blindfold challenge :)

[Bayuk89]

I'm gonna give the specs of my subs but not the make and model, I want my specs to be the dictator if these subs are any good (based on spec not brand) they are TWO 15 in subs going to be in a ported box powered by a 1200 RMS amp. If I give u the specs can u rate how well the sub is build 1-5 scale and two, what cubic feet should i build the box and what frequency for a balance of deep bass but still play the radio if I choose to. Any help is always appreciated

(Re) 3.2 OHMS DVC

(fo) 29.40 Hz

(BL) 9.5 n/a

(Qms) 6.09

(Qes) .81

(Qts.) .72

(Vas) 101.3 liters = 3.577 cubic feet

(Cms) .12mm/N

(Mms) 250 GR

(Sens.) 86.8 dB

(Xmax) .60 in = 15.24 mm

http://www.the12volt.com/caraudio/thiele.asp#_index

Above is the site I read on for explaining what these specs mean BUT I don't know if my specs are good or bad compared to a rockford 15" or a kicker 15" or a sundown 15" so on and so forth.

$$$$ EDIT $$$$

manufacturer recommend 2.3 cu/ft each if sealed or 3.0 cu/ft if ported and recommend porting at 39 hz but I still wanna hit 33-35hz if the specs prove the speaker can handle it... thanks

[Triticum Agricolam]

Alright, I'll play this game.

Those subs have a loose suspension (high Vas) and low motor force. I'm guessing these are on the lower end of the price range (motor force costs money).

The QTS is too high and EPB is too low for these to produce good low frequency output in a ported box. Pretty much no matter where you tune or what size box (within reason) you put them in you are going to get a big peak in output around 50 Hz and things are going to fall off fast below that.

You might be able to get these to work OK in a sealed box, but the QTC is still going to be high, which will hurt low end output.

On a 1-5 scale for ported box usage, these definitely get a 1. My suggestion, find different subs.

[Lakeshow94]

Brutally honest lol

[tboorn]

yeah brutal... but true. with a QTS that high these subs need purely to be in a sealed enclosure.

[Joe X]

Here's what modeling shows for theoretical frequency response inside an average sized vehicle, the following is for 3 net per driver @ 30Hz:

You fail to provide rated power which limits analysis in some ways, anyways trusting the parameters are genuine, arguably those could play low in an in-car environment no issues with the suggested tuning, There are many lower EBP (sealed suggested) subs that can work in ported box.

[Bayuk89]

Thank you joe x for the honest input and helping understand why and what i should look for in a better sub. These are quantum q3000/15D subs (lower end of totum pole). I believe they claim 1200 watts RMS (lol) but im gonna throw 500-650 watts at them to be safe. Already bought them a few months back and had one in a sealed box 2.3 cubic feet. These are going in my work truck and im not gonna replace them till they shell out. So sealed box huh, shoul i stick with the recommended 2.3 cubic feet each or go up or down .2 feet this is obvious not a SQ or SPL sub but i still need to "make it work" thanks again guys, im slowly learning and eventualy i will have top dog gear.... this build is just a stepping stone

[Bayuk89]

Thank you Triticum Agricolam for your help too, i rather have pure honesty than to be BS'ed you guys are great.

[CleanSierra]

You really are about buying kind of half ass equipment huh?

First the amp, now these bargain subs. I can see why you didn't originally name the brand. A GOOD enclosure design and built with quality materials and good cuts will make a huge difference.

I hope you're not going to attempt to cheap out on that material too. Like if you create a thread saying "I know MDF is a better wood but how well do you guys think particle board would work for an enclosure?", I'll be highly disappointed.

[Triticum Agricolam]

Thank you joe x for the honest input and helping understand why and what i should look for in a better sub. These are quantum q3000/15D subs (lower end of totum pole). I believe they claim 1200 watts RMS (lol) but im gonna throw 500-650 watts at them to be safe. Already bought them a few months back and had one in a sealed box 2.3 cubic feet. These are going in my work truck and im not gonna replace them till they shell out. So sealed box huh, shoul i stick with the recommended 2.3 cubic feet each or go up or down .2 feet this is obvious not a SQ or SPL sub but i still need to "make it work" thanks again guys, im slowly learning and eventualy i will have top dog gear.... this build is just a stepping stone

Changing the size of the sealed box isn't going to make much difference. It takes a big change with sealed boxes to see much effect. I would probably stick with the 2.3 cubes the manufacturer recommends.

Now, you could put these in a ported box like Joe X said, and it would gain you some low frequency output. However they are never going to perform like other subs that are more appropriate for ported boxes would. If you are planning on upgrading to different 15" subs down the road and don't want to build a new box when that time comes, I'd suggest building a box that will work well with the subs you will eventually get, and just use it with these subs for now.

[Bayuk89]

Thanks Triticum Agricolam for ur input

Clean sierra, come on dude take a step back please. I already had the 15's from a few months ago "buying blind" and figured im gonna use them since i already have them. As far as the amp goes, a reputable member (BigDWiz) did a amp dyno and review of the rockville m4 amp. Despite the in accuate numbers the amp claimed it still put out what i needed. http://www.stevemeadedesigns.com/board/topic/199548-rockville-rxd-m4-amp-dyno-test-150030006000w/ there is his orginal post, where were u when he posted that ? I have what i have regardless if its good or bad in YOUR eyes. If u dont like my equipment then say "hey man, i see what ur running. If u want better quailty in this size/application here is my recommendation when you want to upgrade" thats how u do it with respect and not haze me with "your about running half ass equipment" sorry i cant afford the equipment or have the knowlege u do.