Crossover Volume Level

It's simple. Forget guidelines except if you are putting signal thru that would be unacceptable to the driver. The drivers speciffy in hz or bcps what their range is. As long as you keep the signal properly attenuated into the driver just pick the sound you like.
Don't worry about arbitrary standards. If like a bassy sound let it go louder. If you like treble let the tweeter get loud. Why doyou think you hear very different sounds from the different speakers you here the same music on.
That said if you can measure Db and cps get reference recording. I have a few which specify what the volume should be in Db a specific frequency. Knowing the sensitivity of the your driver and using a volt meter to measure how many watts you are delivering to the terminals of the driver. This way you can adjust the attenuation of your crossover in -db or degree of your of slope.
The maximum energy capacity for a driver is always given in terms of watts.
The best wine I always say is the wine you like best. That is true for music too.
If you color the tone or create a sound that weren't exactly what the engineers wanted who cares ?As long as you truly like it that way. BTW, the sound of the recording is engineered or made up, in most cases,. Given the limitations of the reproduction equimenmt they assume will be used--- like a car radio. Once a performance in a studio is made they have to mix it i.e. adjust the volumes of the different elements.

If you're tweaking crossovers you really should think about getting a mic to measure exactly what the drivers are doing. You can get setup with a good test mic, like a Behringer ECM8000, mic preamp, and cables for about $150 and possibly e able to use the sound card in your PC. I went ahead a bought a USB external Sound Blaster card for $50 so I can use it with my PCs or laptops. You could also use a cheap Radio Shack meter, but it's not as accurate. You can download Room EQ Wizard for free and that's good enough to get reliable results.

What I've recently done is to use the mic to measure at my normal listening position. I thought I was going to need to do major changes in my crossovers. As it turned out I was able to get very good results throughout the frequency range just by adjusting speaker, and even driver, locations in the room.

Another great tool I found, also free, is a circuit modeling software called Micro-Cap. They have an eval/student version you can download and it will handle circuits up to about 25 components. Plenty good for xovers. It's is very intuitive to use. You build the circuit with elements from the library, supply their values, label the nodes you're interested in, and have it run the analysis. Micro-Cap runs on top of Pspice so it's about as good as it gets.

Measurements can't tell us everything, but they do take the guesswork out of this. You'll cut down a lot of iterations and quickly pay for the mic, preamp, and cables in savings on all those coils and caps you would need to do trial and error.

Thanks for the info. Mechans, I agree the sound I like is the only sound that matters to me. Which recordings do you have DB to CPS levels for? I have Ayre's "Irrational, But Efficacious" cd that I have been using to break in the crossovers, but this recoeding doesn't have set freqs, it sweeps the freqs.
Dan, I'll try the Micro-Cap and thanks for the tips.

And, when you do the testing, please measure each speaker separately -- not together.

I agree that measuring the drivers individually is the way to do crossover development.

If one is measuring what is happening in the room both speakers should be used.

Does anyone have B&W 802 Matrix S3 speaker crossover points they can pass on to me? The new crossover I made is much like the ones from Northcreek. Even though I used the same manufacturers values, I wanted to check to see that with the new componets, that the points haven't shifted.