DIY SUB. I got the amp, I got wood(you can laugh), opinions on whats next?

[polkanddie]

This is my amp, Just got it in a trade. Dayton HPSA500 500W Subwoofer Amplifier. I was thinking about changing it up and using a dual 2ohm woofer, either a kicker L5, Infinity Kappa, Or possibly a Polk?? Any thoughts...

[Face]

What's your budget?

How much space do you have for an enclosure, etc...?

[kawizx9r]

Don't think about how much 'wood' you currently have, you can and should always get more at your local Lowe's or Home Depot or any other lumber provider if you need more of it. I say this because depending on the type of driver you pick up, you might need a large/medium/small box given the drivers T/S parameters. Click the subwoofer link in my signature to get an idea of a few things you'll need along the way. The guys here at CP have been way more help to me than the other forums I've tried so look forward to that :)

Anyway you go with it, best of luck!

-Freddy

[Face]

I hope you're using either MDF or Baltic Birch.

[kawizx9r]

I hope you're using either MDF or Baltic Birch.

+1
Almost forgot about that!

I used MDF for mine (3/4" thick), and it was only 27 bucks for a 4' x 8' board. In fact I still have a 2' x 4' piece left (used half of it for my oversized subwoofer).

[zingo]

What about a Focal W cone driver? If you could find a good price on one, I feel like it would be the most accurate and musical subwoofer around.

http://igs.avhub.com.au/IgnitionSuite/uploads/images/IgnitionSuite_Image(296).jpg

[Face]

What about a Focal W cone driver? If you could find a good price on one, I feel like it would be the most accurate and musical subwoofer around.

http://igs.avhub.com.au/IgnitionSuite/uploads/images/IgnitionSuite_Image(296).jpg

They're nice if you don't mind paying $750 each.

[polkanddie]

Oh wow, that would be nice. This is going to be a low budget project though...Most likely going to find a driver on ebay or CL. I am using 3/4'' mdf, Also this is going to be mainly an HT sub. Has anybody tried the whole passive radiator option before? It looks complicated... anyways, I have an old qlogic I was going to use the ports out of it, or at least the flared ends, would it be easier to just make a slot port?

[polkanddie]

Also I wanted it somewhat compact, I was thinking an 8" or 10", but definitely something that can handle a good 250 rms without a sweat.

[kawizx9r]

Also I wanted it somewhat compact, I was thinking an 8" or 10", but definitely something that can handle a good 250 rms without a sweat.

Like I said above, I think you're looking past a few important things. If you want the sub to work properly and give you the bass you crave, set it up right. All subs are different, and going from a slot-loaded enclosure/ported enclosure/sealed enclosure will yield different sized enclosures. It's not just building a box, putting a port/hole in it and calling it a day. Take it 1 step at a time.

-Freddy

P.S. My sub cost less then $240 to make, not saying its something you can do using the same box-dimensions unless you got a deal on the same driver I used. Just make sure to do it right and you'll be very pleased. I know I am :)

[kawizx9r]

One last thing, here you go. An enclosure volume calculator - http://www.hometheatershack.com/forums/enclosure-volume-calculator/

Talk to someone that has WinISD as well, such software can help you find out what port lengths/diameters/etc. are needed to achieve certain frequencies given said driver/amp.

[Face]

Here's a nice sub that doesn't require a huge box.

http://www.madisound.com/catalog/product_info.php?manufacturers_id=183&products_id=8535

[zingo]

Can't go wrong with Seas!

[Face]

Can't go wrong with Seas!I have a pair of these that will be going into my HT soon. http://www.madisound.com/catalog/product_info.php?cPath=45_228_258&products_id=822

[zarrdoss]

I have the same amp and paired it with a 15" 4 ohm kicker comp vr in a sealed box. it sounds great.





http://www.polkaudio.com/forums/showthread.php?t=85249

[polkanddie]

Ok, I was on newegg this morning, saw what looked like a deal on a 10" Polk DB series sub, guess what 270w rms and 540w max.... same as my amp. Single 4 ohm voice coil. Looks to match up perfect. It was 29.99 shipped. I dont think you can beat that.... here are the specs.... General
Brand Polk Audio
Model db 104
Type Subwoofers
Component
Subwoofer Size 10"
Cone Material Dynamic Balance Polymer Composite dish cone
Surround Material Santoprene surround
Voice Coil Single
Voice Coil Construction 2" Diameter Double venting of the 4-layer Kapton Voice Coil
Damper (Spider) Fire-retardant flat NOMEX Spider
Specification
Peak Power 540W
RMS Power 270W
Frequency Response 28 Hz - 200 Hz
Sensitivity 86 dB
Impedance 4 Ohm
Crossover Point 37 Hz
Thiele/Small Parameters Qms: 7.0, Qes: 0.62, Qts: 0.57, Vas: 0.85 cu. ft., Sd: 54.25 sq. in., Xmax (linear): 0.3 inch, Xmax (mechanical): 1.0 inch, Le: 1.85 mH
Mounting Depth 6.25"

Any suggestions about box dimensions with this info.

amp info is ...
High power class AB output stage
Patented tracking downconverter power supply
Full parametric bass EQ
Phase reversal switch
Advanced soft clip circuitry
Toroidal power supply transformer
Auto On/Off
Power output: 273 watts RMS @ 8 ohms, 540 watts RMS @ 4 ohms
S/N ratio: 98 dB (A weighted)
Crossover: 30 - 200 Hz, 24 dB/octave
Dimensions: 11-15/16" W x 11-15/16" H x 5-1/4" D...

