PPI's new line
01-22-2004, 10:23 PM
#31
50 Watt CAFz'r
Join Date: Mar 2003
Posts: 309
Here's a copy and paste explanation of why subs are 6dB louder with the coils wired in parallel as opposed to series I posted on another forum. I got all this from a physics teacher, too, so I gues that makes it hard to dispute.
Subs are less efficient in series for same reason you can't wire up two different subs in series. I forgot all the technical terms about it, but they don't co-operate as well because of differences in the way resistance effects a series arrangement as opposed to parallel. When you wire a sub in series with another and push on one cone, the other will move in response to the current that you generate by moving a length of wire through a magnetic gap. Usually you can't notice the difference, but if you talk into one sub and listen carefully enough in the other one (and make sure you can't hear the person talking), you can listen to them talk, because of this principal of electricity that was discovered some time ago. The resistance does not effect other subs in a parallel arrangement but I don't know why - it just doesn't. Since the current created moves opposite the direction of the movement of the voice coil, the resistance created in one voice coil detracts from the other's performance and vice versa BUT since we are running a much more powerful current through the voice coils (from your amplifier), the electricity doesn't cancel itself out altogether (giving you a silent sub).
Since I couldn't understand what he talked about really, that might not make as much sense as I want it to but talk to a physics teacher and get them to explain it.
And then here's the other half of that response
slownlow - how does a a dual 2 ohm sub have more options then a dual 4? Wiring a dual 2 in series gives you 4 ohms which often does not extract the full potential out of your amplifiers, and wiring it in parallel gives you 1 ohm which won't go over too well with 2 ohm stable amplifiers. With a dual 2 though you can use most 2 ohm stable 2 channel amps, which would give you full power if you hooked a coil up per channel or series it all together and run it bridged, but then again if you parallel a dual 4 sub you can run one sub per channel.
and now onto DWVW ....
And why would you run your subs at 4 ohm mono? Becausethat could be where the amp makes the most power!
I never said that. We were talking a 2 ohm stable amp, and logic would dictate because of the laws of electricity, the power would be double at 2 ohms then at 4, unless its a JL.
How do the subs know the final load on the amp, their efficiency is unaffected.
I respond to this above.
Power is power, the battery and alt don't care about the load an the amp.
The amp draws power to make power. If my car wasn't written off I would show you how bad the lights dim at 1 ohm (which draws more current) then at 2 ohm (which draws less current)
The wiring has no affect on this equation, it's the power produced by the amp. If an amp goes into protect when paralleled into a load it can't handle it makes zero watt's throwing your observation out the window.
This is why I like 1 ohm stable amps..
I'm not big into buying subs that aren't any better then the ones I already have, so why would I go from an Xmax 4 ohm SVC to say a Thunder8000 4 ohm SVC (which is way worse, anyway)? ......... worse how? I have seen these subs win IASCA SQ contests
Worse how? Not as loud, sloppy sounding at high volumes, etc etc. I don't care about low volume performance since any sub will sound accurate. Then you crank it, and you will discover that the 8000 and Xmax are in totally different classes.
and slownlow, show me a single voice coil IDMAX, W7, W6v2, Resonant Engineering, Brahma, eD A series, or Titanium Elite. Those are real high end subs ... and I don't see any SVCs on that list (doesn't include custom coils).
[ January 22, 2004, 11:25 PM: Message edited by: Bumpin' Nova ]
Subs are less efficient in series for same reason you can't wire up two different subs in series. I forgot all the technical terms about it, but they don't co-operate as well because of differences in the way resistance effects a series arrangement as opposed to parallel. When you wire a sub in series with another and push on one cone, the other will move in response to the current that you generate by moving a length of wire through a magnetic gap. Usually you can't notice the difference, but if you talk into one sub and listen carefully enough in the other one (and make sure you can't hear the person talking), you can listen to them talk, because of this principal of electricity that was discovered some time ago. The resistance does not effect other subs in a parallel arrangement but I don't know why - it just doesn't. Since the current created moves opposite the direction of the movement of the voice coil, the resistance created in one voice coil detracts from the other's performance and vice versa BUT since we are running a much more powerful current through the voice coils (from your amplifier), the electricity doesn't cancel itself out altogether (giving you a silent sub).
Since I couldn't understand what he talked about really, that might not make as much sense as I want it to but talk to a physics teacher and get them to explain it.
And then here's the other half of that response
slownlow - how does a a dual 2 ohm sub have more options then a dual 4? Wiring a dual 2 in series gives you 4 ohms which often does not extract the full potential out of your amplifiers, and wiring it in parallel gives you 1 ohm which won't go over too well with 2 ohm stable amplifiers. With a dual 2 though you can use most 2 ohm stable 2 channel amps, which would give you full power if you hooked a coil up per channel or series it all together and run it bridged, but then again if you parallel a dual 4 sub you can run one sub per channel.
and now onto DWVW ....
And why would you run your subs at 4 ohm mono? Becausethat could be where the amp makes the most power!
