Home » Sponsored » Pi Speakers » 2Pi's completed - now I want a center channel
2Pi's completed - now I want a center channel [message #74391] Wed, 07 November 2012 14:13 Go to next message
willis66 is currently offline  willis66
Messages: 7
Registered: November 2012
Location: Roswell, GA
Esquire
Here is my first build, a pair of 2Pi speakers. I love the sound, but plan on rebuilding them as towers and focusing on a bit more pleasing woodworking. I have good skills in woodworking, but not so much in electronics and crossovers, etc. I have read most everything on this board, but still am not sure how to proceed in adding a center channel.

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I need some help with center speaker idea that I read about on this forum by boblaz, over 10 years ago in this thread. http://audioroundtable.com/forum/index.php?t=msg&goto=38376&&srch=1pi+build#msg_38376
He mentions using a modified 1 Pi with good results, would the 1 Pi work with the 2 Pi's in my room. My thinking is a double 1 pi with a single tweeter in the center. Is this a stupid idea.

My other thought is an additional 2 Pi speaker, but since our screen is so large it would come to just about the bottom of the screen. The benefit of an additional 2 Pi, is the cabinet is already made.

My current set-up has the two subwoofers wired with a y connector off of the subwoofer channel. I have tried to wire has flanking but not sure I did it correctly. Do I just run two set's of wire from the left/right channel to each subwoofer and 2 Pi? My receiver is a Pioneer Elite VSX-01-TXH.

The main uses for the room is movies and some TV, and some music listening if we are playing pool in the other half of the room.

To summarize, I love the 2 Pi's and now need a center that can keep up.

1. I plan on building 2 Pi towers, so can I please have plans for towers Wayne?
2. Would a modified 1 Pi center be to disrespectful to Wayne's hard work? Would it sound good? Surely a lot better than what I have now, that most people think is great. If so I will order a kit for a single 1 Pi and will of course need plans.
3. What is best way to wire flanking subs from one home theater receiver?
4. Does the 4 Pi idea of phantom center channels apply at all to the 2 Pi's?
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Re: 2Pi's completed - now I want a center channel [message #74392 is a reply to message #74391] Wed, 07 November 2012 14:33 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18670
Registered: January 2001
Illuminati (33rd Degree)

Those are great looking speakers, congratulations!

You can use a one Pi as a center where you have one π, two π or two π towers as left/right mains. There is enough spectral match between the three. However, do not lay it on its side or use any sort of horizontal array (drivers side-by-side).

Flanking subs are driven with a low-passed signal of the main speaker they're flanking. Second-order seems best, with crossover around 100Hz. Third-order or fourth-order can be used with a slightly higher crossover, e.g. ~125Hz third-order to ~150Hz fourth-order. But I find the latter approaches are more "localizable", which is not what we want. A flanking sub run second-order blends seamlessly.

Phanton centers work well when the mains generate constant directivity and are setup with the crossed-axes method. They can't be too far apart either; It works best when the physical separation between left and right mains is less than about 15 feet. Part of the cross-axes method is that the listeners must be just behind the point where the axes cross, so if all these conditions are met, phantom centers work very well, providing a believable image. Centers are always preferred, but if the setup is right, a phantom center gives a very satisfying illusion and doesn't lack much.

Re: 2Pi's completed - now I want a center channel [message #74393 is a reply to message #74391] Wed, 07 November 2012 15:46 Go to previous messageGo to next message
willis66 is currently offline  willis66
Messages: 7
Registered: November 2012
Location: Roswell, GA
Esquire
Thanks for the quick reply and the compliments. I quickly threw the boxes together using MDF and vinyl self stick laminate.

Thanks for the crossover reminder, I need one of those Pyle electronic crossovers you posted about some time ago, which are hard to find it seems. I am trying to be value oriented. Even the receiver is second hand.

Once I have the crossover are the wires run in parallel from the amp to the crossover and to the speakers? Will this hurt the amp?


Re: 2Pi's completed - now I want a center channel [message #74394 is a reply to message #74393] Wed, 07 November 2012 15:59 Go to previous messageGo to next message
JCDC is currently offline  JCDC
Messages: 43
Registered: August 2010
Baron
Ideally you want the same speakers for R C L ... But a Tower 2Pi won't fit under the screen.

