Mix shallow mount subs with normal?

[Plutoman 10+ year member]

Yep. See it now.

However, the one thing that bugs me - it's still not the biggest argument to not use multiple subwoofers of different types. While it might sound slightly off, there's not going to be a huge gap - there's only so much difference between the two "instruments", and while the differences might make a difference to a connoisseur of music, to the average person, they won't be able to notice this.

Many people I know can't always tell when pitches are out of tune with each other - let alone a tone that's off from the rest. However, if aiming for a really good sound quality, then it's best to get the same subwoofers, and good ones, too. Bad ones will end up ruining the whole effect anyways.

Hope you had fun flaming me

 

[cotjones 10+ year member]

Yep. See it now.
However, the one thing that bugs me - it's still not the biggest argument to not use multiple subwoofers of different types. While it might sound slightly off, there's not going to be a huge gap - there's only so much difference between the two "instruments", and while the differences might make a difference to a connoisseur of music, to the average person, they won't be able to notice this.

Many people I know can't always tell when pitches are out of tune with each other - let alone a tone that's off from the rest. However, if aiming for a really good sound quality, then it's best to get the same subwoofers, and good ones, too. Bad ones will end up ruining the whole effect anyways.

Hope you had fun flaming me
no no no i didn't mean to flame you, you should've been here to see how bad i got flamed for actually having a multi-sub setup. I ran 4 10w6v2's and 1 13w6v2 Sounded AMAZING i shocked litterally everyone who listened to it. But you'd be suprized how often you can't explain simple things. In anything to do with electricity, things RARELY work exactly like they do on paper, there are simply way to many variables. All i'm trying to tell you is that if you have your heart set on using different speakers just know its possible. However i would defitintely go with same subs and cut back your risk and required effort.

 

[Immacomputer 10+ year member]

when 2 tones are played at the same time through a speaker, in effect, it is only switching back and forth between the tones so fast that you hear them as 2 seperate tones, when they are actually the same waveform when looked at. this also accounts for why it it easier to make a sub get loud using a pure frequency tone, the more tones a speaker plays the more of each tone is missing.
this doesn't matter at all with highs or even mids because there is no possible way you could tell the difference if i played a 2000Hz signal and then attenuated 1/4th of the cycles by playing a 500Hz signal on top of it.

Yea, so that's not what happens. Missing tones... haha what? If you sum two electrical signals, you create a new waveform that has a peak amplitude of the sum of the two peak amplitudes of the separate signals. Each individual signal still exists in this new modulated waveform and each of them can be recovered. There are no missing tones or whatever random you were making up. If you have a .25dB signal at 25hz and modulate it with a .25dB signal at 50hz, you have a new modulated signal with a peak amplitude of .5dB. You can continue to add new signals as long as the peak amplitude doesn't exceed your maximum power output capabilities. Once you try to modulate the signal any further, you will drive the signal into clipping. There is still no lost information here but there is added noise from harmonic distortion. The reason playing a test tone can result in metering higher is because you can dump full power (unclipped) from the amp into a single frequency instead of distributing that power over a range of frequencies that may not all have the same acoustical amplitude.

And the reason why different speakers shouldn't be playing the same electrical signal comes down to distortion. Even though both speakers are seeing the same electrical signal, because they are both different, they will transform that electrical signal into an acoustical signal with a specific transfer function. Since both speakers have different transfer functions but have he same input signal, their acoustical signal will be different. When those two signals get summed acoustically, they will modulate each other and that modulated signal will not be equivalent to its electrical counterpart. The difference between the two is the distortion added to the signal. The distortion is based on the two different transfer functions that have different damping, group delay, frequency responses, and phase responses. Each of those four characteristics are going to alter the new signal in a different way and since they all vary, they will all add to the distortion.

Will it be audible? To some and not to others and it will also depend on how different each speaker is from one another and how different their alignments are. Will it sound terrible? Probably not. Will it be the lowest distortion option? No way in hell.

In anything to do with electricity, things RARELY work exactly like they do on paper...

That's because you don't know what you're doing on paper. Using self made theories and equations based on no real knowledge is not how you work out problems in electronics, acoustics, physics, math, etc..

 

[GAM3OVR 5,000+ posts]

no no no i didn't mean to flame you, you should've been here to see how bad i got flamed for actually having a multi-sub setup. I ran 4 10w6v2's and 1 13w6v2 Sounded AMAZING i shocked litterally everyone who listened to it. But you'd be suprized how often you can't explain simple things. In anything to do with electricity, things RARELY work exactly like they do on paper, there are simply way to many variables. All i'm trying to tell you is that if you have your heart set on using different speakers just know its possible. However i would defitintely go with same subs and cut back your risk and required effort.

