Dollar to Satisfaction Ratio not met.

Probably the main contributor to the problems you are hearing is that the output impedance of the BAT and the input impedance of the DNA-500 are not a good match.

Stereophile's measurements of the VK-51SE indicate a sharp rise in output impedance from 410 ohms across most of the audio band to 4700 ohms at 20Hz. That will result in a significant deep bass rolloff when driving the DNA-500's relatively low 10,000 ohm input impedance. Higher frequencies may also be affected, to the extent that the two impedances vary differently as a function of frequency.

I note, btw, that the input impedance of DNA-225 is far higher than that of the DNA-500, 100K instead of 10K. 100K is an excellent match for the BAT's output impedance.

Another factor might be that if overall gains and sensitivities in the system are such that you are using the BAT's volume control in the upper part of its range, that apparently causes its frequency response to deteriorate considerably. That occurs even when amplifier input impedance is high. See Figure 2 of the Stereophile measurements.

The only solution I can think of that does not involve changing or modifying components would be to add something like a Burson AB160XLR balanced buffer between the two components. That would resolve the impedance matching issue. That particular buffer also apparently provides up to 6db of gain, so you would be using the BAT's volume control at somewhat lower settings, thereby helping the second problem I mentioned, if it is a problem.

Regards,
-- Al

An additional thought: How are you hooking up the sub(s)? I don't know whether or not the two XLR output connectors for each channel that are apparently provided on the BAT are individually buffered, but I would guess that they are not. If that is the case, and if you are connecting a sub to one of those two sets of outputs, that will make the impedance mismatch I described even worse (by a considerable amount, if as is often the case the input impedance of the sub is not high).

If the sub(s) have speaker-level inputs, connecting them to the amplifier outputs would resolve that aspect of the problem, although the preamp-to-power amp mismatch would remain.

Regards,
-- Al

Hi James,

I couldn't find an input impedance spec for the line-level inputs of the Hsu sub. But I would feel pretty certain that the Burson buffer would have no problems driving the combined input impedances of the DNA-500 and either the sub or the Behringer. You would need an xlr y-adapter, such as one of these, to drive the two components from the Burson.

If your Behringer model is the DEQ2496, which is indicated here as having a 22K input impedance on its analog inputs, or if it is another model that is similar in that respect, it cannot be driven by the BAT without significant deep bass rolloff, even if no power amp were connected. But again, that load in combination with the input impedance of the DNA-500 should be no problem for the Burson buffer, or for most other comparable devices.

Regards,
-- Al