This is a Peerless Push-Pull (Non-Isobaric) Project.
This is my first post on this forum and my first DIY speaker project. I have been reading these forums for a while but now I finally have a reason to post here. I currently own a Sony SA-WX700 dual 10" push-pull subwoofer and I've been looking at the M&K push-pull's for a while now but have no desire to spend thousands of dollars on one speaker, nor do I have the money to do so, so here I am. Still being in college, funds are limited. I have been impressed with my little Sony for the last 5 or so years, nice potent little speaker. I really like the sound that the push-pull design produce so I think I'd like to go for a bigger better version, so to speak.
I am fairly certain that I have settled on the push-pull (non-isobaric) design. It has served me well so far and seems to work well for M&K. The idea of good response for music and high output for movies looks promising. I figure I can always find a 15" and try making a ported enclosure sometime in the future. I'd be interested in seeing how a push-pull and a ported sub work together in the same application.
I watch a lot of movies but this subwoofer will also be used with a lot of music. I am planning on slowly upgrading my little home theater setup. I recently purchased a used Denon AVR-2808CI off of ebay and next I plan on up grading my speakers. I figured I'd start with the subwoofer as it's the easiest before getting into attempting to build tweeters. I believe I have the design chosen but I do have some questions.
My design idea:
I started by testing the design in BassBox Pro and once I figured out what volume I needed I used Unigraphics NX3 to model the enclosure.
I am planning on using 1/2" MDF on top of 3/4" MDF for the top, bottom, walls, and lower speaker brace. The other braces are modeled as 1/2" MDF. The dimensions are 16"x20"x33.6" (WxDxH). I'm planning to use T-nuts and bolts where I can and I'm looking at picking two of these up:http://www.deepsurplus.com/Speaker-P...-218-Thickness
I have purchased two Peerless 830952 12" subwoofers on sale from Madisound ($159 each). My original plan was to use the Dayton HPSA1000 1000w amplifier connected to the two 4ohm speakers wired in series (reversed phase on the second one). However, I'm afraid that running the speakers with 500w (250w each) would damage them as they are only rated for 175w RMS, no idea what the peak wattage is rated at.
I only found one person using a similar setup driving two of these Peerless 830952 with the Dayton HPSA1000-R. However, he is having clipping issues now. I noticed he is operating under the assumption that the subwoofers are rated for 350w, not sure if he's assuming that for peak power handling but the only rating I've found actually issued from Tymphany in their catalog (through Madisound) is 175w.http://www.madisound.com/catalog/PDF/830952.pdf
Post about clipping:http://www.avsforum.com/avs-vb/showthread.php?t=1098736
The speakers max out their excursion when being powered with 500w. I'm not sure what the rules are when it comes to discussing xmax vs xmech, so I figured better to be safe than sorry. Also, I would like to be able to have the option to get down to 20hz if possible, even if it's not at max output.
That being the case I'm leaning towards the Oaudio 500w (325w into 8 ohm) amplifier. The modeling only indicates a 2dB drop consistently along the frequency line. I figure the easiest thing for me to do is just get a plate amp with the parametric EQ built in. The Reckhorn A-402 amplifier looked promising (400w into 2 ohm) but I don't feel like waiting 4 to 10 weeks for it to get here, nor did I find any reviews for it anywhere. I have no idea how to setup pro-audio amplifiers and EQ devices so I figure I'll save that for later.
On to the questions:
1) Am I correct in thinking that I don't need sound damping material for this application?
2) What can EQing (maybe some gain) do for me, if anything, in the low frequencies?
3) Is it a good enclosure design and is it strong enough to hold the speakers?
All thoughts, suggestions, and opinions are welcome.