4 way design

Putting together a 4 way design using SB acoustics SB34NRX75-6 12" woofers, thinking of using an SB17NRXC35-8-UC uncoated mid woofer AND a Silver Flute W17RC38-08 to handle the upper bass region.
A pair of Morel CAM 558 2-1/8" Soft Dome Midranges and a pair of Dayton RS28F-4 1-1/8" Silk Dome Tweeters.

Have the woofers in cabinets, plan on ordering mid woofers next week.
My thinking on using two different mid woofers is to smooth out any resonances or nuances.
Any thoughts?
 
Putting together a 4 way design using SB acoustics SB34NRX75-6 12" woofers, thinking of using an SB17NRXC35-8-UC uncoated mid woofer AND a Silver Flute W17RC38-08 to handle the upper bass region.
A pair of Morel CAM 558 2-1/8" Soft Dome Midranges and a pair of Dayton RS28F-4 1-1/8" Silk Dome Tweeters.

Have the woofers in cabinets, plan on ordering mid woofers next week.
My thinking on using two different mid woofers is to smooth out any resonances or nuances.
Any thoughts?


I think you need to slow down. Your plan is completely flawed from the start but you can still save it. Post up a picture of your cabinets with cabinet dimensions and if youre interested we can help you with a design.

The SB12.3 is also a good idea.
 
You should make it compact
Or on the other way, deconstructed, something like Stig EriK :eek:
Yeah, it sounds...dull

I'm thinkin' about some big (not too much) cabinets such as MacIntosh
with a 12" and some angled-on-a-prism little midrange's
With today's technology you can make it with 4 drivers.
 
Since my speakers are many way, I can only say that more than 3 way design by mere mortals will fail. (Or, well, you might be designed to like what you design.)

What about going with an active DSP crossover for the 4 way design? Sorry if I offended the L C R guys. But the question still stands. Wouldn't it be easier to tweak than having a stockpile of L, C, and R available?
 
I think I need to clarify a bit, my post wasn't really clear. There will be one woofer, two mid woofers, two dome midranges and two dome tweeters in each cabinet.
The midrange and tweeters will be slightly angled.
I wanted to build something like an AR LST type design so I may go with 4 mid and 4 tweeters in each cabinet in series parallel.
I don't know if I am a mere mortal in speaker building or not yet. 40+ years in electronics repair with several years in high end audio. Should give me a little edge over the guy on the street. But all suggestions are welcome.
 
I have built an over sized box ~ 9.5 cu.ft. that was going to accommodate bracing that would have taken up a lot of volume but have since have changed my approach.
There were going to be triangular braces filled with sand which would take up several cu.ft. but decided to leave the ends of the triangles open and eventually cut down on the cabinet size.
One of these triangles is installed on an inside end of the box.
The (currently)43.75" long corners will all have triangular bracing that will extend significantly into the sides of the walls to form a diamond-like shape within the box.
Midranges and tweeters will go in a separate box that will sit on top.
This box is 43.75"L X 20"D X 28" H.
http://i49.tinypic.com/2hn19xx.jpg
http://i50.tinypic.com/290rept.jpg
End bracing
http://i45.tinypic.com/2pqvthy.jpg
One end with speaker installed
http://i47.tinypic.com/25irgc0.jpg
 
DSP

What about going with an active DSP crossover for the 4 way design? Sorry if I offended the L C R guys. But the question still stands. Wouldn't it be easier to tweak than having a stockpile of L, C, and R available?
So far I have been reluctant to get very involved with digital audio outside a disc player. Some of the high end class D amps have distortion levels up ~ 2% similar to tube amps. Whereas a good MOSFET amp might be < .01% THD.
Haven't found much in the way of specs for digital crossovers.
 
picowallspeaker, currently I only possess the 12" woofers. I have installed a single woofer in the large cabinet.
I am about to order four mid-woofers. Two per channel. Planning for each cabinet to have one SB17NRXC35-8-UC six inch uncoated mid-woofer and one Silver Flute W17RC38-08 six inch mid-woofer. They will both cover the same frequency range in the upper bass region to maybe 800hz.
Each channel will also have two Morel dome midrange speakers that will cover ~800hz to ~5khz and two Dayton RS28F silk dome tweeters for 5khz to 20khz.
(I am considering four midrange and four tweeters for each channel)
Yes I made one trial box.
The Morel mids and Dayton tweeters will be installed in their own separate box that will sit on top of the large box.