Next best would be to use the same drivers. 2Pi Towers on the sides and a regular 2Pi as center.

And it looks like it'll juuuuuuuust fit!

Cheers,
Jeff
Re: 2Pi's completed - now I want a center channel [message #74401 is a reply to message #74394] Wed, 07 November 2012 19:53 Go to previous messageGo to next message
willis66 is currently offline  willis66
Messages: 7
Registered: November 2012
Location: Roswell, GA
Esquire
That makes the most sense to have all three the same as much as possible. It will just fit, I wonder if the size of the 2 Pi can be shortened a bit and expanded in depth or width, mainly to allow a slight angle to the speaker towards the listener it this is recommended.

In reality most movies we watch are shot wider than 16:9, which is why the screen is so big, I may willing to make the screen smaller in order to get better sound quality.

Thanks for your input.

Regards,

William
Re: 2Pi's completed - now I want a center channel [message #74402 is a reply to message #74393] Wed, 07 November 2012 21:37 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18670
Registered: January 2001
Illuminati (33rd Degree)

willis66 wrote on Wed, 07 November 2012 15:46
Once I have the crossover are the wires run in parallel from the amp to the crossover and to the speakers? Will this hurt the amp?

The preamp levels are paralleled out. If nothing else, just use an RCA Y-splitter. Preamp level inputs are relatively high impedance (usually 50k) and the output driving it is usually on the order of a few tens of ohms, so splitting it won't hurt a thing.

Re: 2Pi's completed - now I want a center channel [message #74409 is a reply to message #74402] Thu, 08 November 2012 16:35 Go to previous messageGo to next message
JCDC is currently offline  JCDC
Messages: 43
Registered: August 2010
Baron
Hey Wayne,

How far out from the walls do the rear-ported 2Pi Towers need to be?

If far out, they will be sort of in the way of the doorway ...

Cheers,
Jeff
Re: 2Pi's completed - now I want a center channel [message #74410 is a reply to message #74409] Thu, 08 November 2012 20:40 Go to previous messageGo to next message
Wayne Parham is currently offline  Wayne Parham
Messages: 18670
Registered: January 2001
Illuminati (33rd Degree)

They don't have to be far from the wall at all, just a few inches. The port is huge and doesn't need much breathing room.

Re: 2Pi's completed - now I want a center channel [message #74412 is a reply to message #74409] Fri, 09 November 2012 06:49 Go to previous messageGo to next message
willis66 is currently offline  willis66
Messages: 7
Registered: November 2012
Location: Roswell, GA
Esquire
Here is the current plan, build 2 Pi Towers for left and right. Reuse one of the current cabinets for the center channel. Shrink the screen size slightly, and make the screen frame 3" instead of 4". This will allow for a better looking soundstage. I will run the subs as flanking with 100 Hz active crossover.

It may be necessary to remove the corner mineral wool for the best sound from the left speaker, this will require testing.

As for the doorway that is actually a 100" opening to the kitchen area in the basement, so the speaker on that side does not really interfere with the doorway.

Next year, I will build two 3 Pi subwoofers for the front and move the two that I have to the rear of the room.
Re: 2Pi's completed - now I want a center channel [message #74414 is a reply to message #74412] Fri, 09 November 2012 08:07 Go to previous messageGo to previous message
JCDC is currently offline  JCDC
Messages: 43
Registered: August 2010
Baron
Only a few inches .... wuhahahaha! Here is my crazy plan!

Build 3 Tower 2Pis.

Lay a Tower 2Pi sideways underneath the screen (put the tweeter on the right of the woofer when standing up). So, you have a Tower laying sideways under the screen with the woofer and tweet aligned vertically with the center of the screen.

The sideways tower covers more to the right than to the left but you could put components in the space on the left. Its tweeter is above the woofer with the same spacing as a regular tower. If the tweeter needs more baffle around it, put a little arch around the tweet. Tip the speaker back a bit so the tweet is pointing at the head of the center seat. Angle in the side speakers so they point at the head of the center seat (Wayne prefers to cross them in front of the center)

Now you have 3 'matching' front channels. Set your amp so the L C R are 'large' and you'll have serious bass. The center will be getting its proper bass which I think is extremely important. Now you can move your other subs around the room to smooth the bass.

I know, it's crazy....

Cheers,
Jeff
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