DVC - change RMS?
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=64511
Printed Date: July 05, 2025 at 7:45 PM
Topic: DVC - change RMS?
Posted By: inforcer958
Subject: DVC - change RMS?
Date Posted: October 17, 2005 at 2:09 AM
ok i have 2 power acoustik BM's 10's - They are 4ohm DVC
- 800 watts power handling
- 400 Watts RMS
what i am wondering is that when i wire these subs so that they are each at 2 ohms. (i know how all that works) does the RMS of the sub change. I am not sure if i can push 400 RMS into the sub if i for say wired it at 8 ohms, or if i wired it at 2 ohms. i just want to be clear b4 i blow some shyt up.
Replies:
Posted By: dwarren
Date Posted: October 17, 2005 at 2:27 AM
The power handeling will not change regardless of the subs resistance. The only change in power will be the output of the amp based on the resistance it sees. What amp are you using? -------------
Posted By: inforcer958
Date Posted: October 23, 2005 at 7:44 PM
i am using a power acousitk TS 1920-2 2 channel 1920 W AMP. I think what i was trying to ask before is.... if u have 2 400W RMS subs DVC. say u bridge them both to 2 ohm using paralell connections and then u [put them in series to make a 1 channel 4 ohm system ( bc my amp doesn't handle 1 ohm) can i only push 400W RMS approx or can i push 800W and will it devide to each sub evenly. so ummm ya
Posted By: stevdart
Date Posted: October 23, 2005 at 9:48 PM
Don't let the fact that they're DVC subs cloud the issue. What if they were SVC subs, what would your reasoning be then? Two subs each capable of 400 watts: 400
400
___ 800 Wire them series/parallel; opposite of what you wrote above, because that is the preferred way to arrive at the total 4 ohm load you want. The amplifier will output power into a 4 ohm bridged load and that power will be divided among the speakers. See Woofer Wiring in the lefthand column for a diagram. ------------- 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: DYohn
Date Posted: October 24, 2005 at 11:11 AM
DVC loudspeakers generally list power ratings for both coils driven. If a DVC woofer is rated at 400 watts, that means each voice coil will actually handle 200 watts. It is important to understand this and de-rate the speaker if you drive only one coil. However, wiring both coils in series or in parallel will not change the total power rating. ------------- Support the12volt.com
Posted By: tcbturbosux
Date Posted: October 25, 2005 at 9:48 AM
You got great taste in sub. Gene Norvel would be proud of you. Ask who Gene is.
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Uncle Gumby
Posted By: inforcer958
Date Posted: October 26, 2005 at 10:18 PM
who is Gene Norvel ? lol
Posted By: infoaudio01
Date Posted: October 30, 2005 at 10:00 PM
stevdart wrote:
Don't let the fact that they're DVC subs cloud the issue. What if they were SVC subs, what would your reasoning be then? Two subs each capable of 400 watts: 400
400
___ 800 Wire them series/parallel; opposite of what you wrote above, because that is the preferred way to arrive at the total 4 ohm load you want. The amplifier will output power into a 4 ohm bridged load and that power will be divided among the speakers. See Woofer Wiring in the lefthand column for a diagram.
Stevedart, why would there be a difference when wiring series/parallel and parallel/series? either way it will yield 4ohms with those subs. 4ohms is 4ohms is it not? please correct me if i am wrong.
Posted By: geepherder
Date Posted: October 31, 2005 at 6:02 AM
The factor you need to remember is they are dual voice coil woofers. That means you have different wiring configurations to choose. If you wire the voice coils (and they're 4 ohms each) on one sub in parallel you get a total 2 ohms. If you wire them in series, you get 8.
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My ex once told me I have a perfect face for radio.
Posted By: stevdart
Date Posted: October 31, 2005 at 7:05 AM
infoaudio01: look at all the wiring diagrams available, including the ones listed on this site. You will see that if there is a choice between the two configurations, that series/parallel will be the one shown. So why isn't this shown both ways so you can pick and choose? Because there is a slight difference. When you link two speakers in series, the first speaker receiving signal will have a slightly higher level of input than the second speaker which is last to get it. At the same time, when you link the two coils of one driver in series the same applies. What is the priority, then? Priority: all woofers in a multi-driver arrangement have identical input/output. By linking coils in series on each one first and the woofers are connected in parallel, all of the drivers will receive the same input. Each woofer is connected at the same time (parallel); each woofer receives the same signal amplitude (level of power). By this you will know that although the difference may not be noticeable in most installations, there is a difference in signal flow when going through a series course than there is when going parallel, which is spontaneous. Also, most DVC subs are tested for parameters while series-wired, although this is not always the case (parameters are used when designing enclosures). There are times when the opposite way of wiring (parallel/series) is necessary to achieve a final load result. In those cases you will see this arrangement listed in the wiring diagrams. There are also other times when it is more convenient for the installer to do it this way when adding to an existing system. But when you are doing all the initial planning, series/parallel should be the first choice in your design. Here are a couple of references for you to look at: https://www.bcae1.com/srsparll.htm
https://www.bcae1.com/spkrmlti.htm ------------- 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: bumpingjeep
Date Posted: October 31, 2005 at 7:22 AM
stevdart is my hero...that is the best i have ever heard that explained ------------- 1987 Huffy...spinners...two 15's custom mounted to the back
Posted By: tcbturbosux
Date Posted: October 31, 2005 at 9:20 AM
Gene Norvel is the Vice Pres. of Power Acoustik. and does most of the designs. Very nice man...met him in okla. @ Petra show. ------------- Uncle Gumby
Posted By: haemphyst
Date Posted: October 31, 2005 at 11:30 AM
stevdart wrote:
Because there is a slight difference. When you link two speakers in series, the first speaker receiving signal will have a slightly higher level of input than the second speaker which is last to get it. At the same time, when you link the two coils of one driver in series the same applies.
