2 x 12's or 1 x 15 ??
11-21-03, 05:31 AM
#16
Lexus Test Driver
I'm not gonna try and be a great big jerk about it, but Mr. Dell....you're wrong any way you slice it.
It sounds good and possible on paper to you, but in the real world both RMMGS4 and I are stating facts and not theories. I too will challenge you to put up a little bit of your credentials (sort of speak) so we can all see where these "theories" are coming from. I don't know RMMGS4 personally, but I have seen his posts for a long time and he sounds like a person that speaks with lots of experience and intelligence. I have a sneaky suspicion that he has probably been involved with sound competitions before, but I will let him chime in on that himself. Personally, I've been involved with sound competitions, equipment, and installation since the early 80's (I'm an old man). I have listened personally to some of the WORLD's best sounding vehicles (Team Gates SQ vehicle, Team Mb Quart, etc.) and some of the WORLD's loudest vehicles (again Team Gates to mention just one was the world record holder for many years). I can assure you that my EAR is more dissearning than the internet article.
All this to say simply that the bottomline generalization/rule of thumb is that the user will have to decide what it is he/she ultimately wants. If they are after SQ and all power will remain equal, the smaller sub will net better results the majority of the time due to speed/effectiveness of the equipment. 15's have almost always been for higher SPL as their main purpose. Sound quality is not usually on their resume. There are always exceptions and they are usually related to poor quality equipment and installation.
The 15, in the scenario of this post specifically, will only be better as it relates to installation. It will be both easier to install and take up less space than 2 12's, unless you grossly under-built the 12's enclosure or choose 2 different kinds of speakers.
I suppose that you also feel that a car bigger wheels/tires will be easier to get moving than the same car with smaller wheels/tires.
Similarly, music transients are measured in milliseconds. All music has transient signals. Music does NOT move in a sine wave pattern. It has sharp peaks and valleys. Those peaks and valleys and the ability for the equipment to reproduce them is what SQ is all about in a nutshell. The bigger massed speaker will have a slightly harder time in making the transition between both shifts. This translates into the "slower" speed RMMGS4 and I are refering to. That in turn translates into a less desirable sound due to the speakers inability to keep up with the music.
It sounds good and possible on paper to you, but in the real world both RMMGS4 and I are stating facts and not theories. I too will challenge you to put up a little bit of your credentials (sort of speak) so we can all see where these "theories" are coming from. I don't know RMMGS4 personally, but I have seen his posts for a long time and he sounds like a person that speaks with lots of experience and intelligence. I have a sneaky suspicion that he has probably been involved with sound competitions before, but I will let him chime in on that himself. Personally, I've been involved with sound competitions, equipment, and installation since the early 80's (I'm an old man). I have listened personally to some of the WORLD's best sounding vehicles (Team Gates SQ vehicle, Team Mb Quart, etc.) and some of the WORLD's loudest vehicles (again Team Gates to mention just one was the world record holder for many years). I can assure you that my EAR is more dissearning than the internet article.
All this to say simply that the bottomline generalization/rule of thumb is that the user will have to decide what it is he/she ultimately wants. If they are after SQ and all power will remain equal, the smaller sub will net better results the majority of the time due to speed/effectiveness of the equipment. 15's have almost always been for higher SPL as their main purpose. Sound quality is not usually on their resume. There are always exceptions and they are usually related to poor quality equipment and installation.
The 15, in the scenario of this post specifically, will only be better as it relates to installation. It will be both easier to install and take up less space than 2 12's, unless you grossly under-built the 12's enclosure or choose 2 different kinds of speakers.
I suppose that you also feel that a car bigger wheels/tires will be easier to get moving than the same car with smaller wheels/tires.
Similarly, music transients are measured in milliseconds. All music has transient signals. Music does NOT move in a sine wave pattern. It has sharp peaks and valleys. Those peaks and valleys and the ability for the equipment to reproduce them is what SQ is all about in a nutshell. The bigger massed speaker will have a slightly harder time in making the transition between both shifts. This translates into the "slower" speed RMMGS4 and I are refering to. That in turn translates into a less desirable sound due to the speakers inability to keep up with the music.
11-21-03, 08:43 AM
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First of all, I need to make this as clear as possible because some of you may not be in the know. One subwoofer is not absolutely 'slower' than another. If you send a driver a 50hz signal, it will move at 50 cycles per second. That's all there is to it. A driver moving slower than another is simply playing a different frequency. What we're discussing here is change in acceleration.
