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jocko_nc
11-27-2005, 07:42 PM
Operation Subwoofer commenced tonite...

Per numerous recommendations: I am going with dual 10.00 inch vented subs based on the Dayton Reference - High Fidelty subwoofers and Dayton 240 watt amps. To recap, I have recently started using two-way midbass / tweeter monitors as my primary speakers. They sound fantastic, but cry out for some deeper bass. With the low-end drop off of the monitors, I expect to crossover at 80-85 Hz. At such high frequencies, I wanted fine detail and wanted to preserve stereo imaging. Furthermore, my new room will be ideally suited for dual subs. I plan to supply these line-level with full range inputs, L and R, filtering highs on each unit.

That said, I will be using an oversize cabinet (2.0 cu ft plus for 10 inch) and will be porting dual 2.00 inch flared ports per. 16 x 16 x 18, woofer front and high, ports front and low. Roman Bednarek (a good guy from Madisound and elsewhere) ran the numbers and they look very attractive. The output and bass extension should be there in spades. If those drivers are as good as claimed, they should sound sweet as well.

If you want all the gory details, I'll post something in DIY.

jocko

jocko_nc
11-27-2005, 07:47 PM
Oh yea... Cost target is $600.00 for the pair. How can I go wrong?

Stay tuned...

kexodusc
11-28-2005, 06:36 AM
Man, oh man, I envy you. Those drivers look like the cat's ass for sure...Sort of a blend of the power of the Titanics with the better sound quality of Dayton's other subs.

Be sure to post some pictures. If Roman is helping you, you're in good hands! I do want all the gory details.

Curious why you chose ported over sealed cabinets?

jocko_nc
11-28-2005, 06:52 AM
That was the recommendation of both PE tech support and Roman, to get the low end extension way down. Roman recommended the cabinet dimensions and the port tubes. I will have to modify the port tubes, correct length is 15 inches. He figures the cabinet will be tuned to 22 Hz and an f3 of 21 Hz. The model shows SPL's fall off 3dB at 22 Hz.. ???. I would be thrilled to get that.

On paper, it looks like a great design. I wonder why most subwoofer designs are big on driver, small on cabinet? Is that a marketing thing?

We'll see how it goes...

jocko

kexodusc
11-28-2005, 08:41 AM
That was the recommendation of both PE tech support and Roman, to get the low end extension way down. Roman recommended the cabinet dimensions and the port tubes. I will have to modify the port tubes, correct length is 15 inches. He figures the cabinet will be tuned to 22 Hz and an f3 of 21 Hz. The model shows SPL's fall off 3dB at 22 Hz.. ???. I would be thrilled to get that.
Cool, figured as much...a sealed 10" would roll off a bit higher and rely more on unpredictable room gain, are you using these in an HT setup, or just for stereo?


On paper, it looks like a great design. I wonder why most subwoofer designs are big on driver, small on cabinet? Is that a marketing thing?


I don't think I'd agree with that...usually there's a tradeoff with cabinet size. You'll lose some power handling and efficiency with a bigger cabinet often, but if the driver is designed such that its parameters like bigger cabinets, then it lends itself to better sound and lower bass extension in return.

I think mass market subs are designed to be more "middle of the road" so they appeal to more people. Look at the PW-2100 by Paradigm...43 L volume, that's not a small box compared to a lot of 10" subs. If they made it 65 litres or something though, fewer people could fit it in. Then you'd also need the xmax available in the driver to handle the added power requirements you'll have with a bigger cabinet. Might call for a larger amplifier, or limit the maximum SPL the sub could safely reach.

In the case of your sub design, my numbers agree with Roman's for a "maximum extension" and flat response criteria. However, as an option, you can cut down 20% of the size and still get a -3dB roll off at 24 Hz, with a 43L volume...(14 X 14 X 18) not bad either....and migh fit into a few more spots.

Again, in your case, given the small change in efficiency loss for going with a larger cabinet, that's exactly what I would do, space permitting. But I'm sure you can understand some people would have space requirements. That's the great thing about DIY'ing subs, you get the perfect sub for your application.

jocko_nc
11-28-2005, 09:28 AM
Music, primarily.

I started out with the HT bug (new equipment after many years) when I bought a DLP HDTV a year ago. AV receiver, center and rear channels, the works. Honestly, however, I found that haven't watched very many movies. Typically: news, sports, and documentaries. I guess there aren't very many movies released that I care to see. Interestingly, I am now back into the music scene. Who knew?

jocko

kexodusc
11-28-2005, 10:37 AM
Awesome...and you felt the need for 2 of these subs??? A man after my own heart....

jocko_nc
11-28-2005, 11:04 AM
Anyone reading this with experience...

Believe it or not, I am having a tough time finding MDF. Here in the furniture capital of the U.S.!

Plywood is easy to work with and very strong, but I expect will cause resonance issues. What do you about cabinet plywood (birch) clad with particle board? 3/4 and/or 1/2, depending what might work best. It will weigh substantially more, but who really cares? Finish will be easy, black satin, to match the others. I may have a go with it.

jocko

GMichael
11-28-2005, 11:50 AM
Anyone reading this with experience...

Believe it or not, I am having a tough time finding MDF. Here in the furniture capital of the U.S.!

Plywood is easy to work with and very strong, but I expect will cause resonance issues. What do you about cabinet plywood (birch) clad with particle board? 3/4 and/or 1/2, depending what might work best. It will weigh substantially more, but who really cares? Finish will be easy, black satin, to match the others. I may have a go with it.

jocko

Do you have a Home Depot or Lowes near by? A 4'x8' sheet of 3/4" should ba around $22.00. And if you have all the dimentions ready they will even cut it all up for you. The first few (5 I think) are free and then .25 cents per cut after that.

jocko_nc
11-28-2005, 01:17 PM
Found a commercial place down the road that will sell retail. 3/4 and 5/8 thicknesses. Every type of plywood known to man. Let that sawdust fly!

jocko

kexodusc
11-28-2005, 01:36 PM
Birch ply is probably the way to go if you can't get MDF. Check the number of plys though, I think you want 13 ply if you can find it.
For subs, MDF is hard to beat...There's a lot of pressure and energy hitting those walls. Be sure to use good bracing. I like shelf braces...just router out a hole 10" diameter in a square piece that will touch 4 walls. Place it in the center and glue all sides...Easy.
H-braces are effective too.

There's tons more complex types of braces out there if your so inclined. Bracing might be more important if you're not using MDF.

Also look for HiDensity Particle Board...HDPB...it's about as strong as MDF..(it's not fibreboard though, a bit different)...

Nice thing about plywood..if you do 45' cuts, finishing it is easier...or use dado cuts for lock mitre joints or rabbet joints, and finish with edge banding....Saves a ton of time veneering!!!