Speaker design

Tube Radio

Tube Radio

Super Member
I plan on updating my DIY speakers with this woofer http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-175 to get better bass response. What I need to know is what the recommended cabinet size should be. I also had the idea of using this sub http://www.crutchfield.com/S-hPxLeY...Audio-MM2154D.html?search=15+subwoofer&tp=111 along with the woofers which would mean smaller boxes for the woofers and make it easier to extend down to 20Hz. I'm also kicking around the idea of using a plate amp on the subwoofer. What do you all think about it? Is this something I should persue or should I keep the Magnavox 12" woofers I'm currently using? If I do use a plate amp I need one about 100 watts with a built in adjustible HPF that is separately adjustible or works in conjunction with the adjustible LPF.
 
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What size is your current cabinet ? Is it ported or sealed ? Any particular reason you chose the pioneer sub ? what are you running your current speakers off of ? Do you want to use that polk in its own sub box ? If you get a nice 15" for your mains , you might not need the polk . Unless you like rattling the siding off of you neighbors house :D . :rockon:

Give me some details and I can work something up for you , if you like . Hopefully we can come up with a great sounding solution . :thmbsp:
 
My current boxes are a pair of 1 cu Ft sealed subwoofer boxes that house the Magnavox 12" woofers. I have the midrange horns and ribbon tweeters in a pair of Realistic MC1000 speaker boxes. I chose the Pioneer sub due to the fact it goes up to 3,000 Hz and the midrange horn is crossed over around 2,800 Hz. I plan on using the Polk sub for the low end below around 100 Hz which will equal a smaller box size for the Pioneer since space is a premium as these will go in a 12' by 12' building. I prefer the subs be front firing. Ideally I want to find a plate amp that has a 6dB high pass crossover and a 12dB low pass crossover since I am using a 6dB crossover on the speakers now. That way the speakers and sub will be more phase correct with each other which will make for a better sounding system. I want to go with a plate amp as it will save me from adding parts to my crossover and will be cheaper in the long run as capacitors and coils for those low crossover frequencies are quite expensive and take up lots of space. I am running the speakers off a Scott LK-72A amplifier with LT-110 FM stereo tuner. I'm wondering if I should get a pre-built subwoofer box from Parts Express with mounting hole for a plate amp or will those boxes be too small. I plan on keeping the sub boxes sealed along with the box for the other three drivers. I'm mainly doing this,because those Magnavox speakers will not last forever although they do handle nicely everything the Scott throws at them. What I may do once we figure out the size of the subwoofer boxes is have a car audio shop make them. Seeing the Pioneers won't have to go below 100 Hz could it be possible to get the same size boxes made for them as for the subwoofers?

Thanks for your assistance so far.
 
With a sealed cabinet , uni-box shows this speaker peaking at 96db around 120htz to 150htz , depending on the enclosure size . This isn't a problem since you plan to cross at 100htz to a sub . The problem is that this speaker is -6db at 1000htz and falling . you said that you want to crossover to your tweeter at 2.8k . The enclosure size would be flexible though since you wont be using this for low bass , your polk will be filling in the bottom end . As for the sub enclosures from PE , you cant beat them for the price , they are really nice . I highly doubt that your local car audio shop could make anything that nice for you at 3x the price , if at all .
 
Tube Radio said:
I plan on updating my DIY speakers with this woofer http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-175 to get better bass response. What I need to know is what the recommended cabinet size should be. I also had the idea of using this sub http://www.crutchfield.com/S-hPxLeY...Audio-MM2154D.html?search=15+subwoofer&tp=111 along with the woofers which would mean smaller boxes for the woofers and make it easier to extend down to 20Hz. I'm also kicking around the idea of using a plate amp on the subwoofer. What do you all think about it? Is this something I should persue or should I keep the Magnavox 12" woofers I'm currently using? If I do use a plate amp I need one about 100 watts with a built in adjustible HPF that is separately adjustible or works in conjunction with the adjustible LPF.
Click to expand...

If you call Parts Express and ask for the technical department, they can model it for you.
 
Is there another 15" 8 ohm speaker that will go from 100 Hz-3000 Hz? Maybe a pro audio driver perhaps? I may go with this subwoofer cabinet http://www.parts-express.com/pe/showdetl.cfm?Partnumber=302-830 and this plate amp http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-804 On the amp does it have a high pass crossover for the high level inputs and also will it work right with only one input connected? I'll list some 15" speakers I found .

Eminence Kappa Pro-15A 15" Cast Frame Driver
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-422

Eminence Deltalite II 2515 Neo 15" Driver
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-595

Eminence Beta-15A 15" Driver
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-410

Eminence Delta-15A 15" Driver 8 Ohm
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-418

Selenium WPU1507-SLF 15" Driver
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-425

Eminence Alpha-15A 15" Driver
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-407

Pyle Pro PPA15 15" PA Speaker
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=292-218

Eminence Gamma-15A-2 15" Driver 8 Ohm
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-454

Selenium 15WS600 15" 600W Woofer
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-393

Eminence Kappalite 3015 Neo 15" Driver
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-597

Let me know which woofers will work best for my application. It seems like Eminence may be a winner as they have more drivers that may suit my needs than the others. I like the buy one get one free deal on the subwoofers. I'm thinking about getting them now so I don't take a chance of that special going away. I may even get a couple of the Parts Express subwoofer boxes for the woofers as well and keep the mids and tweeters mounted in the Realistic MC-1000 speaker cabinets as that would make the speakers easier to move if the need arises and will save me from having to get any boxes built.


