Upgrade Questions

[swift 501]

If the shop is so damn good just ask them and trust whatever bullshit they tell you.

You could also walk to the store with a flip flop on one foot and a running shoe on the other. You will still get to the store..... but try to argue with the people telling you that you are a dumbass for doing it. Lol

Edited July 1, 2012 by swift

[pro-rabbit 64]

Really? Go do some tests on your own and then come back with that one. RCAs and Speaker wire length can/will affect the delay in which each sub will get power. If the delay is enough you have issues. I have tested this several times over in a wide range of systems. In some cases the affect is minimal and others it is drastic and can/will damage the drivers.

Different amps will also affect the delay.

I understand that in some cases as I said it can be minimal, but in a case where you are running different amps...in such a way and in a common chamber enclosure you have a massive chance at more negative results then positive.

[Impious 1,476]

Really? Go do some tests on your own and then come back with that one. RCAs and Speaker wire length can/will affect the delay in which each sub will get power. If the delay is enough you have issues. I have tested this several times over in a wide range of systems. In some cases the affect is minimal and others it is drastic and can/will damage the drivers.

Different amps will also affect the delay.

I understand that in some cases as I said it can be minimal, but in a case where you are running different amps...in such a way and in a common chamber enclosure you have a massive chance at more negative results then positive.

Unless he is wrapping the speaker wire around his car a few times first, which I doubt, then I seriously doubt a foot or two difference of speaker/RCA cable is going to make any audible difference at all. I would question your test methods.

[pro-rabbit 64]

Will I can appreciate your lack of faith and general degrading manner, but as you also have all the answers there is no assisting in some one who just has a negative view.

Feel free to do some real tests and come back to this conversation at any time though.

[Budah93 7]

alright well my question is finally answer thank god. i asked if it would be louder not lectured by guys who think they are car audio gods. I've seen other sytems with 3 15" subs and they have sounded fine i just wanted to know how much i would notice a difference before i spent the money

[pro-rabbit 64]

I never said you could not run 3 15s, the amp situation was the issue.

I also fail to see where that would be the best way to spend extra funds in order to get "louder". Many other options out there that would more then likely net a better overall result.

[Impious 1,476]

Will I can appreciate your lack of faith and general degrading manner, but as you also have all the answers there is no assisting in some one who just has a negative view.

Feel free to do some real tests and come back to this conversation at any time though.

For some "real world tests", let's consider the speed of signal transfer. The speed of electric signal transmission depends on construction and materials of the copper wire, with co-axial cable being on the low end at ~66% the speed of light. I'm going to round this to 70% because I was able to find a wikipedia page that already has already used that number, so it saves me the time of having to manually calculate anything.

With a signal transfer of 70% the speed of light, it would take a signal 4.76 nanoseconds to travel 1m. That's 0.00000000476 seconds to travel ~3 feet.

I'll leave it to the reader to calculate the associated phase shift resulting from a 0.00000000476 second signal delay.

And for reference, that's also many orders of magnitude below the audibility of human hearing for signal delay.

I'll defer to your experience with "real world tests" and await an explanation as to how a 0.00000000476 second delay resulting from extra RCA cable length or speaker cable length is going to cause an audible delay or audible phase shift within the system.

[ssh 924]

Really? Go do some tests on your own and then come back with that one. RCAs and Speaker wire length can/will affect the delay in which each sub will get power. If the delay is enough you have issues. I have tested this several times over in a wide range of systems. In some cases the affect is minimal and others it is drastic and can/will damage the drivers.

Different amps will also affect the delay.

I understand that in some cases as I said it can be minimal, but in a case where you are running different amps...in such a way and in a common chamber enclosure you have a massive chance at more negative results then positive.

How would a delay in the signal damage a speaker (even if they shared a common chamber)?

[pro-rabbit 64]

This was an issue we first found in a vary famous bronco and turned out to be the culprit behind ripping apart certain subs. While in science the book work would make a situation sound impossible or improbable. The reality is it is not. The issue in the Gate's truck was just this reason. This prompted everyone to play around with the idea that even in a basic install it could have an affect and it does. In a SPL setup it normally has an affect as well and is much more noticeable.

Now in the Gate's truck it was the worse possible problem it could be. However with some tuning and new toys to adjust the delay the issue was resolved. In everyday setups a foot of wire typically won't make a difference. However if you add in the amp difference and power difference it becomes more of an issue. It can have an effect similar to have a lower ohm load on one driver.

I will see if I can dig out my exact notes to give you a better idea of the issue and the possible damage it can cause. As I said before, more often then not it causes little to no issues, but that is not always the case.

[helotaxi 46]

That would also mean that the fairly standard method of wiring subs in parallel off the same amp (daisy chain) would have a significant effect. I would be more inclined to believe that the difference in speaker amplitude because of the resistance of the extra wire had an effect than believe that phasing was the issue.

[Impious 1,476]

This was an issue we first found in a vary famous bronco and turned out to be the culprit behind ripping apart certain subs. While in science the book work would make a situation sound impossible or improbable. The reality is it is not.

