This thread is NOT a debate about bi-amping. If you ARE bi-amping please share and participate. I also would like it to NOT turn into an argument over passive and active crossovers. Of course everyone has an opinion and they are welcome to share, but please don't let that take over the topic of gain matching and calibrating.
I've been experimenting with bi and tri-amping. I thought it might be cool to find out what practices others use to set up gain?
In verticle bi-amping I'ts pretty easy. But things get more complicated when you horizontal bi or tr-amp.
With verticle I literally use a db meter and average multiple samples to fine tune it in. But that would not work with horizontal.
I haven't done it yet… but I'm toying with verticle bi-amping my woofer and mids and then horizontal bi-amping my tweeters. But that would compliment gain setting a lot.
What do you guys do?
I work with active crossovers constantly and I just turn the amps up till just before I can hear anything noisey coming from them. Most amps can just be set to max gain and not have anything noisey start but others need to be backed off a tiny bit to stay out of any ultra sensitive input levels.
Then I've done many different tests to get it set so the handoff or crossover point is at the same level with the loss and highs by DB meter but that's only to get it near the setting. You still need to see how the wave is formed since there might be a dip or peak at the crossover point or 1 just begore5 or after that might be able to be controlled by turning up or down one or both may help flatten it but from my experience with 60 or so free programs like REW I can't trust any of them to show trustable results.
So know I do it the best esy. I sit in my listening position and see if the found image and stage are matched pet side with just highs. Then I add bass on both sides and sit and listen to see if the image and stage remains centered and focused. Then I cut the highs and use a DB meter to check that the crossover point is set correctly and then I look at the levels in DBS 1 at a time then match them. Turn off the lows and check the crossover points for same frequency and to make sure the highs are actually reaching that point and slightly behind as the slope says it should. Then check dbs on highs to match . Then I turn on only one side I take a db reading then I play a tone that's centered on the crossover point and turn off the the highs of the lows to see if the meter goes up (property phased) or goes down (out of phase) adjust, retest. Then the other dude same thing. Then add them both and measure for in phase again with both sides. Adjust and retest till a drivers are in phase and same levels
Then I listen and make personal taste adjustments as I please. I will sometimes use my dual 31 band eq if I find anything that can't be fixed without it typically I have 2 points in the lows at 63 needs a 3db cut and 80 needs a 1.5db cut. Highs need a 1db cut at 800 and a 2db boost at 1.2k. then it sounds correct and image is like they are right ther
Ie staging is huge and things need to remain positioned even as notes change with each instrument. If there's movement with an instrumentdud to changed in notes playing then there needs to be right and left side frequency adjustments to correct imbalance of tones. This typically takes me about a month of minor adjustments before I have it perfect for my listing spot.
I honestly can't think of any other way that it can be done and have the best possible sound. It's not going to be set up in an afternoon bevause you need to listen to different tunes to check it out properly.
There's also speaker placrment that needs to be done before eq is introduced since that alone can fix issues that cannot be corrected with crossover settings and phase issues can be caused by placement and can become huge problems when a driver is out by 90 degrees to all others. It will never be able to be set I phase without phase changing ability and typically a physical move needs to take place rather than digitally or actively manipulating it or forcing it into submission to match ithers6. Time alignment features in DSPs are typically useless and only work when things are 10 feet or more in distance and not for 2 inches . Proven that people can't hear when a driver is up to 10 away from the others that make up that sides sound spectrum. This is when drivers are inline with each other but one is moved back further than the other. Moving a tweeter physically behind the woofer and staying in line will be difficult for anyone to be able to tell where it is just by listening. The smearing won't be heard until they are over 10 feet away from each other in distance to the listrners.
This doesn't mean that aligning signals is of no use but it suggests that if they are not perfectly aligned most people can't tell anyway and there's little need to strive for perfection when th signals are constantly changing frequencies that themselves travel at different speeds so one frequency is aligned in the center of the final band but everything higher lower is coming in before or after the middle find arrives. So yes in theory, time alignment is a principal and is unattainable to be set to have each frequency meet your ears exactly at the same time.
It's also not in nature for frequencies of different lengths to reach your ears at the same time most noise we hear is refected off of something while we hear it and after it's heard the brain figures it out for us.
If you sit near field, then it's a different story and you want to reduce size and number of drivers to be able to have the closest tightest band of sound coming from a single point to maintain the correctness of the original source and reduce reflections to maintain imaging and sound stage. This is where solid mid-range reproduction becomes important. No actve crossover needed for single driver systems. No time alignment needed. No crossover parts needed. Quality drivers are important in single driver systems to cover the most frequencies possible with less regard to overall volume in db.
Thetes no wrong way to set up anything but there are logical ways that will get you there in fewer steps but each step needs to be done to be sure youre on the right path as you progress. Skipping one will create a problem that will require you to back track. Forgetting to check phase is common most people think that their speakers are set up properly from the factory and even worse people think that their used speakers are set up properly when it's a huge problem when people are instantly ripping apart crossovers and they have no idea of what they're doing and are just grabbing hold of the fads created in these forums where everyone's first advice is to alter their speakers and the people that do it often have no clue what they're actually doing and speaker wires are constantly being reversed because they don't look at schematics to check the proper wiring.
