can you tell me the frequensis for spl and sql ?
i think sql is around 30 hz but can you tell me for the spl cuz im makin interchangeble ports.
this is my box: 9.8 cubic ft the port is 33 hertz and the sub is a re audio sx 18 inch wat you think
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lilrob
Here's my take, and it's just me. There is no such thing as SQL. There's SPL and there's SQ...and not a twixt between. For SPL, tune to about 40 for a peaked response at about 50. Of course, you have to use a good modeling program to see the results. The best for SQ is a sealed box, but that depends on the sub. Some of them don't respond well in sealed. Porting for SQ generally means using a sub that has a low Fs and tuning the box at about the same Hz as the Fs, which should result in less of a peak in the response. The term SQL was made up by those wishy-washy people who want the best of both worlds. So they made up a term to suit their desires. If you want loud, you can get that with either SQ or SPL.
Edit: I went to the website to look at these subs and I see that RE uses the SQL term. They are playing for the crowd with that. They don't want these subs to be confused with SPL subs, but at the same time they want the potential buyer to know how he can get maximum output. You see that they included a porting option for the extra db's it provides, so it now becomes SQL.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
That box is a little to big for that subwoofer, but you didn't mention how much wattage you plan on running to the sub either.... If you plan on running everything by the recommended specs, then the port tuning frequency is just about right on, but the box is too big.
There is not a "specific" frequency for SPL and SQ. The loudest frequency differs for different setups. It depends on many factors such as enclosure size, subwoofer type, port tuning frequency, cabin gain, etc.... In SPL your basically just trying to find the frequency that "hits" the hardest in your specific setup. (which frequency yields the most decibels?) Since that varies from system to system, so must the frequency. There are many other factors that play their part in how many decibels you hit in SPL, but the frequency at which you play when taking the meter reading is crucial.
What stevdart said IS correct. (of course)lol
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Do whatever makes you happy in life without diminishing the happiness of others
to would tune an SX18 to ~33hz for daily...thats just me though.
if you are going for SPL, its totally different. You would want to tune your box to peak at your vehicles resonance frequency. (You doesnt mean you tune to box TO your res freq...you tune it to peak at that freq...usually the box tuning is 3-6hz lower than your vehicles actually res freq.)
lilrob,
your vehicle is an Explorer...right? those SUV's tend to have res freq's in the ~40-46hz range...that is one reason that SUV's sound great w/ a box tuned low (the 'like' lower frequencies.
but that is also why it is hard to get them really loud (150db+ range)...your see, lower frequency waves carry less energy than high freq wave (ex, its easier to get a 150 is a vehicle that peaks at 65hz than one that peaks at 45hz)
You can get some awesome daily bass out of SUV's, but it just takes alil work to get them in the 148-150dB+ range. (w/ the right tuning and box design, you should be able to get the SX18 in this range...it will just take time, testing, and know-how)
For an SPL port...try 125-150sq inches of port tuned to 38-39hz to start off...then get on a meter and run sine sweeps, cut the port an inch shorter at a time until you get the highest peak.
remember...fire the sub up and the port back...w/ the port mounted cented on the box and pretty low to the floor (~4-5" from the floor, if you use interchangable ports).
thats wath marshall white told me for my box and he said the box will sound loud and good and he saw the picture of the box.
one more question, is true that if i tune a box to the freq of sub it will act as free air (example: i have the re audio sx 18 inch the freq is 33hz, if i tune the box to 33 or 32 it will act as free air ? or not and stick with the 33 hz)
thanks alot
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lilrob
Hi I have an 86 ford f-150 and it has to single bucket seats in it. I made a box that fits perfectly behind the seats and stretches the entier with of the cab. I want to port the box but I do not know what frequency to tune the box at. To remind you i listen to mostly rap music and am looking for it to be loud but still sound good.
The Box....!!!
- 2.83 cu ft
- 1.415 cu ft per side (2 12" subs with a divider)
The System....!!!!
- 2 pioneer TSW306DVC 4ohm model(if you look it up look up TSW306C because the dvc model i wasn't able to see)
- sony xplod xm-1652z 1000w 2 ch amp
-the DVC are ran in series producing 8 ohms and the subs are ran parrell producing a final 4 ohm load
- the amp is bridged for 1000 x 1 @ 4 ohms, 400 rms
If someone could get back to me i would greatly apriciate it. thank you and have a nice day!!!