New forum member, new OB project - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th April 2012, 12:01 AM   #1
diyAudio Member
 
Join Date: Dec 2011
Location: MO
Default New forum member, new OB project

*** Most recent updates (9-1-12) are found here. ***


Hello everyone.

I am a new-ish member to this awesome site and since the wife has just ok'd a new project, I thought I'd start a thread for the build and of course comments and suggestions. But first a background.
I've always been interested in audio, starting first with car stereo systems in high school and venturing into home audio once my car was complete. Some years ago, I set out to create a large 3-way tower which I never saw to completion due to my work schedule.

I became increasingly interested in open baffle designs early last year and decided to take the three way system I had laying in the garage and place them into an open baffle. More research revealed the lack of low-end common in these setups so I decided to include a 12" car audio woofer (MB Quart) in a U-frame, effectively creating a 4-way.

Click the image to open in full size.

I'm using a Behringer EP2000 for the amplifier and running a 50Hz high pass - equalization is done via a +10db bass boost on the home theatre receiver - yes I know not the best solution, but it doesn't sound too bad. And sadly I don't have the equipment to measure the output.

For the very bottom end, I built two sonotube towers tuned to ~20Hz - also running 12s, low passed at 50Hz.
Back to the present:

I've been eyeing the countless projects on this site, as well as others, and the bug keeps biting at me to build . I'm pretty set on staying with open baffles, however I also want to work with some FR drivers. So here's what I'm looking at.
2x MCM 21" woofers (@119 each!)
1x Audio Nirvana Super 12
1x some tweeter, possibly a LPG 25NFA mounted above the AN 12 cone as in the Hammer Dynamics Loudspeaker

Click the image to open in full size.
I'm planning on running a 30Hz high pass on the woofers via the EP2000 and using the receiver for a 50-70Hz lowpass to the "subwoofer", then adjust gain to compensate for bass-drop along with using the bass boost on the receiver. Once again, not the most elegant solution, but until I decide to either get an ultracurve or a mini-dsp, this'll have to do.

I may run the Super 12 with only a highpass at ~100-150hz and no low pass. The tweeter will come in between 5 and 10k (will have to experiment with my ears).

So, with all that said, how's it look? Also, anybody know what the efficiency of the AN12 is? Hopefully the 92dB of the tweeter will complement the AN12 well.

Cheers,
Ben K.

Edit: I should mention this project may take a few months to come to completion. The MCM woofers are on order, but work is keeping me from diving right in. Plus it gives me time to adjust plans if necessary.

Last edited by siruis815; 1st September 2012 at 10:30 PM.
  Reply With Quote
Old 16th April 2012, 03:47 PM   #2
zmyrna is offline zmyrna  United Kingdom
diyAudio Member
 
Join Date: Nov 2009
Location: London
How big is your room?
Those 21"ers may be an overkill.
Consider exchanging them for 15".
On a recent forum discussion most experienced diy'ers agreed that the upper limit for musical woofers were 15"
If you decide to keep them, at least consider putting them on a separate baffle.
Otherwise your main baffles will rattle like crazy.
On another note, you should keep the woofers close to the floor for bass gain.
Are the AN drivers low qts? I remember so.
In that case, you would be better of with a 8-12" driver of around 0.7 qts.
And no whizzer cone please.
  Reply With Quote
Old 16th April 2012, 05:35 PM   #3
diyAudio Member
 
Join Date: Dec 2011
Location: MO
My room isn't overly large, but I do like my music on the louder side. 21s were my choice to mainly further low end extension without going H-frame. I looked long and hard at the alpha-15s, but decided on the MCMs instead. And I understand the 21s won't be as musical, but to play up to maybe 150hz at very low extension they should be alright.

My original plans called for putting both woofers below the FR, however that would put the FRs center at ~52 inches off the floor - a bit high for the sitting position. I'll have to draw up some more plans. Do you think a 3" baffle would still rattle too much? I plan on using 3 1" layers.

I believe the AN12 has a qts anywhere from .26-36. A little on the low side, but should be fine down to 100ish Hz with it being a 12. I also had the 15 in mind, however I don't know for sure about the 150 dollar price increase. I haven't 100% settled on which AN driver yet.