And I realize I may have made a booboo.... It seems I may have too small a sub...

[polkanddie]

I swear I saw 240 rms at 4 ohm on the manny.... let me go find that thing.

[polkanddie]

One last thing, here you go. An enclosure volume calculator - http://www.hometheatershack.com/forums/enclosure-volume-calculator/

Talk to someone that has WinISD as well, such software can help you find out what port lengths/diameters/etc. are needed to achieve certain frequencies given said driver/amp.

Sweeeet thanks dude.

[kawizx9r]

Sweeeet thanks dude.

No problem, and with WinISD + T/S parameters you posted above you'll find out exactly what type of enclosure will work out for you. It'll also give you expected frequency response/etc.

I'm getting output down to 18hz from my DIY subwoofer :D

-Freddy

PS I wouldn't mind grabbing that 500 watter from you, my amp is actually a 250w rms model@4ohms not 240w.

[polkanddie]

Ok, so what does it mean when the website says rms and the manual that came with it says 273max at 8ohms and 540max at 4ohm.... thats kind of misleading if its the latter...

[kawizx9r]

Ok, so what does it mean when the website says rms and the manual that came with it says 273max at 8ohms and 540max at 4ohm.... thats kind of misleading if its the latter...

It's not really misleading, those are the specs given at certain loads IE 273watts@8ohms and 540watts@4ohms. My amp is 150watts@8ohms and 250watts@4ohms.

The max ratings will also state distortion levels/etc. and if you read more about that you'll see whats "acceptable" to state in the manual/specifications. The power actually going to your speakers isn't always a full 273@8/540@4, that's determined by the volume level you're driving them at.

In laments terms, if the speaker being driven is a 4ohm load such as your subwoofer you purchased....your amp will see that 4ohm load and supply it the 1-540 watts (hopefully you don't turn it up that loud).

EDIT: Btw, remember to use all your t/s parameters correctly. I read about a sub or two lost due to crazy over-excursion because the way he had his box ported or sealed.....anyway just do it right. 'Nuff said.

[polkanddie]

Qms: 7.0, Qes: 0.62, Qts: 0.57, Vas: 0.85 cu. ft., Sd: 54.25 sq. in, Ok so what does all this mean... It needs a .85 cubic foot box sealed? I think thats all I would be doing unless I use a sonotube... btw. how would I mount the subwoofer in one of those?

[kawizx9r]

Maybe Ben can chime in later in regards to the sonotube. Btw, sonotubes are usually ported enclosures, the height of the sub makes up for the lack of sq. footage it occupies while still giving you a lengthy-sized port for that deep bass.

You ready to put in all the work to build this sucker? It's not hard at all, but there were some things that I had to do that I didn't like IE caulking my port tube in the inside and sealing everything,etc.

Just today I covered upsome of the nail/screw holes with some wood filler. I'll take a pic of it to show you, but just goes to show I'm not done yet. Will need to cover up the rest of the holes, sand, primer, then paint+sand+paint+sand+paint and then finish it off with a clear coat or something.

[kawizx9r]

Here you go, big SOB.

The lighter colored spots is where I put the wood filler in. Dreading having to take things out such as the plateamp and sub to sand things down and get it ready for paint. Who knows, it might be pushed awhile back and I'll just apply one of those laminates or something.

http://i845.photobucket.com/albums/ab16/sirsoapmaister/SNV12258.jpg

Maggies right next to it :D

[polkanddie]

Noice. I kinda want one to be pretty small and/or in a tube. How are you going to finish it?

[kawizx9r]

Noice. I kinda want one to be pretty small and/or in a tube. How are you going to finish it?

Just like the guy I met told me.....cover up the holes, sand until everythings flush and smooth then primer. Sand, then paint, sand, paint, sand some more (using higher grit paper after every coat) and paint once more. By the 3rd coat or so, I'll be using 600/800 grit sand paper just to smoothen things out if necessary. Should give me a very streamlined look. I'll only do all that if time permits and if I don't just dump the whole idea altogether. I hate not having a sub when listening to music, it's the only reason why it's put together without a finish on it :o

[polkanddie]

I traded my Eosone rsf600's for this amp. It seems like a good deal since I couldnt sell them for the $150 I wanted for them... pretty sad huh.

[polkanddie]

I think I am going to go with a basic square sealed box with good bracing, I might up the mdf to 1" and add some carpet spikes and sometype of grill. Probably the polk one that Ive seen with this woofer..

