repairs, but almost all manufacturers have approved service centers that handle out of warranty work. This is what I am puzzled about, did you not contact one of the manufacturer's service centers?

Good for Ashdown’s willingness to support their products and do the right thing. Since you made the same post with the same inaccurate information over at TalkBass, let me add my response to you here: Just to set the record straight, ICEPower modules are not to be repaired at the component level (with a very few exceptions), because doing so voids the safety certification on the module. This is their official policy and most manufacturers using these modules follow it closely. Besides, it’s usually less expensive to replace than repair do to the high amount of highly skilled labor required to diagnose these faults in high technology. Also, replacement modules are available for all ICEPower modules that have been used in the bass amp industry going back to the very beginning. There are no unavailable modules in their product line, so that information is incorrect. Additionally, Ashdown has used ICEPower in some of their lightweight amps.

Of course accurate, honest specifications are important, but so is understanding the basic principles of the physics behind speakers (and transducers), which is where this whole thread/discussion has become so confusing. Lots of incorrect assumptions resulting in incorrect conclusions.

4 ohm 410's make a lot of sense because many 410's have a real world power handling of between 600 and 1000 watts RMS, and there's more available volume this was as a single cabinet solution. If you want 2 x 410's, than a 2 ohm capable amp is not that difficult to find. It has nothing to do with valves versus solid state, there are plenty of examples of 2 ohm capable amps in both types. If there is enough current available from the amp, then it doesn't matter as they go hand in hand. No, it's all about voltage x current x cosine of the phase angle between the voltage and current (which is the definition of real power). Actually, speakers are a current controlled device, the movement of the cone is due to the opposing magnetic fields, one static and one modulating. based on the current flowing through the voice coil. The force F=I x L x B x sin θ (where θ is the angle between the current I and the magnetic field B) The voltage is what causes the current to flow. Voltage and current exist together, you can't separate them aside from the inclusion of the phase angle between them. The voltage causes the current to flow, the current flows because of the voltage, and the real power is ultimately what matters. Since real power is more difficult to measure, apparent power (which assumes that the power factor (or phase angle between the voltage and current is 1) is most commonly used and is plenty accurate for like comparisons.

Fender operated SWR for 10 years, it was a struggling brand when they bought it and it was still struggling when they shut it down in 2013. The newest products (AmpLite amp and GoLite speakers) were probably the best products in that last 10 years, better than many of the legacy models in terms of build quality and performance, but it was too little too late to save the company. Before somebody accuses me of not knowing the history and those products, I was there working for another one of their companies that was shut down a few months later (after 6 years of ownership).

Different players, music styles, gigs and venues all have different needs. What works for you may no work for another player and there is nothing wrong with this. It doesn't make you more right or the other player more wrong.

The safety regulatory statement for power consumption is required by the standards (UL/cUL/IEC 60065 or 62368) to be stated at a minimum of 1/8-rated "RMS" power at the lowest rated load, which corresponds to a duty cycle of 12.5% (but the manufacturer may at their option use a higher number). This number originated from the hi-fi world where this was considered the approximate duty cycle of an unclipped full range signal (which IMO is unrealistic for bass guitar). If the normal operation of the amp is intended to be compressed, overdriven or distorted, the stated duty cycle may be increased to reflect the additional power consumed under these conditions at the manufacturer's option. Most test labs will test to verify that the amp can sustain the increased duty cycle without failure or presenting a safety/fire hazard under a test sequence called "abnormal conditions" testing, but not always (depending on the lab and the test routine because other abnormal conditions testing elements may suffice).

I'm always interested in what players have to say and what THEY would like to see.

Wise move I think!

Time out in the open generally helps. Tearing it apart and washing the materials may end poorly...