M,
It's slow. Accumulating parts and the person that is building the cabs was swamped and is now on vacation.🙁
Will shoot a pic when I have something to show.
Also been working on Muses for my Salas pre.
Thanks,
Don
It's slow. Accumulating parts and the person that is building the cabs was swamped and is now on vacation.🙁
Will shoot a pic when I have something to show.
Also been working on Muses for my Salas pre.
Thanks,
Don
post #100,
The Volts arrived at Solen yesterday and the cabinet guy is back and set up the cuts from the drawings I sent. Had to learn Sketchup for that.🙁
Not huge progress but the commitment is getting bigger.😀
Enjoy the pause because I am sure there will be questions.😱
Can hardly wait to get started on the physical build.
Don
The Volts arrived at Solen yesterday and the cabinet guy is back and set up the cuts from the drawings I sent. Had to learn Sketchup for that.🙁
Not huge progress but the commitment is getting bigger.😀
Enjoy the pause because I am sure there will be questions.😱
Can hardly wait to get started on the physical build.
Don
parts and questions
Attached is my first pic of the tower project. The volts have arrived. Cabs are coming. Working on parts.
My first question, related to post #84 and #98, it looks like 2 - 4" ports 90mm long for best bass extension. I can cut to different length and am asking if that is a good place to start.
Next question is the xover caps. Mcaps are about 4 times as much as Ecaps for the Mundorf indicated on the parts list. And, for Ct3 and Ct4 there are two different solutions for the same value. One uses an Mcap and one doesn't. Why have both? When and why is the Mcap necessary. I want best sound not just save money but I don't understand why.
Thanks,
Don
Attached is my first pic of the tower project. The volts have arrived. Cabs are coming. Working on parts.
My first question, related to post #84 and #98, it looks like 2 - 4" ports 90mm long for best bass extension. I can cut to different length and am asking if that is a good place to start.
Next question is the xover caps. Mcaps are about 4 times as much as Ecaps for the Mundorf indicated on the parts list. And, for Ct3 and Ct4 there are two different solutions for the same value. One uses an Mcap and one doesn't. Why have both? When and why is the Mcap necessary. I want best sound not just save money but I don't understand why.
Thanks,
Don
Attachments
Just start with the ports a bit longer than what the models suggest and then cut them until you like what you hear. You might also get some spare ports to you can experiment with different lengths by direct comparison.
Do you have the means to measure impedance curves? That would allow you to check / confirm the bass-reflex tuning predicted by the models.
The Ecaps are electrolytics, whereas the Mcaps are metalized film/foils. The more expensive Mcaps are closer to an "theoretical / ideal" capacitor, and will sound better. That's why I suggested the Mcaps where they are relevant for what you hear. The impedance compensation (CT4 / Ecap) is mostly outside the pass-band of the tweeter filter, so this cap will no affect the sound very much. This is why I suggested the cheaper Ecap. You could also use an Mcap for CT4, but I would be surprised if you could hear a difference.
Also, when ordering the xover parts, consider LM2 = 0.39 mH instead of 0.33 mH. I mentioned the LM2 change in the main thread, and I like what I hear so far.
Thanks, M
I understand all the answers and will adjust Lm2.
I do not know how to measure the impedance curves but can probably learn it. For now though I will focus on the build and do that as part of the fine tune. Extra ports will be on order. Lots of details to get right for this to be the build it deserves.
Getting excited. I think I was a little overwhelmed in the very beginning.
Thank you, and Kaffiman and Paul and others for making this happen.
Don
I understand all the answers and will adjust Lm2.
I do not know how to measure the impedance curves but can probably learn it. For now though I will focus on the build and do that as part of the fine tune. Extra ports will be on order. Lots of details to get right for this to be the build it deserves.
Getting excited. I think I was a little overwhelmed in the very beginning.
Thank you, and Kaffiman and Paul and others for making this happen.
Don
Don
A port length of 90 mm using two 4 inch ports and tuning at 38 Hz is not correct.
Using two ports with a diameter of 4 inch and tuning at 38 Hz in a 101 L cabinet volume, the port length has to be 24 cm.
Matthias can you check also please, it has been a while...
Unfortunately I can't check right now, because the Windoze virtual machine stopped working, so I can't run Vituix.
However, take look at the model run in post #83 with a single port with 14.3 cm diameter. That's pretty much equivalent to two 4" ports. The length in the #83 model is 16 cm, so it's indeed a bit longer.
I did double check in Vituix: for two 4 inch ports, VB = 101 L and FB = 38 Hz --> port length = 24 cm.
Port lengths mentioned in post #83 are meant for a higher fB value.
Port lengths mentioned in post #83 are meant for a higher fB value.
update
Attached are pics of the xover resistors and caps. And the CNC cuts for the speaker cabs.
The inductors are still in Estonia and the speakers are in Kansas waiting for the CNC spindle to be repaired so the bass driver flush cut can be made. It will be more accurate than I could get it. I will do the small ones. In the mean time, I am working away on the resin/bento SP-10 plinth (also pic attached). Not to go off topic but both are big upgrade projects.
I will start posting again when I get the cabinets.
Don
Attached are pics of the xover resistors and caps. And the CNC cuts for the speaker cabs.
The inductors are still in Estonia and the speakers are in Kansas waiting for the CNC spindle to be repaired so the bass driver flush cut can be made. It will be more accurate than I could get it. I will do the small ones. In the mean time, I am working away on the resin/bento SP-10 plinth (also pic attached). Not to go off topic but both are big upgrade projects.
I will start posting again when I get the cabinets.
Don
Attachments
Good stuff.
I'm not that often in the Multiway section anymore, but I do check in from time to time
As long as you got the port cutouts, Matthias is spot on regarding keeping the ports long until you've checked things properly. 24cm sounds about right just going through it in my head.
Where did you end up placing the ports?
I'm not that often in the Multiway section anymore, but I do check in from time to time
As long as you got the port cutouts, Matthias is spot on regarding keeping the ports long until you've checked things properly. 24cm sounds about right just going through it in my head.
Where did you end up placing the ports?
K, good question. I think Mathias suggested at the vertical mid point of the volume and I was going to ask about separation. Thinking divide the space width wise at 1/3, 1/3, 1/3. 2 - 4 in ports 24cm long.I am placing them so now would be a good time to make a decision. Thanks for checking in.
Don
Don
No worries, I've hardly done a thing here. Just a few nudges.
Here's one for testing:
Carnival Blues by Urbandawn | Free Listening on SoundCloud
Here's one for testing:
Carnival Blues by Urbandawn | Free Listening on SoundCloud
Hi,
I'm also interested in a floorstanding version of the OSMC. One reason is that I do not want a separate box for the crossover and the second reason is to get some more bass extension.
It has been quite a while since some updates on this project was posted, is it on-hold for now?
/Dominic
I'm also interested in a floorstanding version of the OSMC. One reason is that I do not want a separate box for the crossover and the second reason is to get some more bass extension.
It has been quite a while since some updates on this project was posted, is it on-hold for now?
/Dominic
I don't think there's anything that would stop you from building the OSMC in a bigger box. Just do it! 😀