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Plutoman 10+ year member]

no no no i didn't mean to flame you, you should've been here to see how bad i got flamed for actually having a multi-sub setup. I ran 4 10w6v2's and 1 13w6v2 Sounded AMAZING i shocked litterally everyone who listened to it. But you'd be suprized how often you can't explain simple things. In anything to do with electricity, things RARELY work exactly like they do on paper, there are simply way to many variables. All i'm trying to tell you is that if you have your heart set on using different speakers just know its possible. However i would defitintely go with same subs and cut back your risk and required effort.

Haha, I was kidding with the flaming. You had mentioned a lack of people to flame when I got into a discussion.

I'd probably go with different speakers at different points in the vehicle. There is only so much space to sacrifice in the trunk, and even though most don't hear it as a localized, I tend to hear the bass sounds from where it comes from. Which is why I'd love to have two shallow mount subs under my front two seats, and then one or two subs in the back trunk.

And also, @ Immacomputer. You are repeating some of these things we were saying - for slightly different reasons, but the same end result. It is essentially the same - in orchestral music, you get distortion from different instruments based on the timbre and tone responses of the separate instruments. You get the same with subwoofers. ^^

Just wanted to put that out. I don't know the math involved in acoustics, and sound engineering - I can do physics all day long, and do well, but I still only have a high school education in the courses - and not a lot of experimental evidence behind me except what I can reason through. But, at least we arrived to the same conclusion. Counts for something. Though, your explanation does make more scientific sense, in that it actually describes the effects - it is based off the frequency and phase responses, the damping, and the group delays. It's good to know the exact reasons why.

 

[cotjones 10+ year member]

Yea, so that's not what happens. Missing tones... haha what? If you sum two electrical signals, you create a new waveform that has a peak amplitude of the sum of the two peak amplitudes of the separate signals. Each individual signal still exists in this new modulated waveform and each of them can be recovered. There are no missing tones or whatever random you were making up. If you have a .25dB signal at 25hz and modulate it with a .25dB signal at 50hz, you have a new modulated signal with a peak amplitude of .5dB. You can continue to add new signals as long as the peak amplitude doesn't exceed your maximum power output capabilities. Once you try to modulate the signal any further, you will drive the signal into clipping. There is still no lost information here but there is added noise from harmonic distortion. The reason playing a test tone can result in metering higher is because you can dump full power (unclipped) from the amp into a single frequency instead of distributing that power over a range of frequencies that may not all have the same acoustical amplitude.
And the reason why different speakers shouldn't be playing the same electrical signal comes down to distortion. Even though both speakers are seeing the same electrical signal, because they are both different, they will transform that electrical signal into an acoustical signal with a specific transfer function. Since both speakers have different transfer functions but have he same input signal, their acoustical signal will be different. When those two signals get summed acoustically, they will modulate each other and that modulated signal will not be equivalent to its electrical counterpart. The difference between the two is the distortion added to the signal. The distortion is based on the two different transfer functions that have different damping, group delay, frequency responses, and phase responses. Each of those four characteristics are going to alter the new signal in a different way and since they all vary, they will all add to the distortion.

Will it be audible? To some and not to others and it will also depend on how different each speaker is from one another and how different their alignments are. Will it sound terrible? Probably not. Will it be the lowest distortion option? No way in hell.

That's because you don't know what you're doing on paper. Using self made theories and equations based on no real knowledge is not how you work out problems in electronics, acoustics, physics, math, etc..

Thank you for repeating what i just said...

Here is, as you described it, the new wave form created by summing waves of different frequencies, due to the oscillation of the differences in the wave crests, the signal and reproduced waveform periodically destructively and constructively interfere. This makes the audible distortion go up in the form of the difference between constructive and destructive interference. These are the missing tones i refered to. The 2 separate waveforms have steady, even amplitude while the combined has a peaky amplitude, now imagine how the wave would peak just by nature when adding 4 or 5 signals together. it makes it VERY hard to equalize a system safely because one minute your system will be playing a single waveform nominally just fine, and by adding another signal, you make a signal which isn't necessarily louder to the ear drive your signal into clipping. Also the reason an SPL setup doesn't make the best daily recreational setup...

 

[Immacomputer 10+ year member]

Thank you for repeating what i just said...

Here is, as you described it, the new wave form created by summing waves of different frequencies, due to the oscillation of the differences in the wave crests, the signal and reproduced waveform periodically destructively and constructively interfere. This makes the audible distortion go up in the form of the difference between constructive and destructive interference. These are the missing tones i refered to. The 2 separate waveforms have steady, even amplitude while the combined has a peaky amplitude, now imagine how the wave would peak just by nature when adding 4 or 5 signals together. it makes it VERY hard to equalize a system safely because one minute your system will be playing a single waveform nominally just fine, and by adding another signal, you make a signal which isn't necessarily louder to the ear drive your signal into clipping. Also the reason an SPL setup doesn't make the best daily recreational setup...