[kawizx9r]

I think I am going to go with a basic square sealed box with good bracing, I might up the mdf to 1" and add some carpet spikes and sometype of grill. Probably the polk one that Ive seen with this woofer..

Take it one step at a time ;)

Always double check all your measurements, you don't want things cut out and not lining up properly if at all. 3/4" will suffice, especially for the driver you're using but if you want 1" that'll work too. I chose not to use a grill at all, nothing beats seeing my subwoofer dance like crazy with some bassy music.

[Face]

Just like the guy I met told me.....cover up the holes, sand until everythings flush and smooth then primer. Sand, then paint, sand, paint, sand some more (using higher grit paper after every coat) and paint once more. By the 3rd coat or so, I'll be using 600/800 grit sand paper just to smoothen things out if necessary. Should give me a very streamlined look. I'll only do all that if time permits and if I don't just dump the whole idea altogether. I hate not having a sub when listening to music, it's the only reason why it's put together without a finish on it :oYou're going to need 2-3 coats of primer over MDF.

[ben62670]

The first few coats of primer need to be light too. They are called tack coats to keep the primer from soaking too deep into the MDF.

[kawizx9r]

You're going to need 2-3 coats of primer over MDF.


The first few coats of primer need to be light too. They are called tack coats to keep the primer from soaking too deep into the MDF.

Thanks for that you guys. Over here I'm trying to help someone out with their sub build and still needing some advice myself lol.

[Face]

Coating the MDF if a 50/50 mix of wood glue and water will also do a good job sealing MDF.

[polkanddie]

Qms: 7.0, Qes: 0.62, Qts: 0.57, Vas: 0.85 cu. ft., Sd: 54.25 sq. in..... Can anyone tell me what the Ideal sealed inside volume of my box should be using this info? I really would like to know since my sub will be here in about a day or so.

[polkanddie]

Thanks for all the advice about painting the box and getting it sealed... But alas.... I have to build the box first... lol

[Face]

Download WinISD(it's free) and enter those parameters into it.

Does your amp have bass boost?

[polkanddie]

It has a low pass xover with gain control, phase switch, and EQ. I dont think it would have a bass boost since its a plate amp made for a subwoofer. But I may be wrong.

[polkanddie]

Does 1.57 cu ft sound right?? thats what I got when I put in the info that I found... Eh, thats pretty small. but then I have to mount the amp and take out some for that as well.... Amp is about 5 inches deep. 10x10 cut out.

[kawizx9r]

Does 1.57 cu ft sound right?? thats what I got when I put in the info that I found... Eh, thats pretty small. but then I have to mount the amp and take out some for that as well.... Amp is about 5 inches deep. 10x10 cut out.

You can use a volume calculator or something on that forum I posted to find out the volume your bracing will take as far as anything else going inside the box.

1.57 cu ft sounds about right for your sub, mines over 4 cu ft (at about 17" wide x 21.5" tall x 25" deep).

Double check your plateamp, it might have bass boost like Face suggested, I know several Dayton amplifiers do....and all of them have a chart of what resistor to use in place of R27/R28 in case you manually want to add a bass boost yourself.

[Face]

If this is for HT, you need bass boost for a sealed sub.

[billbillw]

Dude, you really should be looking at a ported box for that sub if you want to do home theater with it. In a sealed box, you loose most of the response below 45Hz. In a HT setup, you want decent response down to 25Hz or lower.

Look at the plot below comparing a ported vs sealed box and you can see how much you are giving up. Sealed is yellow, ported is red.

http://i45.photobucket.com/albums/f94/billbillw/db104ventedplot.jpg


In a 10" size, a sealed box really only works for car audio use. This is because you are trying to minimize box size, but have the car's 'cabin gain' to help boost the low end.

In case you don't see it in the image, the ported box is 2.7 cu ft with a port tuned to about 26Hz. You could shrink the box down some if you used generous amounts of polyfill, but you should read up on that first.

[everpress]

Coating the MDF if a 50/50 mix of wood glue and water will also do a good job sealing MDF.

Face, I'm prepping a couple of RT1000p's that someone gave me. I peeled that rubber stuff off (I would have done this even if some wild cat hadn't started that before I got them- that stuff is ugly), and I'm left with bare MDF.

If I seal the MDF with the WoodGlue/Water mix, should I still use 2 coats of primer? I mean I guess it can't hurt, but since you know what you are doing and this is my first project, it'd be worth asking.

Sorry to jack the thread...

[Face]

I would still use primer.

Be sure to give the glue/water mix and a good sanding beforehand though.

[jinjuku]

This is my amp, Just got it in a trade. Dayton HPSA500 500W Subwoofer Amplifier. I was thinking about changing it up and using a dual 2ohm woofer, either a kicker L5, Infinity Kappa, Or possibly a Polk?? Any thoughts...

For the $150 mark get the Shiva-X (http://www.diycable.com/main/product_info.php?cPath=24&products_id=653) from diycable.com. Most likely one of the best bang for the buck subs out there.

