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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Subwoofer FUD Forum Archive => Topic started by: Eric Wong! on May 20, 2004, 11:15:17 am

Title: Labhorn FAQ
Post by: Eric Wong! on May 20, 2004, 11:15:17 am
I'm trying to put together a FAQ of the questions that seem to be asked over and over to make an easier reference instead of "search the archives", and maybe it can be stickied once all the bugs are worked out.  I know there is one FAQ but it isnt very detailed.

***disclaimer, I have not built one yet nor used one, so please feel free to correct me and there is no guarentee of the accuracy of the info, most of it I have researched or read on this and the old forum***.

Q: Who designed the Labhorn?
A: Tom Danley of ServoDrive.

Q: Is the Labhorn commercially avaiable?
A: No.  

Q: Can I make and sell the Labhorn for profit?
A: NO!  

Q: What is the advantage of the Labhorn?  
A:  It is extremely efficient, can handle alot of power, sounds excellent and plays rather low, can outperform commercial 2 18" counter parts if you DIY.  

Q: What are the disadvantages of the Labhorn?  
A: It is a DIY design so you have to create it; its dimensions are rather large and heavy compared to some of the 2 18" counter parts.  It requires a time delay on the tops to match.  

Q: Can I use the lab in the house?
A: Yes, but the 8 foot ceilings of most domestic settings causes a cancellation (was it 70 hz??).  

Q: What cut sheets are required?
A: Assuming minimal margin for error, 10 5x5 sheets are required for a pair, or 5 4x8 sheets.  

Q: What material should be used?
A: For pro sound, Baltic Birch or Russian Birch (are they the same thing?).  For home theater, you can get away with a less "abuse resistant" material such as MDF or Eurowood.  

Q: Approx how much $ is required to build one?  
A: Assuming you have all the tools and time, approx $200 for wood and $300 for drivers for one horn, and any wheels, nuts bolts etc.

Q: What are the minimal tools required
A: Router, drill, jig saw, circular saw.  Ideally a table saw.  

Q: What material should the access panels be?
A: If its home theater, wood is acceptable, if pro audio, then 1/4" aluminum should be used to dissapate heat. Get the aluminum from a metal shop

Q: How much power can it handle?
A: A crown macro-tech 5000vz amp is a perfect match at a little over 2000 watts per unit.  Some have used a PLX3002 amp bridged on a single unit.  

Q: What is the effective frequency response?
approx 30-80 hz.  

Q: What should it be low passed at?
80 Hz.

Q: what is its nominal impedence?
A: 3 ohms.  2 6 ohm drivers are paralleled.  

Q: Can you use 1 driver instead of 2?
A: Do what you want but it is really designed for 2 drivers.  

Q: How long will it take to build one?
A: Depends on your skill but some people have done it in about 5 hours.  

Q: What is the most difficult/time consuming part of the design?  
A: Building the inner chambers.

Q: What sequence should it be built in?
Cut all the figures, build the inner chambers, then assemble the rest.  There are build sequences posted all over.  

Q: what are mouth extenders?
A: Brad Linz built some nice ones for his home theater, it extends the low freq repsonse and allows the horns to be placed in a perpendicular fashion to the room.  

More Questions I havent answered:
What amount of delay should be applied to tops to time align the bass to the mids and highs?
How much does one weigh and with what construction?
What "low pass/subsonic filter" should be used?  
What is the 10" labhorn?  
What is the minimal amount of power needed?
Whats the difference between the V1, v2 and v3?