# 10" ported vs 12" sealed sub thoughts?



## Redliner99 (Mar 26, 2018)

Possibly looking to upgrade from 2 10" JL w3 in a ported box. Had some people recommend audio frogs and have read great things on them. I do like to turn the bass up a decent amount. I listen to a lot of metal and some electronic/techno type stuff. Would 12s in a sealed box still give me the volume and output that at my 10s do being ported? I have read sealed will provide a tighter more consistent sound.


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## jrock645 (Apr 15, 2015)

This is hugely preferential. Sealed boxes tend to sound cleaner and tighter, but ported subs tend to go lower and really give that rumbly bass some people crave. I don’t think you’re gonna have any problem with 2 12’s not being loud enough but going from ported to sealed, it will sound different.


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## Gump_Runner (Aug 2, 2014)

Redliner99 said:


> Possibly looking to upgrade from 2 10" JL w3 in a ported box. Had some people recommend audio frogs and have read great things on them. I do like to turn the bass up a decent amount. I listen to a lot of metal and some electronic/techno type stuff. Would 12s in a sealed box still give me the volume and output that at my 10s do being ported? I have read sealed will provide a tighter more consistent sound.


Have you tried your w3's in a sealed box. I had a couple w3's in a sealed box that sounded great.


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## JCsAudio (Jun 16, 2014)

jrock645 said:


> This is hugely preferential. Sealed boxes tend to sound cleaner and tighter, but ported subs tend to go lower and really give that rumbly bass some people crave. I don’t think you’re gonna have any problem with 2 12’s not being loud enough but going from ported to sealed, it will sound different.


I agree. I have a ported 10” Alpine SWS sub tuned to 35 Hz and the larger 12” Alpine SWS in a sealed box. The 10” digs just slightly deeper and they are about the same loudness. The sealed 12 will actually go lower eventually because ported boxes roll off quickly after the tuning frequency. This all depends on your tune though.


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## rob feature (Nov 15, 2015)

Your extension probably won't be as good sealed, but that really kinda depends on where you're tuned now. I just went from a sealed 10 to ported (and SD to SA) tuned to 30 Hz and the difference is pretty dramatic. The ported SA plays hella low and hella loud with very little effort, but isn't as quick with transient response. I've been toying with the same idea, but there's no way I'm going to get this sort of extension out of a sealed sub that'll fit in the same space and work with the same power. I really missed that low stuff with the sealed enclosure.


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## Red Saber (Jul 5, 2018)

Sealed will play lower. You can tune a port to boost the low end more. 
If you tune the port to 40hz it will never play low. If you tune it to 30hz it will boost it but it won’t play higher.


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## Hulk2015 (Apr 6, 2015)

Just thinking outside the box here but couldn't the OP go with one 10" ported and one 12" sealed sub to get the best of both worlds?


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## Redliner99 (Mar 26, 2018)

jrock645 said:


> This is hugely preferential. Sealed boxes tend to sound cleaner and tighter, but ported subs tend to go lower and really give that rumbly bass some people crave. I don’t think you’re gonna have any problem with 2 12’s not being loud enough but going from ported to sealed, it will sound different.


I don't think I have heard what quality 12s sealed sound like but tight and more accurate is what I have heard it be described as.


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## Redliner99 (Mar 26, 2018)

Gump_Runner said:


> Have you tried your w3's in a sealed box. I had a couple w3's in a sealed box that sounded great.


I have not main reason being I was under the pretense that would make it more accurate but less output hence the reason of possibly going up to 12" for volume and loudness but to be more accurate


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## Redliner99 (Mar 26, 2018)

Hulk2015 said:


> Just thinking outside the box here but couldn't the OP go with one 10" ported and one 12" sealed sub to get the best of both worlds?


I have heard that this would have weird cancelling effects but I'm not sure it's a good thought though


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## JCsAudio (Jun 16, 2014)

Redliner99 said:


> I have heard that this would have weird cancelling effects but I'm not sure it's a good thought though


Yup, out of phase. That would be tuff to tune!


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## Oscar (Jun 20, 2010)

Not just some phase differences in the output, the group delay of the one with higher amount will mask the other one with less. Pointless.


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## Grinder (Dec 18, 2016)

Exactly ^^^^^^

Lots of misinformation/myth in this thread. Fortunately, all this has been covered at great length here many times before. There are lots of really great threads. Try searching:

site:diymobileaudio.com: sealed vs ported
and/or
site:diymobileaudio.com: mixing different subs


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## Redliner99 (Mar 26, 2018)

Grinder said:


> Exactly ^^^^^^
> 
> Lots of misinformation/myth in this thread. Fortunately, all this has been covered at great length here many times before. There are lots of really great threads. Try searching:
> 
> ...


