No.4

I spent a good portion of the day updating and cleaning up my neglected laptop for this project. It was originally purchased to exclusively run REW, but I have not needed it for a while. Anyways, it is fresh, and now has the MiniDSP 2x4 HD software downloaded and ready to go. When I will actually receive my DSP unit is a whole other question. I did a little reading on the MiniDSP site that answered many of my questions and made this project a little less intimidating. the user manual https://www.minidsp.com/images/documents/miniDSP 2x4 HD User Manual.pdf is very straightforward. If you are thinking about this project but having reservations read through this manual. then read this https://www.minidsp.com/applications/digital-crossovers/minidsp-2x4hd-application/283-2x4-hd-twoway I am very excited about the potential of this project and the doorway into active crossovers. I don't want to get ahead of myself, but, I can already see this opening up unlimited potential for future projects that would normally have been limited by passive crossovers.

My current listening space is treated with ultra touch and roxul panels, so I should be good there. I do not however have the dsp yet. I was hoping to do some measurements with the heils alone but I may have to wait until it arrives. ESS is still in business. You can order the heils from them directly. http://esslabsusa.com/heil-amt/

I was able to cut and glue some wing pieces today. They are not beautiful, but they should be fine for experimenting. I cut these to the same 7 1/4” width that Rudy81 used. This should give me a baseline to expand (or not) upon. I have a spare receiver I can use with my lap top to get some measurements with REW. @Chris A what is the ideal environment to take these measurements? Should I do them out in the room away from any boundaries, or would it be best to measure in room, in the corner, due to the dipole nature of these driver? if I can work out the details of how best to measure this setup, I should be able to start expanding on the wings etc. pretty quickly. good times!

@Delicious2 I like your idea about extending the “wings” I am planning on building a test rig using the same setup as @Rudy81 to start with and get baseline measurements. The next step will be to extend the wings like you are planning. I am also considering making the initial wing on a pivot so I can experiment with the angle of the wings. Like I said previously I have plenty of sacrificial wood to use. I may try a curve as well if time allows. Hopefully this weekend I will have the initial rig cut. I placed the wood on the table saw last night...it’s a slow process.

Panasonic is a huge company that provides all type of components to manufactures worldwide. I would be surprised if every forum user did not own at least one item that has a Panasonic component in it.

@Rudy81 I have a huge stock of wood to use, so I may just do that. I will be using la Scala bass bins, so I will have to decide where I will set the heil on top (distance from diaphragm/ribbon to the front of the cab). That may dictate part of that length as well, unless extending them past the front of the cab has benefit. @Chris A any suggestions there? Directly over the woofers motor? Anyways, Rudy when you tested yours did you just hook the heils up to your amp and start your sweep at 400hz, or were you using the dsp? Did you test in room? I have REW and a mic, but I have not used it in awhile. It will be good to use it again, but I may need some guidance from Chris.

@Rudy81 how did you come up with 7 1/4” width for the wings? Have you tried any other widths?

@Chris A Thanks for the explanation Chris! Great info as usual. I have two amp projects in the cue but I may have to slide this project ahead of them. I have been dying to build something around the Heil, but I only bought one pair while they were initially on sale. I guess I’m off to order another pair!

I’m sorry wasn’t more specific. I would be ditching the passive crossover for this project. My worry is the loss of sound pressure and volume if I lost some of the efficiency of a 104 dB system. Or Am I missing something? Does the DSP account for this to “push” the AMTs closer to the bass bin, or is the bass bin attenuated to the AMTs?

forgive me if I missed the details in one of the previous posts but, I am assuming the two heils are wired in series to result in an 8 ohm measurement. With that said the drivers are rated at 96 dB 1W/1M. Does wiring these in series have any cumulative increase in the sensitivity of the driver? I ask because I am a tube amp user and probably won’t see much more than 5-9 watts. I read through a long thread on Diya about, this but every post seamed to contradict the previous. My diy la Scala should be around 104db, so I really don’t want to lose too much sensitivity.

Speaker hauler

I like em.

I know there is at least one very good thread on diy audio about waveguide design for AMTs. a member there did some experimentation with a design similar to what @Rudy81 has done. I will try to dig up a link. Another thing to think about is, the original ESS AMT 1s, rock monitors etc. had the AMT on top of the speaker towards the front. The sides and front allowed the sound to exit, but the top and back were a solid panel. Given the dipole nature of the driver the back wave would be reflected inside the enclosure and exit the side. Has anyone thought about positioning the AMT somewhat on front of a large horn instead of positioning it at the throat like a conventional compression driver. In essence using the horn to reflect the back wave? edit: I believe the backs of the top area of the ESS speakers was open. The top is a solid panel though. I will have to check mine when I am home. I do still wonder if there is something though to controlling the back wave and making a “waveguide” that is a fixed shape and distance from the AMT.

Looks fine to me. 😎All jokes aside, is there available volume inside that opening, outside of where the speaker is occupying ?

I have been wanting to build a pair of speakers around the GPA 604s for awhile. Just have not found the right deal on drivers. Yours look awesome! I would really like to hear your impressions on the comparison between them and the khorns.

That is just super cool. Great work!

Many hobbies result in finished projects that have more value than the sum of the components involved. Skilled execution has value, especially because not everyone possesses said skills.

@Thaddeus Smith @Khornukopia Better?

Ok, I will see if I can fix it.

@Khornukopia I don’t think so?

The time has come to have my annual meeting with my insurance agent. I have my home owners and all of our vehicles with the same company as the savings are significant. During this meeting the request to catalog the contents of our home will undoubtedly come up. Assigning a value to these contents for the most part is fairly straight forward as most are common consumer goods. However, the topic of my DIY stereo system has been a grey area in previous conversations with my agent. I can calculate the value of the individual purchased components, but how do I value the finished product. Certainly, time and skill need to be calculated in the total value of these items. Unfortunately, due to fact that I am a hoarder of my own creations I have never sold any of my DIY items. One suggestion my agent had was to have someone appraise the value of these items. I would assume that someone involved in similar cottage industry with a history of sales would suffice, but I don’t know for sure. Have any of you ever encountered this situation? I would think heavily modified components would also fall into this category to some extent as well. Let me know your thoughts.

Nope, me too.

Thank you, I am the fourth so i am legally attached to it. The kitchen in my house stores several types of beer, bourbon, wine and many delicious foods that are prepared on a daily basis. My family gravitates around this space in our home. The home in the video really is very cool, however, the kitchen should have been the pearl of that great space. my wife and I do grill regularly too, so a good outdoor space is important too. There are many days the grill and the kitchen are operating in tandem. Music in these spaces is an important element. I need to work on my outdoor system!

Super cool conversion, tons of great spaces and room. Plenty of space for a dedicated listening room somewhere in there. But the kitchen?

A bourbon/whiskey thread, interesting. In the tech mod section at that. Is that the common denominator? Bulleit is what really turned me on to bourbon about ten years ago. For the price, delicious. Rye began as my favorite, however I bounce back and forth now. I have always enjoyed wine and beer, but a good bourbon goes a long way with complex flavors. While this his thread was fledgling I was still working outside tonite, and enjoying a few glasses of makers 46, with one ice cube. Glad to see I wasn’t the only one.