Flex Your PCD Mettle:

[isaeagle4031]

Re: Flex Your PCD Mettle:

What woof would you guys suggest for a roughly 3 cube enclosure? I've got a pair of Altec Lansing Model 14's that I picked up (literally as someone had them sitting on the street for junk clean-up!!) The woofs are shot, I will have to remake the front baffle some for whatever driver I find as this one is about a 11.5" opening.

[fastbike1]

Re: Flex Your PCD Mettle:

If you want to stay inexpensive, I really like the DC300. Check my sig for my Econowave. A quick DC300 model in 3 ft3 ported gives 105 dB F3/F10 30.5/22.1. Fb ~24.3 (3x8).

Sealed in 3ft3, your F3/F10 44.6/24.5 103.6dB

Moving up a bit in price and output, the Dayton PA310 or Eminence Beta 12A-II will also work. Of these 2, the BEta 12A will play a fair bit lower than the PA310.

What woof would you guys suggest for a roughly 3 cube enclosure? I've got a pair of Altec Lansing Model 14's that I picked up (literally as someone had them sitting on the street for junk clean-up!!) The woofs are shot, I will have to remake the front baffle some for whatever driver I find as this one is about a 11.5" opening.

[davepellegrene]

Re: Flex Your PCD Mettle:

Teddy, I want to see pics of your Beyma setup.

We just built an awesome stand mount monitor using the Beyma and an Acoustic Elegance TD10M. The sound is amazing.

Is the top and bottom angles on th guide the same? In the pic it looks like th top has a sharper angle. Interestingly I have been working with a planner in my guides and haven't liked the results so far. The less angle on the throat seem to give better results but wont give much boost unless it is quit large. I was thinking on the lines of what your guides appear to be. Start with a low angle going sharper as it reaches the baffle edge. I was also thinking about doing it as a round guide and cutting the top and bottom off on an angle then gluing on a flat piece. What would you say the top and bottom angles are, around 60 degrees?
Dave

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Is the top and bottom angles on th guide the same? In the pic it looks like th top has a sharper angle. Interestingly I have been working with a planner in my guides and haven't liked the results so far. The less angle on the throat seem to give better results but wont give much boost unless it is quit large. I was thinking on the lines of what your guides appear to be. Start with a low angle going sharper as it reaches the baffle edge. I was also thinking about doing it as a round guide and cutting the top and bottom off on an angle then gluing on a flat piece. What would you say the top and bottom angles are, around 60 degrees?
Dave

Here's the drawing of the guide Dave.

You can see that the angle on the top and bottom is pretty sharp, but it is symmetrical.

[davepellegrene]

Re: Flex Your PCD Mettle:

Here's the drawing of the guide Dave.

You can see that the angle on the top and bottom is pretty sharp, but it is symmetrical.

Thanks Pete, Thats perfect. The planner I'm working with is square but I don't see why the same angles wont work. Any idea what the wave front on a planner is shaped like. I'm assuming different then a dome since the standard round guide even with a square throat doesn't do well.
Dave

[Pete Schumacher]

Re: Flex Your PCD Mettle:

Thanks Pete, Thats perfect. The planner I'm working with is square but I don't see why the same angles wont work. Any idea what the wave front on a planner is shaped like. I'm assuming different then a dome since the standard round guide even with a square throat doesn't do well.
Dave

The directivity is going to be directly tied to the diaphragm shape. With planars like this AMT, or long ribbons, the vertical directivity is going to be narrower, and the horizontal, wide. This is the type of guide you really need to use with such diaphragm shapes.

I'd make a rectangular form, and press your guide using a rectangular plunge instead of the circular dowel you use for domes.

I contemplated using a quarter of an 8" piece of PVC tube, to make the horizontal sides of a guide for large planar devices. The Beyma is pretty much a straight sided guide, with flared ends to meet flush with the baffle. But I wonder how a circular profile might aid/detract from the overall response.

[joew]

Re: Flex Your PCD Mettle:

What woof would you guys suggest for a roughly 3 cube enclosure? I've got a pair of Altec Lansing Model 14's that I picked up (literally as someone had them sitting on the street for junk clean-up!!) The woofs are shot, I will have to remake the front baffle some for whatever driver I find as this one is about a 11.5" opening.

3.0 cu. ft. gives you a lot of options. The DC300 has been a popular choice since the beginnings of the Econowave project and provides good bang for the buck.

