I just picked up a home theater receiver with 7.1 to power the 5.1 speakers I had already been using. I did a search and am surprised I haven't been able to find much discussion of how well these boxes bi-amp. It has been humbling to find that the receiver's auto calibration does a better job at EQ than I do, at least initially. There are just too many moving parts for me. I'm curious and am going to start playing with the 2 front chanels with small KEF satellites good down to 80Hz and add some B-139 helper woofers in a sealed box I have gathering dust and see what the receiver does. I can't imagine others are not already doing this and I would appreciate hearing about how this has worked out for people.
Some AVRs have the bi-amp function built-in, eg my older NAD T757. it can assign back surrounds to duplicate the fronts signal. Whether 5.1 with biamping fronts is better than 7.1 is debatable. Maybe for really high levels of stereo programme yes, but then a proper stereo amp in a non biamp mode does a much better job.
What has been pleasantly surprising to me is that the presence of more electronics in these higher end AVR's is not necessarily mucking things up the way some of the older consumer EQ used to. Another factor is source material and on "truth machine" tube systems with CD horns or full range drivers there is a noticeable differences that systems with less resolution can't reproduce. With streaming music and movies my jury is out on how much resolution is a good thing. Streaming music on my higher resolution systems can set my teeth on edge whereas on the "consumer" stuff it is fine.
I imagine there are difference in sophistication between AVR's but i would like to know, in general, the filter model these boxes employ and whether they boost/shelf or shape response other than filter/cut when bi-amping.
I imagine there are difference in sophistication between AVR's but i would like to know, in general, the filter model these boxes employ and whether they boost/shelf or shape response other than filter/cut when bi-amping.
Each AVR must be checked individually. The claims of "pure analogue direct bypass" cannot be trusted. Nad t757 probably does some processing even when used as multichannel amp utilizing analogue ins and outs. I tried it in an active crossover chain and it is not up to the job. Better use HT multichannel pure amps with no built in dsp for that. Only then you can be sure no dsping is going on. As for the HTprepros I can confirm that Emotiva XMC1 in the reference mode does no processing but it works only for stereo. It is really good though in multichannel processing too, least artefacts.
Last edited:
I have just started using a NAD T763 for tri-amping some speakers out of a minidsp 4x10 and am very pleased with the sound quality. Great value.
The analog inputs bypass any processing save for volume.
The analog inputs bypass any processing save for volume.
I did the same with minidsp 4x10 and NAD T757 and was very disappointed. When I attached Emotiva XPA Gen3 and it was like night and day. I stick to Emotiva.
I will call Emotiva and find out what my UMC-200 7.1 processor actually means when it repurposes the rears to the front low freq. The manual, while adequate for setup, does not get under the covers.
I'm not following where in the chain you guys are using a minidsp. Your NAD receivers already parse the signal. What am I missing?
I'm not following where in the chain you guys are using a minidsp. Your NAD receivers already parse the signal. What am I missing?
Last edited:
Minidsp 4x10 HD serves as preamp/DAC/active XO+EQ processor. It has 8 analogue (Balanced/unbalanced) outputs. For a 3-way active xo/eq speaker you need 6 of those outputs and a 6 channel amp behind them. I tried my NAD T757 in that role via its analogue 7.1 inputs. The sound was not satisfatory and curiously it changed when the setups were switched from direct to analogue bypass. That should not happen if the analogue inputs were connected directly and only to power stages. No such problems and a great sound with Emotiva XPA gen3 amp.
Last edited:
correction
I checked my notes and the sound of NAD T757 (via analogue 7.1 inputs) changed for the BETTER (but not very good) when instead of "analogue bypass" I left the proper menu fields BLANK. Go figure...
I checked my notes and the sound of NAD T757 (via analogue 7.1 inputs) changed for the BETTER (but not very good) when instead of "analogue bypass" I left the proper menu fields BLANK. Go figure...
I just got off the phone with the Emotiva tech. The UMC-200 does nothing more, or less, then reassign the rear channels to duplicate the front left and right. Whatever EQ is applied to the fronts is applied to these rears. This makes sense and so biamping relies on the passive crossover in the speaker. There is no internal electronic crossover functionality in this receiver. But this would be handy for PLXO if one wanted to add a helper woofer.
- Status
- Not open for further replies.