Torres Posted December 27, 2009 Report Share Posted December 27, 2009 80% doesnt refer to output, like...80% install, 20% product (some say 70% install, 30% product...same concept tho). a crap sub in a good box > a good sub in a crap box. if that is indeed your box...take those numbers and subtract 1.5 from each (wood displacement) and multiply the new numbers together. divide by 1728, and you get 2.75. numbers dont lie. here: 21 - 1.5 = 19.5 16.25 - 1.5 = 14.75 18 - 1.5 = 16.5 multiply 19.5 * 14.75 * 16.5 = 4745.8125 divide by 1728 4745.8125 / 1728 = 2.7464192708333333333333333333333333 or 2.75 cubes of airspace. *before* port and sub displacement. so you'll have even less usable space than that. Quote Link to comment Share on other sites More sharing options...
Torres Posted December 27, 2009 Report Share Posted December 27, 2009 and btw...ported boxes need to be larger than sealed boxes. so if previous boxes were sealed...that's why they were smaller Quote Link to comment Share on other sites More sharing options...
Cigarz Posted December 27, 2009 Author Report Share Posted December 27, 2009 (edited) 80% doesnt refer to output, like...80% install, 20% product (some say 70% install, 30% product...same concept tho). a crap sub in a good box > a good sub in a crap box. if that is indeed your box...take those numbers and subtract 1.5 from each (wood displacement) and multiply the new numbers together. divide by 1728, and you get 2.75. numbers dont lie. here:21 - 1.5 = 19.5 16.25 - 1.5 = 14.75 18 - 1.5 = 16.5 multiply 19.5 * 14.75 * 16.5 = 4745.8125 divide by 1728 4745.8125 / 1728 = 2.7464192708333333333333333333333333 or 2.75 cubes of airspace. *before* port and sub displacement. so you'll have even less usable space than that. Wait why subtract 1.5"? the thickness of my MDF is only .50 or .75 so you only subtract that right? So basically can someone deisng me a box then and help me out... I'm really pissed I wasted $50 on a box that they lied about being that big... if it REALLY was 3.4cubes that would would have been perfect, I thought it looked a little small compared to other single 15 builds... I mean a lot of it is my amp right? I mean the sub should STILL move more than it's with a bad box it'll just have less bass right? Edited December 27, 2009 by Cigarz Quote Pontiac Grand Prix SE Stock 105AMP alternator 8guage wiring Pioneer DEH-1100 4 x Infinity Reference 250RMS 1 x Fi SSD 15" Copper Coils D1 1 x Alpine MRP-450 Vented .50MDF tuned @ 40hz Link to comment Share on other sites More sharing options...
Torres Posted December 27, 2009 Report Share Posted December 27, 2009 and just another tidbit of info, i put in random numbers just to get a scale of size, a *usable* 3.5 cube box, after sub, wood, and port displacement would have to be something like 17" high 25" wide 23" deep 4.53 cubes before port and sub displacement, and after wood displacement. port is 3" high, 15.5" wide, and 25" long. displaces .84 cubes of space. put in .2 for the sub. this gives you 3.49 cubes of space, and tunes you to 33.42 hz. Quote Link to comment Share on other sites More sharing options...
Cigarz Posted December 27, 2009 Author Report Share Posted December 27, 2009 and just another tidbit of info, i put in random numbers just to get a scale of size, a *usable* 3.5 cube box, after sub, wood, and port displacement would have to be something like17" high 25" wide 23" deep 4.53 cubes before port and sub displacement, and after wood displacement. port is 3" high, 15.5" wide, and 25" long. displaces .84 cubes of space. put in .2 for the sub. this gives you 3.49 cubes of space, and tunes you to 33.42 hz. Ok well even IF I did have the tool to build a box I couldn't I was the worst kid in shop class, I know nothing about cutting wood and molding and creating a box, I think I would do a terrible job and I'm honestly not going to pay $100 for someone to do it, erm. I'm at a loss So basically my box IS the problem? so if I get a new box 3.50cuft tuned @ 33hz how much louder can I expect my sub to be and will there be more flex? also how much louder will my sub be when im putting 800RMS to it? I mean I don't want to throw MORE money into my system for the same result :-/ Quote Pontiac Grand Prix SE Stock 105AMP alternator 8guage wiring Pioneer DEH-1100 4 x Infinity Reference 250RMS 1 x Fi SSD 15" Copper Coils D1 1 x Alpine MRP-450 Vented .50MDF tuned @ 40hz Link to comment Share on other sites More sharing options...
Torres Posted December 27, 2009 Report Share Posted December 27, 2009 Wait why subtract 1.5"? the thickness of my MDF is only .50 or .75 so you only subtract that right? So basically can someone deisng me a box then and help me out... I'm really pissed I wasted $50 on a box that they lied about being that big... if it REALLY was 3.4cubes that would would have been perfect, I thought it looked a little small compared to other single 15 builds... I mean a lot of it is my amp right? I mean the sub should STILL move more than it's with a bad box it'll just have less bass right? if the thickness of the wood is .75", then say you have a length of 20", you take .75" off for the left side, and .75" off on the right side. so that is 1.5" off the total length, making the length effectively 18.5" long. if it was really 3.4 cubes then i'd say it'd be performing a LOT better. given that the port is still big enough. port area for a 3.5 cube box should range from 42 - 56 sq inches of port total. imo...the sub is performing just like it should in a non-optimal install. so i wouldnt blame your amp. tho...even in a better box, you'll see an upgrade from 400 watts to 800 or more Quote Link to comment Share on other sites More sharing options...
