Replies

1. 
   Billgiblin | Aug 04, 2005 09:13am | #1

   You're right that it would rattle and you would probably have to do a lot of geometry and make the subwoofer part an enclosure of a specific volume. Otherwise the sub os not generating optimal bass. Even with the sub in a seperated compartment of the ent cent you're going to get vibration.

   (Stereo equipment used to be my hobby before woodworking.)

1. 
   WillGeorge | Aug 05, 2005 05:29pm | #7

   You're right that it would rattle and you would probably have to do a lot of geometry and make the subwoofer part an enclosure of a specific volume..
   Correct BUT with the proper 'Tuned Port' you can do almost anything..Way back when Hi-Fi started and I was making amplifiers fro folks (Yes TUBES) they were just getting into that 'Tuned Port' stuff..Look around the web.. Sure to find some info that will help..Even with 16 and 20 inch woofers usually the only problem is a 'turntable'.. You know.. With a needle.. and the neighbors...

2. 
   jkl | Aug 04, 2005 12:23pm | #2

   Is the idea to get a subwoofer driver and mount it in the entertainment center, essentially using the center as the driver's enclosure? (As opposed to buying a full system with its own enclosure and inserting that in the entertainment center.) I don't think either approach is a good idea, but the first one is likely to be dreadful unless you put a lot of constraints on your design and construction. A subwoofer is a system consisting of the driver and a mass of air that modifies and controls the response of the driver to its input. It's the job of the enclosure to provide the appropriate volume of air, either completely sealed in the enclosure or with a carefully determined vent system, typically made with a tube of a specific cross-sectional area and length. So you can't just slap a driver into an entertainment center and have much chance of it sounding good, even apart from the issue of rattling. To complicate things, a subwoofer typically needs a large volume of air that will eat up space in the center that won't be good for anything else. (For instance, my sub is roughly 24 by 24 by 24.)

   Subwoofer placement in a room matters very, very much, too. I certainly found it hard enough to place my sub in my room just in its own enclosure. Presumably your customer wouldn't have much in the way of alternatives if the sub didn't work well in the intended location of the center -- and this could manifest as way too much bass, or way too little.

   Good luck with this!

3. 
   CRAIGCONEY_M | Aug 04, 2005 03:33pm | #3

   I've been told by AV people to keep the sub no more than 5" off the floor in a cabinet.   I've seen plenty of them in cabinets, no one has complained of any problems that I've heard of.

    

4. 
   bones | Aug 04, 2005 04:24pm | #4

   I'll second what the others have said about keeping it close to the floor. When I built my home theatre system a good friend who is an audiophile, explained to me that the best placement is as close to the corner of a room as possible. I have the JBL12" and placement is critical. My friend explained the technical details about wave lenght and surround properties, but I just took his advice. My JBL has rubber feet to isolate vibration and sits about 10" out of the corner and the driver faces the floor instead of facing out. Play with placement, and you will see that it does make a difference. Good luck post some pics of the center when you get it done.

5. 
   wchips | Aug 04, 2005 05:10pm | #5

          HI. Some time ago i bought a crosscut sled at a woodworking show,I belive the name of it is "Dubby board"   One end of the fence has a pivot on it the other end has a thredded bolt that comes agenst a stop,to adjust for squareness. the adjusting end also has a bolt that you can lock it down when squre.

                                       Have a nice day Lee

6. 
   charlesm | Aug 04, 2005 09:13pm | #6

   I have a sub in the bottom cabinet of my entertainment center with acoustic cloth for the door panel and have never had any issues. Excellent bass and no movement or rattle of things in or on the cabinet.

   Charles M

   Freud America, Inc.

7. 
   GrGramps | Aug 07, 2005 01:29am | #8

   Siskiyou,  Without question I would refer you to a forum maintained by Parts Express.  These guys "live" electronics and sound equipment and you will find them just as eager to help as members of our forum and some of them are great woodworkers too.  This link should get you there: http://www.pesupport.com/cgi-bin/config.pl

   If that doesn't work try: http://www.partsexpress.com/ and then click on tech talk.  I refer you to  them simply because when I wanted good sound in my shop for not much money, they had the answers.

   Roy