Argos Tapered Pipe ?s

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Hello all. This will be my first venture into DIY home theater audio. I've done all of my car audio myself and have built several sub boxes out of wood and fiberglass. With what little researching I've done, the number of available drivers is a little daunting. I decided to go with something tried and tested, and I found Andy's tapered pipe via PE (and I fell in love). I searched and could find little on these at all. They will hopefully be replacing my Bose 301 III speakers on the front channels of a Sony 5.1 receiver. This will eventually serve as my progress log, but I have a few questions before collecting components. Hopefully Andy himself can shed some light onto them.

I was originally going to build these out of MDF, but I may decide to use actual wood instead. What would be a proper wood for HT use? (acousticall and visually) Many car audio people have started using Birch ply for wieght but I would like to use something more asthetically pleasing. I've worked with cypress on furniture in the past.

I'm sure the drivers listed with the plans fit both the enclosure and the crossover, but at close the $200 for drivers alone would put uneeded stress on my wallet atm, and I noticed that "similar drivers" would work as well. Which T/S parameters should I be taking into consideration for similarity? And would the lower quality of cheaper drivers really not make it worth waiting to get the more expensive ones?

And finally, I noticed the images linked in the document for the plans for these speakers are all down. I was wondering if anyone could shed some light on this problem, or point me in the right direction.

Well I apologive for the novella I've just created, but I like to prepare as much as possible when beginning new ventures. Thanks for any help and hopefully this forum will help me as much as others have.
 
The pipes were tuned using the Vifa P17WJ. The only other drivers I have used are the Peerless 850122, and the Seas T17RE
The Seas P17REX should also work.

All of these drivers are polyprop drivers and have very smooth roll-off and response and similar (sort of) Vas, Fs, and Qts.

I cannot vouch for any other drivers in the Pipes. Cheaper drivers may not have the same roll-off characteristics, which would mean a more complicated cross-over. They may also not sound as smooth as the drivers mentioned do inthe pipes.

Sorry, I can't point you to any particular cheaper drivers.

Andy_G aka Argos
 
How about the images in the plans for the for the pipes? I had sent an email but I'm sure having a publicly listed address leads to huge amounts of spam. I was hoping to look for wood today, but I can't get any of the dimensions from just the text of the document.

ryan
 
Hi Ryan,
I did send a set of plans via email on 3rd Feb my time. If you didn't get them, email me again.

I don't know why the web files won't work for you, no problem I can find at my end (doesn't mean there isn't one !!). Sorry.

Best Wishes,
Andy G

ps.. nearly every pair I made used 18mm mdf (sometimes covered with 3mm faced veneer or iron on veneer). The pair i made with cheap 18mm pine ply had some resonance problems.
 
further on materials.

I can't comment on birch ply (we don't grow birch down here), but a mate made some using a hardwood ply which worked rather well. the ones I made using soft radiata ply resonated and were a nuisance to fix, requiring front to back braces at regular intervals, a real PITA !!

There are some pics of tapered pipes here.
http://members.optusnet.com.au/~gradds55/ARGOS/taperedpipes.htm
the hardwood ones are 3rd from right, next to Dave's
 
Awesome, thank you very much.
2nd try email finally went through about 10 minutes ago. I guess it's just the distance, maybe a problem with yahoo.

This looks like it'll prove to be quite a project. Luckily by the time it's done the I'll have had a chance to get funds ready for the drivers.

I'll probably be going with a cabinet-grade birch or oak ply, maybe a solid hardwood if my local lumber yard has it cheap enough.

I'm sure I'll have specific questions at some points throughout the build, so I really appreciate the help you've given sofar.

Thanks again.

Ryan
 
So on with the questions I suppose. My gramps has been helping me with this project as asthetics are more important this time around. He's been building furniture and doing woodwork for decades, but we still clash on some things.

The wood layout on the plans calls for cutting every piece from a single sheet. However, this leaves the fronts and backs without a "square" top/bottom.

Should I follow the layout on the plans and simply cut a flat top/bottom and lose height? He suggests that I cut out the fronts and sides from the oak ply I have now and use a cheaper (but still cabinet grade) ply on the back, since doing it the way he suggests will yield fewer pieces from the single sheet.

I'm at a loss. Hopefully you can understand what I'm trying to say.

Thanks again.
Ryan
 
If you draw a centreline then take a right angle from that, you can use a bevel square to get the tops and bottoms right. The small bit of height lost is not a problem.

If your helper wants to do it a different way, go ahead. The plans show how to get the speakers from one sheet if you want, but its totally your call.

Just thinking.. if your ply has a very straight grain, you may want to set out the pieces along the grain rather than the way suggested. But then they will not all fit from one piece of ply. With mdf , that is not an issue, but I can see it may be with a ply.
 
So construction has gone pretty smoothly sofar. Red oak ply looks amazing with a matching veneer edgeband.

Should I seal joints with silicone? I'm not sure as I've never really built for mids... I figure at worst it'd just be overkill.

Also I saw on Dave's that he used a three-wire run down the back. Do the tweeter and mid simply share a ground?

Also do you suggest using sheets of poly-fil or stuffing it in loose after gluing on the top?

Ryan
 
If you look at the circuit diagram, you will see that it can be done with 3 wires running from the x-o. I generally like to run 2 pairs from the x-o, a thick pair for the woof and a thinner pair for the tweeter (purely for marking). Either way works.

For the stuffing I use 1" thick poly wadding cut into strips that get gradually shorter, the first one longer so I can wrap it back over the other strips when done.
I ALWAYS put it in before attaching the back. Dave mentions that he should have done it this way !!
 
Alright so this seems to be a very ignorant question, but this is my first crossover build and I can't seem to find what im looking for online.

I've worked before with circuits using the smaller ribbon resistors. In these cases the direction of current through the resistor always mattered and could be easily identified byt the ribbons. With these resistors and capacitors, not to mention inductors, leave little indication of their intended flow.

So how do I direct my current correctly through each component? The inductors also confused me as to whether or not there was any difference in the two ends.

Sorry for the unexperienced nature of my questions, but I guess I have to start somewhere.

Ryan
 
Thanks a lot. Crossovers are done. Not much to look at but will do the job.

DSC00369.jpg


DSC00370.jpg


Also noticed the P17 isn't labeled either, so I guess polarity isn't an issue here either?
 
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