DrWho Posted March 23, 2005 Share Posted March 23, 2005 btw, you want the ports to open up into the same room (your design makes it looks like they open into the adjacent room?). The port is just like another speaker...all it does is take the backwave of the woofer and reverse the phase so that it works in tandem with the active driver. (basically, you're just using both sides of the active driver). Now that I think about it, you can even put the port on the top side as well (pointing up)...it'd make mounting them on a shelf much easier. I think the reason klipsch got away with putting their ports closer to a boundary than is "ideal" is because they spent the extra time to make sure they tuned it correctly. I have no idea where to begin calculating something like this, especially without being able to see the cabinet itself, but I wouls assume the space between the end of the port and the side of the cabinet probably acted as if the port itself was slightly longer...kinda like a longer port with a bend in it. If you're really concerned about keeping the exact same tuning frequency, then you could always install the port such that it's next to a boundary just like it is in the RC-7...perhaps you could even install an extra boundary to accomplish this (that would also double up as cabinet bracing). If you do the woofers on the top/tweeter on the bottom approach, then I would suggest putting the ports in the top of the cabinet pointing up. Then install a horizontal baffle inside the cabinet that sits the same distance from the end of the port. Pardon the crude drawing, lol: Likewise, if you put the woofers on the bottom, then put the ports on the bottom and do the same thing. Just make sure you don't build the baffle thing so large that air can't move around it easily. Keeping it close to the woofers will help keep the air flowing around. If you're clever, you can make the cabinet so that this can be an aftermod if you don't like how the bass sounds after you finisih building. If you ask me, I don't think any of this will have any audible effects. (so basically, i'm just writing for the sake of writing). Quote Link to comment Share on other sites More sharing options...
m00n Posted March 23, 2005 Author Share Posted March 23, 2005 I'd like to make it clear that, that original stick drawing formula that I posted? That is NOT a klipsch speaker. That is just some trigonometry image that someone posted for me in diyaudio that was to help me figure out the volume of an odd shaped box such as the KPT enclosure. As far as ports, my goal was to have them port out to the front, I had considered porting them to the top. Not sure how that would sound, but it may be ok. opps gotta run... gotta meeting to get to.. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 24, 2005 Share Posted March 24, 2005 Well be sure to post us some pics of your final layout. It sounds like a really cool mod and now it seems like we have the chance to see how good your woodworking skills are Quote Link to comment Share on other sites More sharing options...
Olorin Posted March 24, 2005 Share Posted March 24, 2005 Hey m00n, sorry for being so late to the party. I think you're on the right track with porting out the top. I think Colter's suggestion that the tweeter go at the bottom of the speaker is a good one. Who and CTBB are right on that the only thing you really have to do dimensions-wise is to make sure that the internal volume stays the same as the original speaker. FWIW, as far as port placement, the rule I've always heard is one port diameter minimum from any obstruction. Two can't hurt and may be better, but this is the first time I've heard two instead of one. Your project sounds like fun. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 24, 2005 Share Posted March 24, 2005 woah, why did i say double!?! yikes, thanks for pointing that out...here's a snippet from online just in case anyone wants a better source than some punk kid: ---------------- Where should I put the ports? Ports should be placed at least one diameter away from any adjacent walls. If this is not possible to do this, the tuning frequency for a given port length will be lower than that predicted by the equations, and this may adversely affect the results. - http://www.diysubwoofers.org/prt/ported4.htm ---------------- Sorry for not being more careful, I should have known better *slaps own wrists* Quote Link to comment Share on other sites More sharing options...
m00n Posted March 24, 2005 Author Share Posted March 24, 2005 Hey cool thanks guys!!! Right now I need to get some driver information so I can plug those values into WinISD. These are the values that I need. Once I can get those, I think I can procede. The values you see in this image are from some random driver I selected. Quote Link to comment Share on other sites More sharing options...
DrWho Posted March 25, 2005 Share Posted March 25, 2005 I highly doubt klipsch is going to be willing to divulge that information which means you're gonna have to find someone to run the tests for you. I think I read once that you could probably go to a local high-end car audio installer and they might have the necessary testing equipment. They'd prob you charge you a good penny to do it though. I can't think of anybody on the forum that has the test equipment. Quote Link to comment Share on other sites More sharing options...
mungkiman Posted March 25, 2005 Share Posted March 25, 2005 Hey m00n, once you angle the speakers down towards the listening area, won't the ports be away from the wall as a result? I don't know the port location of your speakers, but inverting them might help to get as far away from the wall as possible. Chris Quote Link to comment Share on other sites More sharing options...
m00n Posted March 25, 2005 Author Share Posted March 25, 2005 Cris, you need to come over and have a listen and take a look at my delima. I want to tilt my RC7s, but... They would stick too far out into the room. My room is only 10' wide as it is. Then to have some RC7s sticking at least 12" into the room on each side really creats some issues with people banging their heads into them and what not. So, my other solution was to create cubbies in the walls they could slide into, however, this is no easy task as I wanted them angled at the same time. On top of that... I'd have to create enough air behind them so the ports could breat. To just build cubbies where they would sit straight up is one thing, but them to have them angled as well is a framing task that I'm a bit hisitant to tackle. Quote Link to comment Share on other sites More sharing options...
m00n Posted March 25, 2005 Author Share Posted March 25, 2005 ---------------- On 3/25/2005 11:24:35 AM DrWho wrote: I highly doubt klipsch is going to be willing to divulge that information ---------------- Oh... I didn't realize this was taboo information. I thought it was just information that was not readily available. Quote Link to comment Share on other sites More sharing options...
Olorin Posted March 25, 2005 Share Posted March 25, 2005 mOOn, don't worry about it. Just make the internal volume of the new box the same as the internal volume of the old box, and make the new ports the same diameter and length as the old ports. Klipsch did all the modeling for you. All you have to do is build boxes. Quote Link to comment Share on other sites More sharing options...
m00n Posted March 25, 2005 Author Share Posted March 25, 2005 Yeah, I guess that's true. For what ever reason i was thinking I needed it to use WinSID, but I guess I really don't need that info. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 25, 2005 Share Posted March 25, 2005 m00n, Let's make this as easy as possible. Look at my attached drawing. The rectangular box volume is easy: A x B x C For the angled section, it is just as easy: D x B x 1/2 of C Add the two volumes together. If you can't figure this out I'll try to explain. edit: My son walked in and said -- A + 1/2 of D x B x C. That makes it even easier! Don't put the ports on the top, they will just collect dust or whateve else small that might end up there. How long are the port tubes? You could put them on the sides. With the sides clamped together, you could drill those holes at one time. Don't make more work for yourself than you have to. Marvel Quote Link to comment Share on other sites More sharing options...
Olorin Posted March 25, 2005 Share Posted March 25, 2005 I'd expect any dust to get blown out in pretty short order. This is m00n we're talking about here. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 25, 2005 Share Posted March 25, 2005 LOL, I wasn't thinking about that. Quote Link to comment Share on other sites More sharing options...
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