The "latest and greatest" commercial open baffle speakers by MACO have a version made from solid granite. I can't imagine the shipping cost on those! Haha! So your soapstone experience, IMHO, makes total sense from a non-resonant construction point of view. Go for it and report back!
Acora (?) makes there speaker boxes out of local Canadian granite. Can’t imagine the cost of shipping.
dave
dave
Is it possible to replace the 20mh iron core inductor with an air core?
For me, it's easy to wind this inductor, it would cost me something around 20 dollars.
Getting this recommended inductor is much more difficult and much more expensive, for me.
tks
For me, it's easy to wind this inductor, it would cost me something around 20 dollars.
Getting this recommended inductor is much more difficult and much more expensive, for me.
tks
Pano, I noticed a difference in Vifa polarity from the original Manzanila 15 (post #455) to the latest version (post #2502). I noticed the same with the Manzi 12, and those have the same component values as the original. Why is the polarity now reversed in the Vifa?
Well, I finished up a test build of the later 15"/GRS version (the one with the 80Hz "crossover" for the woofer) and had a brief listening session this afternoon. First impression is that the bass reaches quite low. Seriously. NO SHORTAGE of bass unless you listen to organ music. Even then... The bass isn't quite as tight as I'd like but it's not bad at all. Especially at the price. And...that's with wings that are smaller than they should. It only has the rear wings (no front extensions yet) and they are probably 2.5" or so deep.
I also used the Fountek FE85s that I had on hand which seem to me reasonably close to the Peerless, albeit a little more sensitive. They need padding, although perhaps not the full 8R, but that may be because the bass isn't as strong as it should be given the wings (overall sensitivity is fairly low too, again perhaps due to the wings and "tweeter/fullrange" padding). I'm using the bass trap for the tweeter but not one for the woofer. Using an 8R L-pad as a trimmer for tweeter output (to find the sweet spot) and a 16R L-pad for the bass trap. The high end seems decent but it's hard to tell because...
There seems to be a pretty big upper bass/midrange hole. And for anyone who was reading carefully, I decided against the 70Hz low pass unit I have and am using the 80Hz unit. I haven't done a sweep and don't have the ability to measure the frequency response, so it's hard to be certain. In general the sound is impressive but has an odd quality that led me to think of the midrange hole. I'm going to try to at least do a frequency sweep to see if I can hear anything off.
I'd gladly hear any ideas about the midrange. The Fountek is the big difference, of course, so maybe there's something going on with that but it's rolloff seems slower than the Peerless, so I'd think it would. fill in even better. Despite all that I'm quite impressed by the sound from this inexpensive OB. If anyone were squeamish about the bass response, I wouldn't imagine you'd be disappointed. It's really surprising to me how strong it is. But...in its current form, it isn't likely to work on my 2wpc tube SE amp...
Photos at some point.
I also used the Fountek FE85s that I had on hand which seem to me reasonably close to the Peerless, albeit a little more sensitive. They need padding, although perhaps not the full 8R, but that may be because the bass isn't as strong as it should be given the wings (overall sensitivity is fairly low too, again perhaps due to the wings and "tweeter/fullrange" padding). I'm using the bass trap for the tweeter but not one for the woofer. Using an 8R L-pad as a trimmer for tweeter output (to find the sweet spot) and a 16R L-pad for the bass trap. The high end seems decent but it's hard to tell because...
There seems to be a pretty big upper bass/midrange hole. And for anyone who was reading carefully, I decided against the 70Hz low pass unit I have and am using the 80Hz unit. I haven't done a sweep and don't have the ability to measure the frequency response, so it's hard to be certain. In general the sound is impressive but has an odd quality that led me to think of the midrange hole. I'm going to try to at least do a frequency sweep to see if I can hear anything off.
I'd gladly hear any ideas about the midrange. The Fountek is the big difference, of course, so maybe there's something going on with that but it's rolloff seems slower than the Peerless, so I'd think it would. fill in even better. Despite all that I'm quite impressed by the sound from this inexpensive OB. If anyone were squeamish about the bass response, I wouldn't imagine you'd be disappointed. It's really surprising to me how strong it is. But...in its current form, it isn't likely to work on my 2wpc tube SE amp...
Photos at some point.
So regarding the mid hole, part of me wonders about the crossover. The cap value with the tweeter seems to put the "tweeter" cutoff kinda high...3k maybe? Combined with an 80Hz low pass point, that seems like a BIG gap. I know it's not that simple, and I recall reading somewhere in this thread that there's a reason for this and that it works, but I can't find it. Any thoughts or comments? If I can fix the problem area (what I'm calling a hole), this thing has pretty huge potential...
A search of this thread using the terms crossover and frequency will help.
Best I can tell from the posts the crossover frequency is somewhere between 700 and 800 hz. It's deceptive because open baffle crossovers aren't the same as the crossovers in boxes.
Here's a good explanation of the woofer inductor trick. Keep in mind that this post was back when the Manzi was using the original tweeter and the crossover was different than it is on the current build. But the concepts of how to make open baffle bass sound right are the same.
https://www.diyaudio.com/community/threads/fast-fun-inexpensive-ob-project.110583/post-2181408
Best I can tell from the posts the crossover frequency is somewhere between 700 and 800 hz. It's deceptive because open baffle crossovers aren't the same as the crossovers in boxes.
Here's a good explanation of the woofer inductor trick. Keep in mind that this post was back when the Manzi was using the original tweeter and the crossover was different than it is on the current build. But the concepts of how to make open baffle bass sound right are the same.
https://www.diyaudio.com/community/threads/fast-fun-inexpensive-ob-project.110583/post-2181408
Thanks Barryso. I've been dealing with loss in my family so hard to get much done right now. I'm going to play with bigger caps for the "tweeter" and see if I can fill in that hole. May try some other things, but that link makes me realize it isn't simple. Hoping to use this to expand my understanding of crossovers and OBs.
Hi Carlp,
Condolences on your loss. Hope things ease up soon.
Here's Pano's explanation of how the crossover works. He put the link into the 1st post of this thread so it's easy to find. Hope it helps.
https://www.diyaudio.com/community/threads/fast-fun-inexpensive-ob-project.110583/post-4573958
Barry
Condolences on your loss. Hope things ease up soon.
Here's Pano's explanation of how the crossover works. He put the link into the 1st post of this thread so it's easy to find. Hope it helps.
https://www.diyaudio.com/community/threads/fast-fun-inexpensive-ob-project.110583/post-4573958
Barry
Hi Carlp,
Hope things are going better now.
I didn't pay enough attention to your post the first time it was posted and didn't realize you were building the "new" version of the Manzi. Very cool.
As for bass, if you don't have the front wing installed it's not going to have the correct bass response and that will likely be an issue with the mids, too.
This likely adds to the bass issues. John would sweat the details on his designs so it's worth getting them close to spec.
Try adding some cardboard to add wings to the front and maybe extend them on the rear. Be curious as to how they sound after doing that.
Let us know how you make out.
Barry
Thx Barry. I will get back to them before too long I hope, and try out cardboard or even adding wood to the fronts and add to the rear of the wings. I know I can't expect performance as it was designed if I don't build it as designed... ;-D. I will definitely work on them more, and may well purchase the correct "tweeters" once my budget frees up a bit. That's part of the problem too. Even if I add more to the wings, I may not get the response the exact design gets. It's just the FE85s look so similar to the design tweeters. I was quite astounded at the bass response in any case, much more than most people would expect from an OB, which gives me hope it will eventually perform quite well. And if it does, I'll be building a much more classy baffle.