I can't put it any better than Mr Wiggins:
"What is a driver? It's a current driven motor. F=ma. What can vary with time? Not mass - that's fixed for a given driver. It just scales the acceleration to the force. Thus if you want to change the force of the motor (and remember, SPL is a function of force), then you need to change the accleration.
What is the acceleration? BL times current - BLi. Does BL change with time? It shouldn't (and flat BL drivers approach this over most of their excursion range). So what are we left with? Current. What resists changes in current? Inductance.
Mass simply isn't a factor when it comes to transient response. It is a factor in terms of SPL, but not transient response."
Also, how do you explain a 15" driver such as the Lambda TD 15(http://www.lambdacoustics.com/drivers/TD15H.html) with Mms 129grams being able to play up to 2khz yet sounding fantastic? Clearly the need to change acceleration is more demanding at 2khz than the maximum frequency a normal subwoofer should be playing, say 80hz. There are certainly subwoofers out there with similar moving masses... the answer is that the Lambda has an Le of a paltry .3 millihenries. The TD's voice coils have practically no trouble 'letting go of current.' Compare this to a driver that few look highly upon in terms of SQ, the MTX 8104, which has an Le of 2.7 mh.
Now I wasn't considering it until now as I the OP was speaking of two 12" drivers vs. one 15", but if we are talking about one 12" against one 15", we must consider another factor. To produce, say 120db, a 12" subwoofer may have to reach nearly full excursion to pruduce said SPL. But take a 15" version of the same driver, and we need not push the speaker to it's limits. This helps keep BL high and thus control of the suspension improves.
"I too will challenge you to put up a little bit of your credentials (sort of speak) so we can all see where these "theories" are coming from."
I would prefer not to. Last time I participated in a pissing match, I got the short end of the stick (regardless of how correct I was in the matter). But how hard is it to believe that I've had the opportunity to compare different sizes of the same model speaker?
Last but not least, I truly believe that many people who think 10"s sound 'tighter' than 15"s are experiencing a placebo effect or simply have not heard said drivers in appropriate enclosures. I can't stress enough that the enclosure has as much an effect on frequency response as does the driver itself.
I can't put it any better than Mr Wiggins:
"What is a driver? It's a current driven motor. F=ma. What can vary with time? Not mass - that's fixed for a given driver. It just scales the acceleration to the force. Thus if you want to change the force of the motor (and remember, SPL is a function of force), then you need to change the accleration.
What is the acceleration? BL times current - BLi. Does BL change with time? It shouldn't (and flat BL drivers approach this over most of their excursion range). So what are we left with? Current. What resists changes in current? Inductance.
Mass simply isn't a factor when it comes to transient response. It is a factor in terms of SPL, but not transient response."
Also, how do you explain a 15" driver such as the Lambda TD 15(http://www.lambdacoustics.com/drivers/TD15H.html) with Mms 129grams being able to play up to 2khz yet sounding fantastic? Clearly the need to change acceleration is more demanding at 2khz than the maximum frequency a normal subwoofer should be playing, say 80hz. There are certainly subwoofers out there with similar moving masses... the answer is that the Lambda has an Le of a paltry .3 millihenries. The TD's voice coils have practically no trouble 'letting go of current.' Compare this to a driver that few look highly upon in terms of SQ, the MTX 8104, which has an Le of 2.7 mh.
Now I wasn't considering it until now as I the OP was speaking of two 12" drivers vs. one 15", but if we are talking about one 12" against one 15", we must consider another factor. To produce, say 120db, a 12" subwoofer may have to reach nearly full excursion to pruduce said SPL. But take a 15" version of the same driver, and we need not push the speaker to it's limits. This helps keep BL high and thus control of the suspension improves.
"I too will challenge you to put up a little bit of your credentials (sort of speak) so we can all see where these "theories" are coming from."
I would prefer not to. Last time I participated in a pissing match, I got the short end of the stick (regardless of how correct I was in the matter). But how hard is it to believe that I've had the opportunity to compare different sizes of the same model speaker?
Last but not least, I truly believe that many people who think 10"s sound 'tighter' than 15"s are experiencing a placebo effect or simply have not heard said drivers in appropriate enclosures. I can't stress enough that the enclosure has as much an effect on frequency response as does the driver itself.
11-21-03, 11:08 AM
#18
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Ok I think it remains on my choice to choose between the 2 12 or 1 15...I just needed an advice, depending on ur experience guys !
I like the bass and I think that I am more a SPL fan than a SQ fan in audio...But I like them both !!!
I have already experienced 2 12 and its good...But I think that one DVC 15 unch sub could make the job like the 2 12, if not higer.
Could you give me an advice on that ?