The science books say it's impossible or improbable.....because it's impossible or improbable. There is nothing that changes in this particular scenario between the science theory and reality that would make the latter different than the former. The signal transmission is simply too fast to make any noticeable difference at the distances we are discussing. If you think the Bronco somehow defied the laws of physics, I'm sorry to disappoint you....but it did not.

If what you are claiming is true, there are a hundred different scenarios in audio applications where this would rear it's ugly head. Helotaxi listed one such aspect above. Another issue would be with amplifier RCA pass-through outputs....you wouldn't be able to use them due to the time delay involved. Overall this issue of time delay would be a significant factor in every system design. The fact is that it isn't. And the reason it isn't is because of the physics involved, and these physics are the same between the science books and the "real world". It's simply too quick of a signal transfer to make any noticeable difference.

I'm sure there were some bugs in the system in the Bronco. And I'm sure you made some changes that corrected them. I'm not disagreeing with that aspect of your experience. What I am saying, however, is that you are ascribing the differences that existed to the wrong variable. It wasn't due to a time delay resulting from a difference in RCA/speaker wire. It's simply not possible according to the laws of physics.

[pro-rabbit 64]

Once again you have done nothing but look over what I said. I never said it will cause a huge issue in every application. However it can and does in others. There are more variables then just the speed of which the signal can possibly travel at. There are a wide range of various things that can and will alter the speed at which a signal can/will travel. The bronco was a severe worse case scenario. It truly was, and it did not defy physics, it did however have the exact issue of what we are discussing.

On a daily basis the worse issue I came across was the use of different wire(speaker or RCA)and the use of a second amp independently from the first in a common chamber enclosure. If you are knowledgeable in physics, then you should know that the delay is not really the issue. It just can cause the issue. As I said though, there are a far to many variables to sit here and just say yes/no to anything. However, to simply dismiss it as falsehood simply because basic math would show that the the delay is almost non existent considering all things are equal.

[pro-rabbit 64]

As for as wiring basic series/parallel there is actually proper and improper ways of doing it. Anyone with basic background in electrical would tell you that, but in most cases those differences truly are almost non measurable. Assuming wiring and such are all equal to each other and not varied in gauge or product quality.

[Impious 1,476]

Once again you have done nothing but look over what I said. I never said it will cause a huge issue in every application. However it can and does in others. There are more variables then just the speed of which the signal can possibly travel at. There are a wide range of various things that can and will alter the speed at which a signal can/will travel. The bronco was a severe worse case scenario. It truly was, and it did not defy physics, it did however have the exact issue of what we are discussing.

I haven't overlooked anything you have said. You are overlooking the fact you are ascribing the issues you had to the wrong variable. It wasn't due to differences in arrival time of the signal due to differences in cable length, either directly or indirectly.

You have yet to give any explanation consistent with the laws of physics that would allow what you have stated to be true, other than "I've seen it, so just believe me." You've stated scenarios in which you think it was the cause of the issue, and again I will tell you that you are ascribing any differences to the wrong variable. No matter what cable was used, no matter what amplifier was used, no matter if they were common chamber or separate chambers.....the signal transfer is going to be such a significant percentage of the speed of light that it is not the issue.

If I get time later and if I can get my measurement setup to work properly, I will measure the difference in impulse response between different cable lengths and post the results. If what you are claiming is true, then it will be readily apparent in the impulse response measurements.

[Budah93 7]

You guys saying there are other ways to make my system louder what would you suggest doing. My buddy sold the 3rd sub i was gonna buy and i don't want to pay full price to buy a 3rd. You said bigger box so what dimmensions and port size would you do to make them loud also what amp you recommend using. I'm a freshman in college to i don't have alot of money to work with but i do have some!

[helotaxi 46]

As for as wiring basic series/parallel there is actually proper and improper ways of doing it. Anyone with basic background in electrical would tell you that, but in most cases those differences truly are almost non measurable. Assuming wiring and such are all equal to each other and not varied in gauge or product quality.

They are more measureable than the difference in signal arrival time between 2 sections of wire with a foot difference in length. You'll see a bigger difference in phase from the slight differences in each driver's coil, motor and suspension.

I know how to go about wiring subs so they don't interact. It isn't rocket science. And I'm talking about straight parallel wiring where you make a run from the amp to the + of the first driver and from there to the + of the second driver and so on, and do the same for the -.

[SS Teacher 177]

I don't know about anybody else, but I found the dialogue between Impious and pro-rabbit far more entertaining and informative than the original poster and his refusal to listen to anybody other than his lame-ass shop!

[Impious 1,476]

Feel free to do some real tests and come back to this conversation at any time though.

Took you up on your sarcastic suggestion and performed some "real world tests".

Measurement system consisted of my laptop connected to an M-audio Mobile Pre using a Dayton EMM-6 mic. This was connected to my HT receiver driving a Coustic 306P 7" mid. So this includes the entire signal chain, from source to amplifier to speaker reproduction. I used HOLMImpulse to perform the measurements.

The short cables consisted of a 3' Dayton RCA cable and 3.5' length of Stinger 14ga speaker wire.

