Testing audiophile claims and myths
Jan 31, 2013 at 1:48 PM Post #1,801 of 17,336
My understanding:
 
active:
crossovers are pre-amplification and so only the modified signals are amplified and send to the two different driver sets
 
passive:
all driver sets receive the same full spectrum signal, and crossovers are done after receiving this full spectrum amplified signal. 
 
Feb 1, 2013 at 11:56 AM Post #1,802 of 17,336
So Liam if I understand you correctly, no matter what signal is sent to the HF or LF drivers by the Amp in a Bi-Amp configuration, it will be altered by the speaker crossover anyway? Hence, the effects of Bi-Amping is eliminated?

Correct?
 
Feb 1, 2013 at 12:12 PM Post #1,803 of 17,336
No, not entirely - in a passive system you still have separate power for the different drivers, and that can mean less drain on the amp during higher impedance frequencies and passages for potentially better dynamics. 
 
In an active system you get better gains still, since only modified (pre-crossed over signal) is amplified and sent directly to the drivers. 
 
But - whether any of this offers a marked improvement over a standard system is something that would have to be tested properly. Some people swear by it. Some people (Linkwitz) design their speakers specifically for it. Personally, I think it's overkill for most users. Room treatment and better driver/speaker selection for the task would solve most problems the majority of listeners run into. 
 
Feb 1, 2013 at 1:56 PM Post #1,804 of 17,336
Personally, I think just having enough power, speakers capable of putting out great sound and careful equalization are what you really need. I don't think biamping buys you much of anything. Better to put that money into better speakers.
 
5:1 and a good DSP will make a huge difference too.
 
Feb 2, 2013 at 11:11 PM Post #1,805 of 17,336
On the subject of bi-wiring, bi-amping, passive or active, I will tell you that personally I have tried them all!
 
In the late 80s/early 90s when all this bi-wiring etc. thing got going I was very much into every craze that came along, including all kinds of voodoo about cables (costing me money I could so well have spent much more wisely).
 
Today I think one really needs to stand back from these things and do a broader assessment before wasting a lot of time and energy which could be much better spent elsewhere.
 
There is a problem with conventional speakers which is that as yet we don't have drivers capable of doing the entire audible frequency range, not at reasonable prices anyway. So we have this compromise of using two or more drivers. The problem is in matching these drivers, making sure that when the signal crosses from one to another, the listener can't hear the "join" or detect too much of a difference between the drivers. However, obviously the differences between the drivers are absolutely massive when compared with the kind of differences achievable by using, say, separate but identical amplifiers. When I write, massive, I would guess the differences between the two different drivers are in the order of millions or billions times greater than the differences achieved by the two identical amplifiers, or even more-so, the differences achieved by using two identical cables which are both connected at the amplifier output.
 
So, when buying speakers buy ones made by a manufacturer who has attended well to the issue of ensuring that the crossover has been well managed between the two drivers. That is what is required.
 
If someone can tell if their speakers are bi-wired or bi-amped with identical amplifiers in a double blind listening test, then I will be delighted and very very surprised.
 
I will now give a suggestion for anyone that is attempting to get a better quality of reproduction from their Hi Fi with loudspeakers. If you have got a reasonable good transparent source, amplifier and speakers then what you need to address is the room they are in. It is the acoustics of the room which destroys you ability to hear what is on your CD, LP or digital file. It is not because your speaker cables are not pure enough in their composition of copper. It is not because your speaker cables are not numerous enough. You probably don't need to "upgrade" any part of your Hi Fi system at all. What you need to do is deploy acoustic treatments to your room.
 
This is the big secret of getting good sound from Hi Fis (with speakers). The reason it is a secret is that there is no money to be made in room treatment by all those Hi Fi companies pushing you to buy the latest version of whatever they make. The Hi Fi magazines don't review room treatments because they don't come neatly in a box with a quote from the Shakyamuni Buddha on it.
 
