Moley

First off I don't want to take off the plastic covering as it will look bad. I had a feeling today to go to visions electronics and check out prefab boxes. There was a box there that is dual 12", 1.5 cubes per and tuned to 37hz. In the begining I was thinking about 2 12's or 3 10's so I figured what the heck and asked the salesman if I could see if the box would fit in my car. He said ok no prob and we gave it a go. After removing a small plastic panel and shifting the box like a tetris piece, sure enough it barely went in. I was ecstatic. Now like MR2NR said, and I quote.

" If you are after ideal response or are trying to rip the bra off of your passenger, you are looking at the equation wrong. Look at the space you have available, then choose a sub(s) for that application and finally the amp to power it. "

I have the max size airspace I can get in that car. Now I need to find 2 12" subs that will work at 1.5 per and I allready have a big amp to run it. So I got my wish of 2 12's and they will run at full power. ( not at 1.33 ohms ) Oh and the port on that box is facing forward so everything will be directed forward. So what subs to get?

What about these: http://www.audiosavings.com/products/12-Inch-Car-Subwoofer/PAIR-RE-AUDIO-SXX12D4-SXX-12-4000w-SUBWOOFERS-SXX12-D4/(2)+SXX12D4.aspx

or these:http://www.sonicelectronix.com/item_16665_Pioneer+TS-W3002D4.html

I know that it has been said that drivers are better in optimal airspace and that minimum airspace = minimum performance. I don't know the recommended air space for the pioneers but the RE subs need 1.5 - 2.0 cf per so ya they will be minimum but I think that this setup will be far better than 3 10" drivers in an even smaller than minimal box, ya figure? I am on the right track here guys or what?

Lord Huggington

iTrader: (1)

Everything forward is usually better and more so if you block the rest of the trunk. When using more than the minimum space the gain could be exponential so 10's could get louder and have better response on the same power. 1.5 is perfect for a beefy 10. Watch youtube vids of 2 DD9510's etc. These subs are designed for trucks. Read reviews.

(2) SXX12D4
Price: $459.95
Mounting Depth - 6.9"
Mounting Hole Diameter - 11.2"
Overall Diameter - 12.5"
Bolt Hole Circle - 11.75"
Motor Width - 7.3"
Motor Depth - 3.44"
Basket Depth - 3.46"
Displacement - 0.16 cu. ft.
Weight - 24.5 lbs

Each sub sees 1.34 cf3. RE says 1.5 is "compact". You'd probably want to invert them.

Pioneer TS-W3002D4
RMS: 1000 watts
Price: $174.99
Frequency response: 20-150 Hz
Sensitivity: 90 dB
Mounting Depth: 7-1/2"

Still, one 12 or two 10s on 2k is probably going to be better. 1.35 is perfect for an Icon. If you want loud get DD.

MR2NR

iTrader: (66)

What guy does not like a set of Double D's....

Moley

Do you think that if I put polyfill in the box that it would at help enough to offset the sub displacement and bring it to 1.5 cubes each? ( virtual of course ) I really want to stick with the 12's so I hope polyfill will help. Still 2 12" re's in 1.34 cubes each would pound more than what I had which was 2 10" re's in .975 cubes each and that was loud. So if the re's that I had were running just below minimum and sounded fine than in theory the 12's just below minimum would be better. If I inverted the subs how much space would I gain? I think that I would have the room to do that but is inverting the subs going to sound as good as normal mount? I heard somewhere that I would here motor noise or something.

Lord Huggington

iTrader: (1)

If you invert the sub you don't subtract it from the total airspace, you don't gain space. You don't need to phase the subs, they'll sound the same, and bass is non-directional. You'll probably hear more motor noise but the subs will drown it out. I hear more cone noise using a sealed box. Polyfill, YahooAnswers says use 1lbs per cube. It makes the box act larger, gives a slightly lower tune, and dampens resonances. Put it on the walls.