I never said that. We were talking a 2 ohm stable amp, and logic would dictate because of the laws of electricity, the power would be double at 2 ohms then at 4, unless its a JL.
How do the subs know the final load on the amp, their efficiency is unaffected.
I respond to this above.
Power is power, the battery and alt don't care about the load an the amp.
The amp draws power to make power. If my car wasn't written off I would show you how bad the lights dim at 1 ohm (which draws more current) then at 2 ohm (which draws less current)
The wiring has no affect on this equation, it's the power produced by the amp. If an amp goes into protect when paralleled into a load it can't handle it makes zero watt's throwing your observation out the window.
This is why I like 1 ohm stable amps..
I'm not big into buying subs that aren't any better then the ones I already have, so why would I go from an Xmax 4 ohm SVC to say a Thunder8000 4 ohm SVC (which is way worse, anyway)? ......... worse how? I have seen these subs win IASCA SQ contests
Worse how? Not as loud, sloppy sounding at high volumes, etc etc. I don't care about low volume performance since any sub will sound accurate. Then you crank it, and you will discover that the 8000 and Xmax are in totally different classes.
[ January 22, 2004, 11:25 PM: Message edited by: Bumpin' Nova ]
01-22-2004, 10:33 PM
#32
Guest
Posts: n/a
What you posted from the "physics teacher" has nothing to do with what we are talking about. Of course every link in a series connection has an effect on the whole chain unlike parallel. Every one who has tried to find that one burnt out light in a christmas light string knows about that. But it has nothing to do with efficiency. Do the light bulbs in a series string shine different than those in a parallel string, no.
01-23-2004, 12:29 AM
#33
500 Watt CAFz'r
Join Date: Aug 2001
Posts: 866
Ok now im confused, where did I ever say that dual 2 ohm sub have more options that dual 4?
The whole point of this post I am making is that you said that "Now its great that PPI amps are 1 ohm stable"
I am still wondering why running an amp into 1 ohm is better?
IT gives you Zero wiring flexability over a 2 ohm mono stable amp or a 4 ohm for that matter.
Just buy subs that match the amp you choose to buy.
The whole point of this post I am making is that you said that "Now its great that PPI amps are 1 ohm stable"
I am still wondering why running an amp into 1 ohm is better?
IT gives you Zero wiring flexability over a 2 ohm mono stable amp or a 4 ohm for that matter.
Just buy subs that match the amp you choose to buy.
01-23-2004, 01:01 AM
#34
Guest
Posts: n/a
Originally posted by Bumpin' Nova:
And why would you run your subs at 4 ohm mono? Becausethat could be where the amp makes the most power!
I never said that. We were talking a 2 ohm stable amp, and logic would dictate because of the laws of electricity, the power would be double at 2 ohms then at 4, unless its a JL.
And why would you run your subs at 4 ohm mono? Becausethat could be where the amp makes the most power!
I never said that. We were talking a 2 ohm stable amp, and logic would dictate because of the laws of electricity, the power would be double at 2 ohms then at 4, unless its a JL.
they had built in current limiting
oh yeah I've listened to both the PG xmax subs and the mtx 8000's .........both sounded good to me [img]graemlins/dunno.gif[/img]
01-23-2004, 10:02 AM
#35
500 Watt CAFz'r
Join Date: Aug 2001
Posts: 866
Thats the funny thing, so many guy think they know , but really they dont.
Have you made a direct comparison of the 8000 and Xmax? Probly not!
Let me guess, people in forums or your buddy said that he heard they are no good, do they must suck right?
I remember this forum raving about the Beyond Audio drivers. Before I made comment on this product being made in a guys basement, I actually listened to a few cars with them.
Most I encountered were SPL variety and couldnt make any determination on sound Q.
But one forum member said he was going to a car show, and was yapping about how great his beyong audio SOUNDED!. Let me tell you I listened to this woofer and it sounded like ***!!. One of the worst things I had heard.
SO what were my conclusions?
1} not that the beyond audio sucked, but hopefully he just has no idea how to design a box.
2} That most people who think there stuff sounds good have absolutely no clue about car audio and would rather have a bad stereo than say I have XXX brand that is not the flavour of the year
Have you made a direct comparison of the 8000 and Xmax? Probly not!
Let me guess, people in forums or your buddy said that he heard they are no good, do they must suck right?
I remember this forum raving about the Beyond Audio drivers. Before I made comment on this product being made in a guys basement, I actually listened to a few cars with them.
Most I encountered were SPL variety and couldnt make any determination on sound Q.
But one forum member said he was going to a car show, and was yapping about how great his beyong audio SOUNDED!. Let me tell you I listened to this woofer and it sounded like ***!!. One of the worst things I had heard.
SO what were my conclusions?
1} not that the beyond audio sucked, but hopefully he just has no idea how to design a box.