I like the bass and I think that I am more a SPL fan than a SQ fan in audio...But I like them both !!!
I have already experienced 2 12 and its good...But I think that one DVC 15 unch sub could make the job like the 2 12, if not higer.
Could you give me an advice on that ?
11-21-03, 11:34 AM
#19
Lexus Test Driver
Once again, you're barking up the wrong tree.
The 50hz example does not apply to speed. It implies sound. The smaller speaker will require less power (which presumably is constant) to move at a said frequency because it has less mass to move. It will also not put out as much SPL at the same level, but it will be easier to move simply because of less mass. Music, not electricity, has very ragged transient shifts in frequencies. Therefore, the question is not if both speakers can go to 50hz or not....it really (when you refer to SQ) becomes a question of which speaker can shift from 50hz to 80hz to 65hz and back again with the least amount of effort while yielding you the highest returns. The laws of Physics still apply. A body in motion tends to stay in motion. Remember, a speaker is simply an electric air pump. It moves air into frequencies which are audible to the human ears. Hence the bigger the cone, the bigger the sound. Hence the bigger the pump, the bigger the amount of air it can move. Hence also, the bigger pump is not going to be as easy to move up and down as the smaller one. The bigger pump will only move more air IF you move it up and down faster and more often but that is going to require MORE power too. And since we have to assume a constant (i.e. limited) amount of power, you will NOT be able to move it faster or more often because you will be tapped out at some point. Think of it as power-to-weight ratio is on cars. A lighter car requires less amount of HP to move at the same speed as a heavier car therefore it is possible to move the lighter car faster than the heavier car if the HP is the same on both cars. Right? Follow now?
Now, if you put more power to the driver....the above power-to-weight ratio scenario would still apply except now the playing field levels. Just like it does with cars. Put enough HP into the heavier car and it too can be fast or faster than the lighter car, unless it too finds more HP. BUT anyway you slice it, if you keep the power the same.....the lighter car will ALWAYS be faster than the heavier car simply due to mass.
Yes, you can make a 15 sound awesome if you put it in it's optimum enclosure in a vaccum. Unfortunately, we don't drive in a bus sized vaccum. As I have tried to explain several times, in a "real world" car environment you have to choose your poison. The young man that initially started this thread did not specify so we are left to assume his preference. Even so, when you compare a single 15 to dual 12's there really is no comparison:
If you have 1 car, X size.
If you have 2 12's of Y brand or 1 15 of the same brand.
If you have Z brand amp with say 200W/channel.
In that scenario, you will get both more SPL and SQ using the 2 12's instead of a single 15 because the amount of power and space is constant and limited. If you are concerned with the amount of left over space, you could THEN choose the single 15 in order to minimize the enclosure size. If enclosure size is not an issue and both enclosures are built to exact standards of each driver, you will STILL have higher SPL and SQ with the 2 spkr setup because you both more surface area (i.e. SPL) and less mass (i.e. smaller driver).
If the scenario were to change, then the equation would be totally different as would application. Again, if brands were not constant the you could also argue that X brand is better than Y brand and therefore a driver of any size from X brand would be better than a larger/smaller than Y simply due to quality of the speaker. That was not specified in the initial post, so we are left to assume that all variables are constant.
We could go on and on, but at this point if my analogy doesn't convince you differently.....then lest just agree to disagree and let others voice their opinions based on the data given.
The 50hz example does not apply to speed. It implies sound. The smaller speaker will require less power (which presumably is constant) to move at a said frequency because it has less mass to move. It will also not put out as much SPL at the same level, but it will be easier to move simply because of less mass. Music, not electricity, has very ragged transient shifts in frequencies. Therefore, the question is not if both speakers can go to 50hz or not....it really (when you refer to SQ) becomes a question of which speaker can shift from 50hz to 80hz to 65hz and back again with the least amount of effort while yielding you the highest returns. The laws of Physics still apply. A body in motion tends to stay in motion. Remember, a speaker is simply an electric air pump. It moves air into frequencies which are audible to the human ears. Hence the bigger the cone, the bigger the sound. Hence the bigger the pump, the bigger the amount of air it can move. Hence also, the bigger pump is not going to be as easy to move up and down as the smaller one. The bigger pump will only move more air IF you move it up and down faster and more often but that is going to require MORE power too. And since we have to assume a constant (i.e. limited) amount of power, you will NOT be able to move it faster or more often because you will be tapped out at some point. Think of it as power-to-weight ratio is on cars. A lighter car requires less amount of HP to move at the same speed as a heavier car therefore it is possible to move the lighter car faster than the heavier car if the HP is the same on both cars. Right? Follow now?