Moley

Cool. I bought the box and going to order the subs soon. I thought I might have the room to invert but no. So I am going to buy the re's and put them in then add polyfill. You said that polyfill will not only make the box seem larger but it will lower the tuning frequency. By how much do you figure? The box is tuned at 37 hz and the re's call for 35 hz compact ( 1.5 cubes ) so with poly the subs should see at least 1.5 ( I hope ) and lower the tuning a bit to make a good match. I know it's not ideal but its damn close to the min that re recommends so I think I should be golden. What do ya think? This gonna work? btw why do so many companys eg bassworx, q logic sell these boxes and they are all around 1.5 cubes for 12's. They must work or they wouldn't sell them.

oh just to add, you said that blocking the rest of the trunk is a good idea. Do you mean completly sealed off. The box almost blocks the sides for air getting through. Should I put like a wood baffle all around the box and caulk it to seal it off or what.

Lord Huggington

iTrader: (1)

There are no polyfill calculators so tuning is a guess, have a starting ratio and test. Pre-fab boxes are designed for smaller drivers, they need to fit in all vehicles so they'll sell, just because they sell them with 1.5 cf3 doesn't mean they care about your custom sub and custom goals. To block the rest of trunk, I'd use fiberglass but a piece of wood is going to work. It's not just the air, it's the vibration from the back of the trunk you want to minimize. Soundwaves bouncing from the rear of the trunk into the cabin cause cancellation. If it's practical, block both ends of the box and stuff the rest of the trunk with blankets. There's a lot of deadening tutorials. It's caused by one thing hitting another so if you just put a spacer between them and stop air movement in the trunk with blankets you're good to go. Fiberglass is easy as pie - you place sheets of fiberglass where you want it to go and tape it (usually on something you built - so you can take it out), coat it over and over, sand, and paint. Looks sweet atleast.

If you switch up.. the best setup you could have with that box is probably two inverted DD 9510's on 3k. Those **** so hard.

Tony Dehnke

It's a pre-fab - they are built to fit in a car (#1 factor) - be "about" the right size to work with a wide range of subs

Given how precise you are with your output and sound expectations I'd recommend you rethink what you are doing and go see some good shops in your area - review the options they can help you with.

A couple things to remember with all the #'s floating around here - I'd be willing to be that most subs are going to vary 5%+ from specs, MDF leaks 5% etc etc - don't get so hung up on the #'s on that side.. Find a sub/s that requires less air than you have as a min and are better in the amount of air you have.

Poly in a ported box isn't going to have the effect it would in a sealed box IMO.

If you go with a prefab - get in there and make sure you seal it up well, and add some bracing.

Lord Huggington

iTrader: (1)

Bassworx uses rabbit joints & bracing and I think they use 2-2.5 for 12's. MDF leaks 5%?

Moley

The bassworx boxes that I have uses are tough as nails. The airspace for the 12's in the reference and the gloss series is 1.5 cubes per. I would have liked to get the bassworx box but the design wouldn't allow it to fit in my car so I got the q-logic and it just went in. Still 1.5 per. I looked at the constrction and it seems solid. The way the port is designed adds bracing as it is. The differnece between the bassworx and the q-logic is that the bassworx has 2 seperate chambers and the q-logic shares a chamer. I dont' think that that matters though unless one sub blows from what I hear. Anyways I think the box is solid enough. The box build plan I had went out the window for me. I think I just got lazy. Easier to buy a prefab. I don't know what other subs are out there that are a decent price like the re's that will run in 1.5 cubes. I think dd is way out of my price range. I wan't 2 12's for 500 or under plus shipping. Lilke a said earlier I had 2 10 inch re's in a prefab that was 1 cube per and they pounded hard and went low enough for me so why wouldn't those same subs but in 12's work in a prefab at 1.5 each. Makes sense to me. Like tonydehnke says I am getting too hung up on #'s. I think that this setup will work just fine in that car and will pound harder than the 2 10's that I had. It might not be ideal but its still going to be good. As far as poly goes I will still put it in the ported box. if I don't like it I can just take it out. And for sealing of the trunk I think I will just make a piece of wook to fit but I can't use blankets or anything in the trunk cause I still want to be practical and have room for groceries lol. In short I just want some good old awesome boom that will impress that was more than what I had. And there is no reason why 2 12" re sx's in a prefab box won't accomplish that.