I would say go for the Infinity Kappa 12VQ if they were still in production. I haven't seen the specs for the the Kappa 120.w9 that is (I believe) it's replacement. They blinged the 120.w9 up and it looks terrible IMO.

[jinjuku]

You're going to need 2-3 coats of primer over MDF.

MDF especially on the cut edge will soak primer. One trick is to hit the edge with a thin film of glue. Just use your finger or a small .5 or 1 inch paint brush to apply it and let it dry then primer.

The finished side of MDF won't need as much attention. I still use Killz oil based primer on MDF.

[Krazyz1]

Part Express.com will have everything you need including books on speaker design. A un ported sub is best but takes a big amp to move it. A slotted port tends to make less "chuffing" sounds then a single round port due to area of relief.

[jinjuku]

Part Express.com will have everything you need including books on speaker design. A un ported sub is best but takes a big amp to move it. A slotted port tends to make less "chuffing" sounds then a single round port due to area of relief.

A sealed sub isn't better or worse then Ported/Passive Radiator/Band Pass/T Line/IB subs. It's different for sure. Better/Worse is just subjective. It depends.

Not only does a sealed sub take more amp, it takes eq.

[kawizx9r]

billbillw, +1 on the ported enclosure.

I thought about mentioning this as well to polkanddie since that sub doesn't seem to get very low by itself, a ported enclosure would help in this situation. Since he's looking for a 'small enclosure' his best bet might actually be a sonotube imo.

[polkanddie]

The amp has an EQ. Its 540w max. which matches the driver I ordered. it should arrive tommorrow or saturday the latest. Also Im not looking to get kicked out of my apartment. So I think sealed will be good... and simpler... Also. I think ill make it downfiring to somewhat match the look of my towers.

[kawizx9r]

The amp has an EQ. Its 540w max. which matches the driver I ordered. it should arrive tommorrow or saturday the latest. Also Im not looking to get kicked out of my apartment. So I think sealed will be good... and simpler... Also. I think ill make it downfiring to somewhat match the look of my towers.

If you're going sealed then I suggest you use solarseal caulk for the inner seams to completely seal things up. This by no means is "the best" but with personal experience I love the way it sealed everything up in my sub.

Downfiring can affect the subwoofer depending what the floor is underneath it. I'd say front firing is a little more forgiving in that respect, but it's your subwoofer so totally your decision. Don't try to compromise your box just to make it "look better" or "smaller" than it should be. ;)

[Face]

Unless you're concerned about the cone being damaged, go front firing.

[polkanddie]

Points taken. Front firing will allow me to show it off a bit... instead of saying hey look i got this box and it makes boom boom sounds. I kinda like watching the woofer move. It will be a carpeted floor so... Quite right. Thanks to everyone for all the advice, and I WILL be taking pics of all the progress in building this... even though it wont be as exciting as an ubercomplicated box. The woofer is only one state away... I should be seeing it tommorrow!!!

[kawizx9r]

Points taken. Front firing will allow me to show it off a bit... instead of saying hey look i got this box and it makes boom boom sounds. I kinda like watching the woofer move. It will be a carpeted floor so... Quite right. Thanks to everyone for all the advice, and I WILL be taking pics of all the progress in building this... even though it wont be as exciting as an ubercomplicated box. The woofer is only one state away... I should be seeing it tommorrow!!!

DO take pictures of every major step you take :D

I've gotta add that pic I posted up on this thread onto my thread just to keep things updated......now I just need to go pick up my woodglue I left at a friends and do the 50/50 mix of water/glue. Would that be easily sanded down with 400grit, 200grit or wet/dry sandpaper because I can imagine the glue/water mix might need some sanding.

[polkanddie]

I think if you read back someone said that it definitely would need some sanding. Now I cant wait til the sub shows up so I can get everything together. This is gonna be fun.

[kawizx9r]

I think if you read back someone said that it definitely would need some sanding. Now I cant wait til the sub shows up so I can get everything together. This is gonna be fun.

That was in regards to primer/paint, not the glue/water mix but I'll sand it anyway. Got plenty of 400grit paper left, so its not coarse enough to get rid of the improvised sealant but enough to make it smooth if need be.

You figure out the box dimensions you'll be using? You have all the materials needed for completion of the box?

[polkanddie]

I put the specs in that program and it told me 1.57... but i took a look at the polk manual on the sub I have and it says recommended .66 in a sealed enclosure....curious....

[kawizx9r]

I put the specs in that program and it told me 1.57... but i took a look at the polk manual on the sub I have and it says recommended .66 in a sealed enclosure....curious....

Manual for that sub suggests a smaller box because it's taking into consideration the fact that it'll be inside a trunk/etc which will pretty much act like a big enclosure IE 'cabin gain'

Just disregard it, I think that was said earlier about using a car sub :)

[polkanddie]

Makes sense. Thanks again :)
So what are you gonna do with those rt1000's??
I just recently got some and I love em.

[kawizx9r]

Makes sense. Thanks again :)
So what are you gonna do with those rt1000's??
I just recently got some and I love em.