Dude, I have never said you were wrong before, but I have to this time. "That is wrong." There are NO, and cannot be ANY, differences whatsoever...
Number one: The signal is an AC signal, so for one half of the waveform, the current pushes from one direction, (electrically, one woofer will get the current "first") and the other half of the waveform, it pushes from the other direction (electrically, the other woofer will get the current "first")... if it even matters at all - which it doesn't. Read on.
Number two: ANY TIME EQUAL RESISTANCES ARE WIRED IN SERIES, THE VOLTAGE DROP ACROSS THEM IS IDENTICAL. This is basic Ohm's Law, man... And it will hold true whether you have two woofers or two HUNDRED woofers. You know this stuff... IF there are differences in the voltage drop across the voicecoils, it is not because "one of them is connected first", it is because there is a difference in the voice coils... Because the voltage drop is the same, AND in AC presentation, there cannot be any difference in the output of the drivers, based specifically on where they are in the electrical chain.
Number three: There have been discussions on this board, referencing Dan Wiggins, that even if voice coils are wire 180 degrees out of phase from one another, there will be NO danger of damaging the voice coils whatsoever, so I am not really certain what you were trying to say with the last line. Because number one and two are true, and number three applies, your last line will have nothing to do with anything, even if it meant something. ------------- 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: October 31, 2005 at 6:28 PM
Actually, Dave, you've corrected me before a couple of times...but that's how I learn things. I have a pornographic memory so you know I don't forget much of what I read. Close to two years ago I read through the JL help info and tutorials, including the info reprinted below: https://mobile.jlaudio.com/support_pages.php?page_id=161 Please note that when wiring multiple drivers it is recommended that series connections between drivers be avoided at all costs. This does not include series connections made between voice coils on the same driver. For more information, please consult our dual voice coil tutorial. Additionally, if you have an idea for a wiring configuration and you do not see it here, chances are you should re-think its implementation (in other words, don't do it). You will more than likely find that the results will be less than optimal. https://mobile.jlaudio.com/support_pages.php?page_id=163 ...Because all driver-to-driver wiring should be done in parallel and two 8 ohm drivers wired in parallel will yield a 4 ohm final impedance.
It is far less desirable to make subwoofer to subwoofer connections in series. Because of slight and unavoidable differences between speakers and because of the high likelihood of uneven loading between different speakers in a car, there will be slight differences in the mechanical behavior of the two speakers in series. These differences in movement result in induced voltage (called back EMF) being created by the speakers across the series connection. This effect causes a problem when two speakers which behave differently are connected in series because the speakers can modulate each other (cause each other to move), resulting in distortion. The problem becomes more serious as more speakers are connected in series. A good experiment to show the effect of back EMF is the following: connect four speakers in series and short the positive and negative input leads of the series circuit. Push down on one cone with your hand; you will notice that the three other speakers will move in the opposite direction of the one you are pushing. Now, reconnect the speakers in parallel, short the inputs and push down on one cone. The speakers will not modulate each other because each one is shorted directly. Back EMF modulation is not a concern when the voice coils of a dual voice coil speaker are wired n series to each other because the coils are physically coupled on one moving mass. Therefore, they cannot possibly modulate each other because they cannot move independently. My memory didn't serve me as well as I wanted, though, with my statement: At the same time, when you link the two coils of one driver in series the same applies. What is the priority, then? ...if this info is the basis for what I wrote. And I didn't remember where I saw this info, so I didn't review the alleged reason when I answered the post here this morning...thus I winged it best as I could. Oh well...I'll remember all this the next time the subject comes up, including your argument. Since I read this I have noticed that wiring diagrams always favor series/parallel, where they certainly could show the wiring the other way instead. And I have read nothing from any of our resident experts, including you Dave, that specifically addressed this question. So I've had this impression all this time. I'll have to keep an eye out for pros and cons on the subject. And now I presume you'll get onto JL right away and let them know of their 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.
Posted By: haemphyst
Date Posted: October 31, 2005 at 7:39 PM
Ok, I like the argument...
POWER WISE, it cannot matter, and this is where I stand. The power dissipated across the drivers will be identical, either way it is done, and both drivers will dissipate 50% of the total power provided. I read both of those pages, and while most of what is said there is, indeed sound, and to most extents, true, I still maintain that it won't matter.
The back EMF? OK, I'll give ya that, 'cause I was overlooking that aspect. Having never done their experiment, (I will soon though) I cannot speak to the effectiveness of the results obtained.
Most diagrams do indeed favor the series/parallel wiring diagram, but I cannot believe it is for any kind of performance advantage. When wiring DVC woofers, it is usually EASIER to wire the coils in series, then in parallel, I think this is why we see that type of wiring scheme most often.
Potentially, given the new light of back-EMF, but ONLY for back-EMF, there may be some differences between series/parallel, and parallel/series wiring. Acoustically, I don't think there would be any difference, or if there is, very little difference.
Between your pornographic memory, and my photostatic remembery, we oughta know everything by now, eh? I always said I had a photographic memory, I just sometimes forget to load the film!
Oh, and I have already told JL they were wrong... they took it in the proper spirit  ------------- 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: October 31, 2005 at 8:45 PM
My fault for relaying that bit of information so poorly. I knew the basis but not the real reason, and it probably would have resulted in a different response from you, Dave, had I waited until I had enough time to find the backup source before answering. "Winging it" often puts me in the hot seat, but this time I made hero status! :) ------------- 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: geepherder
Date Posted: October 31, 2005 at 8:50 PM
Okay, good then. I thought I was going to have to step in and correct you Steve, but it looks like it's been handled.
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My ex once told me I have a perfect face for radio.
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