Home » Sponsored » Pi Speakers » So how does this all work then..? (I'd like a slice of Pi, please. But how?)
So how does this all work then..? [message #67506] Mon, 09 May 2011 12:29 Go to next message
spacejazz is currently offline  spacejazz
Messages: 6
Registered: May 2011
Location: Australia
Esquire
Hi,

I've made my way here from reading the Econowave threads, which branched off in other directions, one being here.

I really like what I see but living on flattest continent on earth, the kits will be prohibitive to ship. So I came to the forums with the idea to haggle for plans and crossovers. The idea of using the B&C DE250 with a good woofer (JBL and AE are too expensive for now, but provide an upgrade path?)

Is it possible to purchase the plans with xo's suited to pre-determined drivers? I need help with woofer choice, clearly, but once that is established, is it possible?


Sincerely

Ken.
Re: So how does this all work then..? [message #67507 is a reply to message #67506] Mon, 09 May 2011 12:55 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18783
Registered: January 2001
Illuminati (33rd Degree)

Decide which model you'd like to build, let me know, and I'll send plans. The link below has a whitepaper on our design philosophies:
I agree with you on shipping costs - Outside of North America, it's sometimes more economical to source the drivers locally. The crossovers can be shipped at reasonable cost though. You can buy the unpopulated crossover boards or fully assembled ones.

Re: So how does this all work then..? [message #67509 is a reply to message #67507] Mon, 09 May 2011 13:27 Go to previous messageGo to next message
spacejazz is currently offline  spacejazz
Messages: 6
Registered: May 2011
Location: Australia
Esquire
Good morning Wayne,

Thank you for the response and the interesting read.

The Three Pi will fit the bill nicely. My room is quite modest at approximately 13 x 16ft. I would like to try a 12" because I love the dynamics I've heard from some 10's in there. The reason I'd like to try this speaker design is I'm still to own a pair of speakers that are playing loud without appearing so (lack of compression and or distortion?)

If I could purchase boards with loose components then I'm a happy camper. Built is fine too!

As to the woofer. Which? Is the Eminence the only alternative to the AE TD12S? If so, then the Eminence it is. If there is something that fits in the middle somewhere in performance then I'd love to know which.

Should I be moving this conversation to email?


Cheers

Ken.
Re: So how does this all work then..? [message #67510 is a reply to message #67509] Mon, 09 May 2011 13:45 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18783
Registered: January 2001
Illuminati (33rd Degree)

Actually, as long as you're comfortable with it, I like having these discussions in public on the forum. It allows others the benefit of the information contained in our dialog.

So three π it is. I'll send plans.

The two midwoofers available for this model are the Eminence Delta 12LF and the Acoustics Elegance TD12S. The crossover has been tested and optimized for those two drivers. You can always build with the Eminence woofer, and then upgrade to the TD12S later. I realize it is fairly expensive, especially with shipping added, but I must say it's a very nice driver.

Re: So how does this all work then..? [message #67511 is a reply to message #67510] Mon, 09 May 2011 14:16 Go to previous messageGo to next message
spacejazz is currently offline  spacejazz
Messages: 6
Registered: May 2011
Location: Australia
Esquire
Suits me to have it out in the open. I only asked with regards to keeping dollar figures in private - for your benefit of course.

The Eminence appears to be a solid foundation to build upon and are available locally. The AE drivers certainly look drool worthy - I've been eying them off for too long. I'm sure they will make a great upgrade when the funds permit (I write 'funds' instead of using her name!)

What kind of usable bottom end can be expected from the Eminence, and for future reference, is there much more from the AE driver?

I don't expect the bottom octave and realise this is one of the compromises of using pro drivers. eff vs absolute extension (do I see a sub in the future?)


Cheers

Ken.



Re: So how does this all work then..? [message #67512 is a reply to message #67511] Mon, 09 May 2011 14:59 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18783
Registered: January 2001
Illuminati (33rd Degree)

The biggest difference in the Eminence and AE drivers is in the midrange, actually. It's smoother and distortion is lower because of flux stabilization rings. The bass is good either way, although all my speakers are high-efficiency designs which means they don't reach to 20Hz by any means. They have powerful bass, but you can always increase deep bass extension with subs. More importantly, using the multisub concept, you can smooth room modes. There's more information about that in the last few pages of the whitepaper in my earlier post.

