Combination of 1st order and 2nd order crossover in 3 way box


I'm re-doing some old Sansui 3 way boxes.  Is it crazy to use a 2nd order crossover between the mids and highs but a 1st order between mids and lows.  I want to crossover at 375Hz and 3K Hz.  With the response of the mid and high drivers I think they would be better served with a steeper slope at the 3k mark.  Does anybody have a crossover designer to help me with this or am I going to cause more phasing problems that will negate the benefits?
dannybad
Erik,
    I have all of the driver specs but I haven't tested them in the box.  I was more asking the question about combining different order crossovers so that I can learn more about them and to learn people's thoughts on them.  I have since found a lot of info on it.  With just the driver spec's in mind I think it would be beneficial to protect the tweeter with a second order order high pass slope and the mid range driver would do well with a second order low pass slope given it's problems around 8k.  I plan on getting a good reading from them once they are in the box and going from there.  I will take a look at your simulated speaker.  I'm just in this for the fun of it.  Thanks
Danny,


If you don't know the driver response, and acoustic offsets you can't possibly be talking about crossover typologies yet.


You really are a lot further than you think.  May I strongly suggest, try your hand with the simulated speaker I posted. See if you can make it work. If you start a thread on DIYaudio let me know and I'll jump in and discuss.


The simulated speaker is free, and you will learn a great deal quickly.


Best,

Erik
erik_squires
You always respond well to my posts and I appreciate it.  I will post on diy as you suggested.  I am certainly just experimenting as that is how I learn best.  I think a standard 1st order crossover will work well in this situation as I have selected drivers (mostly Dayton stuff) that will work together but I have to get them in the box first and send some pink noise through them to see what happens in the box so I can better design the crossover.  
A first order crossover on the low and mid drivers will start and stop both of them at the same time. Because of that, if they are different sizes (depth) and mounted flush on a 90 degree vertical baffle, the sound of each driver will arrive at your ears at a different time, creating more of phase shift problem. First order xovers look deceptively simple; but just take a look at Jim Thiel’s designs where he has about three dozen components for a first order three-way. Anything but simple.
Hey, diyaudio.com is probably a better place for this question.


The poles are picked based on the electroacousutic blending. You can't just willy-nilly pick new ones without being able to simulate the whole speaker. Also, asymmetric filters are pretty normal.


The only time I might suggest you should consider more aggressive slopes are usually to protect a driver, especially the tweeter.


It sounds like you are not nearly ready to start this, but I encourage you to go on your path. If you'd like, I posted all the simulation files for a speaker online.  Why don't you try your hand at it? You can remove all the parts and compare to the reference design when you are done.


https://speakermakersjourney.blogspot.com/2016/02/the-lm-1-bookshelf-version.html