Edit: my dream subs would be a pair of Ampeg V4B bass cabs with proper 15" woofers in them. Bet I could annoy the neighbors with those :D
 
So are you going to be installing the speakers into the realistic cabinets and crossing them to a mid ?
The PE box may work . It is 2.5 cft and the info at crutchfields says 1.5 cft . I cant find any T/S parameters on that site for the polks either . The plate amp says that it has low/high , input/output . You may need to call PE tech and ask them about the inputs . I would think if you were only going to put one input to it , you would not get stereo out .

Do you plan to put the 15's back into the realistic cabinet with the mids and tweets ?
 
No the Realistic cabinets (originaly had 8 inch woofers) only have the mids and tweets in them. I plan on getting two more of the Parts Express subwoofer boxes for the woofers. I plan on using two subs each with their own plate amp. If the plate amp does not have a high pass crossover for the speaker level inputs I will have to add a capacitor to my current crossover so the woofer does not have to handle the frequencies the subwoofer is going to handle. That would also lighten the load on my Scott LK-72A amp. The only problem is setting the plate amp's variable crossover and volume properly to suit my taste. I like how you can change a couple resistors in the plate amp and get different levels and frequencies of bass bost or get flat response. I don't need 240 watts on the sub, but the subwoofer cabinet is made for that plate amp and it seemed logical to use that amp. All I'm waiting on is to know which woofer is best to use for the upper bass-2,800 Hz. With my cureent woofers when I crank the volume to 11 :D I can feel the drums hit. I will be keeping the Magnavox woofers so I can easily put them back in the system if the need arises. I used these speakers and the LK-72A amp at a cookout we had at work last Summer and they sounded just as good outdors as they do in my 12' X 12' building. I'm still amazed at how well my first DIY speaker project sounds. When I put these speakers together originally I never expected them to sound so good. I am using this horn lens http://www.parts-express.com/pe/showdetl.cfm?Partnumber=270-308 with this compression driver http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-446 form the mids. I'm using this tweeter http://www.parts-express.com/pe/showdetl.cfm?Partnumber=277-112 for the highs. I will attach my crossover.
 

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Thanks. I'll go with the first one. I'll keep posting as I workon this project. I will build these in stages as it is rather expensive.

Woofers $269.94
Plate amps $230.00
Subwoofer boxes $238.58
Woofer boxes $238.58
Subwoofers $149.99
For a grand total of 1,127.09 not including shipping.

I will buy the subwoofers first on my next paycheck to ensure I get the buy 1 get 1 free deal. Setting up the speakers will be quite interesting.

Should be well worth it. When I get done I will report on how these speakers sound. I expect more punchiness and better overall sound in the bass and mids. I'm thnking that 15" will integrate better with the midrange horn as the L-pad on the horn is turned down almost to zero in order to balance it with the 12" woofer.
 
Oh man , It should sound really nice if you have your mid turned down that far .

Those 15s are made just for this , mid-bass . LMAO , your gonna shake the

house . :banana::music:


Were you ever able to find out if the plate amps have high pass out ? And what the roll of can be adjusted to ? How do you plan to hook up to the plate amps ? I assume you are going to go from the plate amps to your main speakers . You may just want to run a single polk/box/amp . Keep the extra as a spare . You will already have more than enough bass . It would also make hooking it up easy , avoid having to bridge at the amp inputs from your receiver ( which your Scott might not like ). Plus ..... it would save you $250.00 !!!
 
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I could use one amp and sub, but I like the bass to be in stereo as some songs may have low bass on one channel with no low bass on the other channel and a single sub would ruin the effect. I have no idea if the plate amp has a high pass out or not, but I will test it when I get the amps and see if it does or not. If not would I just add a cap of the proper value for the crossover frequency I choose in series with the high level speaker output terminals? I'm not sure what the impedance of the speaker level terminals are, but I would bet it is the impedance of the speaker that is connected to the speaker level output terminals. I will go from the plate amps to my speakers. Yes I had to turn the mid down that far so it wouldn't over-power the woofer. I can say that compression driver with the 8 inch horn lens sounds like a cone midrange with all the benefits of a compression driver. I chose them, because I'm usually very close to the speakers when I'm listening to them due to the fact that I'm usually on my computer as well. These speakers sound the best of any I have heard so far and a lot of that has to do with the Scott LK-72A amp I'm using. I like the L-pads on the mids and tweeters as I can adjust them to the amplifier they are connected to. Once I get everything set in stone I will mark where the normal settings are on all the controls on the speakers.
 
Looks like I may have to start on this project sooner than I thought. The 12" woofer in the left speaker has developed an intermittent buzz. It may be the spider coming un-glued on one side, but I'm not too sure and I don't feel like pulling it out of the speaker box since I used plumbers putty to form the seal between the speaker and box. I must say for whast they are those 12" Magnavox woofers pound. I almost never run my Scott at full power as it's not needed in my 12' x 12' building.
 
Unfortunately it is the speaker :tears:. I will concentrate on getting the subwoofers going first. Then I will get the woofers later on.
 
That sucks , sorry to hear that . I hate it when stuff like that happens , it ruins your plan/time table . Sometimes it can ruin your plan financially as well .

Did you end up getting those polk subs while they had that special ? If so , what do you think of the build quality on them .
 
Not yet. The deal is still going.I'm hoping to do something when I get my tax returns back. I did drive these speakers very hard at times at nearly the full output of the Scott amp which is about 35-40 WPC.
 
Tube Radio said:
I could use one amp and sub, but I like the bass to be in stereo as some songs may have low bass on one channel with no low bass on the other channel and a single sub would ruin the effect. ...
Click to expand...
For low frequencies, below 100Hz or so, there is no apparent directivity, in other words you can't really tell where the bass frequencies are comming from. Therefore, you can either sum the two channels on the plate amp (if it has stereo mixing inputs) and drive a single subwoofer driver without any loss of imaging.
 
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