Re: So how does this all work then..? [message #67513 is a reply to message #67512] Mon, 09 May 2011 15:21 Go to previous messageGo to next message
spacejazz is currently offline  spacejazz
Messages: 6
Registered: May 2011
Location: Australia
Esquire
Right then. Between your white paper, the JBL write up and multi-subs I've retired from reading due to a knot in the brain. From this point onwards any mis-information, incorrect statements, even typo's, are directly related to this condition that seems to be occurring with rapid frequency the more I look into loudspeakers.

Does the Apollo upgrade to the AE drivers relate to the JBL article or is that purely for power handling?

A designer I will never be!

So lets talk business. How much are the xo's and how would you like them to be paid for?

Also, I'm assuming that the cabinets use 3/4" (18 - 19mm) material. I have some 16mm furniture grade birch plywood, will this suffice with a little extra bracing?

So many questions. I'm not trying to be a pain in the proverbial... honestly Wink


Cheers

Ken.
Re: So how does this all work then..? [message #67514 is a reply to message #67513] Mon, 09 May 2011 15:52 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18783
Registered: January 2001
Illuminati (33rd Degree)

You're not being a pain, no trouble at all. That's what we're here for!

And I know what you mean about the information overload! Sometimes, it can be just a bit too much. All the little details, and all for just two moving parts. Laughing

You can purchase the crossover boards (populated or unpopulated) at the Pi Speakers shopping cart. See the link for prices. You can also use the shopping cart to get shipping quotes. Just put the items in the cart and start the checkout process. It will ask your address and provide a shipping quote before requesting payment information. You can order at that time if you want but you don't have to.

The smaller wood thickness (16mm or 5/8") is not a problem but I can't say for sure that the furniture grade plywood will satisfy. It's a little bit of an unknown, in that you can never tell if plywood has internal voids or not. Some plywoods - even pretty good panels - have voids between laminates that may contain debris. If there are any voids that contain debris, it will buzz.

Sometimes, pretty often, actually, you'll build a cabinet that sounds pretty good for several months or even a year or two and then one day you notice it buzzes. You'll think you have a problem with a driver and replace it, only to find the same sound. Then you'll realize it's the cabinet. What happens is the debris is held in place with a little bit of glue that squishes into the void during manufacturing but then later, the debris breaks loose. So that's the problem with plywoods. Those voids - the debris inside, actually - makes most plywoods a problem.

One plywood product that almost always works well is Baltic birch. The laminates are thinner and the glue is more likely to fill a void, leaving nowhere for debris to move.

Onto the woofer. The "stock" TD12S driver has a Faraday ring, and the Apollo upgrade adds to that. It's mostly for thermal control.

As an aside, there are three things in play with the conductive metal embedded in the magnet. One is flux modulation control, making a sort of bucking circuit. Another is the modification to voice coil impedance. And a third is wicking the heat out of the core. All three things can be improved by putting (thermally/electrically) conductive material in the motor core. Of course, this reduces the amount of magnetic material in the core, so you have to make that back up. But with proper placement of conductive material, you can improve flux stability, thermal dissipation and voice coil inductance linearity. The thing is, the optimum positions for the conductive material are different, depending on which of these things you want to optimize.

Re: So how does this all work then..? [message #67637 is a reply to message #67513] Mon, 16 May 2011 06:17 Go to previous messageGo to next message
Cangaceiro99 is currently offline  Cangaceiro99
Messages: 5
Registered: March 2011
Location: Melbourne
Esquire
Hi Ken,

I'm in Melbourne, just about to do build some 4 pi speakers too. I sourced de250 & 2226h. Have just to order crossovers from Wayne & source the horns from somewhere.

I thought it may be worth mentioning that essential audio in melb stock those eminence woofers, but if you're prepared to wait a few weeks, I've noticed that second hand 2226h or 2225 come up on ebay every few weeks and have been selling for about $200-250 each. That's only a little more than the stock eminence 12 new from essential audio and is how i bought mine.

I was considering td12s before that, but price of shipping makes it difficult. Wayne has mentioned that 2226h is pretty special mid woofer. From what i understand has less breakup up high.

Wayne,

Is it possible to EQ the speakers to give more bass? i will be listening at moderate levels without a sub woofer, just wondering how much EQ would be reasonable without damaging the speakers/ ruining the sound? Flat to mid 30s?

Thanks,

Paul





Re: So how does this all work then..? [message #67643 is a reply to message #67637] Mon, 16 May 2011 10:09 Go to previous messageGo to previous message
Wayne Parham is currently offline  Wayne Parham
Messages: 18783
Registered: January 2001
Illuminati (33rd Degree)

The cabinet is tuned to 38Hz so you can safely boost bass down to that point. However, it would be much better to use multisubs, because then you'll not only gain the extension but also smooth room modes.

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