Honestly? Most likely just get rid of them....I've had them for what over 8years now? They are my first Polks, and I don't even use them since they just sit here as 'rear surrounds' but they're not hooked up to anything.

[polkanddie]

Just wondering are yours black or rosewood? and blue or black woofers? I really wish I could find someone who would like to trade bc I have the rosewood cs1000p. You know what you could do... put em up on CL and use the cash to get the HPSA1000 for your sub!!!! Now that would be an amp....Think about it....4x the power you have now....can you imagine...

[kawizx9r]

Just wondering are yours black or rosewood? and blue or black woofers? I really wish I could find someone who would like to trade bc I have the rosewood cs1000p. You know what you could do... put em up on CL and use the cash to get the HPSA1000 for your sub!!!! Now that would be an amp....Think about it....4x the power you have now....can you imagine...

I built my sub properly, and it pounds like hell. Even if its only a 250watt amp....or if I used a 500/1000 watt amp, at the levels I use my sub I wouldn't be using all that power. It hits deep and I mean deep bass that I didn't know existed on some movie soundtracks and music.

As for the RT's, all the P series use black drivers and the i series use blue drivers. Mine are black, and have a black finish on them. Still in pretty damn good shape too. As far as selling them though, just too lazy but if I did I'd just use that money to either save up for a better tubed preamp later in the future or just buy some nice IC's.

[polkanddie]

Yea, Im hoping for the same results with mine. Ive built boxes before, but nothing too complicated.

[ben62670]

Going completely flat on paper doesn't tell the whole story. Don't worry about a nice sooth roll off. Environmental gain helps in most situations. The WINisd pic posted before has a bad hump. The design needed to be tuned lower.
Ben

[billbillw]

Going completely flat on paper doesn't tell the whole story. Don't worry about a nice sooth roll off. Environmental gain helps in most situations. The WINisd pic posted before has a bad hump. The design needed to be tuned lower.
Ben

Ben,
Tuning lower still leaves that hump, but makes everything down low drop down significantly. That plot was the ideal quasi-Butterworth alignment for that driver given the published specs. Its an inexpensive car sub, so it doesn't go perfectly flat no matter what.

Polkanddie,
I really think you should reconsider going with a ported enclosure. Its much easier to turn things down (to avoid apartment eviction) than it is to crank things up to compensate for a negative ~10dB in the 25-30Hz range. There is a lot of material down there in movies. Remember that 3dB is perceived to be twice as loud. So 10dB is more than 3 times louder! I really think you will be disappointed in the response with a sealed box and that 10" sub. In a sealed box, you probably won't see much more low bass than what you already have with your tower speakers.


If it were a 12" or 15" sub, maybe you could do sealed, but with only a 10", you need to get every advantage you can with respect to frequency response. Building a ported sub is not really that much harder than a sealed, especially when you have modern software to do the calculations for you. Just cut an extra hole for the port, and buy a flared port kit, cut the port a little longer than specified, try it out, if the response is soft, cut a little off the port and try again.

If the box size is an issue, you can use ~1lb of polyfill per cubic foot of box to get a perceived increase of about .3-.4cf ft/lb. So, if the software says 2.7 cu ft, you could probably build it around 2 cu ft and stuff it with 2lbs of polyfill. Keep the port length the same as with the 2.7cu ft box. Also, remember to subtract the port volume out of the box size since it doesn't get counted towards the net box size.

[sophie]

bill,
i don't think a 3db difference is perceived as twice the volume, but it does require twice the power. I have read somewhere that a 10db difference is perceived as approximately twice the volume.....not sure about the 10db thing but i know that 3db does dot sound twice as loud.

Payton

[billbillw]

bill,
i don't think a 3db difference is perceived as twice the volume, but it does require twice the power. I have read somewhere that a 10db difference is perceived as approximately twice the volume.....not sure about the 10db thing but i know that 3db does dot sound twice as loud.

Payton

OK, your right. 3dB is doubling of the acoustical energy, but we don't perceive it like that. My bad. Years of misinformation are hard to overcome...

Either way, the sub that is being built here will sound at least at 2 times as loud in the lower frequencies if he builds a ported version.

[kawizx9r]

OK, your right. 3dB is doubling of the acoustical energy, but we don't perceive it like that. My bad. Years of misinformation are hard to overcome...

Either way, the sub that is being built here will sound at least at 2 times as loud in the lower frequencies if he builds a ported version.

+1

Heck, I even did that with my 12"

[polkanddie]

Ok, the sub didnt arrive today, but the tracker says its in NC... So I saw a design for an infinity kappa vq sub with a slot port at the bottom that I liked. Im pretty sure I can work that into my enclosure.

[kawizx9r]

Ok, the sub didnt arrive today, but the tracker says its in NC... So I saw a design for an infinity kappa vq sub with a slot port at the bottom that I liked. Im pretty sure I can work that into my enclosure.

(Flared) Port > Slot loaded enclosure imo.

Like I mentioned before, don't change up the subwoofer simply to make it "look" more appealing.

