16th October 2012
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#1 | | Gear interested
Joined: Oct 2012
Posts: 8
Thread Starter | Building my own Subwoofers and Crossovers
Hi. I'm looking for some advice on how to upgrade my monitor system to incorporate a subwoofer. I want to try building my own subwoofers, and wanted some advice because I've never done it before.
What I have now:
2 Mackie HR824-MK2's mounted at eye level on either side of my workstation. They're spread at about a 70 degree angle and about 2.5 ft from my face.
The problem:
The Mackies are good, but I feel like they get a little muddy in the bass region when the volume is loud. I think the problem is that they represent the bass fine for a short distance, but bass frequencies are as much about the feeling as the actual sound. I want to put a woofer under the table so that I can really feel how that bass is going to feel when people play my music on a big sound system.
The questions:
1) How cost efficient would it be to take on this project? What percent cost would I be saving building my own system vs buying an equivalent sub?
2) By adding a sub, do I need to HPF my Mackies? The goal here is to have a nice even distribution of bass all around my work station, so I'd rather not HPF them. On the other hand, I want to avoid phase cancellation.
3) My Mbox2 puts out a stereo signal. If I only want to use 1 diaphragm, do I need a mixer to combine the signal?
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16th October 2012
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#2 | | Gear Guru
Joined: Oct 2002 Location: New Milford, CT, USA
Posts: 13,105
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Quote:
Originally Posted by Yakoby125  The Mackies are good, but I feel like they get a little muddy in the bass region when the volume is loud. I think the problem is that they represent the bass fine for a short distance, but bass frequencies are as much about the feeling as the actual sound. | This is incorrect. The muddiness you experience is surely due to your room, so the solution is bass traps, not a subwoofer.
I generally advise against using a sub with a 2-channel system. Surround systems for vies need a sub, but with stereo music it's usually better to have full range speakers (like your 824s) without a sub.
--Ethan The Acoustic Treatment Experts | |
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16th October 2012
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#3 | | Gear interested
Joined: Oct 2012
Posts: 8
Thread Starter |
I agree that the muddiness is from the room, but I only have that problem if the volume is up really loud. The advantage of having a sub under the table is that I can have the volume relatively quiet, but still feel the bass in my legs.
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17th October 2012
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#4 | | Lives for gear
Joined: Jul 2010 Location: Skövde, Sweden
Posts: 1,161
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Originally Posted by Yakoby125 The advantage of having a sub under the table is that I can have the volume relatively quiet, but still feel the bass in my legs. | It's very late here in Sweden and i'm getting really tired... This sentence had me laughing until i literally cried, so i would just like to say thank you for that and good night!
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17th October 2012
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#5 | | Lives for gear
Joined: Mar 2009 Location: The O.C. |
I'll speak to the actual Sub-woofer building, if are still wanting to do that after the above advice (and laughter)... 
First, unless you have lots of experience with speaker modeling software, a complete understanding of Theil-Small parameters, a good wood shop that can turn out nice projects without loosing a finger - you would be hard pressed to save any money building your own sub. You could easily spend double (especially counting your time as an hourly rate) than to find a decent sub (assuming you really need it). If you want to build something, how 'bout some really good bass traps?? You'll be surprised at how even things become (at any volume) with proper trapping.
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17th October 2012
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#6 | | Gear addict
Joined: Sep 2012 Location: Atlanta, GA & Bradford, UK
Posts: 358
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A friend of mine has the Mackie HR824-MKIIs as well and I find them pretty muddy all around...not only at high SPL. Perhaps the muddiness you hear is due to the cabinet resonating? They aren't ported so it wouldn't be port resonance. I wonder if yours have a flaw? Do you still have a warranty with the manufacturer?
I wouldn't suggest using a sub unless your room is heavily acoustically treated though. They can do more damage than good if you aren't careful.
Edit: Also, with an acoustically treated room, you usually don't have to turn up the speakers as loud...a lot of times people try to overcompensate for nulls in their room by turning the speakers up and it won't ever really help.
In terms of hooking a sub up...if you buy a pre-built one, you don't need multiple outs from your interface. Most studio subs come with stereo inputs, stereo outputs, and a crossover built in. You would run stereo out of your M-box, stereo in to the subwoofer, L to left monitor, R to right monitor.
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18th October 2012
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#7 | | Gear interested
Joined: Oct 2012
Posts: 8
Thread Starter |
Thanks to those of you who offered help
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22nd October 2012
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#8 | | Lives for gear
Joined: May 2009
Posts: 3,365
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Having witnessed the design and build of countless subwoofers, I can give you a few do's and don'ts...
1) Do not assume that ANYTHING involving subs is simple.
2) The advice to treat your room first is spot on. Do it!
3) Cabinet resonance is the enemy of every speaker designer. Subwoofer designers need to address this even more. Go to a high end audiophile store and do the "knuckle test" - use a knuckle to thump the cabinets in different spots and listen to the sound of the cabinet. Now go to a store that sells inexpensive gear and do the same test. Hear the difference? Laminating the box, for example having a well-braced MDF inner box and a thin plywood exterior box can work and opinions on a proper adhesive vary widely. Some sandwich in a layer of MLV.
4) I assume you plan to build your own passive crossover? Study, study and study some more. Don't cut corners and revisit #1 above.
5) Subs add LF energy to the room. If the room has problems in the LF, the sub will help you to better hear your room problems. (Yes, this is redundant with #2, because it is ignored by so many sub-buyers.)
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