Now, if you put more power to the driver....the above power-to-weight ratio scenario would still apply except now the playing field levels. Just like it does with cars. Put enough HP into the heavier car and it too can be fast or faster than the lighter car, unless it too finds more HP. BUT anyway you slice it, if you keep the power the same.....the lighter car will ALWAYS be faster than the heavier car simply due to mass.
Yes, you can make a 15 sound awesome if you put it in it's optimum enclosure in a vaccum. Unfortunately, we don't drive in a bus sized vaccum. As I have tried to explain several times, in a "real world" car environment you have to choose your poison. The young man that initially started this thread did not specify so we are left to assume his preference. Even so, when you compare a single 15 to dual 12's there really is no comparison:
If you have 1 car, X size.
If you have 2 12's of Y brand or 1 15 of the same brand.
If you have Z brand amp with say 200W/channel.
In that scenario, you will get both more SPL and SQ using the 2 12's instead of a single 15 because the amount of power and space is constant and limited. If you are concerned with the amount of left over space, you could THEN choose the single 15 in order to minimize the enclosure size. If enclosure size is not an issue and both enclosures are built to exact standards of each driver, you will STILL have higher SPL and SQ with the 2 spkr setup because you both more surface area (i.e. SPL) and less mass (i.e. smaller driver).
If the scenario were to change, then the equation would be totally different as would application. Again, if brands were not constant the you could also argue that X brand is better than Y brand and therefore a driver of any size from X brand would be better than a larger/smaller than Y simply due to quality of the speaker. That was not specified in the initial post, so we are left to assume that all variables are constant.
We could go on and on, but at this point if my analogy doesn't convince you differently.....then lest just agree to disagree and let others voice their opinions based on the data given.
11-21-03, 02:14 PM
#21
Lexus Test Driver
Originally posted by Darius2004
THIS is why I love ClubLexus.com
THIS is why I love ClubLexus.com
Let me know and I'll give you a guys website where I got mine from. He's in Miami and is really cool guy. Great service and prices to boot. I love mine, except I should of listened and gotten them staggered. I may still do that anyway, when I need new tires.
11-21-03, 02:48 PM
#22
I absolutely agree with jmecbr900.
Though the referenced article speaks about the voice coil's inductance being the major factor, it is simply NOT the only factor. Mass is absolutely a major factor. As the cone's mass goes up, the rest of the mechanical suspension must be sized accordingly, to handle the increased electromagnetic forces involved, and all the other imperfections in the suspension that are also factors, like friction. The argument that a 15" woof running at 100 Hz is the same as a 12" woof running at 100 Hz is ONLY applicable for steady-state, unless EVERY single parameter that can possibly affect that woofer's transient nature has been proportionately sized, including all parasitic R-L-Cs. The shape of the attacks of music is important down to the fraction of a cycle level - this is partly what separates great audiophile equipment from the masses - and there are higher freqs contained in those transitions that are not necessarily related to the fundamental, and reproduction of those is required for good SQ. So the larger woofer must have the same frequency bandwidth (same cutoff on the higher end) to match the smaller woofer, and this is usually NOT the case. Unfortunately, most 15" woofers suspension and electromagnetics are not made proportionately larger and stronger than the 12"'s out there, mostly due to cost and weight reasons. I'm sure there are some excellent 15"s out there, and I'm sure they're expensive. Better off going with the (2) 12's.
Though the referenced article speaks about the voice coil's inductance being the major factor, it is simply NOT the only factor. Mass is absolutely a major factor. As the cone's mass goes up, the rest of the mechanical suspension must be sized accordingly, to handle the increased electromagnetic forces involved, and all the other imperfections in the suspension that are also factors, like friction. The argument that a 15" woof running at 100 Hz is the same as a 12" woof running at 100 Hz is ONLY applicable for steady-state, unless EVERY single parameter that can possibly affect that woofer's transient nature has been proportionately sized, including all parasitic R-L-Cs. The shape of the attacks of music is important down to the fraction of a cycle level - this is partly what separates great audiophile equipment from the masses - and there are higher freqs contained in those transitions that are not necessarily related to the fundamental, and reproduction of those is required for good SQ. So the larger woofer must have the same frequency bandwidth (same cutoff on the higher end) to match the smaller woofer, and this is usually NOT the case. Unfortunately, most 15" woofers suspension and electromagnetics are not made proportionately larger and stronger than the 12"'s out there, mostly due to cost and weight reasons. I'm sure there are some excellent 15"s out there, and I'm sure they're expensive. Better off going with the (2) 12's.
