[planet10]

I still haven't been able to gather anymore information on the slot design. Mr Pass is MIA as far as email is concerned

Visit the thread on diyAudio. Likely all you need to know is there.

On a little bit happier note, the Alpair 10.2's are beautiful, very well made drivers. Even my girlfriend likes them! She's glad I chose the gold version.

Indeed they are. They actually aren't gold, but copper. Gold is an artifact from the 1st gen when you could actually get gold cones.

dave

[planet10]

I do hope you don't plan on using that wire?

I'd suggest something much skinner & solid core (CAT 5 strands work well). Then you can rid yourself of the clip connectors and solder directly to the terminals.

dave

[Chops]

Visit the thread on diyAudio. Likely all you need to know is there.

Indeed they are. They actually aren't gold, but copper. Gold is an artifact from the 1st gen when you could actually get gold cones.

dave

I have visited that thread, several times in fact. Yes, there's information there, but not detailed information. There's no construction plans or pictures. There's no real dimensions given. It's all kind of vague, general information about the design and a LOT of controversy on how it works, why it or why not it works and the front output vs rear output.

I know the cones are copper, but that's what MA refers to them as still, hence why I called them "gold".

[Chops]

I do hope you don't plan on using that wire?

I'd suggest something much skinner & solid core (CAT 5 strands work well). Then you can rid yourself of the clip connectors and solder directly to the terminals.

dave

Again, this is only a temp setup for the break-in period.

Also, I'm a big believer in not believing all the hoopla about different speaker wires. At least, not all the "extreme" theories about different wires. Most of it is BS or only detectable by computers.

What I've got going here is perfectly fine for now. I'm definitely not doing any critical listening with these speakers yet.

[Chops]

On a side note, I must say that these little drivers have some "punch" to them. I'm listening to SmoothLounge.com on vTuner and I can clearly hear some solid, tight, punchy bass. That's a bit of a shock for two reasons; one being that they are mounted on a small 12" x 12" baffle, and two being that the actual cone size of these drivers is more like 4 to 4.5", not 6" as they are referred to. The cone is about the same size as the Fostex FE127En's I had. The Peerless India 6" drivers in my X-Statik's dwarf the 10.2's cones, yet they are supposed to be the same size.

I'm not complaining at all or claiming that the 10.2's are being falsely advertised. I'm just stating an observation.

Right now, they have roughly 11 hours of continuous play time on them. They still have that hollow, cupped sound to them, and even though they have treble, it's a bit recessed. I am finally starting to see the cones move just the slightest bit.

[planet10]

actual cone size of these drivers is more like 4 to 4.5", not 6"

5.25" nominal. Actual cone diameter (no basket or surround) is 98mm vrs FE127's 82mm

dave

[Chops]

Another update on the break-in...

Very holographic and three dimensional. They completely disappear. The sound stage they throw out into the room expand well beyond them and sometimes even the walls of the room. The midrange is starting to sound better now, not as cupped and hollow sounding as before. Treble is getting to be a little better too. Still smooth but a little more extended. And I still can't get over the bass these are putting out into the room with these tiny baffles. And if you put your head right in front of one of them, they are pumping out some very decent, deep bass. Quite exciting!

From my girlfriend, she has stopped in her tracks several times already, asking what I said or what that noise was. She swore I was talking or one of the cats were doing something in the room. She says she can't believe how "real" these speakers sound. The three times she's said this, she was either sitting next to me on the couch, standing in the kitchen, and one time standing behind the right speaker headed to the bedroom. One time she thought I dumped my drink on the carpet, only to find out I didn't have a drink at all.

[JohnR]

Sounds promising 

[megasat16]

Not having read the whole thread, it may have been pointed out that you should be using Alp10.2 with some kind of High Pass filter above 200Hz for OB config. It's really easy to push the 10.2 into loading.

I have Alp12 in OB and enjoying every minute of it. I also have 10.2 (a whole lot of them) for the Line Array build soon.

[Chops]

Sounds promising 

Yes, they sound very promising indeed!

[Chops]

Not having read the whole thread, it may have been pointed out that you should be using Alp10.2 with some kind of High Pass filter above 200Hz for OB config. It's really easy to push the 10.2 into loading.

I have Alp12 in OB and enjoying every minute of it. I also have 10.2 (a whole lot of them) for the Line Array build soon.

I'm only playing them fullrange for the 500 hour break-in period. After that, they'll be going on proper sized baffles with six 8" woofers below each one. My goal is a crossover point somewhere between 150-200Hz. Maybe as low as 100Hz.

[Chops]

As I just wrote in another forum, this project has been at a standstill for the past couple of weeks.

I have been caught up in a couple of other things that have required my attention, time and funds. Not only that, but there still hasn't been any useful information on this design. I've tried contacting a couple of people (one of which is the creator of this design), and have heard NOTHING back from either one. It's not that they're not around because they're both still making posts all over the boards. I think it's just a sheer lack of interest or they simply don't care.

