AudioCircle
Industry Circles => GR Research => Topic started by: JustPlainNuts on 12 Feb 2024, 10:29 pm
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So, it’s been a journey. I discovered Danny and Gr-Research a few years ago and thanks to his tutelage via his YouTube videos, email exchanges and a phone call have brought be up to a whole new level of understanding in speaker design and audio reproduction. I have been studying audio since high school in the 80’s and the learning never stops. Thank you, Danny, for sharing your knowledge.
I’ve built several of Danny’s designs such as the X-LS Encores and the Encore Center speakers. I’ve used the flat packs and took some liberty on the Encore designs for a custom project as well.
I am a hobbyist and like branching out and experimenting with audio, so I have decided to take some liberties with Danny’s X-Statik design. First, I want to double the amount of low frequency drivers so that there will be two of the M-165-16’s in a sealed enclosure at the bottom of the speaker and two more above the MTM drivers in a sealed enclosure also. For stability, the sides of each speaker will be very similar to the NX-Tremes in that the inside side of the speaker will be a solid piece of MDF and the outside side of the speaker will be open for the MTM section of the speaker but sealed for the low frequency drivers. I hope this all makes sense.
Next, I will replace the M-165-16 drivers in the MTM section with the M165NQ/16 drivers. The tweeter will remain the T26SG driver. I will measure the responses and build a new crossover for the speaker. The speaker should be around 80 inches tall in total. My hopes are to increase the overall sensitivity of the speaker and I am hoping to lose the resisters on the tweeter. I feel like the MTM section and the low frequency sections will be very closely matched in sensitivity and doubling up on the woofers will help compensate for baffle step loss.
I am calling this new speaker the X-TC. I am open to anyone’s constructive criticism, feedback or suggestions.
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It sounds doable.
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Oh cool! As a fellow X-statik owner, I will watch this with great interest. Don't forget the pictures :wink:.
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Wow! Love the positive vibes!
I turned a major corner today on my custom speaker project. I finished the 3 speaker pods that will house the midrange-tweeter-midrange (MTM) speakers in a "D'appolito" configuration. My hope is the rounded edges of the pods will minimize and randomize sound wave diffraction from the front of the speaker baffle. They have the side benefit of looking cool too. The drivers' outside edge will end where the rounded
(https://www.audiocircle.com/image.php?id=261499)
taper begins.
It only took me about a dozen attempts and a few sheets of MDF to get this right. I am not a woodworker and I do not have the best equipment, the workshop or experience to get this project right. But I have the will to power through it all in order to build an awesome set of speakers.
These 3 pods are for the front left-center-right (LCR) speakers for me and my wife's custom home theater build coming soon.
The MTM pod build includes two 3/4" pieces of MDF glued together and a 1.5 inch rounded router bit used to round off the baffle edges. The router bit I am using is huge at 3" wide and will chew through a board in a heartbeat so it took a whole lotta patience to get these pods done correctly. To be continued...
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Looks cool, and will definitely require a custom crossover.
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Danny, the starting point for me going astray from the original X-statik design was understanding the X-over would be a total new design based on the new response. I have taken what I call a deep dive into X-over design and response management with the X-over. It hasn't been until recently that I feel confident enough to take measurements and design a X-over from the ground up.
My family and friends think I am crazy from deviating from your designs and I know and appreciate that you have spent a lifetime perfecting them, but to me, experimenting, failing and learning is all part of the journey in great sounding audio. And I am wide open to any suggestions from the members of this forum along the way...
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Danny, the starting point for me going astray from the original X-statik design was understanding the X-over would be a total new design based on the new response. I have taken what I call a deep dive into X-over design and response management with the X-over. It hasn't been until recently that I feel confident enough to take measurements and design a X-over from the ground up.
My family and friends think I am crazy from deviating from your designs and I know and appreciate that you have spent a lifetime perfecting them, but to me, experimenting, failing and learning is all part of the journey in great sounding audio. And I am wide open to any suggestions from the members of this forum along the way...
Experimenting and trying things is how you learn.
If it were me though, I would keep the X-Statik as is for a reference and then you have something to compare to.
You can also email or post your response measurements to get feedback on what to change or do next.
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I would like some input from the Forum about internal speaker wire gauge. I ordered some PTFE 16 gauge stranded copper cable, but I feel given the size of this speaker build, it would be better to have 12 gauge as the input wire to the crossover and then 12 gauge to the low frequency drivers on the top and bottom of the speaker. Then I am thinking 14 gauge wire to the mid-range drivers and either 14 gauge or 16 gauge going to the tweeter.
I did a search on the forum and read a couple of threads about this topic, but there was no definitive answer I could find on this topic. Thoughts?
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It really comes down to preference, there's not a big difference between them. In our NX series tower kits we supply 16 gauge for the tweeter mids and 14 gauge for the lower bass drivers.
You can use whatever you prefer.
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Looks cool, and will definitely require a custom crossover.
Danny, the MTM rounded bezel is 10.25" round for each Mid-range and 7" round at the tweeter at the bezel's widest. The bezel is rounded off with a 1.5" rounded router bit making the inside rounded area 7.25" with just enough room to mount the 165NQ drivers and 4" for the tweeter. My idea was to have the bezel round off beginning at the edge of each driver. This rounded off bezel will be mounted on the front of the normal 8.5" front bezel that will be 76" tall and the tweeter will be centered at 38".
My question is do you think this addition bezel will cause more response issues despite the rounded sides than just an 8.5" wide bezel with rounded sides? I love the way the rounded edges looks on this bezel, but I would much rather have better sound than a cool factor. What are your thoughts and anyone else who wants to chime in?
