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Not a dumb question, but maybe not the right one.

Based on your question, I'm guessing that your assumption is that the only thing that could affect the bass quality/quantity is the amp that is directly connected to the woofer. But surely one could hear different bass quality/quantity from different preamps even though there is no direct connection.

Similarly with a powered woofer, the built-in amp is presumably designed to be transparent to the input signal (in order to maintain coherency between the outputs of the woofers and the other drivers). So just as different preamps can affect the quality/quantity of the bass, it would seem that a power amp before the final power amp could do the same thing.

On the other hand audiophiles are taught to believe that the things in the amp that affect the quality/quantity of the bass are things like "damping factor", "peak current delivery", "transformer rating", and so forth. With this model, neither the power amp nor the preamp could affect the bass quality/quantity of a powered woofer as all of these parameters are provided by the final amp in the chain.

Since we all know that the preamp *does* affect the sound, clearly the audiophile model is incomplete at best, and completely erroneous at worst.

Another example of this was the call I received from a customer who wanted to know the VA rating of the power transformer in one of our power amps. His current setup was not giving him enough bass impact and he was given to understand that having a "heavy duty" power supply would mitigate or eliminate the problem he was hearing.

I told him that we never give out the VA rating of our transformers because it is a nearly meaningless spec. In the first place, there is no standard way to measure the VA rating. Depending on how much temperature rise is allowable and what the duty cycle is, any given transformer can have a VA rating that varies by a factor of two (or more!). A much better way (assuming that you are comparing toroids to toroids, or C-cores to C-cores, et cetera) is to simply note the weight of the transformer. This is a far more accurate indicator of the mettle of a transformer than is the VA rating.

But worse yet is the fact that neither VA rating nor weight has been shown to be a major factor (let alone the dominant one) in achieving bass quantity/quality. In the end the customer purchased a used V-5xe sight unseen (it was used and there were no dealers near him where he lived in Eastern Europe). It was a pig in the poke but he wrote to me that it produced the best bass of any amp he had ever owned. Which doesn't mean a lot to you unless you had the same speakers and had owned the same amps. But it meant a lot to him as he was finally happy with his system.

Back to RD's review. In his post he notes that the amp produced similar quantity/quality of bass on three different speakers despite the fact that there was an internal amp connected to the woofer. He said that he will do a follow-up with non-powered speakers, but I would be willing to bet that he will hear essentially the same thing.

It makes sense from one standpoint, but from another makes zero sense. Most of audio is like that...


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