What do you mean by no whizzer cone? As I understand, the ANs all come with whizzers.

For reference, my current baffles are ~40 inches tall.

EDIT: Anybody in the Raleigh area want to come by and measure my current system?

Last edited by siruis815; 16th April 2012 at 05:43 PM.
  Reply With Quote
Old 16th April 2012, 05:57 PM   #4
jim1961 is offline jim1961  United States
diyAudio Member
 
Join Date: Apr 2012
Location: Dublin, Texas
If this intended to be a full range speaker, I wouldnt recommend running a 12" woofer up to 5-10k at all.
  Reply With Quote
Old 16th April 2012, 06:05 PM   #5
diyAudio Member
 
Join Date: Dec 2011
Location: MO
The AN are full rangers no? I figured they should be good up to at least 5k. I do plan on having the tweeter in there for the very high end.
  Reply With Quote
Old 16th April 2012, 08:37 PM   #6
diyAudio Member
 
chris661's Avatar
 
Join Date: Feb 2008
Location: Sheffield
Blog Entries: 8
Quote:
Originally Posted by zmyrna View Post
On a recent forum discussion most experienced diy'ers agreed that the upper limit for musical woofers were 15"
Citation needed please: I've heard good and bad both sides of that border.

A pair of 21"s a side may well be considered overkill (call it headroom ). But I'm sure that none of your friends/family/whatever have seen woofers that big before: I'd go for it for the wow factor.

I'd consider going for a 12" coaxial for the midrange and up.

Chris
  Reply With Quote
Old 17th April 2012, 01:27 AM   #7
jim1961 is offline jim1961  United States
diyAudio Member
 
Join Date: Apr 2012
Location: Dublin, Texas
Quote:
Originally Posted by siruis815 View Post
The AN are full rangers no? I figured they should be good up to at least 5k. I do plan on having the tweeter in there for the very high end.
My concern was the off axis response mostly.
  Reply With Quote
Old 17th April 2012, 01:59 AM   #8
diyAudio Member
 
Join Date: Dec 2011
Location: MO
Off axis response is partly why I am swaying towards using the Super 12 with a 1" tweeter to cover 5k+ freqs.

I am 100% set on using the 21s as they are already purchased. Do you guys think the upper 21 will be okay above the FR?

Thanks for all the reply's so far. Keep them coming! Pics of the drivers will hopefully be uploaded by Saturday night
  Reply With Quote
Old 17th April 2012, 02:24 AM   #9
diyAudio Member
 
Join Date: Dec 2011
Location: MO
I've also been eyeing the 8" L Cao fullrange driver that popped up on the forums.
  Reply With Quote
Old 17th April 2012, 09:53 AM   #10
zmyrna is offline zmyrna  United Kingdom
diyAudio Member
 
Join Date: Nov 2009
Location: London
Sirius,
Yes the AN driver is indeed a fullranger.
It is designed to be a point source/fullrange in a big box.
If you are having a 3 way design there is not much point in AN.
And yes they all have whizzer cones and there is also no point in a wc if you are going to add a tweeter. If you have to use the AN12 then perhaps you can remove the wc.
But then I haven't seen successful OBs using AN drivers. That says sth. It is probably better to use a 8" with 0.7 qts rather than a 12" with lower qts.
My suggestion for bass:
Use one 21" per side with a plate amp if necessary. Put the 21" on a separate baffle.
And then build a 3 way main baffle:
Tweeter
8" mid with qts around 0.7
and one or two filler 12" woofers below the mid.
I can't remember the forum reference for the musicality comment. But the argument is that over 15" two things happen:
1. cone gets too heavy
2. cone breaks more easily because of large surface
So it is probably best to use such big drivers for only under 50Hz with a steep crossover.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New member in the forum burtcheca Multi-Way 5 27th April 2010 06:50 PM
Forum donation in honour of a forum member tinitus Everything Else 0 25th October 2009 01:45 PM
A New Forum Member. jfran Introductions 4 28th July 2007 05:03 AM


New To Site? Need Help?

All times are GMT. The time now is 06:42 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2