Whatever the case may be, it's got me to the point of putting a halt on the entire project. I haven't even been breaking in the Alpair drivers anymore. They're just sitting here in the baffles collecting dust for the past couple of weeks. I'm debating either selling all the drivers before I invest (waste) anymore time or money on it, or go in a totally different direction and build something completely different.

It's pretty sad when you show a few people a genuine interest in their products or designs and want to try and build your own using their products or designs only to find out that they refuse to offer any kind of support, or answer a simple email. I guess they just don't give a crap. Who knows.

So as it is, the twelve woofers are just sitting in the closet taking up space, the Alpairs are not being used for anything but a paper weight, and the thought of going on further on this project is totally dead at the moment. Very disappointing and somewhat depressing...

[JohnR]

 

Did you simulate your desired baffle size in Edge? That would be a good next step.

[Chops]

No because I don't know the first thing about that software. I DL'ed it and couldn't get anything to work. After messing with it for about 30 minutes, I uninstalled it.

[planet10]

Chops,

Don't expect to be spoon fed. It is diy.

Everything you need to know about the top baffle (and a lot on the bottom baffle) are in MJK's articles (and duplicated in a 1000+ other places).

The slot load baffle has been done so little there are few examples on the ground. Nelson was generous enuff to post an article (probably the most concise on Enjoy the Music) with all you need to know to start. While offering a little different behavior nearfield, farfield it acts just like any other flat baffle but with the benefit of being able to tale advantage of push-push to reduce the newtonian load on the baffle reducing baffle borne colouration. I have sketches going back over a decade just for the purpose of getting that advantage.

Do your homework, only you are going to build this.

dave

[Chops]

Another one with the whole "spoon fed" speech. You must have read the other thread...

As I said in that thread...

"I don't want to be "spoon fed". I would however like to have a little bit more information to go on before starting any cutting. There's virtually no info on the innards of the slot itself.

If each pair of woofers are indeed in separate compartments, how tight are those compartments? Is it equivalent to having three ripoles stacked with their back sides totally open? Do those compartments terminate before the opening of the slot? And if so, how far from the opening?

The pics of the slot loaded open baffle are very vague. There's no well lit, close up shots of the slot. All you see is a black slot on a light bare baffle. No details to speak of.

All I really need are some details on the darn slot and I'd probably be willing to start on the building. But without knowing anything about the slot thus far, I refuse to go anywhere with this project."


Also, I can't count how many times I've searched both the forums and Google about "slot ported open baffles" to only find the few threads on the two forums I belong to, and the Enjoy the Music article. There is not that much information out there, and whatever info IS out there is just the links to these forums that I've already seen and read.

[Poultrygeist]

Build some MJK H-frame Alphas for your Alpairs and be done with it.

[JohnR]

Another one with the whole "spoon fed" speech. You must have read the other thread...

As I said in that thread...

"I don't want to be "spoon fed". I would however like to have a little bit more information to go on before starting any cutting. There's virtually no info on the innards of the slot itself.

If each pair of woofers are indeed in separate compartments, how tight are those compartments? Is it equivalent to having three ripoles stacked with their back sides totally open? Do those compartments terminate before the opening of the slot? And if so, how far from the opening?

The pics of the slot loaded open baffle are very vague. There's no well lit, close up shots of the slot. All you see is a black slot on a light bare baffle. No details to speak of.

All I really need are some details on the darn slot and I'd probably be willing to start on the building. But without knowing anything about the slot thus far, I refuse to go anywhere with this project."


Also, I can't count how many times I've searched both the forums and Google about "slot ported open baffles" to only find the few threads on the two forums I belong to, and the Enjoy the Music article. There is not that much information out there, and whatever info IS out there is just the links to these forums that I've already seen and read.

Did you see the pictures of JohnK's scale model?

http://www.diyaudio.com/forums/multi-way/195734-nelson-pass-slot-loaded-open-baffle-project-20.html#post2700050

[MJK]

Also, I can't count how many times I've searched both the forums and Google about "slot ported open baffles" to only find the few threads on the two forums I belong to, and the Enjoy the Music article. There is not that much information out there, and whatever info IS out there is just the links to these forums that I've already seen and read.

I am sure Nelson provided all of the details he had on hand. He probably designed the slot loaded OB based on his vast knowledge, experiences, and inherent understanding of loudspeaker design. Then he built it and listened. Maybe he tweaked later, I don't know.

So when it comes to building a different design using different drivers you are starting at square one, you have to do all the work yourself. Nobody has prior knowledge to share. If it were my project I would write the software required to do a trade-off study to optimize the geometry and driver choice, then I would build and test. But that is just my method.

So you are left blazing a new trail, getting frustrated that people are not helping seems pointless since they probably have nothing to offer. You are the design leader. You can either do the engineering work or drop back and go in a different direction, your call.

[Chops]

Build some MJK H-frame Alphas for your Alpairs and be done with it.

I'm trying to keep this as compact and WAF as possible, so no big baffles to support 15" drivers.