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DaBaller504
10-14-2003, 02:39 PM
Ok I understand saying 33htz it is what your box is tuned too. But can someone just better explain that too me. Does it mean like at 33 htz. will your system sound the best or hit the highest DB amount? Please help me a little bit.

LoneRanger
10-14-2003, 04:19 PM
Ok I understand saying 33htz it is what your box is tuned too. But can someone just better explain that too me. Does it mean like at 33 htz. will your system sound the best or hit the highest DB amount? Please help me a little bit.

the tuning frequency simply represents the frequency at which your box is most efficient. by adjusting this, you can change the way the speaker reacts. high-tuned boxes tend to be peaky (high efficiency across a small bandpass) whereas low tuned boxes tend to have a flat response (similar efficiency across a large bandpass)

the tuning frequency is usually between 3 and 6 notes lower than the loud note. for example, my daily use box is tuned to 33hz, but it gets loudest at 37hz.

to help you understand, try this. pick up a test disk that has sine waves on it (meca or iasca test disc or make your own with a frequency generator) and play a frequency quite a bit lower than your tuning frequency (if you're tuned to 33, play 22). The sub will move a lot, even at low volumes and very little sound will be made if any. Now play your tuning frequency. The sub will barely move and it will be loud.

This occurs because the box is very inefficient at playing 22 hz and because of this, the sub will move like crazy and won't make much noise. You'll also see a very high impedence at the amp. When you play a note within the subwoofer's bandpass, it picks up the gain from the port and lets the box do some of the work, therefore it doesn't have to move so much and the impedence at the amp will be the lowest at and around the tuning frequency.

The actual physics behind all this would take me an hour and a lot of thumbing thru my text books to explain fully, but if you need more info, hit me up on AIM (screen name donnballenger) and I'd be more than happy to talk your leg off about it :)

DaBaller504
10-15-2003, 09:43 AM
alrite i understand what you are saying now. now what is the advantage or disadvantage of a higher tuning freq or lower?

LoneRanger
10-15-2003, 12:06 PM
alrite i understand what you are saying now. now what is the advantage or disadvantage of a higher tuning freq or lower?


high-tuned boxes tend to be peaky (high efficiency across a small bandpass)

This is helpful for SPL. You want a box that spikes very high in efficiency and has a very low ohm load at the desired tuning frequency, but falls off drasticly before and after the spike. At competitions, subs are "burped" at a single note, so it doesn't matter what it sounds like on other notes.


whereas low tuned boxes tend to have a flat response (similar efficiency across a large bandpass)

You want a sound quality-oriented enclosure to play notes with the same impact all the way across the board so that it doesn't play some notes very loud and others very softly, like is described above.

DaBaller504
10-15-2003, 12:35 PM
ok I am starting to understand better

DaBaller504
10-15-2003, 12:36 PM
why do u want it to have a very low ohm load????

DaBaller504
10-16-2003, 09:09 AM
yah i know that, but sometimes the lower the ohms is not better, you will send your sub to much power, I just read into the statement to much, i know all about impedences and stuff, but I just read to far into it, i was thinking you meant the lower the ohm load the better, my bad on that

LoneRanger
10-16-2003, 03:10 PM
yah i know that, but sometimes the lower the ohms is not better, you will send your sub to much power, I just read into the statement to much, i know all about impedences and stuff, but I just read to far into it, i was thinking you meant the lower the ohm load the better, my bad on that

For all-out SPL purposes, lower ohm load IS better. your sub will take power far beyond it's rated ability for a few seconds at a time (ie a burp). The trick is to know when to turn it off so it doesn't fry your sub.

In a daily driving setup with a low tuned box, the impedence fluxuates constantly depending on the note being played, but it will only see any given ohm load for a few seconds at a time at most. Just because you have your sub wired to a certain ohm load doesn't mean that's the load it always presents the amp. In fact, the amp will rarely if ever see this load.

Redford
10-18-2003, 10:46 AM
So if you tune your box to 45 Hz and you're in an SPL Competition you want to play something around 52 Hz?

LoneRanger
10-18-2003, 11:14 AM
So if you tune your box to 45 Hz and you're in an SPL Competition you want to play something around 52 Hz?

it depends on the box. there's no real way to predict exactly where youre peak is going to be.....even the best CAD's can't. Only way to find out is to put it on a mic.

DaBaller504
10-20-2003, 08:57 AM
yah, got ya. i know what ya mean with burps, but my amp will rarely see my 1 ohm load???

LoneRanger
10-20-2003, 11:17 AM
yah, got ya. i know what ya mean with burps, but my amp will rarely see my 1 ohm load???

notes above and below the tuning frequency will present a higher ohm load. if you want to see for yourself what i'm talking about, try putting a digital multimeter ($36 at radio shack) on ohms and putting the posi and neg on the amplifier's output terminals while it's playing a song......it'll go crazy!

DaBaller504
10-20-2003, 11:33 AM
yah I was planning on buying one
now if I put it on while no song is playing, will it show the resistance that my amp is seeing from my subs? i wired the subs 1 ohm, will it show that????