[JustPlainNuts]

[JustPlainNuts]

[KTS]

Looks awesome! You have put a lot of thought and sweat equity into those bad boys! Well done.

[JustPlainNuts]

Here are my initial gated measurements. I am using REW and have the gate at .002 seconds. The mic is 1 meter away. This is my first time taking speaker measurements so I am wide open to suggestions and pointers.

This is just the two NQ midrange drivers.

[JustPlainNuts]

Waterfall for the NQ midrange drivers:

[JustPlainNuts]

This is the Tweeter's response:

[JustPlainNuts]

And here is the tweeter's waterfall response:

[JustPlainNuts]

Here is the tweeter and the midrange response together. They seem to be pretty evenly matched in output. I am thinking 1800Hz would be a good crossover point for these. Does anyone else have input on the crossover point for the tweeter and midrange?

[Danny Richie]

I would highly recommend sending or bringing in one of the speakers for a crossover design.

[JustPlainNuts]

Danny, I said at the beginning of this thread, I would have never attempted to design and build my own speaker had I not discovered GR-Research and your YouTube videos. The Audio Circles community is awesome also! I have nothing but appreciation for you sharing your knowledge with the DIY community and especially your offer to design the crossover for the speaker I am building, but I am asking you for one thing. Let me fail. I know you see things, issues, problems with this design way before I see them. Let me figure them out.

My friends and family think I am insane to deviate from your designs, but in my mind where’s the fun and how can one learn if they don’t experiment and shake things up. However, if I wreck the car or wind up in crossover design purgatory, I’ll ask you for help. You have provided me with the knowledge base and you are the reason why I am here and doing this. Thank you!

[Early B.]

You're just plain nuts!

[KTS]

Every time I see this picture, it makes me think Bruce Wayne is building speakers! I love the look!

[Danny Richie]

I have nothing but appreciation for you sharing your knowledge with the DIY community and especially your offer to design the crossover for the speaker I am building, but I am asking you for one thing. Let me fail. I know you see things, issues, problems with this design way before I see them. Let me figure them out.

Got it.

I am going to give you a few helpful hints though that might make things real easy, or at least a lot easier.

Moving the mids forward of the woofers is going to make getting the phase (time arrival) adjusted pretty tricky. It would actually be easier if the outer woofers were forward 6" or more to the mids. It gets harder when you go the other way.

So, there is a simple fix.

Because the M165NQ woofers will easily play down into the 120Hz to 150Hz range that opens them up to an easy solution.

Power the outer woofers with a separate subwoofer plate amp with adjustable phase and crossover point. Then you can easily dial in the phase and amplitude to balance everything out. Flexibility is good to have.

Then you can just work on the crossover from the mids to the tweeter. That should actually be real easy. Those drivers are really well behaved.

[Danny Richie]

Oh, and it looks really cool!

[JustPlainNuts]

Thank you Danny. I thought about the distance difference with the woofers and the mids, but kept telling myself the wave lengths are so long below 200hz it shouldn't be an issue. Adding a plate amp would be a punt of last resort for me. I'd like to see if I can make it work without that if at all possible. Another idea might be to add the same rounded bezel for each of the woofers. If I did this, would you keep all the drivers at the same distance or would it be better to extend the woofers out 6" like you mentioned?

Right now I am using the same crossover on the tweeter as the X-Statics and I think the tweeter's response looks good. The midrange I had to play with a good bit. I kept moving the inductor and capacitor values up to get rid of a hump at 3.5K and a dip at 5.5k. I have 4mH coil and a 30uF cap on the mids in the measurement below. The tweeter by itself was smooth but when I added the midrange I got the peek and dip. Lowering the crossover point on the mid helped tame these.

The issue I have at this point is a huge hump at about 240hz. I don't really know what is causing that. Thoughts? This is just the mids and tweeter with no woofers yet.
 

 

[JustPlainNuts]

I think the crazy peak at 240hz might be a room harmonic. I am using a 0.002 second gated measurement and the mic is one meter out from the speaker, but my ceilings in my basement are only 85 inches. I did some math and 85 inches equates to a 79.8Hz axial mode and the second harmonic of this is 239.5Hz. Tomorrow, I'll take the speaker outside and measure it out there to see if this changes...

[JustPlainNuts]

So I figured out what was causing the huge peak at 240Hz. I watched Danny's video on Open Baffle Basics 3 over and over yesterday and looked at his various measurements with the different length wings and decided my short wing was way too long and that was what was causing the peak. My short wing was 3.5" long but because of the thick front baffle I have on my speaker it actually added another 1.5" to the length of the wing for a total of 5".

I really did not want to take the finished speaker back out to my work area and start cutting and routering things again with the mess and the dust it would generate, but... I did. Below is the pictures of the carnage in modifying the short wing. I cut the wing down to 1/2", rounded it with the router and sanded everything before repainting the speaker. The wing is now 1/2" + the 1.5" deep bezel = 2 inches deep.

[JustPlainNuts]

I took measurements again once I had the drivers installed again. I ran the measures just on the midrange and the 240Hz peak was gone! I played with the midrange crossover some more and went back to a 3mH coil and 15uF cap for the lowpass. There is still some waviness at the bottom end of the midrange's response, but overall much improved from what I had before with the longer wing. The measurement below is the midrange and tweeter together. I am very happy with the tweeter's response. The response of both sets of drivers together are super flat from 600Hz up. I am very happy with that! I have some ideas on how to flatten the bottom end of the midrange a little and still working on the high-pass for the midrange and the crossover for the woofers. See below where I am so far with the response:

[Danny Richie]

Wing lengths are tricky. That is why are often make wings out of Styrofoam and test and measure lots of wing lengths to see what is most ideal for each application.