Today I had my system metered and it hit a 130.2. I've got a 250 watt max Kenwood amp- (Bridged mono) 2-12in Pioneer DVC(2003 series) and a Kenwood head unit. I know the amp is way too small for these subs. A new Ample Audio 1100dx amp is coming very soon and a tune ported box, I will have better numbers to post then. Question-- Do u guys think this a really lame score for what i have?

 

130 is excellant. the highest db's at car domain is 172.6

got a picture of your setup by any chance?

 

#1

 

#2

 

For a pair of 12s, 130 is pretty low. With a good amp, I would expect those subs to be capable of around 135.

Before you use the new box, try just upgrading the amp. I'm guessing that your "tune poted box" means a ported box. If that's the case, unless it was built specifically for those subs, the odds are that it won't provide the kind of results that you're looking for. A generic ported box that wasn't built specifically for the speaker in question tends to produce a very peaky response where you get a lot of output within one narrow range, and very little outside of that range. Those are known as "one note wonders".

 

#3 The amp and box will be changed. I'm going to make a ported box that will fit snug around the sides.

 

The amp is really small I'm getting 250 max out of it. It holds a 15 amp fuse that was fine til I got these new subs. Now i have to run a 25 amp just to keep it on and after 1 minute of hard hitting it goes into protection. I'm not worried about blowing anything. If the amp lets go then no prob cause its getting replaced, and the subs can be replaced as long as i don't poke anything in them.I was just playing with this small amp to see what it had. With my new amp I'm hoping for a 140 db. That being my goal for this car.

 

putting a bigger fuse in there is not gonna change your output. if it goes into protection, its probably a wiring problem. im guessing you bridged them or something and made it to an ohm value that is too low for that amp.

with those subs, i wouldnt count on ever hitting 140 dbs w/o some major tuning. not saying it isnt possible, just not very likely.

130 is nowhere near 170. in theory, 133 db would be twice as loud as 130. doing a little quick math here:

172-130=42
42/3=14
2^14=16384

so, that would make 172 db 16384 times as loud as 130. now i know there are other variables and these numbers arent exactly right, but its not that far off. you have to realize, it takes alot to increase your spl even 5 db let alone 40.

anyways, ive rambled enough. good luck with your setup bird and i hope you improve your numbers.

 

I realize that putting a bigger fuse won't change the output. It only allows to stay on without blowing the fuse. So far as it going into protection it because i'm running it to death. It is ohm'd too low for the amp and it gets too hot and shuts down. There is no wiring problem I promise you. Thanks for the compliments

 

nice to know u know ur stff. is there an equation to figure out what DB ull be running or do u have to get it tested?

 

There are some equations that will help you estimate your SPL, but they are pretty complicated and require specific information about the subs that I don't believe the typical published T/S parameters provide. Plus, those equations don't take into account tuning, box design, etc.

Long story short: Just test it.

 

thats a really nice box did you make it? if you get your new one what do you plan on doing with that one? do you have any plans or measurments on it? i think it looks very nice.

 

it would make things alot easier if there were, but like jim said, it would be very difficult. actually, it is almost impossible without a meter. simply because in the real world, there are just too many variables. you could probably get a decent estimate from the formulas jim speaks of. chances are though, that to get the info and variables you need to plug into the formulas would be just as difficult as just having it miced. you can either take it to a competition or get an audiocontrol epiq 150. the latter is much more expensive, but you would have a decent idea of what you were pushing at any given time.

on a little side note, does anyone have any experience with the 150? i have considered getting one, but who knows.

hey bird, are you blowing fuses or is it just going into protection?

 

another guy who's gonna be running ample amps. nice i love mine. now i just need to try and find a matching 2-4 channel amp for the comps.

 

Sorry but i didn't build the box so I dont have exact measurements for it. Well so far as I'm concerned the old (2 weeks old) box will be up for grabs when I'm finished with the new one. Thanks for the comps

 

If i put the 15 amp fuse in it -it will blow the fuse at hard playing levels. When i put the 25 amp fuse in and play it HARD it gets way too hot and goes into protection, It doesn't blow the 25 amp fuse. Like I said his isn't a problem cause a bigger and better amp is on its way. This was just for fun.

