very simple question

[cotjones 10+ year member]

Does anyone have a link to an actual test where it was proved that 2 different sized subs playing different frequecies caused cancellation? Otherwise it's a lot of speculation.

X2

 

[cotjones 10+ year member]

The best way to adjust your xovers and tune everything would be to find an SPL meter. Play a tone sweep at a lower volume and look at the results. Using that method you could set your xovers and gains to get the flattest response.

You could get by with a radioshack spl meter. You can buy them for about $36.

yeah but i figured id go ahead and get like a lab setup since radio shack's only goes to 120 db's and i'm past that with only a 500 watt amp... i don't have the 2 1000/s hooked up yet i'm savein ta buy em but i have hooked up some of my buddies 1000/'s to see wat it'd sound like... felt like the back door was gunna fly off lol

 

[squeak9798 5,000+ posts]

Cancellation is not the issue....or even a issue.

The issue is that you are wasting resources (namely; money), real estate, time and energy on something that will provide minimal advantages at best.

Subwoofers play a rather limited range of frequencies...and most subwoofers on the market are well equipped to competently cover this entire range. There is little to no advantages in attempting to split this limited range of frequencies between multiple drivers.

Yes, your idea can "work" when setup properly. But, again....there's little to no point in expending your money, time, energy and space within the vehicle to pursuing such an endeavor. The cons outweigh the pros by a substantial margin.

If you want to do for some odd reason....go for it. But it'll be a rather large waste in just about every sense.

to go further on what he said the component idea was my inspiration...

Component sets and subwoofers are not comparable.

Components comprise multiple drivers for very different reasons.

 

[squeak9798 5,000+ posts]

And why is it threads with titles like "a simple question" always end up going on for 5+ pages ?

 

[cotjones 10+ year member]

Cancellation is not the issue....or even a issue.

lots of people on here would dissagree... lol but as far as my money goes reguardless on how much better it sounds... it does def. sound better... or at least have the potential to... and the price difference isn't that great for the output i'm getting plus i have a knew idea maby the reason i'm not getting cancellation as it is... even with one amp on them is the fact that one is reverse mounted... come to think of it it was the same way in all 4 systems i've done like this but the 3 others were with a 12 and 2 10's... would not the reversed mounting also reverse the phase of the wave eliminating phase cancellation? just a thought?i'l post a diagram explaining this new question...

 

[squeak9798 5,000+ posts]

but as far as my money goes reguardless on how much better it sounds... it does def. sound better...

Is that why no sound quality world champion (I can think of) has ever done it ?

Because it sounds so much better ?

Honestly; You're wishful thinking rather than basing your decision on reality.

and the price difference isn't that great for the output i'm getting

The difference in output between a pair of 12's and a 12 + two 10's (for example) would be border-line inaudible at best.

Again, I think you're stuck more on wishful thinking than reality.

plus i have a knew idea maby the reason i'm not getting cancellation as it is... even with one amp on them is the fact that one is reverse mounted... come to think of it it was the same way in all 4 systems i've done like this but the 3 others were with a 12 and 2 10's... would not the reversed mounting also reverse the phase of the wave eliminating phase cancellation? just a thought?i'l post a diagram explaining this new question...

Honestly, cancellation isn't really a relevant concern IMO. In a vehicle in subbass frequencies with subwoofers located in a common area we are dealing more with common compression/rarefaction of the air than we are actual "soundwaves". As long as they are wired in relative phase so they are all compressing the air at the same time....it won't really matter. Same reason you typically don't need to wire two subs "out of phase" if they are on opposite sides of the trunk facing each other....the wavelengths are simply too long to matter, as long as the subs are both compressing the air at the same time.

 

[cotjones 10+ year member]

so you don't think 15's and 10's sound different apart from output?

 

[cotjones 10+ year member]

Is that why no sound quality world champion (I can think of) has ever done it ?

i haven't had much luck finding a place to see the record of world champions but i've seen plenty of demo cars's with different size sub setups

 

[leonsv 10+ year member]

i haven't had much luck finding a place to see the record of world champions but i've seen plenty of demo cars's with different size sub setups

do you mean showcars that try to cram every single product that the company makes into it or a car that has a good balance of equipment with even better installation at sq competitions?

theres a pretty big different...

just cause it looks pretty doesn't mean it'll sound pretty //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[squeak9798 5,000+ posts]

so you don't think 15's and 10's sound different apart from output?

