Hi Aggielaw -
The previous responses here have provided a lot of good information about upgrading your Hafler amp, but have not addressed the question of bi-amping with your DNA-0.5 Rev A. Whether this can be made to work well (or at all) depends on what you have in mind. If you are thinking of "passive bi-amlification" (using the speaker's own internal crossover networks), this works best with a matched pair of amps. It can be made to work with 2 different amps, but this is far more difficult and rarely works well unless the crossover point is very low - around 100Hz. Even then you will need some way to independently adjust the input level to the amp with higher sensitivity - almost certainly the DNA-0.5 in this instance.
Some of the problems I have mentioned can be overcome by using an adjustable electronic crossover, but this introduces a whole new set of issues, some of which are technically difficult.
So, the "mix-and-match" approach to bi-amping is rather problematic, in my estimation. On the other hand, it can work very well indeed with a matched amplifier pair. You may want to consider moving in this direction in the long run. Another DNA-0.5 or Hafler can be arranged to match what you have now, and I believe this will give you the most flexibility and best performance. In addition, the DNA amps can be converted to true balance monoblock operation, delivering over 400 Watts per into 8 ohms. That should satisfy your taste for more power ;-)
Please give me a call if you would like to go over the various options.
Happy holidays,
Steve McCormack
www.SMcAudio.com
The previous responses here have provided a lot of good information about upgrading your Hafler amp, but have not addressed the question of bi-amping with your DNA-0.5 Rev A. Whether this can be made to work well (or at all) depends on what you have in mind. If you are thinking of "passive bi-amlification" (using the speaker's own internal crossover networks), this works best with a matched pair of amps. It can be made to work with 2 different amps, but this is far more difficult and rarely works well unless the crossover point is very low - around 100Hz. Even then you will need some way to independently adjust the input level to the amp with higher sensitivity - almost certainly the DNA-0.5 in this instance.
Some of the problems I have mentioned can be overcome by using an adjustable electronic crossover, but this introduces a whole new set of issues, some of which are technically difficult.
So, the "mix-and-match" approach to bi-amping is rather problematic, in my estimation. On the other hand, it can work very well indeed with a matched amplifier pair. You may want to consider moving in this direction in the long run. Another DNA-0.5 or Hafler can be arranged to match what you have now, and I believe this will give you the most flexibility and best performance. In addition, the DNA amps can be converted to true balance monoblock operation, delivering over 400 Watts per into 8 ohms. That should satisfy your taste for more power ;-)
Please give me a call if you would like to go over the various options.
Happy holidays,
Steve McCormack
www.SMcAudio.com