Is bi amping worth it ?

@billpete I believe that John Curl is the chief designer for Parasound, so their amps are going to be very good.  I don't know that Krell is better than Parasound.  I just know that they are more expensive.  I like to say that today's $10,000 wonder is tomorrow's $5500 white elephant.  

Chances are if you were to sub in a Krell amp into your system, that it would sound a bit different.  Depending upon your opinion, it might be better or not.  It's my expectation that the difference between your Parasound and a Krell would not be huge.  But if you were to compare either of them to an amp from someone like Adcom or Cambridge Audio, that you would hear greater differences.   I think that Parasound is closer to Krell than it is to Adcom.

But were you to remove your passive crossover altogether and replace it with an active crossover, a pile of Adcom amps and level match them properly, you'd be surprised at how good it would sound.  

In practice with home systems, it is mostly in DIY builds that you see people using active crossovers and a pile of lower cost amps.  You really can't sell a commercial loudspeaker and then tell the customer they have to buy an active crossover, a pile of low cost amps and be sure to level match them when they get home.

Pro audio systems have been doing active crossovers for decades.

@ditusa --

+1

@russbutton --

+1

@russbutton wrote:

The do very different things.  An equalizer alters the system response.  Typically the operate on ten bands across the audio spectrum.  

A crossover, either passive or active, is designed to separate out the signals being sent to the loudspeaker drivers.  High frequencies for the tweeter and low frequencies for the bass driver.  If you have a 3-way system, then the crossover has the added function of allowing only an intended band of signals for the mid-range driver.

But as you know an active, electronic crossover/DSP also has an equalizer function in the amplitude domain integral to its design "raison d’être." Apart from dividing the signal sent from the preamp and passing it on to the power amps with chosen filter slopes, types, cut-off frequencies, delay etc., each driver band also has its overall gain setting and a number of PEQ’s (i.e.: Parametric EQ):

In my own Xilica DSP there are 8 such PEQ’s for each driver band (3 of them per channel for a 3-way system), and that means the opportunity to choose up to 8 specific frequencies (in single Hz increments) within each of these bands that can be positively or negatively gained in 0.25dB steps from a chosen Q-factor (i.e.: the sloping width around each of these frequencies). That means 3x8 PEQ’s + the overall gain structure for the 3 individual driver bands.  

In fact there’s also an "equalizer" function in the time domain in the shape of delay settings; IIR filters that applies a specific delay to the whole of each frequency band, and linear phase FIR filters that have some 65,000 delay points over the frequency spectrum (obviously not done manually).

Which is to say: functionally an active crossover is also an equalizer, whereas an equalizer is only that. What’s more and not least: with an active crossover the equalization is done at the heart of the crossover itself, and not as an additional hardware component. What an active crossover lacks in the number of equalizer bands it can make up for getting the overall gain structure of each driver band right from the outset, which is the easier part. The rest with PEQ’s is fine tuning, but also the hairier aspect that can really lift the overall performance. 

@russbutton John Curl designed a number of amps and preamps for Parasound. Cost dictated the parts that would be used to keep most of them at competitive prices. I know he designed the PLD preamps and they are silver wired, dual mono design but do so with a single power supply, not sure how that works but it is a nice preamp. I have a PLD2000 and used it for over 20 years until it began to have problems. Nothing major, the balance pot failed and I can't find a dual mono balance pot anywhere. I finally have found someone who can fix it with or without the pot. 

John Curl also designed the HCA amps, they may also be silver wired, I can't remember. I do remember reading from JC himself saying that if he were to do them again, he would use copper at least for the ic's. He also has many suggestions to make these amps and preamps better with some mods. Again, they were done on a budget and supposedly some relatively simple mods can make them considerably better.........so it is said. JC also designed the JC designated mono blocks and other later Parasound gear. I think the JC1's are said to be some of his finest work. They are not cheap.

I believe Nelson Pass is the designer of the Adcom amps and they have been highly regarded over the years as good bang for the buck pieces that don't break the bank. It seem to me that Pass and Curl have opposite ideas on how to build quality. I think NP also did  the old Threshold amps and maybe others and on to his own Pass Labs. Seems to me that Pass is a keep it simple approach and I like that approach, I've just never had it. Curl designed pieces seem very complicated. I have read that some of the mods, even the ones that Curl himself advocated, involved removing a fair amount of parts. Not sure what that means.

I give up, Agon is running terribly for me today.

@phusis Most of the pro grade active crossovers do not have DSP EQ, particularly the low cost ones.  Active crossovers have been around for at least 60 years.  DSP EQ as a feature is relatively new.  I have a miniDSP DDRC24, so I know what they can do.

 

@erik_squires and @russbotton (as well as OP)

Thank you for your informative input. I have learned a lot from you this morning.

This was a nice read. Unusual in the 'blast' climate we seem to be in.

You both contribute positively to our community and I wanted to say how much I personally am grateful for that . There are others here too that I am missing, but I wanted to let you know as I was reading through this.

Thanks,

Ken