2 x 8" verses 1 x 12" ??
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=49217
Printed Date: May 10, 2025 at 5:10 AM
Topic: 2 x 8" verses 1 x 12" ??
Posted By: diavr
Subject: 2 x 8" verses 1 x 12" ??
Date Posted: February 02, 2005 at 4:13 PM
Hey. I have a 12" 300w RMS Pioneer sub in an undersized enclosure (+-30% - vented). It was ported to touch on low freq (35Hz at -3db point) and with reasonable gain (4db @ 60Hz). It doesn't sound bad and I can feel some SPLs.
Someone listened to the setup today and recommended that I rather replace current sub with 2 x 8" Rockford subs. They would then be able to give the 2 x subs the required volume and output would significant more!! I'm concerned about the following:
- Will I get similar or more SPLs?
- Will the 8" subs go as low a 12"?
- Does it make sense, will this really make a big improvement? Any feedback will be appreciated.
Replies:
Posted By: supradude
Date Posted: February 02, 2005 at 6:54 PM
Can you supply more info? Is the 12 a DVC or SVC sub? What type of amp are you using?
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'85 Toy
Posted By: bullman96
Date Posted: February 02, 2005 at 7:22 PM
we need to know the model subs. but in general, i would doubt 2 8's would be louder than a 12. of course there are exceptions but i doubt this is one of them. they will definately not go as low and sound as clean as a 12.
Posted By: bullman96
Date Posted: February 02, 2005 at 7:25 PM
the cone area, even with both the 8's would be 14". even if they do happen to be more loud, you wont be able to hear all that much of a difference
Posted By: stevdart
Date Posted: February 02, 2005 at 10:56 PM
8" subs are ususally less efficient than 12" woofers, so you would need more power to run them. If you get good ones, and build the proper vented enclosure, and supply the power they need, you should easily increase the SPL. But it requires more than just leaving everything as it is and switching out subs. You're concerned with them hitting as low as a 12"? All things being equal, no. Generally you're not concerned with both hitting low and SPL with the same setup. But if 35Hz is your point of reference for low, then that would be no problem with good 8" subs. I can't speak for Rockfords as I'm not familiar with the build quality. ------------- 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: kfr01
Date Posted: February 02, 2005 at 11:18 PM
Stevdart's post is good. I'd only like to add that it totally depends on the specific subwoofers you are comparing - both on the 8" side and the 12" side. Get some enclosure modeling software like WinISDpro (free) or any of the other programs available on the internet. Learn it. Use it. While they aren't perfect, especially the free ones, they can give you a good approximation of what to expect when comparing two systems.
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New Project: 2003 Pathfinder
Posted By: bullman96
Date Posted: February 02, 2005 at 11:29 PM
kfr, you should start recommending jbl speakershop. it is more accurate. it will give a better comparison.
Posted By: kfr01
Date Posted: February 03, 2005 at 12:05 AM
Last I checked JBL Speakershop was _not_ freeware or shareware. Correct me if I'm wrong.
Please tell me how the JBL speakershop calculations and the WinISD pro calculations differ.
In what ways is WinISD flawed?
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New Project: 2003 Pathfinder
Posted By: stevdart
Date Posted: February 03, 2005 at 8:21 AM
I have yet to hear a valid reason, either..........although this sort of warning about WinISD has been posted by a few people. Like kfr01, I need reasons why so I can do the research necessary to come to my own conclusion. Otherwise, without reasons, I consider it tongue-wagging and propagation of myths. Steven K. (the only person I've seen here attempt to back up such a claim) gave one example recently, but the difference in the two programs he referred to was quite small in the realm of things....and based on only one test showing a difference in volume (result), not an error in or omission of equations, or something else as concrete. His example alone wouldn't cause me to search out and buy a different program. WinISD takes a little time to get used to, as does any software. I suspect there are those who give up too quickly on it because they hear that they're wasting their time anyway. It's a great learning aid, and if the math of building enclosures overwhelms you (as it does me), it's a great tool. Bottom line: If you want to be critical of program recommendations, back it up. (Please) ------------- 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: bullman96
Date Posted: February 03, 2005 at 12:20 PM
when see how drivers will perform, i have been using winisd instead of leap for sake of ease. one day i decided to check winisd against leap and found it was a cubix foot off. thats a huge mistake. i got jbl speakershop, and although it is a little of on some calculation, it is not off enough to say to yourself "holy sh*t." if you want me to do the math out on a drive then compare it to winsisd's results. but i think we cam all agree that leap is pretty accurate
Posted By: kfr01
Date Posted: February 03, 2005 at 2:11 PM
Fine. But WHERE is the error? Is it in some of the pre-loaded driver data, is it in some of the parameters that WinISD automatically fills in? Do the errors only happen with sealed boxes? Ported?
Saying, "this one time, when looking at this one calculation, with this one driver it was wrong" doesn't help me at all. :-)
I'm not going to pirate Leap, JBL Speakerbox, or any other commercial software for that matter - and I won't recommend others do either. Please tell me what, specifically, is wrong with WinISD.
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New Project: 2003 Pathfinder
Posted By: stevdart
Date Posted: February 03, 2005 at 6:00 PM
I wouldn't count errant pre-loaded driver data against any of the programs. If the user doesn't have sense enough to check all the basic parameters against the ones he has from the manufacturer....then he more than likely doesn't have sense enough to use the program without error.
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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.
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