[polkanddie]

Ive heard that if you flare slotted ports it works just as well with less "chuffing"

[kawizx9r]

Ive heard that if you flare slotted ports it works just as well with less "chuffing"

I still say flared port tubes....using WinISD you can determine how long of a port you'll need as well as diameters (to reach available frequencies/spl levels that the sub can produce), something I think you'd have a little more trouble finding out when using a slot-loaded enclosure. Up to you though really, I just think you should take into consideration some of the advice given on here so you can build yourself a better capable sub :)

[polkanddie]

Ups sucks.... its not going to be here until monday. I guess ill just have to start without it... I downloaded winISD pro so Ill start there. Flared ports are in the mix for sure.

[polkanddie]

This WINisd pro is awesome!!!!!!!!!!!!!!!!!!!!!!!! And Ive finally found the dimensions that I want for the box. I still have to draw it out, but I am making it 4.5 cubic feet. 18"x 1" slot port. The curve was good, and I will have room for it without making it a coffee table. Plus it should be easy to make. I am extending the box and having the amp mounted in a separate chamber. I am starting tommorrow, so expect some pics soon!! woofer is "scheduled" to come monday. Hopefully I can finish most of the box tommorrow. Wish me luck!

[billbillw]

This WINisd pro is awesome!!!!!!!!!!!!!!!!!!!!!!!! And Ive finally found the dimensions that I want for the box. I still have to draw it out, but I am making it 4.5 cubic feet. 18"x 1" slot port. The curve was good, and I will have room for it without making it a coffee table. Plus it should be easy to make. I am extending the box and having the amp mounted in a separate chamber. I am starting tommorrow, so expect some pics soon!! woofer is "scheduled" to come monday. Hopefully I can finish most of the box tommorrow. Wish me luck!

4.5 cubic foot seems awfully large for a 10" sub.

Check your calcs (and input parameters) because I had it at 2.7 cubic foot. Use the parameters directly from Polk. Just download the manual for the db104. Make sure you keep the units correct.

[polkanddie]

Ill recheck and see what it gives me.

[polkanddie]

I did input all the parameters that i got from the manual. ill try and post the curve I got from all that.

[kawizx9r]

4.5 cubic foot seems awfully large for a 10" sub.

Check your calcs (and input parameters) because I had it at 2.7 cubic foot. Use the parameters directly from Polk. Just download the manual for the db104. Make sure you keep the units correct.

+1

My 12" requires a large box and I get frequencies down to 18hz, and it's 4.1cu ft. For your 10" that's only capable of free air response@25hz I doubt you need anything that large. By the way, did you really mean 1" x 18" port? I can see port noise coming from that small thing but I could be wrong.

[billbillw]

+1

My 12" requires a large box and I get frequencies down to 18hz, and it's 4.1cu ft. For your 10" that's only capable of free air response@25hz I doubt you need anything that large. By the way, did you really mean 1" x 18" port? I can see port noise coming from that small thing but I could be wrong.

Yes, I meant to say something about that. With a slotted port, you should not have the dimension ration of 1:6 or wider. 1:18 is too narrow and won't sound right.

There is some good reading here:
http://mobile.jlaudio.com/support_pages.php?page_id=141

Also, there is an easy Slot ported box calculator at the RE website:
http://reaudio.com/speaker_box/LPort_Box_Calc.html

Try different combinations until you get the desired box size and port tuning frequency. The calculator will then give you the cut sizes for each panel.

[polkanddie]

http://www.audioreview.com/channels/audioreview/images/products/product_327901.jpg

So what is the ratio for this sub? it looks to be no more than and inch and a half. Velodyne makes good gear too...

[polkanddie]

How about this, 2 cubic foot box, port 1.5"x12"x(14"long) tuned to 37 hz

[Face]

Round, flared ports are quieter and more efficient.

[kawizx9r]

http://www.audioreview.com/channels/audioreview/images/products/product_327901.jpg

So what is the ratio for this sub? it looks to be no more than and inch and a half. Velodyne makes good gear too...

That's a completely different sub, and that company (like any other) builds enclosures specifically for their drivers.


How about this, 2 cubic foot box, port 1.5"x12"x(14"long) tuned to 37 hz

37hz is a bit high imo, are you still using WinISD? Don't just throw numbers out there because it'll work, you're trying to get the most out of your sub now.

[kawizx9r]

You need to build something already, 3 pages and no pics! :mad: lol

Did you find out the dimensions you'll be using for your sub? Friend and I did mine keeping the outside measurements in mind, no need to over complicate things for a simple enclosure.

[polkanddie]

That's a completely different sub, and that company (like any other) builds enclosures specifically for their drivers.

And that is exactly what I have been trying to do, but if I tune it to 20 hz the curve it gives me a very steep drop around 50hz which is not good imo. Well 28 is about as low as I can go with this driver. I wasnt just "throwing" numbers in there. I was on a budget building this subwoofer. I bought this sub only matching up power handling. And it was cheap, as you can see it is a car sub. Not an HT driver. So. I am building the enclosure specifically for my driver just as you said.