I hadn't planned on doing 2 different sizes but thank you for the info!


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## Grinder (Dec 18, 2016)

https://www.diymobileaudio.com/foru.../129299-designed-sealed-ported-explained.html

https://www.diymobileaudio.com/foru...ry-dogma/168197-vented-boxes-not-sq-myth.html

https://www.diymobileaudio.com/foru...sion/11192-sealed-vs-ported-sq-myth-fact.html


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## Grinder (Dec 18, 2016)

Redliner99 said:


> I hadn't planned on doing 2 different sizes but thank you for the info!


In case you missed it, there was this suggestion as well: site:diymobileaudio.com: sealed vs ported
https://www.google.com/search?rlz=1.......0...1c..64.psy-ab..0.0.0....0.JJmlI0ZHpOI


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## Grinder (Dec 18, 2016)

https://www.diymobileaudio.com/foru...a/87371-fast-bass-slow-bass-myth-vs-fact.html

https://www.diymobileaudio.com/foru...ssion/148354-somethings-up-dbs-cone-area.html

https://www.diymobileaudio.com/foru...stry-dogma/113166-designed-sealed-ported.html

https://www.diymobileaudio.com/foru...sion/102122-dual-10-vs-single-12-subs-sq.html


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## Redliner99 (Mar 26, 2018)

Grinder said:


> https://www.diymobileaudio.com/foru...a/87371-fast-bass-slow-bass-myth-vs-fact.html
> 
> https://www.diymobileaudio.com/foru...ssion/148354-somethings-up-dbs-cone-area.html
> 
> ...


I'll look those over! I spent awhile looking but couldn't find much info thank you for showing me the links.


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## Grinder (Dec 18, 2016)

Redliner99 said:


> I'll look those over! I spent awhile looking but couldn't find much info thank you for showing me the links.



In case you're not already familiar with this, you'll find some of those threads (and many more useful threads) here: https://www.diymobileaudio.com/foru...cussion/94500-list-usefull-diyma-threads.html


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## Holmz (Jul 12, 2017)

If one was able to correct a speaker(s) group delay then one could mix any combo.

If some version of Box has ringing or some other artefact that cannot be corrected then the various boxes will still sound different.

I suppose it comes down to whether transient response is a bigger deal than the group delay... or if the group delay is corrected, then is the transcient response going to be a problem?

For me I will go with some high gain box, and remove the groups delay as well as possible.
If I have a massive amp, then maybe I would have gone sealed.


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## Red Saber (Jul 5, 2018)

For the longest time I was ported only. Because I could never get the low end right from sealed. Not anymore. You can’t go off recommend sealed specs, you have to go much larger. As large as possible to get that F3 down


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## P0234 (Jul 5, 2018)

*Re: 10&quot; ported vs 12&quot; sealed sub thoughts?*

Smaller drivers are always more punchy. I like rock and pop, and some classic rap, for me four 8s have always had the punch I like and take up the same air space as two 12s. They can get low if the box is larger and especially if you dial in about 3db of boost at 35hz. 

And 8" subs are always on clearance because no one wants them.


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## Hulk2015 (Apr 6, 2015)

*Re: 10&quot; ported vs 12&quot; sealed sub thoughts?*



P0234 said:


> Smaller drivers are always more punchy. I like rock and pop, and some classic rap, for me four 8s have always had the punch I like and take up the same air space as two 12s. They can get low if the box is larger and especially if you dial in about 3db of boost at 35hz.
> 
> And 8" subs are always on clearance because no one wants them.


The SA-8 V.3 D4 - Sundown Audio 8" 500W RMS Dual 4-Ohm SA Series Subwoofer is a good choice.

https://www.amazon.com/SA-8-V-3-D4-...&qid=1531841284&sr=8-1&keywords=sundown+8+sub

and this box:

https://www.amazon.com/LAB-SlapBox-..._rd_t=40701&psc=1&refRID=Z9N6PEZQG79GJTNA7PRB


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## Grinder (Dec 18, 2016)

P0234 said:


> *Smaller drivers are always more punchy*. I like rock and pop, and some classic rap, for me four 8s have always had the punch I like and take up the same air space as two 12s. They can get low if the box is larger and especially if you dial in about 3db of boost at 35hz.
> 
> And 8" subs are always on clearance because no one wants them.