Cigarz Posted December 27, 2009 Author Report Share Posted December 27, 2009 if the thickness of the wood is .75", then say you have a length of 20", you take .75" off for the left side, and .75" off on the right side. so that is 1.5" off the total length, making the length effectively 18.5" long.if it was really 3.4 cubes then i'd say it'd be performing a LOT better. given that the port is still big enough. port area for a 3.5 cube box should range from 42 - 56 sq inches of port total. imo...the sub is performing just like it should in a non-optimal install. so i wouldnt blame your amp. tho...even in a better box, you'll see an upgrade from 400 watts to 800 or more So even if I used this box i'd see a huge difference going from 400-800? im guessing right? and if I installed a new box I would get even lower? I read that the only difference between not having a smaller box is lows are less effective... TBH all bass notes are extremely quiet im telling you dude the sub is BARELY moving at my amps rated voltage... I don't see how the box could limit subwoofer movement, I know a better box would give me more and better bass but if I have to work with what I go right now I want to know if it's possible and how much im losing out on keeping this box. Quote Pontiac Grand Prix SE Stock 105AMP alternator 8guage wiring Pioneer DEH-1100 4 x Infinity Reference 250RMS 1 x Fi SSD 15" Copper Coils D1 1 x Alpine MRP-450 Vented .50MDF tuned @ 40hz Link to comment Share on other sites More sharing options...
Torres Posted December 27, 2009 Report Share Posted December 27, 2009 Ok well even IF I did have the tool to build a box I couldn't I was the worst kid in shop class, I know nothing about cutting wood and molding and creating a box, I think I would do a terrible job and I'm honestly not going to pay $100 for someone to do it, erm. I'm at a loss So basically my box IS the problem? so if I get a new box 3.50cuft tuned @ 33hz how much louder can I expect my sub to be and will there be more flex? also how much louder will my sub be when im putting 800RMS to it? I mean I don't want to throw MORE money into my system for the same result :-/ where are you located? if you are located around the cincinnati area i'd help you build the box. just supply materials. but to build and ship would be too costly. i'm almost certain your box is the problem. throwing double the power on it will theoretically be 'twice' as loud, tho that's more so on the meter. i think it takes about 10 db to be considered twice as loud to the ear? i remember reading about it...but could be mixed up. a properly built box will yield much better results. in my opinion prefabs are never the way to go. you coulda spent 25-30 on a sheet of wood, made it (if you or someone you knew could make one), and cover it with paint or carpet and be under the 50-60 dollar range you spent on the prefab and not be in this predicament. Quote Link to comment Share on other sites More sharing options...
Cigarz Posted December 27, 2009 Author Report Share Posted December 27, 2009 where are you located? if you are located around the cincinnati area i'd help you build the box. just supply materials. but to build and ship would be too costly. i'm almost certain your box is the problem. throwing double the power on it will theoretically be 'twice' as loud, tho that's more so on the meter. i think it takes about 10 db to be considered twice as loud to the ear? i remember reading about it...but could be mixed up. a properly built box will yield much better results. in my opinion prefabs are never the way to go. you coulda spent 25-30 on a sheet of wood, made it (if you or someone you knew could make one), and cover it with paint or carpet and be under the 50-60 dollar range you spent on the prefab and not be in this predicament. Wouldnt I need: Wood Glue Caulk PolyResin Wood Screws .75 MDF PAINT/CARPET I dont know about you but all of that seems like it would be more than $60... or am I overpreparing? If it's really that easy to make a box I'm sure I can do it, I've just never attempted, I could have my dad help me I suppose, I mean what supplies would I need? and NO im not in cinncinati area I live in new england, maine. Quote Pontiac Grand Prix SE Stock 105AMP alternator 8guage wiring Pioneer DEH-1100 4 x Infinity Reference 250RMS 1 x Fi SSD 15" Copper Coils D1 1 x Alpine MRP-450 Vented .50MDF tuned @ 40hz Link to comment Share on other sites More sharing options...
Torres Posted December 27, 2009 Report Share Posted December 27, 2009 a smaller box increases impedance rise on the amp (so a 1 ohm load isnt REALLY a 1 ohm load...it'll be a little higher), but allows for increased power handling. and yes...effects the lows to an extent. larger boxes somewhat decrease power handling, increases the lows to an extent, and lowers impedance rise on the amp. but in most cases should be within the manufacturers recommendations. port area/length also play a role. you said you used a tone you generated? try using a 50 hz test tone from here http://realmofexcursion.com/index.php?pageid=audio_downloads i'd suggest a bass mekanik tone...but i forget what level his are recorded at. Quote Link to comment Share on other sites More sharing options...
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