hz and tuning numbers not making sense
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=84457
Printed Date: April 28, 2024 at 5:06 PM
Topic: hz and tuning numbers not making sense
Posted By: wildchildbmx6
Subject: hz and tuning numbers not making sense
Date Posted: October 22, 2006 at 2:42 PM
im new to the technical aspect of tuning so be easy. i am hooking up a pair of 15" subs in my expedition. the box i built is sectioned for each sub and each is 3 cubic feet. i have used all the calculators trying to determine port length. but it seems that the fs is to low. it states on the web site that the fs is 19hz. when i plug everything in it tell me the port needs to be somewhere like 56 inches long. thats not right. what should i do to fix this problem? what is the best frequency range to tune the sub to? i want them to be as loud as possible, im not all that worried about sound quality. if you want to look at the subs stats clcik here--- https://mdcaraudio.com/sidewinder15.html if there is a better box to build besides for ported i would appreciate some guidance
Replies:
Posted By: aznboi3644
Date Posted: October 22, 2006 at 3:18 PM
Fs is the resonancy frequency of the sub. This is not what you have to tune the enclosure for.
Tuning that low is not necessary at all...a tuning between 35-40 is good for all around music.
You can use a single 6 inch diameter port that is about 16 inches long and will give you a tuning approx 35Hz
Trying plugging in 40Hz as the Fb of the box and see how long it needs to be
Bigger the port the longer it needs to be to be tuned to same as a smaller port.
Lower the tuning to longer the port needs to be
Posted By: wildchildbmx6
Date Posted: October 22, 2006 at 3:37 PM
am i heading in the right direction by using a ported enclosure? i want to use slot ports, are there any downsides?
Posted By: aznboi3644
Date Posted: October 22, 2006 at 7:18 PM
There are no down sides to a slot port...a port is a port.
I would call the customer service and ask them about what would be best...because if the chambers are already 3 cu ft than with port displacement they are going to be even smaller...
I would go ahead and keep it sealed at first for a couple weeks and see if you like how it sounds. But mount the woofers so there is room for two 4 inch or one 6 inch round port on the baffle board in case you want to port it later on
Posted By: killer sonata
Date Posted: October 22, 2006 at 8:44 PM
what kind of bass are you going for? loud and obnoxious? something good for everyday listening? or accented low freqs?
Posted By: wildchildbmx6
Date Posted: October 22, 2006 at 8:53 PM
im going for the kind of bass that shakes other peoples cars. but since on on a budget i cant buy a high end sub. i know the dealer of some mass destruction subs. they are decently loud in a ported box. he showed me a 12 in a 3 cube ported box, he hooked it up to the 25 watt shop stereo and it was shaking the walls. im going for over all obnoxious or at minumum just plain rude.
Posted By: killer sonata
Date Posted: October 22, 2006 at 9:03 PM
so basically you want to impress other people in other cars by wizing them off? lol. im just messing. id say tune the box to 35-38hz and call it a day. Tha will give you what you need/want
Posted By: wildchildbmx6
Date Posted: October 23, 2006 at 3:15 PM
the company recommends a 2ft^3 ported box. so i figured 3ft^3 would be good enough. how big should i make it then?
Posted By: aznboi3644
Date Posted: October 23, 2006 at 3:51 PM
Yes...they may "recommend" 2 cu ft...but in all seriousness a 15 inch subwoofer needs more than 2 cubic feet of airspace to sound good and play well in a ported enclosure.
I'd say go ahead and make that box a slot vent and see how it sounds since it is what the manufacturer "recommends". Then build a different one that is of proper size.
Download WinISD and see how the response curve is on that thing
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