And the myth lives on... 

https://www.diymobileaudio.com/foru...a/87371-fast-bass-slow-bass-myth-vs-fact.html

https://www.diymobileaudio.com/foru...ma/93666-larger-subwoofers-=-flabby-bass.html

https://www.diymobileaudio.com/foru...myth-more-cone-area-=-deeper-slower-bass.html


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## P0234 (Jul 5, 2018)

Grinder said:


> And the myth lives on...
> 
> https://www.diymobileaudio.com/foru...a/87371-fast-bass-slow-bass-myth-vs-fact.html
> 
> ...


Cool. Post as many links as you like. I grew up in an era where you could go to a store and listen to 5 or 6 brands of subs on a soundboard in different sizes. The smaller drivers were always more punchy. Always. Ocassionally a 10 with tons of power behind it would get close to an 8 but 12s and 15s sounded like poo on rock. Forget about an 18. 

Sure with some great midbass speakers you can mask some of that but there is a reason 12" midbass speakers are in short supply. 

And last but not least I've got two boxes right now, one with a single 8 and one with a single twelve. With nothing other than swapping wires, the 8 is way more punchy. The 12 does go way lower. And yup they are the same brand and model speaker.


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## Grinder (Dec 18, 2016)

P0234 said:


> Cool. Post as many links as you like. I grew up in an era where you could go to a store and listen to 5 or 6 brands of subs on a soundboard in different sizes. The smaller drivers were always more punchy. Always. Ocassionally a 10 with tons of power behind it would get close to an 8 but 12s and 15s sounded like poo on rock. Forget about an 18.
> 
> Sure with some great midbass speakers you can mask some of that but there is a reason 12" midbass speakers are in short supply.
> 
> And last but not least I've got two boxes right now, one with a single 8 and one with a single twelve. With nothing other than swapping wires, the 8 is way more punchy. The 12 does go way lower. And yup they are the same brand and model speaker.


I have no doubt that those are your experiences.


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## SPLEclipse (Aug 17, 2012)

Holy **** guys.

Two different subs do not somehow magically cancel out. This assumed axiom has been around since rec.audio.car literally since the beginning of the internet and it's completely wrong.

Group delay is the measure of rate of change of the phase angle difference through the spectrum due to different delay at different frequencies (typically due to a resonant system being used to increase amplitude). This phase "lag" is often attributed to the sloppy sound of highly resonant systems, but this is debatable. In any case, it will not somehow make one speaker mask another. I should also point out that if you were to EQ a sealed speaker to have the same frequency response as it would have in a vented enclosure group delay will also go up. Phase data is derived from frequency data, you can't change one without the other.

As for what type of enclosure the OP should use - there's no way to give a blanket recommendation. OP should measure his response and determine what he wants to change, then start modeling to see if those changes can be accomplished through whatever alignment is needed.

One more thing to point out: at frequencies above the range where the enclosure dominates, the subs just acts as a direct radiator and there is no difference between sealed or vented. You're out of the region where capacitance dominates and into the region where inductance dominates. Higher frequencies don't change just because a sub is in a vented enclosure, although the large gain in amplitude at tuning can often make it seem like the sub is more quiet at higher frequencies.


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## Red Saber (Jul 5, 2018)

They both play sub bass. More cone area will have more output. 
The 8s are punchy because the boxes are to small


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## P0234 (Jul 5, 2018)

Red Saber said:


> They both play sub bass. More cone area will have more output.
> The 8s are punchy because the boxes are to small


So if I make a tiny box for an 18, it will be nice and punchy like an 8?:laugh: I can do the reverse right, and make a huge box for an 8 and it will sound as good as the 18 on the lows?


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## Red Saber (Jul 5, 2018)

The 18 will have more output


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## fastlane (Apr 6, 2009)

P0234 said:


> So if I make a tiny box for an 18, it will be nice and punchy like an 8?:laugh: I can do the reverse right, and make a huge box for an 8 and it will sound as good as the 18 on the lows?


I run 12 18's in my home theater and I can tell you, they are every bit as "punchy" as any other size driver. In fact I run 15" mains and 10" surrounds. Size has nothing to do with speed. I really wish people would stop spewing misinformation. 

For those building enclosures. I'd really encourage everyone to download WinISD and learn how to use it. It's a very valuable tool for modeling the right enclosure to the driver based on the parameters. Some mentioned just tossing a sealed in a really large enclosure. Well that can help with low end extension, but at the risk of bottoming the driver from over excursion. 

And yes mixing sealed and ported causes issues due to gd. 

Some vehicles benefit from sealed due to the cabin gain complementing the natural rol loff of the driver.


