Sub enclosure for memphis M3 15"
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=45817
Printed Date: May 03, 2024 at 1:21 PM
Topic: Sub enclosure for memphis M3 15"
Posted By: AJRXtreme
Subject: Sub enclosure for memphis M3 15"
Date Posted: December 22, 2004 at 10:59 PM
I went to the local memphis dealer in my area and he said i would not want my box tuned at 28hz. He said he had his box tuned at 38hz with 2 M3's and he couldnt pick up anything on those subs. He said to tune it at 48hz and I would be very happy with it. He also said that if its at 28hz that the only people that would here it is the cops parked 3 blocks away. So I could go with either the 28hz tuned box and get tickets and only be able to pick up the very low lows, or i could go with a 48hz box and be able to pick up most low notes and the sound of the sub wouldnt sound blowy. Could you tell me if this would be right or is he just blowing smoke up my a$$.
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03 F150 on 24's
HU:Pioneer DVD5700
Frt:MC57
Subs:(12)S12L7
Amps:(3)KX2500.1's, MC-2004
Replies:
Posted By: stevdart
Date Posted: December 22, 2004 at 11:23 PM
https://www.memphiscaraudio.com/LiveImages/114/3/DocumentURL.pdf All the parameters are listed. If you were to plug them into some software like I just did, you would see that tuning the box at 48Hz would be a disaster. You'll be best going with 3 to 3.6 ft^3 (per sub) tuned 26 to 28 Hz. A box net at 3.6 ft with a port 4 x 9 would tune it at 28Hz and would be sweet. Don't worry, you'll hear the whole range you want out of it. Actually, the cabin gain will be more in the range starting at 48Hz too, and would only further make it worse at that high tuning point. Don't try making the box smaller. The manual gives you box specs at 3 ft tuned at 38Hz and I wouldn't go any higher than that.
Posted By: AJRXtreme
Date Posted: December 22, 2004 at 11:36 PM
I plan on powering it by a memphis 500D amp. Should I use any crossovers?
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03 F150 on 24's
HU:Pioneer DVD5700
Frt:MC57
Subs:(12)S12L7
Amps:(3)KX2500.1's, MC-2004
Posted By: stevdart
Date Posted: December 23, 2004 at 12:04 AM
https://www.memphiscaraudio.com/products/details.asp?id=24 Great amp, it has all you will need: adjustable subsonic filter and low pass crossover. Set the subsonic filter to just above the tuning freq (to about 30 Hz or so) and set the LPF to about 80 Hz. Then you can adjust the LPF a little to sound best blending with your midbass drivers. I just caught a look at your sig. Are you adding the 15 to what you show? If so, I'll leave suggestions to others because that is something I wouldn't do.
Posted By: kfr01
Date Posted: December 23, 2004 at 12:05 AM
You should ALWAYS use low pass crossovers with a sub. Since you already have the 2 10" drivers up front I would cross the M3 over at 60-70hz or so.
If you go ported I would also use a subsonic crossover at 20hz.
I agree with Stevdart. 43hz would be a horrible idea. 26-28hz would be great.
Your installer, in my opinion, is WAY off base with this one. Below the tuning frequency the subwoofer will start losing control and distorting. By making the tuning frequency as high as 48hz you're opening the door for quite a bit of distortion.
Also, correct me if I'm wrong pros, but isn't the installer a little wrong about how sound waves work. Low frequency waves are long, of course, but it isn't like you need to be standing at the end of them to hear them. As long as the wave oscillates by your ear you’ll hear those low frequencies, right?
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New Project: 2003 Pathfinder
Posted By: jeffchilcott
Date Posted: December 23, 2004 at 12:10 AM
your going to want to insure that you use a low freq cut off. most of the memphis amps have them. In a box that big, if you somehow hit a not around 20-25 hz....Most music dosent even play that low....it could prove to be fatal
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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place
Posted By: stevdart
Date Posted: December 23, 2004 at 12:14 AM
The lowest Hz are the longest waves and can be heard at the greatest distances. It seems the guy is trying to diminish the whole concept of using a 15" sub, or just did a bad install for himself and was trying to figure out a way it could sound better. And some think that when you tune a box to a certain frequency, as you must do when venting, that you only hear that particular frequency. You would be able to hear the entire bandpass region in the car, as kfr01 said.
Posted By: AJRXtreme
Date Posted: December 25, 2004 at 1:09 AM
Stevdart, Waht do u mean about adding the 15 for what i show? Can someone give me exact deminsions for a vented box for the 15" M3. Im afraid if i tell the guy i want it tuned at 28hz, hes just gonna go against what i say and build the box differently. I need axact measurements that i can tell him to build so i make sure he builds the box right. I want it vented and to be as big as it needs to. I also need to know if i buy the 500D from memphis, should i buy anything else for the sub? Like crossover? Please help! Thankyou
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03 F150 on 24's
HU:Pioneer DVD5700
Frt:MC57
Subs:(12)S12L7
Amps:(3)KX2500.1's, MC-2004
Posted By: biker8018
Date Posted: December 25, 2004 at 12:19 PM
1-800-467-2400 ask for tech assistance and stop guessing. That is all those guys do is come up with the best sounding boxes for their subs. On paper some designs look terrible but as a Memphis dealer I can say they work.
Posted By: kfr01
Date Posted: December 25, 2004 at 12:53 PM
Biker: I'm sure Memphis's designs are all peachy and pretty, but they design one or two generic designs for what most people want. If our friend ARJX wants something different, wouldn't it be rather foolish to just say, "memphis designs are always the best fit."...? ARJX: We told you in a previous post how large the box needs to be. There are volume calculators on the left hand side that tell you the appropriate dimensions. ARJX: There will be a crossover built into the amp. ------------- New Project: 2003 Pathfinder
Posted By: AJRXtreme
Date Posted: December 25, 2004 at 4:10 PM
Thank you sooooo much guys. I think I have this set. The box will probably be made in late Jan or early Feb. I will post pics of it when it is built. Later
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03 F150 on 24's
HU:Pioneer DVD5700
Frt:MC57
Subs:(12)S12L7
Amps:(3)KX2500.1's, MC-2004
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