I hope that explains it better.
 
What about going with an active DSP crossover for the 4 way design? Sorry if I offended the L C R guys. But the question still stands. Wouldn't it be easier to tweak than having a stockpile of L, C, and R available?

I have been using a band equipment 3-way stereo to biamp forever. I assume and active DSP takes input (stereo, etc.) and puts out the same thing analog to analog?

That would be great.

P
 
Building a speaker isnt just wiring up a bunch of drivers and using textbook crossovers..... Not to come across as a d***, but you have a lot of reading to do before trying to tackle a speaker design, let alone a complex one.

The Speaker Building Bible

I don't understand why you thought that I believed, building a speaker is just wiring up a bunch of drivers and using textbook crossovers. I said nothing to indicate this was my belief or my expectation.
Why do you think I need to do a lot of reading before I design a speaker system? Is it because my approach is unconventional or?
I'm curious.
 
So you're actually going to measure the TS parameters, and the frequency response/impedance of all of these drivers in the box you have, then combine the results in an advanced modeling program that can handle 4 way designs?

I can get to that later. What I am curious about is what did I say that indicated I could not do that or didn't understand these concepts?
 
Putting together a 4 way design using SB acoustics SB34NRX75-6 12" woofers, thinking of using an SB17NRXC35-8-UC uncoated mid woofer AND a Silver Flute W17RC38-08 to handle the upper bass region.
A pair of Morel CAM 558 2-1/8" Soft Dome Midranges and a pair of Dayton RS28F-4 1-1/8" Silk Dome Tweeters.

Have the woofers in cabinets, plan on ordering mid woofers next week.
My thinking on using two different mid woofers is to smooth out any resonances or nuances.
Any thoughts?

picowallspeaker, currently I only possess the 12" woofers. I have installed a single woofer in the large cabinet.
I am about to order four mid-woofers. Two per channel. Planning for each cabinet to have one SB17NRXC35-8-UC six inch uncoated mid-woofer and one Silver Flute W17RC38-08 six inch mid-woofer. They will both cover the same frequency range in the upper bass region to maybe 800hz.
Each channel will also have two Morel dome midrange speakers that will cover ~800hz to ~5khz and two Dayton RS28F silk dome tweeters for 5khz to 20khz.
(I am considering four midrange and four tweeters for each channel)
Yes I made one trial box.
The Morel mids and Dayton tweeters will be installed in their own separate box that will sit on top of the large box.

I hope that explains it better.

I can get to that later. What I am curious about is what did I say that indicated I could not do that or didn't understand these concepts?

Those two posts. You want two completely different drivers covering the same range, you want to use two tweeters and cross them at a very high frequency, you already have your crossover points figured out. Anyways, if you know what you're doing then by all means design yourself the speaker you want....
 
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The point is the choice of the speakers
And how are they planned to 'fit', to 'cope' ....

The listener (on the other side) asks for a point source, for correctness and easy identification of direction etc etc.

Mounting two speakers aside, it makes a pronounced polar lobe etc etc.

On the other side, if power and detail are requested, each speaker contributes to overall sound is some manner. But usually you don't see drivers with same diameter and from different brands ( only custom , that's the exception ) on the same baffle; also for tweeters, the multi tweeter arrangement is seldom viewed, and those cases are by people who really didn't understand what they were doing :rolleyes:

So if you aren't to approach a kind of vertical array ... which is another kind of emission, kind of cylindrical source, and it might work :confused:

A good way to resolve the problem, because you've got a problem:D:cool:
is the use-per-function POV scientific path .
Separated cabinets each for each speaker is good. This leads to the arrangement of the whole thing, so easily you'd return to START many times in the design stage, it's a schedule to be verified and accomplished in each step . :eek:

PS I saw a project of the early '80s which was a rivisitation/upgrade of the popular speaker AR10 Pi's as in those years it was easy to see a 10" with a tweeter only :eek:
The purpose was to make the tweeter at ear level so a complete re-make of the enclosure ( midrange and tweeter on a separate baffle/box at the top) and using a 10" from the professional line; usually the Pro drivers are much powerful and very efficient, so a good match was to put it in a little volume and working with the various Q points in the crossover stage, it became a quick and powerful mid-bass ...
 
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