Todd W

I am thinking of building a subwoofer for my home stereo. I just don't see off-the shelf ones that make sense for price/features that I want. I have a Denon AVR 3801 receiver (7x105W) and B&W 603S2 main speakers. I will fill out the center and rears with same series B&W's soon, running old stuff for now.

I want a sub that is strong, but musical. The B&W's are not the loudest speakers in the world, so the sub does not have to be overwhelming. I do want it to go into the low 20Hz range. I was wondering if double 10's would do it, or if I would need two 12's? I have room for a decent sized cabinet. I was also thinking of using a 2x100W spare receiver to power it for now, and getting a better amplifier later (therfore the two driver design). Would I want one driver in the front and the other in the rear, or one in the bottom and one in the front or rear?

I can build a top quality cabinet. I am willing to spend money on good drivers. I will select the actual components later, I am just interested in general design philosophy right now. Thanks.

octane 93

<ul><li><a href="http://www.diysubwoofers.org/">http://www.diysubwoofers.org/</a</li></ul>

ChuckH

...a bipolar configuration, so certainly 2-10's would be more than adequate if the components and design are good. BTW, mine is made by Mirage and is about 7 years old. It's a great subwoofer, IMO, and my friend likes it better than his 10" M&K woofer. I know that doesn't help you much with design, but it does show that 8" woofers can get you into your Hz range.

jlh28@work

First, low 20Hz range will be difficult to reproduce with any volume without a large driver. There are tons of trade-offs to consider. First a sealed design will produce the most accurate sound for music but it is the least efficient. A ported design will produce more volume at the cost of some accuracy. If you want to discuss options e-mail me and I can help you out. Also go to www.madisound.com and click on the speaker discussion page and read posts about sub design. A great book to read is The Loudspeaker Design Cookbook. So far I have built 7 subwoofers. 4 sealed (My favorite) 2 ported and 1 bandpass.

Jeff

jlh28@yahoo.com

Pelican Pete

The Sunfire True Sub, made by Bob Carver, is an impressive piece of equipment. It is TINY. And actually it contains two 10" drivers -- I think they are in push-pull configuration, but I don't remember for sure.
That thing plays LOUD and relatively clean -- especially for its size.

I ended up buying a Velodyne HGS12 which is a single sealed 12" in a slightly larger cabinet than the Sunfire. The Sunfire is a 12" cube, and the Velodyne is a 14" cube. It is much cleaner for music (servo controlled driver), and still has plenty of rumble for home theatre.

Incidentally, do not be concerned with 24Hz for home theatre OR music. Most of the punch that you feel in movies is around the 40-60Hz range.
In fact, THX specifications require that a sub be high-passed at 30Hz. The lower frequencies aren't really audible anyway -- at least not with any detail to speak of.
Even music does not go much below 40Hz. And most of the bass that we hear in music is in the 60-80Hz range.

I have personally tested my Velodyne down to 18Hz.
So I know it can do it. But when I flip the 30Hz highpass switch, I cannot tell a difference in the bass. In fact it sounds cleaner when I eliminate the lower frequencies, so they do not resonate.

Good luck. It sounds like you have a fun project ahead of you! And I am sure that the fruits of your labor will make you enjoy your sub even more than I enjoy my storebought sub.

-- Peter

Philbertt

Check out ACI at the link below. They sell direct so the prices avoid the typical high-end markup. I currently have the Titan sub and it really is great. It goes down to 20Hz and is extremely musical. It sells for $800 I believe. They also offer the driver and amp in a kit form allowing you to build your own cabinet.

A site I like is Soundstage.com which offers pretty insightful reviews of mid to hi end components. They have an excellent review of the Titan. View it at http://www.soundstage.com/entry11.htm

Good luck,
Phil<ul><li><a href="http://www.audioc.com">http://www.audioc.com</a</li></ul>

shinichie

Choosing the right components for a cool Home Theatre Design really counts. It is one of the many ways to feel relaxed at home with total entertainment plus the gift of a peacefull atmosphere.