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## Red Saber (Jul 5, 2018)

fastlane said:


> I run 12 18's in my home theater and I can tell you, they are every bit as "punchy" as any other size driver. In fact I run 15" mains and 10" surrounds. Size has nothing to do with speed. I really wish people would stop spewing misinformation.
> 
> For those building enclosures. I'd really encourage everyone to download WinISD and learn how to use it. It's a very valuable tool for modeling the right enclosure to the driver based on the parameters. Some mentioned just tossing a sealed in a really large enclosure. Well that can help with low end extension, but at the risk of bottoming the driver from over excursion.
> 
> ...


Yes you have to watch the power but the more efficient enclosure won’t need as much. Look at IB installs.


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## P0234 (Jul 5, 2018)

fastlane said:


> I run 12 18's in my home theater and I can tell you, they are every bit as "punchy" as any other size driver. In fact I run 15" mains and 10" surrounds. Size has nothing to do with speed. I really wish people would stop spewing misinformation.
> 
> For those building enclosures. I'd really encourage everyone to download WinISD and learn how to use it. It's a very valuable tool for modeling the right enclosure to the driver based on the parameters. Some mentioned just tossing a sealed in a really large enclosure. Well that can help with low end extension, but at the risk of bottoming the driver from over excursion.
> 
> ...


So could you explain to me why my 8 and 12 in subs sound very different to my ears? The 12 isn't much louder, but it sure is deeper and kick drums sound muddy while they sound crisp on an 8?


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## Grinder (Dec 18, 2016)

P0234 said:


> So could you explain to me why my 8 and 12 in subs sound very different to my ears? The 12 isn't much louder, but it sure is deeper and kick drums sound muddy while they sound crisp on an 8?


https://www.youtube.com/watch?v=Opy2Y2r_nns


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## fastlane (Apr 6, 2009)

Red Saber said:


> Yes you have to watch the power but the more efficient enclosure won’t need as much. Look at IB installs.


What do you mean more efficient enclosure? We are comparing sealed vs slightly smaller sealed right? 



P0234 said:


> So could you explain to me why my 8 and 12 in subs sound very different to my ears? The 12 isn't much louder, but it sure is deeper and kick drums sound muddy while they sound crisp on an 8?


I'm confused; are we talking about sonic characteristics or speed? 

There are a ton of variables here. Enclosure size, type, power, etc. etc. Distortion plays a huge role in perceived sound. The more transparent my subs, the happier I am.


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## GreatLaBroski (Jan 20, 2018)

P0234 said:


> Cool. Post as many links as you like. I grew up in an era where you could go to a store and listen to 5 or 6 brands of subs on a soundboard in different sizes. The smaller drivers were always more punchy. Always. Ocassionally a 10 with tons of power behind it would get close to an 8 but 12s and 15s sounded like poo on rock. Forget about an 18.
> 
> Sure with some great midbass speakers you can mask some of that but there is a reason 12" midbass speakers are in short supply.
> 
> And last but not least I've got two boxes right now, one with a single 8 and one with a single twelve. With nothing other than swapping wires, the 8 is way more punchy. The 12 does go way lower. And yup they are the same brand and model speaker.


Smaller drivers are easier to design with lower MMS, and therefore can be faster than some larger drivers. However you're conflating the size of the driver and the dynamic response lent to the drivers by the mms / bl ratio. Typically smaller drivers will have a lighter moving assembly weight + weight of displaced air (MMS), which if the motors are sized similarly to their larger brothers, will result in faster dynamic response. (Yes this is a generalization, and other factors like inductance and enclosure dampening come into play, but it's accurate at face value).

There are slow 10" drivers and slow 15" drivers, just as there are fast 15's and fast 10's. An example of an exceptionally quick 15" would be some of the ones made by Acoustic Elegance. Alternatively, a servo controlled subwoofer should be much faster than the same driver non-servo controlled.


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## fastlane (Apr 6, 2009)

GreatLaBroski said:


> An example of an exceptionally quick 15" would be some of the ones made by Acoustic Elegance.


Which is what I run for mains in my theater. TD15m. Nothing slow about them.


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## P0234 (Jul 5, 2018)

GreatLaBroski said:


> Smaller drivers are easier to design with lower MMS, and therefore can be faster than some larger drivers. However you're conflating the size of the driver and the dynamic response lent to the drivers by the mms / bl ratio. Typically smaller drivers will have a lighter moving assembly weight + weight of displaced air (MMS), which if the motors are sized similarly to their larger brothers, will result in faster dynamic response. (Yes this is a generalization, and other factors like inductance and enclosure dampening come into play, but it's accurate at face value).
> 
> There are slow 10" drivers and slow 15" drivers, just as there are fast 15's and fast 10's. An example of an exceptionally quick 15" would be some of the ones made by Acoustic Elegance. Alternatively, a servo controlled subwoofer should be much faster than the same driver non-servo controlled.