[kawizx9r]

And that is exactly what I have been trying to do, but if I tune it to 20 hz the curve it gives me a very steep drop around 50hz which is not good imo. Well 28 is about as low as I can go with this driver. I wasnt just "throwing" numbers in there. I was on a budget building this subwoofer. I bought this sub only matching up power handling. And it was cheap, as you can see it is a car sub. Not an HT driver. So. I am building the enclosure specifically for my driver just as you said.

There's another thread on here that specifically uses a car sub. Of course, different enclosure size/etc. than what you will be using (and different from what I used) but it'll give you another project to take a look at to give you some ideas.

http://www.polkaudio.com/forums/showthread.php?t=71073&highlight=MID+BASS+MODULE

Both his and mine have the same type center brace going, with the cutout being the diameter of the driver but his is completely finished and came out real nice looking.

[polkanddie]

The next day I have off work is Wed. But I took everyones advice and I am building the box to the tune of 28 hz, 2 cubic feet, 1.5"x12" port. And WILL be posting pics, I owe you guys that much!! lol.

[polkanddie]

That does look good, I will put similar bracing in mine. Thanks to everyone (kawizx9r, bill, and FACE especially) for all the great advice, I think its time to put this plan into action, Driver arrives tommorrow, Building will commence Wednesday. I bid you good day. The next time I post will hopefully have some good pictures for you.

[billbillw]

The next day I have off work is Wed. But I took everyones advice and I am building the box to the tune of 28 hz, 2 cubic feet, 1.5"x12" port. And WILL be posting pics, I owe you guys that much!! lol.

slot port or round? If you are using a round, don't go smaller than 4" ID.

I still think you are doing something wrong. When I model that sub, its closer to 2.9 cubic feet and 25-26Hz tune. Are you are using the data for the db104? That is the sub you are getting from Newegg. There is major differences between the current db1040, the db104, and the earliest db10.

Use the data in this download:
http://www.polkaudio.com/downloads/manuals/car/DBSubwoofer_Manual.pdf

Enter in the parameters in the order that they are listed in WinISD (right to left, top to bottom). Use the tab function between each parameter and that will calculate certain feilds. If the program calculates a field, do not change it.

After that, do a new project, select vented, and choose C4 or QB3 alignment (really not much difference), and that should be your ideal size and tuning frequency.

Like I said before, you can shrink the box some (about .3 cubic foot per pound of polyfill/per cubic foot). 1lb/cubic foot is about the max you will get benefit.

If you are going with a slotted port, You really should keep the ratio 1:6 or wider. That means if 2" x 12", no narrower. That will give you a really long port (>30"). That's about double the length of a 4" port.

If you decide to use flanged (flared) ports, make sure you do the 'end correction' adjustment for either one or two flanged ends. It changes the length of the port. Read the directions that come with the port carefully with respect to how you measure the port length. I'm pretty sure you only measure the non-flared portion of the port when cutting it. Also double check the actual inside diameter of the port when you receive it. The 4" port might not actually be 4" ID.

[polkanddie]

so, with the overwhelming opposition to my slot port, I will take your advice. I worked it with what you gave me and it looked really good. thanks again. 3.0 cubic feet. 4"tube x14.2" long. tuned to 26hz.

[polkanddie]

http://picture.vzw.com/mi/451003604_1571808787_0.jpeg?limitsize=345,345&outquality=56&ext=.jpg&border=2,0,0,0

You wanted pics, Here is one just to show you that they are coming. Sub arrived today...3days late. But thats ups for you, at least the sub works.... :) Drawing up the plans as we speak. I take it everyone thinks this is the best for my sub? I am really excited to be working on this, this is gonna be an awesome sub thanks to you guys.

[polkanddie]

Ok, here is a wild card, I got my hands on some 1.25" thick bulletproof plexiglass, I dont think I have enough to do the whole enclosure but I do have enough to at least the top and one or 2 sides... any thoughts? I think it would be awesome to be able to see inside the enclosure, the even if I just do the front I dont know what kind of bit to use with the router....any thoughts on that either??

[sophie]

can't see the pic. says file is unavailable.

Payton

[polkanddie]

Crap. Ill fix that tommorrow when I start building. I hope to get most of the enclosure put together tommorrow. Thanks for the tip Freddy!

[kawizx9r]

Crap. Ill fix that tommorrow when I start building. I hope to get most of the enclosure put together tommorrow. Thanks for the tip Freddy!

Yep, no problem :)

[polkanddie]

You were talking like a drop in type window right? Idk I might just scrap the whole idea, it seems like a lot more work. But if it goes right, it might also be worth it in the end. Ill see tommorrow. Be looking for pictures by the end of the day. Ill try not to disappoint. :)

[kawizx9r]

Doubt you'll disappoint, long as we see some work done! :p

I've yet to finish mine, but I did pick up some primer. Just need to take out the amp and driver to sand it down some, but I'm not doing it yet cause I hate being without a subwoofer.