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Made some more progress on the speaker project this weekend. I've been experimenting with the rounded off front speaker bezel and not quite sure how to do the trim work around the woofers...
(https://www.audiocircle.com/image.php?id=261817)
(https://www.audiocircle.com/image.php?id=261814)
(https://www.audiocircle.com/image.php?id=261815)
(https://www.audiocircle.com/image.php?id=261816)
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Very cool! Looking forward to seeing the progress. :popcorn:
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Made some more progress on the X-TC speaker project this weekend. All the work so far has been on the front baffle. Soon to follow are the speaker sides and supports and the speaker as a whole coming together. Stay tuned...
(https://www.audiocircle.com/image.php?id=262213)
(https://www.audiocircle.com/image.php?id=262214)
(https://www.audiocircle.com/image.php?id=262215)
(https://www.audiocircle.com/image.php?id=262217)
(https://www.audiocircle.com/image.php?id=262218)
(https://www.audiocircle.com/image.php?id=262219)
(https://www.audiocircle.com/image.php?id=262220)
(https://www.audiocircle.com/image.php?id=262222)
(https://www.audiocircle.com/image.php?id=262224)
(https://www.audiocircle.com/image.php?id=262225)
(https://www.audiocircle.com/image.php?id=262226)
(https://www.audiocircle.com/image.php?id=262227)
(https://www.audiocircle.com/image.php?id=262229)
(https://www.audiocircle.com/image.php?id=262230)
(https://www.audiocircle.com/image.php?id=262231)
(https://www.audiocircle.com/image.php?id=262232)
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The bevels on the baffle look great! Is that some kind of sandable primer, or what finish are you going with?
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Before you painted them I thought they looked like boobs, lol.
In all black they look pretty mean.
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My best friend keeps calling them boobies as well. Okay, maybe I have some affinity for sexy curves...
I just spray painted these with flat black primer so I could see any blemishes or things I need to fill with wood filler and/or sand with sandpaper. The final finish will be some sort of flat back as these LCRs will be going behind an acoustically transparent screen and I need them to disappear both sonically and visually.
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More progress on the new speakers. I had some PTO I needed to take or lose it so guess what I did all during my long weekend other than fish?
I am very happy with how the speakers are coming together. I am literally making up various parts of the design as I go. New ideas pop up as I make progress. I have a notebook where I write my ideas down and draw pictures. I also plan out the steps for each day I am working on the speaker and write them down so I can think through the process. Here are the latest pictures...
(https://www.audiocircle.com/image.php?id=262972)
(https://www.audiocircle.com/image.php?id=262973)
(https://www.audiocircle.com/image.php?id=262974)
(https://www.audiocircle.com/image.php?id=262975)
(https://www.audiocircle.com/image.php?id=262976)
(https://www.audiocircle.com/image.php?id=262977)
(https://www.audiocircle.com/image.php?id=262978)
(https://www.audiocircle.com/image.php?id=262979)
(https://www.audiocircle.com/image.php?id=262969)
(https://www.audiocircle.com/image.php?id=262970)
(https://www.audiocircle.com/image.php?id=262971)
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Somehow the order of my pictures got all out of whack, but I think one can see the progression once they have seen all the pictures.
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Very cool. Like your outside workshop !!!
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(https://www.audiocircle.com/image.php?id=263362)
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(https://www.audiocircle.com/image.php?id=263363)
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(https://www.audiocircle.com/image.php?id=263364)
(https://www.audiocircle.com/image.php?id=263365)
(https://www.audiocircle.com/image.php?id=263367)
(https://www.audiocircle.com/image.php?id=263367)
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Looks awesome! You have put a lot of thought and sweat equity into those bad boys! Well done.
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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.
(https://www.audiocircle.com/image.php?id=263404)
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Waterfall for the NQ midrange drivers:
(https://www.audiocircle.com/image.php?id=263403)
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This is the Tweeter's response:
(https://www.audiocircle.com/image.php?id=263405)
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And here is the tweeter's waterfall response:
(https://www.audiocircle.com/image.php?id=263406)
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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?
(https://www.audiocircle.com/image.php?id=263407)
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I would highly recommend sending or bringing in one of the speakers for a crossover design.
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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!
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You're just plain nuts!
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(https://www.audiocircle.com/image.php?id=263363)
Every time I see this picture, it makes me think Bruce Wayne is building speakers! I love the look!
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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.
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Oh, and it looks really cool!
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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.
(https://www.audiocircle.com/image.php?id=263548)
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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...
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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.
(https://www.audiocircle.com/image.php?id=263626)
(https://www.audiocircle.com/image.php?id=263627)
(https://www.audiocircle.com/image.php?id=263628)
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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:
(https://www.audiocircle.com/image.php?id=263629)
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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.
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This is a very interesting thread to me, as I too (against all prevailing wisdom), wish to take the x-statik as a starting point and follow my own path. My personal interest is to fuse (some might say bastardise) it with the Brute.
In my working life I am a marine upholsterer and soft materials fabricator, creating luxury yacht interiors for the well-heeled. I want to apply those skills to the creation of something beautiful for myself.
I bought a x-statik kit some time ago but regularly see comments that they are great but need bass support. I have no desire to return to active subs. I neither want two more large boxes in my room or the constant tweaking... so my plan is to pair the x-statik MTM with the 12" acoustinators in seperate closed cabinets.
I am interested to read how you deal with the crossover/measurements issues.