Output and low frequency extension are the primary differences, yes.

i haven't had much luck finding a place to see the record of world champions but i've seen plenty of demo cars's with different size sub setups

And a demo/show car is very, very, very different from building a system with the express intent of making it as accurate in it's musical reproduction as possible.

 

[cotjones 10+ year member]

Output and low frequency extension are the primary differences, yes.


And a demo/show car is very, very, very different from building a system with the express intent of making it as accurate in it's musical reproduction as possible.

so i'm not getting the best of both worlds having both in the car? the 10's will allways be optimal(highest spl) when delivering a punchier sound... while the 13 will always be optimal delivering a boomy sound beside that with enclosures... you can either get the punch or a boom impossible to compromise both with one encloser sometimes the sub is such good quality that the difference is bearable... but as a rule enclosers have a great deal to do with the type and feel of sound... smaller sealed boxes mean less reverberation and thus a tighter... more acurate sound with less output.... bigger sealed boxes or ported give more output but there is more reverberation so the sound isn't reproduced quite as accurate so that there is more of a boomy, or sloppy rolling than a punch even so sometimes this rolling effect is desired... a box can be acurratly enough tuned to compromise the 2 well.... but my method is bassically using 2 opimized systems mixed vs. 1 compromised alone

 

[squeak9798 5,000+ posts]

so i'm not getting the best of both worlds having both in the car? the 10's will allways be optimal(highest spl) when delivering a punchier sound... while the 13 will always be optimal delivering a boomy sound

Again, fantasy world vs reality.

A 10" sub is not "punchier" than a 13 (or 15). The diameter of the sub literally has nothing to do with high frequency output within the limited bandwidth we are dealing with. Likewise, that "boomy" sound is what some people prefer to call actual subbass. Not overemphasized midbass coming from a subwoofer....which is that "punch" you are referring to.

beside that with enclosures... you can either get the punch or a boom impossible to compromise both with one encloser sometimes the sub is such good quality that the difference is bearable...

Then you have no idea how to optimally design an enclosure for a subwoofer, integrate it into a system and properly tune it.

but as a rule enclosers have a great deal to do with the type and feel of sound...

Agreed.

smaller sealed boxes mean less reverberation and thus a tighter... more acurate sound with less output....

Uhh....no.

You are incorrect in thinking that a smaller sealed enclosure is "more accurate" than a larger sealed enclosure. The exact opposite is indeed true.

Not sure what you mean by "less reverberation"...but smaller sealed enclosures actually have worse damping characteristics. That "tight punchy" sound isn't higher accuracy...it's an overemphasis of the upper bass/lower midbass frequency range.

They likewise have higher peak output than a larger sealed enclosure, and have less low frequency extension than a larger sealed enclosure.

bigger sealed boxes or ported give more output but there is more reverberation so the sound isn't reproduced quite as accurate so that there is more of a boomy, or sloppy rolling than a punch

Again, incorrect.

Larger sealed enclosures have less peak output than a small sealed enclosure, but more low frequency extension.

Larger sealed enclosures also lack the overemphasis of the upper bass (i.e. flatter frequency response) which is the reason they don't have that "punchy" sound. The "boomy muddy" sound many people ignorantly attribute to larger sealed enclosures is actually increased low frequency extension.....i.e. true subbass output....something they didn't have with those small sealed enclosures.

Likewise, larger sealed enclosures (i.e. lower Qtc) also have better damping characteristics than smaller sealed.

a box can be acurratly enough tuned to compromise the 2 well.... but my method is bassically using 2 opimized systems mixed vs. 1 compromised alone

You aren't "optimizing" anything, sorry to tell you.

It seems that much of your reasons for wanting to do this simply comes from your misunderstanding of many of these topics.

A single size of subwoofer(s), in a well designed enclosure (or no enclosure at all if dealing with infinite baffle, the preferred method among many "audiophile" types), with proper tuning and integration will do exactly what you want.