If you're interested in spending a little more and want a sealed enclsoure, check out the Peerless SLS 830669:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-1118

Or if you want a ported box, you might take a look at Dayton Designer Series DS315-8, which bwaslo has recently posted encouraging results with:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-434

Another option that wouldn't involve cutting the cabinets would be to have the original woofers serviced at the PE Speaker Repair Center:

http://www.parts-express.com/speakerrepaircenter/index.cfm

[teddytusen]

Re: Flex Your PCD Mettle:

The WG on the Arcus (white stand mount above) is simply the stock WG painted white.

Those are massive speakers you have there. My friend here in town is upgrading his HT, and I know he'd love to see your set up. His will be in-wall, but I think he's leaning toward a 15" woofer and CSS Planar 1, which we now have on order. I can' t wait to begin testing that new CSS Planar 1. The Planar 2 looked incredible from the data Dave Thomas took a while back, and I understand the Planar 1 is designed for 500Hz operation.

They are massive, no doubt. 208 liters is too large for most livingrooms, and that is why I went for the Econowave`s there. Not shure, but I might go for Econo as surrounds in my HT. The TPL-150H is a bit to expensive for all channels. I am currently building a center with the TPL-150H and one 15P80Nd.

The Planar 1 (and 2) was new to me. Interesting.

[davepellegrene]

Re: Flex Your PCD Mettle:

The directivity is going to be directly tied to the diaphragm shape. With planars like this AMT, or long ribbons, the vertical directivity is going to be narrower, and the horizontal, wide. This is the type of guide you really need to use with such diaphragm shapes.

I'd make a rectangular form, and press your guide using a rectangular plunge instead of the circular dowel you use for domes.

I contemplated using a quarter of an 8" piece of PVC tube, to make the horizontal sides of a guide for large planar devices. The Beyma is pretty much a straight sided guide, with flared ends to meet flush with the baffle. But I wonder how a circular profile might aid/detract from the overall response.

I tried a 4" piece of PVC cut into 1/3 pieces laid flat with 45degree corners and it did not do all that well. It looks as though your guide has the exact opposite profile a standard guide has.
The planner I have is 1" square and I do have a tip made square to match the size an shape. I'll have to try a square or rectangle shape at the baffle but I have a feeling the horizontal shape of your guide may be the key to a good boost down low without creating cancellation from a steep throat.
Dave

[isaeagle4031]

Re: Flex Your PCD Mettle:

The cost to recone my model 14's is $95/ea! Seems silly to me then to spend that much on them when I can replace them with much better units for less money. Even redesigning the crossovers (upgrading as well) doesn't seem to justify the expense. So I will look into the dayton units and a couple of eminence as well.

[donprice]

Re: Flex Your PCD Mettle:

So I will look into the dayton units and a couple of eminence as well.

You might want to ditch the whole system (for some real $) and start over if you aren't into the vintage Atlec stuff. I bet you can fund some nice builds of what you really want. Real nice:D

[isaeagle4031]

Re: Flex Your PCD Mettle:

That's probably what I will end up doing. Too many projects going on right now. I may part these out and scrap the cabinets. They need quite a bit of work to restore and the value just isn't there.

[qfish]

Re: Flex Your PCD Mettle:

Hi all!
It was kind of hysterical purchase :D
Anybody tried this www.sicaspeakers.com/sshfd1.html ?

[dtruck]

Re: Flex Your PCD Mettle:

Paging Pete? I'm getting very confused in PCD here. I can measure from one location, generate frds with min phase, import everything, put in the geometry, overlay the summed measurement, find a z-offset that matches, and go on from there. The only thing is, the offset doesn't seem to make any sense. I am using a woofer that is a little deeper than most, with the magnet center a few centimeters back from the compression driver. In PCD 7, I got a z-offset of +11.5cm for the woofer if I leave the CD at 0. That's on the CD axis. That seems a bit odd, right? According the update notes, that means the acoustic center of the woofer is closer to the mic?

I figured a good sanity check would be to re-do everything way down on the woofer axis. When I did that, I got +8cm for the woofer. Since I'm on the woofer axis now, the woofer is close to the mic, and the CD is farther from it, so shouldn't I have gotten a higher offset? Or, is the offset number supposed to be straight back from the zero plane? If that's the case, I should have gotten the same offset at both locations, right? If so, maybe it was measurement error, but I'm hoping you can tell me what I should be seeing so I don't start chasing my tail here. Thanks!

[Pete Schumacher]

Re: Flex Your PCD Mettle:

It's not unusual for the woofer to be forward of the tweeter acoustic center, even if the magnet isn't, especially with horn loaded CDs.

The way you derived the relative offsets should be accurate. I'd trust it and start developing your crossover based on that. You'll know if you got it right when you take the system response.