Last edited by engin_ear; 11-21-03 at 02:54 PM.
11-21-03, 04:23 PM
#23
Lexus Champion
Originally posted by jmecbr900
Not to change the subject, but you are going with the EVO's too?
Let me know and I'll give you a guys website where I got mine from. He's in Miami and is really cool guy. Great service and prices to boot. I love mine, except I should of listened and gotten them staggered. I may still do that anyway, when I need new tires.
Not to change the subject, but you are going with the EVO's too?
Let me know and I'll give you a guys website where I got mine from. He's in Miami and is really cool guy. Great service and prices to boot. I love mine, except I should of listened and gotten them staggered. I may still do that anyway, when I need new tires.
Yeah Buddy -I'm going with the EVO's. I saw the chrome ones on a BMW a couple days ago and DAMN!! Even the front's have a 1 inch lip! I don't know about staggered for the same reason you told me you didn't get them. That makes a lot of sense. Especially when tires are 200.00 each!
PM me with your guys info. I was going to get them from WheelsNext.com because they offer free springs ( I can pawn them off on ebay) Free Rim Repair, and free shipping.
11-21-03, 06:07 PM
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Ok 2 12's.
NOW...I decided to choose Audiobahn for my next subs...is it or not a good idea ? Still remainning with the JBL1200.1 amp.
by the way, go check out IkeSound for good prices in car audio !
NOW...I decided to choose Audiobahn for my next subs...is it or not a good idea ? Still remainning with the JBL1200.1 amp.
by the way, go check out IkeSound for good prices in car audio !
11-21-03, 08:59 PM
#25
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Originally posted by binelus
Ok 2 12's.
NOW...I decided to choose Audiobahn for my next subs...is it or not a good idea ? Still remainning with the JBL1200.1 amp.
by the way, go check out IkeSound for good prices in car audio !
Ok 2 12's.
NOW...I decided to choose Audiobahn for my next subs...is it or not a good idea ? Still remainning with the JBL1200.1 amp.
by the way, go check out IkeSound for good prices in car audio !
the JBL 1200.1 amp puts out 600W x 1 @ 4 ohms.
what model Audiobahn subs are you getting? what are the power ratings for them?
11-21-03, 11:19 PM
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Originally posted by binelus
Ok 2 12's.
NOW...I decided to choose Audiobahn for my next subs...is it or not a good idea ? Still remainning with the JBL1200.1 amp.
by the way, go check out IkeSound for good prices in car audio !
Ok 2 12's.
NOW...I decided to choose Audiobahn for my next subs...is it or not a good idea ? Still remainning with the JBL1200.1 amp.
by the way, go check out IkeSound for good prices in car audio !
11-22-03, 01:07 PM
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For the sub :
PHAT 2” Multi-layer Foam Surround
120 oz. Magnet
Stamped and Balanced Aluminum Cone
6 mm Thick Cast Flame Basket
Multi-Connect Lug-Lock Terminals
Mounting Depth: 6 3/4”
Hole Cutout: 10 7/8”
Outer Diameter: 12 1/2”
Size: 12 inch
Rec. Sealed Box Dims: 0.50 - 1.25 cu.ft.
Rec. Ported Box Dims: 1.30 - 3.20 cu.ft.
Free Air Usage: not recommended
Sensitivity: 96.4 dB
Frequency Response: 20-500 Hz
Recommended RMS Power: 1100W
Peak Power Handling: 2200W
Impedance: dual 4 ohms
PHAT 2” Multi-layer Foam Surround
120 oz. Magnet
Stamped and Balanced Aluminum Cone
6 mm Thick Cast Flame Basket
Multi-Connect Lug-Lock Terminals
Mounting Depth: 6 3/4”
Hole Cutout: 10 7/8”
Outer Diameter: 12 1/2”
Size: 12 inch
Rec. Sealed Box Dims: 0.50 - 1.25 cu.ft.
Rec. Ported Box Dims: 1.30 - 3.20 cu.ft.
Free Air Usage: not recommended
Sensitivity: 96.4 dB
Frequency Response: 20-500 Hz
Recommended RMS Power: 1100W
Peak Power Handling: 2200W
Impedance: dual 4 ohms
11-22-03, 02:06 PM
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That's pretty sketchy when a company doesn't release T/S specs for there speakers. Not only can one not design a proper enclsosure, but without Qts/VAS, I wouldn't even know what KIND of enclosure to use. Since it's not recommended for IB use, I'd guess it's fairly overdamped and thus would prefer ported...