 

[cotjones 10+ year member]

Again, fantasy world vs reality.
A 10" sub is not "punchier" than a 13 (or 15). The diameter of the sub literally has nothing to do with high frequency output within the limited bandwidth we are dealing with. Likewise, that "boomy" sound is what some people prefer to call actual subbass. Not overemphasized midbass coming from a subwoofer....which is that "punch" you are referring to.

exactly you just said the same thing i said in more words... that PUNCHY sound comes more from 10's because they emphasize middbase... and geting lower sub frequencies out of them requires crossover settings to make them play lower frequencies... but i'm not doing that... i'm letting them over emphasise middbase and letting the big one over emphasize the sub bass... the 10's play what they are most comforatable with and letting the big one handle what it's more comforatable with... 80- 90 hertz from a 13 would sound like **** at least not be very loud at all... but from a 10 it can hit the range decently(not great... but decently) i don't think anyone would argue against the fact that a 10 is better suited for higher frequencies than a 13 also as far as sound goes there might not be much difference but in air movement there is... because a sound wave is only how the air is moving in the car... you get a different "feel" of the sound comeing from the subs... for example i can almost allways without seeing the setup tell what size subs there are in the car between 10's and 15's and that has nothing to do with spl because there is a car up the road that hit 144 with 2 10's, reguardless the 10's soundwaves are different than the 13's the best way i can explain it is that... your getting one large sound wave from a large sub as opposed to many small waves from smaller subs... to get the same amount of spl... i really discovered this to be true when i heard 2 systems one with 3 10's the other with 1 15... we adjusted them to the same spl and set a glass of water on them both the one with the 15 had the water jumping much more than the one with the 10's... i understand that the test isn't exactly scientific since they were diff cars but they were still similar... an explorer and a gmc jimmy

 

[squeak9798 5,000+ posts]

exactly you just said the same thing i said in more words... that PUNCHY sound comes more from 10's because they emphasize middbase...

Sorry, I should have clarified better.

That "punchy" sound has nothing to do with subwoofer size. A 10" is not inherently anymore "punchy" than a larger diameter sub.

The descriptive terms you are using are related to frequency response, not woofer diameter.

You create that same "punch" with any diameter subwoofer (assuming it's not inductance limited) by simply creating a nice little hump in the upper bass frequencies. It has nothing to do with woofer diameter.

There are many 10" subs on the market that perform very poorly in the near-midbass frequencies. There is nothing inherent there about the diameter of the woofer.

80- 90 hertz from a 13 would sound like **** at least not be very loud at all...

Not sure where you are getting that from....but it's not accurate in the slightest.

High frequency extension is primarily dictated by inductance, not diameter.

A friend of mine, for example, ran his 15" subs up to 90hz. The vehicle qualified for world finals that year, and likely would have placed very well if it wasn't for an equipment malfunction.

but from a 10 it can hit the range decently(not great... but decently)

Not inherently. And to the contrary, so can many larger-than-10" subwoofers.

For some reason you have this misconception that 10" drivers inherently play higher....which is simply not the case.

With the limited bandwidth we are dealing with, inductance is the limiting factor in how high the subwoofer is capable of playing. Diameter plays virtually no role.

Give me a 10" subwoofer with high inductance and watch it fall flat on it's face trying to reproduce higher frequencies. Likewise give me a 15" with reasonable inductance and watch it excel well at those frequencies.

Also, it's very possible for any size subwoofer to hit those frequencies very well. Depends on the inductance and vehicle acoustics....but not diameter.

i don't think anyone would argue against the fact that a 10 is better suited for higher frequencies than a 13

Anyone with a relatively decent concept of loudspeaker dynamics would disagree with that statement.

for example i can almost allways without seeing the setup tell what size subs there are in the car between 10's and 15's and that has nothing to do with spl because there is a car up the road that hit 144 with 2 10's, reguardless the 10's soundwaves are different than the 13's the best way i can explain it is that...

Now you're just hallucinating

your getting one large sound wave from a large sub as opposed to many small waves from smaller subs... to get the same amount of spl...

Huh ? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

i really discovered this to be true when i heard 2 systems one with 3 10's the other with 1 15... we adjusted them to the same spl and set a glass of water on them both the one with the 15 had the water jumping much more than the one with the 10's... i understand that the test isn't exactly scientific since they were diff cars but they were still similar... an explorer and a gmc jimmy

Uhh.....wow.....I'm not even sure how to respond that that nonsense //content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif

Honestly; You need to spend some time actually learning about these topics before you begin formulating any more inherent "truths".....because so far you are waayyy off base....and that's leading you to faulty conclusions.

 

[Flipx99 5,000+ posts]

I am glad cot did not answer when I was trying to make my 12 extend to 70 @ -6db.

As for OP, brad knows his stuff and I would trust him, with the exception of the spelling of role (not roll, as in 3rd paragraph)