posted
OK..so if i read this correctly......to peak at the 1/4 wave (27hz in my case) the back wave needs to go 3x as far as the front wave....right?? Then for a full wave (110hz in my case) the rear wave needs to go 2x as far as the front wave......right?? Well 27 & 110hz are not practical in street class (110hz being ilegal) so would a 1/2 wave be OK???? That would be 55hz....but how far would the back wave need to go? 2 1/2 X as far???
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posted
That was a good article up to the point where your frequency is chosen based on the distance to the mic...Where did that come from?
Posts: 1259 | From: Fullerton. CA ,USA | Registered: Oct 1999
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posted
I thought that one was supposed to tune to the frequency it tells you when you do the equation. my note is a 54Hz in a SS1-2 NW set up and when my box was tuned at 50Hz I was doing about 150-151Db after I retuned the vent to 54Hz I jumped to around a 155Db. I still keep burping my 54 Hz. Am I supposed to tune a couple of Hz lower than the note I play? And if so could any knowledgable people please clarify this for me. thanx bunch!!
posted
Where your port is in relation to the box and the vehicle can change your tuning. If your port is on a side wall it is effectively longer (by 1/2 the width of the port) and if that port is on the side of a vehicle then is longer as well. I would imagine that when you tuned your port to 54, the box and vehicle actually lowered your tuning down to around 50Hz. The number you get from the math is close, and one usually needs to adjust it a little for max SPL.
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quote:Originally posted by festivaman: so basically if yu had a 50" mic to a pillar. you need 150" from back of front all to back wall to front of car
From my understanding of this what you would actually need (in theory) is 150" total distance when measured... From the back of the speaker dustcap (imaginary spot), to the middle of the back wall of your box, to the middle of the port opening, to the mic
So there's a total of 3 sections for the backwave to travel and when the measurements from all three are added together you should try to get your 150" distance (assuming that you have 50" from the front of the dustcap to the mic)
Is that a correct assumption?
-------------------- I'm so happy, Cuz today I found my friends, They're in my head. Posts: 130 | From: Melbourne, Australia | Registered: Jun 2002
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posted
what if my mic placment to a pillar is 46" but i only have about 28 " of box depth total.46*3=138. i only have 102". car still does 161's but i need morecan i cheet this wave by some how cuaseing th e wave to rteflect and be longer to get the correct 1/4 wave?
-------------------- i got a wanna bee loud festiva ss1-2 8-concept 2400d 2 quad concept 15,6 battaries Posts: 58 | From: north carolina | Registered: Dec 2002
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