 

well email me when you get your new one if you want to sell it. injection@hvc.rr.com thanks

 

i think we may be on the same page now bird. the amp you're using is basically there to hold up the system til you get a better amp, right?

hey camp? i have an ample 4 channel on my highs. i sounds great. there are a few things i dont like but i dont know that other amps wouldnt do the same thing. the one i have in like 50w x4 @ 4 ohms i think. if you have speakers that can take that kinda power, thats what i would suggest. it like 10 times better than running off the hu. good luck.

 

yea to make it a lil simpler to what that dude said

if your hitting 130 db

in order to hit 3db higher. going by using the same subs and amp. you would have to doube your power and double i beleive the cone space.

so you would need in theory 4 of those subs and 500 watts max to hit 133 db using that same equipment.

 

this is a good example of what i was saying. though, im pretty sure doubling the power OR doubling the cone area would do it. you dont need both.

 

You're correct. Double the power will result in 3dB more, assuming that the subs have a linear output capability.

Likewise, double the cone area will produce double the SPL. One benefit to doubling your subs is that when you wire it, you can get 1/2 the impedance, which will help the amp produce double the power if it's got that capability. So... double the subs and double the power all at once, so you can usually expect (a theoretical) 6dB gain when adding a 2nd sub to an amp that can handle the lower impedance.

 

cause and effect.

 

its been a few years since i worked in the shop. but i knew i was somewhere on the right track with that.

 

Another think not to forget is that porting an enclosure, as long as the box is made correctly for the speakers it holds, will give you about a 3db increase also.

So if you add twice as much power, and port the box (correctly), you may be able to hit higher than I did with only one 8 ohm 12" sub. 135.5 db

I need to have it tested again. At that time it was an MTX Thunder 3000 in a sealed enclosure. Now I have a 12", 4 ohm Pioneer IMPP in a ported encloser tuned at 38 hz. Even a 1-2 db increase would make me happy.

Good luck with whatever you decide.

 

not many people now how to port a box. even some "professionals dont even know"

 

tamu-- yes i believe we're thinking the same, thanks for your input. This lil amp was one i had and wanted to see what it would do with this subs. I will have better numbers with the new stuff. I really learn some new stuff by searching the post and I just wanted to see everyone's thought on what it done like this. My buddy is an installer/dealer and he will test my car for nothing( as long as I keep buying from him anyway) so this was just for fun. Thanks to everyone for their replys.

 

True.

The cool thing is, when you buy from a company that has a good reputation (not Roadmaster, Pyramid, Volfenhag, etc.) they give you the proper specs.

If your box is going to be a different size than what they suggest, then you call their tech support and they'll tell you what size to make the port(s).

Another advantage of brands with un-lame names. :sillylol:

 

how hard is it to port a box? if i can get two extra Dbs with that then thatd make my day. is there any posts out there on how to?

 

Do a search for win ISD. It's a pretty sweet program.

I'm still learning about it, but I built a 1.5 Cf ported box tuned for 35 HZ, and it showed a gain of 3-4 DB for my woofer.

I plan on picking up a SPL meter, and testing before and afters once I have the time to build a ported box.

 

Yeah my 12" crank hit 138.9dB on a 250W MTX Blue thunder amp.
And that is just one (1) 12" sub.

 

The amp in this test is rated at 40x2 RMS and bridged power is 120x1. I was getting everything I could out of her.



Lowcamaro--- not bad numbers for that.

 

Yeah, its pretty decent. Ive gone into a couple of stereo comp in the one woofer class. Out of the 4 i have been in ive taken 1st place 2 of the time and second place the other two times. Not too bad for and old 600W High Voltage Competition Dr. Crankenstein i got for $100. Picked up the amp on sale for $150. These are canadian prices of course.