subwoofer frequency for sq
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=106648
Printed Date: July 07, 2025 at 4:51 PM
Topic: subwoofer frequency for sq
Posted By: mystadp
Subject: subwoofer frequency for sq
Date Posted: August 08, 2008 at 7:25 AM
I'm using WinISD to design a box for my Yukon. I was wonder what frequency a typical 15 to 18 subwoofer should drop below the -3 db mark. Right now my curve goes up steady to about plus 15 or so at 45-50 hertz and then starts to slop down and crosses the -3 db mark at about 27 hertz and crosses the 0db mark around 32 hertz. Is this good? Im modeling to cerwin vega stroker 18s. Im looking for SQ first and im sure it will be loud enough so im not worried about that. Also, I was wondering if it would be better accoustically to have the speakers and ports facing straight back at the door or having a slight wedge design to face the speakers and ports more toward the rear window area... Like I said, Im looking for sound quality first. and SPL im sure will be there. Any help or advice would be greatly appreciated.
Replies:
Posted By: haemphyst
Date Posted: August 08, 2008 at 10:54 AM
My opinions appear here. SQ is my LIFE, so I think I know of what I speak.
Firstly, if you are using CV, I doubt HIGHLY that SQ is a high priority to you.
Secondly, for an in-car install, that would be OK, but I think that sounds a little (make that a LOT) "whumpy" to be considered SQ. That's bandpass response curves there, man! 15dB hot at 50Hz is what many would call a "One Note Wonder". A "Ground Pounder". FAR too small an enclosure.
The Strokers are hardly SQ woofers, at least not in any reasonably sized enclosure. Any decent 12" can hit an F3 of 22 to 25 in a proper box. I have a 10" in my car, with USEABLE output to around 20 or 22Hz. An 18" should be more in the 20Hz range for an SQ installation, especially vented.
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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: stevdart
Date Posted: August 08, 2008 at 9:31 PM
Yeah, you're working with the wrong woofer for SQ. The stroker is made for one-note SPL. That is what it's designed for and that is what it does.
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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.
Posted By: mystadp
Date Posted: August 09, 2008 at 12:57 AM
Sorry guys, I didnt really choose the subwoofer. I bought an astro van from my uncle a while back with 3 complete rockford fanatic Q 51/4 component sets in the front doors, eclipse 4x6s in the dash and another component set in the rear. It had 4 bucket seats, 6 stroker 18s, 3 2250sx Orion amps, and 2 2150sx Orion amps, and three professional grade trojan large deep cycle batteries in the rear. It was mostly an old school set up, but the components, better batteries, eclipse deck, eq, and changer were added a few years back. I had never really looked into buying new stereo equipment for my daily driver so when I decided to strip the van I figured what the hell. The compenent sets are pretty nice, and I knew from the start the vega's werent the best sub to deliver the SQ, but one key factor plays in, and that is that I have them and dont have to spend any money on subs. So I guess I should have posted that originally. Anyways, what I was looking for was some opinions on what I should shoot for to get me the best possible for these subs. The only reason Im putting two of them in my truck is so that I can have something louder than most of the youngsters I hear driving around town and I want it to be there when I want to crank it. But like I said, I dont want to spend the money on new equipment just yet. Let just say my motorcycle racing season is killing me on gas, and pulling the trailer doesnt help gas mileage. I appreciate the responses and hope to get some more encouraging news that these subs even stand a chance of coming up with a nice sounding combo.
Posted By: mystadp
Date Posted: August 09, 2008 at 1:02 AM
Sorry, a correction to my first post, 3 to 5 db strong at 50 herts
Posted By: haemphyst
Date Posted: August 09, 2008 at 8:49 AM
Free is good.  I appreciate free! (I say "free"... You had to buy a van! LOL) I mean "I have them, and I want to use them" = "free".
With that list of components, it sounds like your uncle was into loud ONLY. Basing my judgement on the era of where these all come from, the Eclipse deck (model number?), and the Eclipse plates were at least good or better parts. The Orion sx amps were OK, fidelity-wise, but the amps, RF and CV stuff is RIGHT out of the SPL lanes. Even back "in the day", I would have NEVER chosen (and at that time, I was SELLING) those products.
3 to 5 dB is certainly better. The Strokers are still not an SQ driver. As stevdart mentioned, those woofers are designed with one thing (really) in mind. How much of your Yukon's space do you want to give up? I won't be able to help with actual dimensions, but if you tell me how much space you want to part with, I'll try plugging the T/S numbers into a different enclosure software. (I use JBL Speakershop) ------------- It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
Posted By: mystadp
Date Posted: August 10, 2008 at 8:18 AM
LOL, Well, I guess I kinda look at it as free. I bought the van 3 or 4 years ago for $2500, I think I got a pretty good deal.. the van has shaved door handles, custom paint, 4 buckets all custom wrapped, moon roof, ect. Not to mention that list of equipment.. Yes, The subs and amps were installed somewhere between 12 and 15 years ago (I believe).. Im sure when he bought them they were fairly new to the market. Yes, he was the kind of person back then where the one thing he wanted was to be louder than anyone else. Anyways, eclipse 5443 is the head unit, and the 2101 is the EQ. The numbers I pluged in were 6.94 ft^3 at 31.25 hertz tuning freq per speaker. I can only go 48 inches wide for the total box, and I didnt want to go much more that 24 inches tall, and I would like to stay under 30 inches deep. i would probly be willing to loose up around 14 cubic feet or so.
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