In the early 90s I stopped wasting my time with messing around with cables and other tweaks and I instead I did some pretty extensive room treatments in the listening room I had at that time. Even though my room treatments were actually fairly crap compared to those that an expert in that area might achieve, the results were stunning. I firmly believe that a modest Hi Fi in a well acoustically treated room will easily best the very most high end system you could construct placed in an untreated room.
 
So, to all who are interested in getting good sound in a room in their home I recommend, stop reading Hi Fi magazines and blogs (most of them are the enemy of good reproduction). Instead read this:
 
Master-Handbook-of-Acoustics-Everest-F-Alton-9780071603324.jpg

 
and search out information on DIY room acoustics on the Internet. You will find a lot.
 
I have read the Master Handbook of Acoustics from cover to cover, (actually I have the fourth edition at present) and I will tell you it is fascinating indeed. I think you will enjoy it immensely and be surprised at the kind of problems you have to address acoustically.
 
 
 
 
Feb 2, 2013 at 11:16 PM Post #1,806 of 17,336
You have to be single to do room treatment. Wives don't allow it.
 
Feb 2, 2013 at 11:26 PM Post #1,808 of 17,336
Women and bass traps don't mix. That's why most hifi nuts get banished to the basement, the one room in the house with the worst acoustics!
 
Feb 3, 2013 at 12:21 AM Post #1,810 of 17,336
One could see marriage as a challenge!
 
Feb 3, 2013 at 4:32 PM Post #1,812 of 17,336
Came across this in one of the cable threads on my local forum. ABX and DBT's were mentioned as evidence of the fact that people can't reliably tell the difference between cables and the reply :
 
Considering that even in the blind A/B you have high ratio of those that claim to hear the difference, even the low % of the "correct" answer cannot discount the FACT that listeners believe they hear the difference which automatically negates any scientifically obtained result.
 
I really want to put this person in his place. 
biggrin.gif

 
Feb 3, 2013 at 7:58 PM Post #1,813 of 17,336
Quote:
Came across this in one of the cable threads on my local forum. ABX and DBT's were mentioned as evidence of the fact that people can't reliably tell the difference between cables and the reply :
 
Considering that even in the blind A/B you have high ratio of those that claim to hear the difference, even the low % of the "correct" answer cannot discount the FACT that listeners believe they hear the difference which automatically negates any scientifically obtained result.
 
I really want to put this person in his place. 
biggrin.gif

 
 
Simple " "Reality is that which, when you stop believing in it, doesn’t go away." (Philip K. Dick)
 
Feb 4, 2013 at 4:35 AM Post #1,814 of 17,336
Hmmm....
 
Would it be perfectly fine to combine those room acoustic panels with canvas art coverings? 
 
 
Just how many panels would a small room need? You don't need to blanket the wall and ceilings like a studio....I hope.
 
 
 

 
Feb 4, 2013 at 6:34 AM Post #1,815 of 17,336
Quote:
Hmmm....
Would it be perfectly fine to combine those room acoustic panels with canvas art coverings? 
 
 
Just how many panels would a small room need? You don't need to blanket the wall and ceilings like a studio....I hope.

 
Hard to go into detail here, what you need, usually is to put a lot of treatments in the corners of the room first of all. It is pretty intrusive, personally I think that it needs to be a dedicated listening room really.
 
You need to reduce the amount of bass and midrange energy in the room and this requires really deep boxy or columnar absorbing units in all the corners. When I did it in the dedicated room I used to have I built very large units for the four corners of the room, from floor to ceiling. Then hung deep absorbing units around all the edges of the ceiling. The room, in fact becomes quite a bit smaller really.
 
Once you have reduced the bass and midrange energy, then you manage the secondary reflections.
 
To manage those reflections you can use reflective panels in the centre of the walls and in the centre of the ceiling. These are ideally replaceable with panels of different materials and also these panels are to be adjustable for angle.
 

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