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Ok, I'll go back to round. :B
-Dennis
-Dennis
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Exocer, I think you are right, I hadn't noticed that before.
-DennisComment
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Ahhh.. wellerrr.. they-had-complications! :Pbut I definitely thought it had 34mm one-way linear excursion.
When Father Thomas speaks, you better listen. :T glad we got that squared away.Ok, I'll go back to round.
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Port mouth. If he is referring to an external wall of the port being 1" behind a driver motor, I supspect that would be ok if the vent is no more than 1" diameter, though I'd personally leave more clearance than that. If you are going to build such a beast, overkill every aspect you possibly can.OK I see what maybe the issue is. Steve are you speaking of the port wall or the bottom mouth of the port?..or maybe both
Agreed ;x(When Father Thomas speaks, you better listenComment
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Okay, here is where I was on the round version...
-DennisAttached FilesComment
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The 1" venting clearance is for the pole of the driver insider the box not the port. That is only really necessary when you are dealing with extremely tight conditions.
The 34mm xmax was too high relative to the very linear lms4k. There is no standard for xmax so I'm trying to keep it at least consistent from driver to driver. I hope you can appreciate that, if not, just know that we are doing our best to be as honest as possible. I think what we are going to do is stop disclosing xmax all together and simply provide the gap height and coil winding height along with dynamic high signal measurements of the Bl curve and compliance curve. That should be far more relevant that a silly number that no one can agree one in the first place.
Also our forums were hacked but we have a backup from only the day before. I have to take up security issues with Invision. I'm not too happy. I should have them back up tomorrow when I return from vacation. Why do they always hack us when I leave!!
-Kyle
-TCSKyle
TC SoundsComment
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Yeah, but don't all the computer modeling programs we use (Unibox, WinISD) require Xmax?Originally posted by RemotiaComment
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I definitely agree that this will be helpful. We would be able to determine Xmax on our own from the Bl curve and see how linear the motors perform. Would you guys think about including Cms, as well as Le curves? That would be awesome. ThanksOriginally posted by RemotiaComment
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Sure, but what is it? Many of the higher end programs don't call for it, but rather the gap height and coil height in the first place.Originally posted by ---k---
If we do change our convention, we will post information pertaining to how to
calculate various xmax standards.
Good question.Kyle
TC SoundsComment
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Will Le, Cms curves be included as well?Comment
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So...does the cylindrical port version of the design (on the previous page) look ok to you guys?
-DennisComment
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I like that idea, as well. If only more manufacturers were more willing to provide us with such information....I definitely agree that this will be helpful. We would be able to determine Xmax on our own from the Bl curve and see how linear the motors perform. Would you guys think about including Cms, as well as Le curves? That would be awesome. ThanksComment
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Enough monkeying around- today I ordered the 2 drivers from soundsplinter, they are in stock, and I could receive them before the weekend (crosses fingers). Not that it matters since I have no cabinet or amp yet, but since the whole design is based on those drivers at this point, I figured I'd better get them and get it done with. :T
-DennisComment
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Yes, get some momemtum going. The design is sound - take it from a plan on paper to the real thing. I'd stick with the 10" cylinder port.Enough monkeying around- today I ordered the 2 drivers from soundsplinter, they are in stock, and I could receive them before the weekend (crosses fingers). Not that it matters since I have no cabinet or amp yet, but since the whole design is based on those drivers at this point, I figured I'd better get them and get it done withComment
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Drivers are in transit, and due to be delivered tomorrow in time for the weekend! Woohoo!
You are right Steve, I'm sticking with the 10" cylinder port, it should end up at 36" long per the last design I had drawn up.
-DennisComment
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Man, I have bought a lot of stuff I've always wanted in the last few days... :B
-Dewalt 621 Router
-Grizzly 10" Table Saw
-2 Buttkicker Amps
The 2 SS drivers arrived a couple of weeks ago and just sitting in the box just waiting to be used!
I built 3 flexy racks for all the equipment at the front of my room, and I'm finally going to level the shelves and put them in place this weekend, then I have the space set aside next to them for the subwoofer.
And it looks like I'll be building it my damn self, since none of my cabinet maker sources/ friends of the family, etc. have come through for me. :T
So, more info. to come, but first I have to get that table saw assembled- will hopefully get it before the end of the week so I can take care of that over the weekend.
I bought a 48" long piece of Sonotube from my local HD, but here's a strange thing- when I actually measure the inside diameter of the tube, it's a little bit more than 10"- more like 10-3/8", and the walls are pretty much exactly 1/8" thick. Will this slightly larger diameter make any difference in the tuning of the sub??
Also, when I finalized the design- the port turned out to be about 37.5" long, but when I plugged the numbers into Unibox, it actually wanted an even longer port for the 15HZ tune (more like 38.5" if I remember correctly). Anyone feel like double checking my numbers for me? ;x(
Box volume is 617L total, 517L after bracing, port, etc.
-DennisComment
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Cool! New toys :TDanishComment
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If you want to reach a simulated tune of 15hz without exceeding 36" of port length (which I count seperate from flares), you will need to go bigger than 517 effective liters. However, if you want the real world tune to come in ~15hz, 36" long port with flares on both ends will probably do the trick. I modeled my sub with a 14.7hz tune and ended up with a 13.5hz tune. Steve's was modeled with a 16.2hz tune and he ended up with a tune below 15hz. I wouldn't worry about it too much.
With the ID coming in at 10 and 3/8", that certainly doesn't help in this regard, but's fine. You have two options. You can be a bit of a guinea pig and try using a port longer than 36" to see if the first port resonance causes any issues, or you can increase enclosure size. The first scenario seems more likely. I guess I would try 40"?Comment
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I think I will return to HD and trade the tube in for one of the other 10" ones- as I recall, they seem to be labeled at a certain size, but with slight variations. I should have been clued in when I saw 2 tubes both marked 10" but with one inside the other. :P
The way the design is right now, I end up with 36.1" long port, plus 3/4" rounded flares on each end, so 37.6" total. It sounds like if I go to a *true* 10" diameter tube, this should work perfectly, correct?
Other than that question, everything else is a go on the sub. I even received the amps just today (went with 2 Buttkickers, so I guess I'm sort of a guinea pig in one respect already).
I'm waiting for the table saw to be delivered, then I have to assemble the thing, so there's a few more things to do, but I think my target of showing off the finished sub in time for Thanksgiving is still plausible.
-DennisComment
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:B Actually, I'd aim to pick up one of the smallest ones. A 10" port for this design gives you lots of leeway in regards to compression and chuffing limits even at full power, so if you can find one that's maybe 9-10" ID, you'd still be well in the clear.I should have been clued in when I saw 2 tubes both marked 10" but with one inside the other.Comment
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Yeah, good call, a little less than 10" will work ok I think. I'll stop at HD tonight and see what they have left...
-DennisComment
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Success! I found sonotube labeled 10" that is actually 9-7/8" diameter, so that should work perfectly! I also finished installing the 3 flexy racks at the front of the room, and the space is cleared out for the sub now.
Table saw arrived today via freight, so when I get home I'll check it out and assemble during the week. I should be able to start cutting the panels out this weekend if all goes well!! Yippee!!
-DennisComment
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