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-   -   Peerless 830668 10"s bi-amped music only system (http://www.diyaudio.com/forums/subwoofers/223534-peerless-830668-10-s-bi-amped-music-only-system.html)

mikemarion 14th November 2012 12:42 AM

Peerless 830668 10"s bi-amped music only system
 
Hi All-

I've been lurking for quite awhile but this is my first post here.

I bought a pair of Peerless 830668 10" subs for my bi-amped home audio (music only) rig.

I am replacing a pair of 15" PA speakers (with the tweeters unplugged) crossed at 125hz or so with the Rane MX22 active x-over.... so, I think fidelity should improve.

In the past I have built ported enclosures, but as this is a music only system I'm thinking of going sealed.

The amp driving the subs is a Soundcraftsmen S860 that does 205 at 8 ohms.

The box that seems to fit the space comes out to be 1.76 cu ft (not figuring for driver displacement). At 22 inches tall, it is 3 inches shorter than the current subs. I think that is ok, since I angle up the speakers. I could make the tweeters ear level but the WAF will suffer.

I listen to electronic music, 80s, techno... so, I don't think I need to go down to 20hz. (i like a bit of boom and a "popular sound")

I solicit your feedback on:
-Enclosure type (sealed vs. ported)
-Volume of the enclosure
-Tweeter angle vs. level
-etc.

Thanks in advance!

Here are the current plans:
https://lh5.googleusercontent.com/-P...1303/plans.jpg

This is how the system looks currently:
https://lh5.googleusercontent.com/-f...o_11-10-12.jpg

Electronics (close up):
https://lh3.googleusercontent.com/-c...k_11-10-12.jpg

The satellite speaker build:
https://plus.google.com/u/0/photos/1...21792152051425

42l sample box:
http://www.tymphany.com/files/resour...ote_830668.pdf

wintermute 14th November 2012 01:23 AM

Hi Mike and welcome :) If you haven't already done so I would suggest downloading one of the sim programs and putting the T/S specs of the woofers into it and looking at what you get with sealed/vented.

You have a fair amount of power available so running sealed with a Linkwitz transform may be an option.

I personally use unibox for modelling (needs microsoft excell) a lot of people use winisdpro which is a standalone app.

I'm not experienced with using tilt rather than height to get tweeters essenitally "on axis" at the listening position (mine are at ear height when seated). I would think the main trade off with tilting up would be changes to ceiling bounce (which may work out well) floor bounce would I guess be reduced.

Tony.

mikemarion 14th November 2012 03:10 AM

Thanks Tony.

I have used WinISDPro Alpha before. So, I'll try that.

Here is the driver T/S using the specs from Madisound:
https://lh5.googleusercontent.com/-s...iver_specs.jpg

Here are two plots. The yellow line is the default (unacceptably large at 6.7 cu ft) and then my desired size (in green) at 1.75 cu ft. F3 is 44.3Hz:
https://lh6.googleusercontent.com/-9...in_ISD_pro.jpg

So, this backs up what I've seen online... The question is: Will I be happy with a speaker with an F3 of 44Hz or should I look at a ported design?

Drew Eckhardt 14th November 2012 03:30 AM

2 Attachment(s)
Quote:

Originally Posted by mikemarion (Post 3240795)
So, this backs up what I've seen online... The question is: Will I be happy with a speaker with an F3 of 44Hz or should I look at a ported design?

You should loose your fear of Linkwitz transforms and gain the ability to pick box size and extension mostly independently where box size can be used as a tool to make the amplifier clip before the driver bottoms.

Ex: Linkwitz Pluto+. Peerless 830668, .5 cubic feet, second order high pass response with F = 20Hz, Q = .5, F3 = 30Hz.

Pluto + subwoofer

http://www.diyaudio.com/forums/attac...1&d=1352867437

http://www.diyaudio.com/forums/attac...1&d=1352867437

mikemarion 14th November 2012 09:29 PM

I have the DEQ2496 that has five band of parametric equalization available... would that work to provide the the necessary subwoofer equalization so that I can avoid the Linkwitz transforms that I am afraid of.

mikemarion 17th November 2012 01:47 PM

The design goals that won out were:
(1) I am building a speaker stand as well as a sub
(2) The 3/4 MFD I purchased was cut roughly into quarters
(3) I only want to measure to a 1/4" and then use a router to clean up the edges once assembled

Here are the plans:

https://lh6.googleusercontent.com/-_...n_cut_list.jpg

I won't start cutting until later today or tomorrow so feedback is still appreciated.

mikemarion 18th November 2012 02:58 PM

Yesterday I cut all the panels. Starting assembly today.

The screws you see are all internal, just so I didn't have to clamp the glue blocks in place while they dry.

Photos:

https://lh6.googleusercontent.com/-s.../s1164/024.JPG

https://lh3.googleusercontent.com/-u...c/s776/027.JPG

https://lh5.googleusercontent.com/-1.../s1164/029.JPG

mikemarion 18th November 2012 10:47 PM

I bought a 50oz pack of POLY-FIL at Walmart to stuff the speaker enclosures. Any guess how much I should use?

Here is the progress:

https://lh3.googleusercontent.com/-K...k/s776/031.JPG

https://lh5.googleusercontent.com/-r.../s1164/033.JPG

https://lh4.googleusercontent.com/-S.../s1164/036.JPG

mikemarion 19th November 2012 03:05 PM

Online I see people recommend stuffing with .5 to 1.5 pounds per cu ft.
If I use all 50oz that I bought I am at about .8 or .9 pounds per cu ft.

Tonight I can clean up the edges with the router and sand the enclosure.

Here us is what it looks like now:

https://lh6.googleusercontent.com/--...-57-08_811.jpg

https://lh3.googleusercontent.com/-K...-57-02_352.jpg

https://lh6.googleusercontent.com/-e...6-57-13_25.jpg

https://lh4.googleusercontent.com/-G...-57-45_819.jpg

wintermute 19th November 2012 07:15 PM

Hi Milke are you going to put any cross bracing in there? You will get panel resonsonces with a box that big without something tying opposite sides together :)

On the stuffing, there is an active thread at the moment in multiway discussing that very point :)

Tony.


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