Getting spl numbers up

[Miles 128]

I've got a 2.4 cube box tuned to 30 hz with a 3" aero port. The sub is a Fi Bl 12 getting about 750 watts off a Powerbass ASA1500.1. I went to comp last sunday and did a 136.8 at 44hz. If I made the port tuned to 35 hz, or even 38 hz, would my score go up? I'm not too worried about the competition in my class since I am sitting in 2nd place in the circuit, but it's always nice to be louder.

[tezin87 0]

what vehicle is it in?

[Miles 128]

It's behind the seats of a 99 Dodge 1500 single cab. Here's a picture.

[tezin87 0]

I have a regular cab ranger and I know how hard it is to get loud in a truck. I'm thinking about doing a similar setup this summer but with a 10'' bl because I have nowhere near enough room for a 12''. The only thing I can think of for you to do would be to do a blowthrough, or add more power because bl's can take alot more than 750 watts. But considering the space you have I'd say you have an excellent score and I can't wait to make some money so I can start my build. How do you like the bl for daily music?

[shizzzon 461]

was 44hz the loudest when you got metered?

Did u just pick some random numbers or somethin?

In my crown vic i used to have, i was tuned to 29hz and scored a 144.3 @ 31hz off of 1 15 and 667w of actual metered power off of a 1500w amp.

But the actual Fs of the car that i later found out was 41hz. 31hz was louder than the Fs of the car because the peak of the box was so strong evidently...that and with be being tuned so low, it was near impossible to get to the higher notes effectively without a sudden roll off.

Since you are tuned to 30hz, try notes right above that if you havent already.

[Miles 128]

I have a regular cab ranger and I know how hard it is to get loud in a truck. I'm thinking about doing a similar setup this summer but with a 10'' bl because I have nowhere near enough room for a 12''. The only thing I can think of for you to do would be to do a blowthrough, or add more power because bl's can take alot more than 750 watts. But considering the space you have I'd say you have an excellent score and I can't wait to make some money so I can start my build. How do you like the bl for daily music?

Well, I kind of kick myself in the butt for ordering it D1, but now I have the option of getting a better amp and running it at .5 ohms. And to answer your question on playing music, I think it is very acurate. The sub is mainly to get loud, but it does an excellent job at playing music. It was the same price as the Q, but the Bl will handle more power, and I just liked it better.

And to shizzon, I did a sweep to find the highest hitting hz I could get. Even though sitting inside the truck while it was sweeping, it felt extremely strong at about 35 hz and a little under, but I guess the meter doesn't lie. My setup is a low end monster, which is why I originally thought it would meter at about 31 or 32.

[tezin87 0]

what are the dimensions of that box? what size aero did you use?

[Miles 128]

what are the dimensions of that box? what size aero did you use?

I've got a 2.4 cube box tuned to 30 hz with a 3" aero port. I don't remember the actual demensions of the box. Where the sub is it's 6" at the top and 10" at the bottom.

[tezin87 0]

Any port noise with a 3'' aero? That would be the biggest I could use because with 1.25@33hz using a 4'' port would be impossible for me. But maybe that is your problem? Maybe you could go with a larger port if you can find somewhere else to locate it. Like maybe moving the sub closer to the passenger side wall and have a 4'' aero firing up towards the roof?

[Miles 128]

There is some port noise, but that is the biggest I could fit there. And yes, I checked every possible place to put the port, and that is the only practicle place to put it. But, I'm still happen with the loudness of my setup, and so far I'm sitting second in my class, so I not that worried about getting louder.

[tezin87 0]

well congratulations it all looks real good

[audio-neon 34]

Honestly your port and tuning are killing you. I would build a competition box, 2.2 cubes with a 6" aero (place the inside edge of the aero on the outer side of the box and port away from the box.) Tune the box to 40hz.

If you had ~2500 watts I would even shrink the box back to 2.0 cubes.

Seriously though a 3" aeroport is robbing you of efficiency and dB's.

[audio-neon 34]

With only 750 watts I would actually build a 3.6 cubic foot box tuned to 40 hz with a slot port, about 60 sq. inches of port, or a pair of 4" aero's.

*edit*

Now that I have read your entire post. I would still suggest building a competition box, tuned higher (read 38-40hz) and use atleast a 4" aero. I would than either upgrade your amp or order a dual 2 ohm recone if available and swap them out.

You made a minute mistake; in your case I would have ordered a Q, it would have been louder for low end and probably even louder than your bl because it is more efficient as it is designed for 1000 watts rms it would have softer spiders etc. It also has more x-max and could probably take a 2000 watt burp at 40+ hz in a properly designed enclosure.

[Miles 128]

Well, since this is the biggest possible box I could have made if I still wanted to use my center console and not have the passenger seat crambed all the way up, it's good enough. And again, 1 3" aero port is the most I can put in this box. I can't go to the other side because the sub is in the way. I did just swap in a 35 hz tuned port, and it does seem louder in the 35-45 hz range, but of course it lacks a little in the lower hz range. But I'm going to comp the 20th of june and I'll report back on how the 35 hz port worked out.

[cman0655555 0]

Where are you metering? Also can you have doors windows etc open. If so play around with that you never know what might work. Also i would add more port surface area if you could fit it. Do you have any room between the side of the box and the drivers side door panel? if so you could try to port it out that side so it would have something to reflect off of. Also you could seal up the box, find the resonant freq. of the truck, then tune the box to that so you get the most cabin gain.

[KU40 173]

yeah it seems just upping your tune is about all you can do (I'd have actually gone a little higher yet, like 40 hz). Also, playing a single frequency instead of a sweep will help in future competitions. This is mainly due to your amp pulling power from the electrical system during the upper frequencies before it gets down to your sweet spot, which lowers your voltage and subsequently power to your sub. But the problem now is that you switched ports, so your box may get louder at a different frequency now. Do you get two runs on the meter or just one? if you got two you could do a sweep, have them tell you your best frequency, then burp it the second time through.

[Miles 128]

In the comps I go to they allow you to have your windows down, door open, whatever. I hit my highest with both windows all the way down. The competitons I go to are put on by a guy called dBSteve (midwestspl.com) and I'm going to all the ones in Joplin, Mo and Pittsburgh, KS. I live in Cherryvale, KS btw so that's why I'm only going to them comps (god, gas prices suck). And at the last soundoff, only 5 people showed up, so me and this other kid paid out $10 for entering, and got to play around on the mike when there wasn't anbody around that wanted metered.

And to KU40, I do have a center port tube tuned to 38 hz. I haven't tested it yet, but I will here later. The kid I went along with (he's got a ranger with 2 Fi Bl 18's, and the link to the build log is under Build Logs on this forum) is thinking about getting a TermLab for himself and setting up a booth during the summer and charging people for using it. The only reason he's doing his is because now he has a big enough system that every little dB counts, and the nearest meter is about 70 miles away. And, it would be good for me to tune my stuff without going very far( he lives 15 miles away from me).

[cman0655555 0]

yea i would definently try to get on the meter and test as much as you can try metering in both seats. Also make sure you have your seats all the way forward closest to the dash as possible that might help. There are plenty of good suggestions on here try a few of them.