2} That most people who think there stuff sounds good have absolutely no clue about car audio and would rather have a bad stereo than say I have XXX brand that is not the flavour of the year
01-23-2004, 12:06 PM
#36
50 Watt CAFz'r
Join Date: Mar 2003
Posts: 309
That whole physics thing was responding to why subs are louder wire in parallel and makes perfect sense if you have any brains. I guess subs aren't electrical conductors anymore and they actually are powered by magical forces not governed by any laws of physics human beings on this earth have discovered. Ask a university prof, if you want, about which is more efficient and I'm sure you'll not understand it but he'll make a compelling argument to why subs are louder in parallel
slownlow you just agreed with me. I said the only advantage was running amps into 1 ohm was the extra flexibility. I was going to buy PPI amps in the past but couldn't because they were only stable to 2 ohm
Once again I'll say you can't always replace everything at one time. I can't buy a new amp every time I buy new subs and vice versa. On a two ohm stable amp, two SVC 4 ohm subs will be getting the most out of the amp while two DVC 4 ohm subs will getting half the power and would be a gigantic step backwards in terms of volume. I can't always say I have the foresight to know what sort of amps are going to come after CES, so why would I know six months in advance what ohm coils I should get? It's not practical to replace everything at once every twelve months.
I've heard two Thunder8000s in a recommended ported box (with a Rockford 500bd, a far superior amp to my Sony) in my friends Dakota and they sound like garbage compared to my old Xmaxs which were in a recommended ported box in my old Nova (with a Sony Xplod no less, 300w each). The Xmaxs sounded so much better then the 8000s it wasn't even funny. Push them to their limits and you will see that the Xmax can still be musical while the 8000s start stumbling. I never assume what I woofer sounds like from other peoples reviews.
slownlow you just agreed with me. I said the only advantage was running amps into 1 ohm was the extra flexibility. I was going to buy PPI amps in the past but couldn't because they were only stable to 2 ohm
Once again I'll say you can't always replace everything at one time. I can't buy a new amp every time I buy new subs and vice versa. On a two ohm stable amp, two SVC 4 ohm subs will be getting the most out of the amp while two DVC 4 ohm subs will getting half the power and would be a gigantic step backwards in terms of volume. I can't always say I have the foresight to know what sort of amps are going to come after CES, so why would I know six months in advance what ohm coils I should get? It's not practical to replace everything at once every twelve months.
I've heard two Thunder8000s in a recommended ported box (with a Rockford 500bd, a far superior amp to my Sony) in my friends Dakota and they sound like garbage compared to my old Xmaxs which were in a recommended ported box in my old Nova (with a Sony Xplod no less, 300w each). The Xmaxs sounded so much better then the 8000s it wasn't even funny. Push them to their limits and you will see that the Xmax can still be musical while the 8000s start stumbling. I never assume what I woofer sounds like from other peoples reviews.
01-23-2004, 12:31 PM
#37
The only way to have a fair comparison, is to have it mounted and wired in your vehicle, remember cabin gain? it will definitely play into the equation. The box as well is a determining factor in the output and sq of the sub. Just because brand x sub says it can operate in a ported enclosure up to 50 cu.ft does not mean that it must be played in an enclosure of that displacement. I can take any sub and make it sound good, just by changing the size of the box, making it a sealed box or a ported box. Even a lowly old Lear Jet sub from 14 years ago can sound great and did sound great with the proper box.
01-23-2004, 12:56 PM
#38
Guest
Posts: n/a
Originally posted by Bumpin' Nova:
That whole physics thing was responding to why subs are louder wire in parallel and makes perfect sense if you have any brains. I guess subs aren't electrical conductors anymore and they actually are powered by magical forces not governed by any laws of physics human beings on this earth have discovered. Ask a university prof, if you want, about which is more efficient and I'm sure you'll not understand it but he'll make a compelling argument to why subs are louder in parallel
That whole physics thing was responding to why subs are louder wire in parallel and makes perfect sense if you have any brains. I guess subs aren't electrical conductors anymore and they actually are powered by magical forces not governed by any laws of physics human beings on this earth have discovered. Ask a university prof, if you want, about which is more efficient and I'm sure you'll not understand it but he'll make a compelling argument to why subs are louder in parallel
Again specs mean nothing when it comes to SQ.
01-23-2004, 02:02 PM
#39
Originally posted by slow/n\low:
Thats the funny thing, so many guy think they know , but really they dont.
Have you made a direct comparison of the 8000 and Xmax? Probly not!
Let me guess, people in forums or your buddy said that he heard they are no good, do they must suck right?
Thats the funny thing, so many guy think they know , but really they dont.
Have you made a direct comparison of the 8000 and Xmax? Probly not!
Let me guess, people in forums or your buddy said that he heard they are no good, do they must suck right?
If Dodgeram says he listened to both subs then chances are, he did, why would he need to lie to you? Not only that but I would imagine that he's been around car audio a lot longer than you. If he says something, you should listen cause he's likely right.
And so what if you heard a BA sub that sounded like junk, that was one sub, and it was more likely than not the box that was to blame for the bad sound because I happen to know that Don builds a solid sub. I've heard Focal subs that sound bad, does that mean the sub is garbage? No it's probably the install.
