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description: Audio advice and discussions with audiophiles and professionals. Free discussion forums, open to all and frequented by industry experts. Ask questions and get advice on stereos, speakers, hi-end amplifiers, pre-amps, home theater, tube hi-fi, turntables, vinyl, tweaks, music, films, video, DVDs and more.
items: Pro Series 4 Pi answers.
items: Re: Pro Series 4 Pi answers.
items: Those woofers look like Toby's !
items: Re: Those woofers look like Toby's !
items: Thanks! (nt)
items: Braces and stuffing - Sounds like teenage girl topics

Pro Series 4 Pi answers.
type: item
description: Lots of questions, here are some answers. The port is 3.5" x 6" x 10" long, and it really has to be that for everything to fit. You can see in the photo below that there isn't a lot of room on the baffle. The port just fits, and it looks pretty good like that to me. The downside is that forces the tweeter to be horizontally offset a little bit, which in turn shifts the vertical coverage angle slightly towards a diagonal. But the null angle is wide, so this is of little consequence. Response of the speaker is nice and flat from 100Hz to 16kHz-18kHz, depending on the compression driver chosen. Rolloff on the bottom is nice and gradual because the alignment is slightly overdamped. Rolloff begins around 60Hz and is -10dB down at 30Hz. This makes a good conjugate for room gain in small to medium sized rooms, sounding very powerful and clean all the way down to the lowest bass frequencies. The crossover is asymmetrical, with some overlap between 1.2kHz and 1.6kHz. The tweeter receives very little energy below 1.6kHz because the slope is third-order. Summing is perfect on-axis, and off-axis at any angle in the horizontal plane. The angular coverage of the tweeter is 90 degrees in the horizontal plane, which matches the woofer's pattern in the crossover overlap region. The tweeter's vertical pattern above 2kHz is 40 degrees, and summing between woofer and tweeter is in-phase at any angle within this arc in the vertical plane. Anti-phase nulls form outside the vertical coverage angle, punctuating the pattern in the crossover range. Impedance is fairly flat between 8-10 ohms from 100Hz to 1kHz, rising slightly above 1kHz to 12 ohms. Below 100Hz, impedance forms the classic bass-reflex curve with two peaks, one at 15Hz and the other at 70Hz. Impedance at 15Hz is 35 ohms and at 70Hz is 25 ohms. Impedance between these peaks is 8 ohms. Power handling is 600 Wrms. Recommended placement is in corners facing inwards 45 degrees (like Pi cornerhorns) or back against a wall. I do not …
creator: Wayne Parham
date: 2001-06-16T20:56:51-00:00

Re: Pro Series 4 Pi answers.
type: item
description: Are their any braces or stuffing in the cabinets? What material do you recommend the boxes be built from?
creator: James W. Johnson
date: 2001-06-17T17:32:58-00:00

Re: Pro Series 4 Pi answers.
type: item
description: I must admit that the main reason I want to build these speakers is to get really high SPLs with little distortion, I like realistic music playback. My current speakers are 92dB sensitive and handle about 200watts...this gets me around 92dB RMS with 100dB peaks ....and 100dB peaks on these is really pushing their limits, they start to distort, furthermore I have blown 4 tweeters in these speakers over the last year. They are the Kit281 Speakers from Adire Audio.
creator: James W. Johnson
date: 2001-06-17T17:39:45-00:00

Re: Pro Series 4 Pi answers.
type: item
description: Here is the Pic.....
creator: James W. Johnson
date: 2001-06-17T17:42:11-00:00

Re: Pro Series 4 Pi answers.
type: item
description: Sorry to load up your forum with questions, I probably should just give you a call.... but what would be a step up from the 4Pis if I wanted some more SPLs and less distortion? Thanks Alot!
creator: James W. Johnson
date: 2001-06-17T18:26:22-00:00

Those woofers look like Toby's !
type: item
description: Are they? I will ck the link again!
creator: RBP
date: 2001-06-17T20:57:13-00:00

Re: Those woofers look like Toby's !
type: item
description: They are Adire Audio's AV8, made by Eminence.
creator: James W. Johnson
date: 2001-06-17T22:04:09-00:00

Re: Pro Series 4 Pi answers.
type: item
description: Seven Pi cornerhorns are the only speakers I know of that I would consider to be a "step up" from four Pi's. Let me make a suggestion: Why not build your four Pi's and listen to them for a while before considering what you may or may not want as an "upgrade." The four Pi speaker is a very capable speaker, and at risk of sounding immodest I have to admit I know of no better loudspeaker of its size, anywhere.
creator: Wayne Parham
date: 2001-06-18T04:36:52-00:00

Thanks! (nt)
type: item
description: .
creator: RBP
date: 2001-06-18T04:38:11-00:00

Braces and stuffing - Sounds like teenage girl topics
type: item
description: Had to make a silly comment. Braces and stuffing. It's the end of the weekend; Please forgive. :-) Anyway, put braces tying front to back panels together and side to side. The braces should be put between the woofer and tweeter. R13 insulation should be put on the back, bottom and side. Also hang a sheet on the braces, spanning the cross-section of the cabinet. This will attenuate midrange inside the cabinet but let bass pass right though. As for wood to build your cabinets, use MDF or Baltic Birch. The braces can be made of any hardwood, 1"x2" works great.
creator: Wayne Parham
date: 2001-06-18T04:54:35-00:00