The long cables consisted of a 17' Stinger RCA cable and 10.5' length of Stinger 14ga speaker wire.

The first (red) measurement was with the short RCA cable & short speaker wire.

The second (blue) measurement was with the long RCA cable and short speaker wire.

The third (green) measurement was with the long RCA cable and long speaker wire.

As you can see from the graph, the measurements at the initial impulse for all three measurements pretty well overlay each other. Within the resolution of the measurement (tenths of a millisecond), they are for all intents and purposes identical. If there were going to be significant differences due to cable length, it would be revealed here in the impulse measurement as the "slow" signal cable transfer would have an initial impulse later in time.

The results indicate rather definitively that there is not going to be any real world difference in the performance of the system due to any realistic differences in speaker wire (7' difference) or RCA cable (14' difference) lengths within a typical car audio system.

In summary.....the physics dictates that the differences are beyond the realm of audibility and well below a level that would affect system performance in the slightest. Real world testing confirms this to be true as there was no realistic difference in impulse response time between cables with relatively large (relative to typical audio cables) length differences.

So, we are left to revert back to my original analysis. You are simply attributing the issues you experienced in various systems to the wrong variable. The variable you are attempting to claim was the cause of the issue, delayed signal transmission due to varying lengths of cables, can simply not be the cause......either directly or indirectly. If you have an explanation as to how any of the systems you described were able to defy the laws of physics, I'd be more than interested in hearing about it. Otherwise, we'll agree they obey the laws of physics and you're understanding of the cause of the the issues within the systems was simply incorrect.

*For reference, the impulse is negative because the mic was located on the rear side of the speaker when I measured. Also, an absolute time measurement isn't important here, we simply needed to determine what the relative differences in impulse time between measurements were. As long as the results are consistent, the absolute value isn't of consequence. So the absolute value of the impulse isn't properly aligned as I simply didn't take the time to mess with it as the results were consistent. I took multiple measurements with each cable to verify the results were consistent with each cable.

Damn, the picture is smaller than I had hoped I think it still conveys the information though.

[Impious 1,476]

You guys saying there are other ways to make my system louder what would you suggest doing. My buddy sold the 3rd sub i was gonna buy and i don't want to pay full price to buy a 3rd. You said bigger box so what dimmensions and port size would you do to make them loud also what amp you recommend using. I'm a freshman in college to i don't have alot of money to work with but i do have some!

What are the details of the enclosure they are in now, and how much room do you have in the vehicle that you are willing to dedicate to the enclosure?

[///M5 2,833]

Some further clarity on the snake oil that is in the world of cabling. If you cannot measure a difference in LCR of the cable you WILL NOT hear a difference either. Our ears flat out seriously suck balls compared to measurement equipment.

[Budah93 7]

I don't know about anybody else, but I found the dialogue between Impious and pro-rabbit far more entertaining and informative than the original poster and his refusal to listen to anybody other than his lame-ass shop!

I was listening to them but they never gave me answer besides "that's a bad idea" what makes them better than any other installer? The fact that they think they know everything about car audio there is to know?? I just wanted to know if it would make it louder not don't do it its a bad idea.

[///M5 2,833]

I don't know about anybody else, but I found the dialogue between Impious and pro-rabbit far more entertaining and informative than the original poster and his refusal to listen to anybody other than his lame-ass shop!

I was listening to them but they never gave me answer besides "that's a bad idea" what makes them better than any other installer? The fact that they think they know everything about car audio there is to know?? I just wanted to know if it would make it louder not don't do it its a bad idea.

That actually was answered. What makes "bad idea" better than what the installer said is that they are right and the installer is wrong. And since you just wanted to know if it would make it louder or if it was a bad idea I think your question was answered.

Perhaps if you said, here is what I have, here is what space I have and I want to get louder you'd have gotten the help you sought.

[Budah93 7]

I literally just wanted to know if 3 subs would be noticeably louder and one person answered that for me

[ssh 924]

I literally just wanted to know if 3 subs would be noticeably louder and one person answered that for me

If you increase cone area, and enclosure volume isn't prohibiting then it should be louder.

However, your way of going about it is a BAD IDEA.

If you put 35" tires on three of your wheels on your Jimmy, and the last wheel had a 33" tire, would it still drive, and function? Yes, but it's not a good idea now is it?

I know your thread got a little side tracked, but it was informative among other things, even if it didn't exactly pertain to your question.

So yes you can put 3 drivers in the same enclosure, use one amp for two drivers, and a third amp for the last driver, but there will be a difference in signal & power between the "groups," and it's very likely that this combination will not sound correct.

You would be better off using three drivers with the same coil configuration, and wire at or above 1ohm (presuming your amp is 1ohm stable) with your current single amp. If your current enclosure does not offer adequate volume for the three drivers then a new enclosure should be in order.

[Budah93 7]

you can't run 3 d4s at 1 ohm for 1 and 2nd off your analogy is in valid if everything is set up correctly and i have all the meters neccesary to do so. Each sub will get the same amount of power have the same amount of volume in the box