You're drawing false conclusions from information you don't fully understand like you think you do. There are also no mission tones. Both frequencies are present in the new signal and both can be extracted back to 100% of their original material (that means no distortion). What goes on between two different transfer functions isn't a problem with frequency modulation (like you pictured) but with amplitude and phase modulation. This amplitude and phase modulation creates a new signal acoustically that differs from it's electrical equivalent.

Frequency modulation has nothing to do with making EQ complex. It also has nothing at all to do with why SPL systems are not musically inclined as what you're thinking about is that they have a peaky frequency response.

Do you know what music is? Do you know what pink noise is?

 

[cotjones 10+ year member]

You're drawing false conclusions from information you don't fully understand like you think you do. There are also no mission tones. Both frequencies are present in the new signal and both can be extracted back to 100% of their original material (that means no distortion). What goes on between two different transfer functions isn't a problem with frequency modulation (like you pictured) but with amplitude and phase modulation. This amplitude and phase modulation creates a new signal acoustically that differs from it's electrical equivalent.
Frequency modulation has nothing to do with making EQ complex. It also has nothing at all to do with why SPL systems are not musically inclined as what you're thinking about is that they have a peaky frequency response.

Do you know what music is? Do you know what pink noise is?

I understand what I'm saying perfectly... you, on the other hand, do not... the two separate waves are what (say 2 different instruments) would play, and when you record them and mix them together electronically you get the 3rd wave... Acoustically the wave sounds perfectly fine, despite the interference, because the interference as a whole cancels out, however, AS I SAID!!!! electronically the signal required to play multiple frequencies at the same time requires that the wave peak higher to obtain the same output of a single waveform which means if your system is tuned to peak at a single tone (as one might in an SPL setup) and then you added another tone, the signals would increase in peak amplitude (not acoustic output) making clipping more likely. Of course Most amplifiers worth a crap compensate for the signal gain and loss.

You should really start paying attention

 

[mokedaddy 5,000+ posts]

Cot giving advice? //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

OMG thats almost as good as if it was King Ranch.

//content.invisioncic.com/y282845/emoticons/hilarious.gif.02a037aad04aa96f19982b298a3d70a8.gif

 

[cotjones 10+ year member]

OH MY GOD THIS IS THE SIMPLEST THING TO UNDERSTAND!!!!!!

This has been completely thread jacked but oh well

OK lets do an experiment...

Do you have an audio editing program? I use final cut pro for everything, but if you don't have something like that you can download a decently accurate one off lime wire called cool edit pro.

This Will work better if your computer has subs but i have a laptop and i can still hear the sounds fine so you should be ok...

Now use the tone generator to generate a Sine wave with a frequency of 200 Hz and no modulation make the volume near half as loud as your computer would normally be... (you don't want to blow your speakers.) now insert this wave into the mutitrack view.

Create a second sine wave with a frequency of 225Hz and no modulation. Make sure to keep the volume set to the same level on both waves. also insert this wave into the multi track view.

now place both of your waves on top of each other (so that they would play at the same time) and mix them down to a single new waveform.

You will get a wave similar to the one in the picture i posted. notice now that the audible volume will be very close to the same as the individual waves (probably closest to the 225hz wave which is because the small speakers are more efficient with higher frequencies) , yet parts of the waves have nearly doubled in amplitude.

What you need to take away from this is that Acoustically There is nothing wrong with 2 waves playing at the same time through the speaker, in fact that is how your brain would interpret the Sound anyway since you only have one eardrum per ear, however, the ELECTRONIC component of the system will mean that you could easily have a signal clipping even when the volume is the same as a signal that isn't clipping.

This enables you to increase your output significantly with X amount of power by using a pure sine wave rather than a modulated one when your amplifiers are near their peak output performance. However, if you are going for an SQ setup this tells you to get an amp with some headroom. having an amp that will give you your desired output at 75% of its capacity will reduce the possibility of clipping vs. an amp seeing the same output but at 90% capacity. of course the application will vary from amp to amp.

This is something I see happen very commonly with JL audio buyers, and indeed I'm guilty of doing it in the past too...

JL audio Slash series are very high quality amps and are sometimes referred to as "under-rated" this is because the 1000watt version can actually put out 1200-1300 or more conditionally... well calling them Under-rated would be false. the amp is made to run 1000 watts or less. the extra wattage capability is only to ensure minimal clipping, giving some of the best SQ while producing 1000w. if you are going to run the amp at 1200 watts, you might as well buy sony xplode or dual. You will often hear people complain about the W7 being "BOOMY" in my experience i have to contribute alot of this which is really acoustic interference to this same factor, the rest is mostly installation. Just because you can send 2000 watts to a sub before magic smoke comes out, doesn't mean it was designed to do it sounding good