[polkanddie]

http://photos-g.ak.fbcdn.net/hphotos-ak-snc1/hs090.snc3/15753_163943484266_814854266_2621512_2035316_n.jpg

http://photos-d.ak.fbcdn.net/hphotos-ak-snc1/hs110.snc3/15753_163943494266_814854266_2621514_2665373_n.jpg

http://photos-a.ak.fbcdn.net/hphotos-ak-snc1/hs090.snc3/15753_163943524266_814854266_2621518_4824114_n.jpg

http://photos-g.ak.fbcdn.net/hphotos-ak-snc1/hs090.snc3/15753_163943529266_814854266_2621519_775186_n.jpg

http://photos-b.ak.fbcdn.net/hphotos-ak-snc1/hs110.snc3/15753_163943534266_814854266_2621520_5917155_n.jpg

http://photos-h.ak.fbcdn.net/hphotos-ak-snc1/hs110.snc3/15753_163943539266_814854266_2621521_327707_n.jpg

http://photos-f.ak.fbcdn.net/hphotos-ak-snc1/hs110.snc3/15753_163943549266_814854266_2621522_748803_n.jpg

[polkanddie]

http://photos-d.ak.fbcdn.net/hphotos-ak-snc1/hs110.snc3/15753_163943554266_814854266_2621523_5039290_n.jpg

http://photos-a.ak.fbcdn.net/hphotos-ak-snc1/hs090.snc3/15753_163943559266_814854266_2621524_6024441_n.jpg

[polkanddie]

Still a lot of work to do, a decent amount of wood filler, I still have to mount the amp, and run larger gauge wire... other than that, it looks pretty good for 2 hrs work, and sounds realllllllly good, thanks to everyone who gave me advice, especially about porting. it worked out very well. I will post more pics after its done to show you the finished project!!!

[kawizx9r]

Looks really nice and clean, I like the port too since it looks real nice paired with the sub.

Did you seal the seams inside the subwoofer and create a nice seal for both the port and driver to the cabinet? I used some left over Mortite caulk cord so I didn't have any air-leakage and Solarseal for the inner seams of my sub.

It doesn't look too big either, but I would've braced it still. Glad to hear you're liking it though!

-Freddy

[polkanddie]

Sealing and finishing is still on my to do list. wood filler on the outside, but yes I sealed the port. the amp has its own enclosure also. I love what it does for movies so far.

[kawizx9r]

Sealing and finishing is still on my to do list. wood filler on the outside, but yes I sealed the port. the amp has its own enclosure also. I love what it does for movies so far.

Ok.

In my experience, I used solvent-based wood filler and it sticks pretty well to the MDF board.

As for sealing the inside, when you do get to it...leave it out to air out and dry for at least 24hours before messing with it some. I also noticed you didn't use any foam/polyfill/etc., you'd be surprised how much bigger it makes your box sound. I used acoustic foam in place of polyfill but it sounded as if bass was better controlled as opposed to just being in a big empty box.

[polkanddie]

I cant wait until its sanded, painted, and matching everything else. Thanks Freddy!

[kawizx9r]

I cant wait until its sanded, painted, and matching everything else. Thanks Freddy!

No prob, although I mixed things up. I used water-based woodfiller as opposed to solvent. Also got primer but I need to finish sanding it before doing anything more.

[polkanddie]

Yea, it seems like finishing it takes longer than building it. maybe on my next day off... I also am using waterbased filler, are you using spikes on yours at all?

[kawizx9r]

Yea, it seems like finishing it takes longer than building it. maybe on my next day off... I also am using waterbased filler, are you using spikes on yours at all?

Nope, I have hardwood floors throughout my whole place and although I can buy those spikes that sit on....what look like little pegs to prevent any damage to my floors, but I'll just put it off.

If anything I'll put on some of those sturdy rubber feet on it whenever I feel like taking it apart. I'm NOT going to pull this thing around, flip it over to attach some feet and then roll it back over and set it up. It weighs nearly 100lbs (95lb is a closer number), it's large (21 1/2"x 17"x 25") and extremely awkward and difficult to grab and carry. That and I'd rather be lazy :p

It sits on a piece of carpet I cut out, and if I need to move it around I just slide it on the rug across the floor.

[polkanddie]

yea, I have carpet, but Im not sure if I will get that much of a difference since mine is also around 100lbs, measurements 13.5x19.5x30. yea its a bit long, but it does the trick and I have room.

[kawizx9r]

Yo, how's that subwoofer coming along?

Took mine out to sand, figured I'd do it by hand since the power sander.....well MDF sands down easily and I didn't want to overdo anything by accident. Sanded the sucker down, and put some primer on it. Just pulled it inside since it's been outside drying for hours and so far everything looks really good.

Pics are on my diy-sub thread :D

[polkanddie]

Sweet, my next day off is Saturday, I plan on doing the same. I cant wait til its completely finished, Its kind of an eyesore since I just got a new mahagony tv stand. Ill go check out yours so If I can make any improvements on mine!! :)