I realize that different brands and models behave differently. My assertion is that within the same brand and line of subs, the smaller the driver, the more punch it has. The larger the driver, the lower the frequency response. I'm sure there is an exception somewhere but that has been my experience in listening to way too many speakers.


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## fastlane (Apr 6, 2009)

P0234 said:


> I realize that different brands and models behave differently. My assertion is that within the same brand and line of subs, the smaller the driver, the more punch it has. The larger the driver, the lower the frequency response. I'm sure there is an exception somewhere but that has been my experience in listening to way too many speakers.


There is 0 discernible difference between my TD10 and TD15 (in regards to your concerns comparing the two). Could there be a measurable difference; possibly. Nothing that I could pick out, outside of obvious factors comparing drivers of drastically different displacement. 

If this were the case you would see a lot more configurations of multiple small drivers. Hell, I would have used a 6" driver in my HT rig instead of a 15.


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## Holmz (Jul 12, 2017)

SPLEclipse said:


> ...
> As for what type of enclosure the OP should use - there's no way to give a blanket recommendation. OP should measure his response and determine what he wants to change, then start modeling to see if those changes can be accomplished through whatever alignment is needed.
> ...


As a blanket statement: "In the end-to-end system, generally less group delay is better."




SPLEclipse said:


> ...
> Group delay is the measure of rate of change of the phase angle difference through the spectrum due to different delay at different frequencies


Group delay is the time-delay vs Freq.
https://en.wikipedia.org/wiki/Group_delay_and_phase_delay




SPLEclipse said:


> ...
> Group delay...
> ... In any case, it will not somehow make one speaker mask another. I should also point out that if you were to EQ a sealed speaker to have the same frequency response as it would have in a vented enclosure group delay will also go up. Phase data is derived from frequency data, you can't change one without the other.
> ...


One can make either a sealed or a port have minimal group delay if one is willing to suffer some overall delay.

And one can also have the minimal group delay and simultaneously have the frequency response varying across the band to have the output become flat.

Amplitude, phase, and group delay are not by definition "tied together" in an equilization-DSP. Whether designing that filter is easy or difficult is another matter.


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## SPLEclipse (Aug 17, 2012)

You are referring to phase delay, which is the difference in phase angles between frequencies without taking into account the angle of the rate of change of the phase difference. There will always be phase delay between differing frequencies when looking at the audible spectrum because wavelengths are different. At lower frequencies you might only be 20 degrees through a phase rotation while a higher frequency is already through several cycles, so several hundred degrees of phase rotation.

As for your last statement Fourier disagrees. The time and frequency domain are intrinsically tied together, although it's possible to measure just one or the other independently (for example with non-periodic pink noise).

It is certainly possible to have whatever frequency response you desire with minimal group delay, however because we typically use capacitive/inductive means to increase amplitude its typical for group delay to increase with a corresponding peak in amplitude at whatever frequencies you are boosting.

In any event, there is no credible evidence that I've seen that group delay is even audible at lower frequencies (within reason of course). You can assume it would be around a cycle worth of delay (or around 30ms at 30hz) based on extrapolation of audibility at other frequencies, but even if it's above 30ms the corresponding increase in amplitude is far more noticeable than the increase in GD.


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## Holmz (Jul 12, 2017)

SPLEclipse said:


> You are referring to phase delay, which is the difference in phase angles between frequencies without taking into account the angle of the rate of change of the phase difference. There will always be phase delay between differing frequencies when looking at the audible spectrum because wavelengths are different. At lower frequencies you might only be 20 degrees through a phase rotation while a higher frequency is already through several cycles, so several hundred degrees of phase rotation.
> 
> As for your last statement Fourier disagrees. The time and frequency domain are intrinsically tied together, although it's possible to measure just one or the other independently (for example with non-periodic pink noise).
> 
> ...


Whether or not it is audible, the bottom line is that the group delay can be corrected by use of a FIR-based DSP, and that same filter can also do the amplitude EQ.
This is not the same process as an FFT, but usually an FFT is used in the analysis.

So lets assume that both a sealed and some other box can be made identical in terms of group delay and amplitude response. And if the group delay is not audible, then we can then assume that the group delay is already close enough to not be audible after correction (<-- a shameless tautology )...

So then what else can make the two boxes sound different if it is group delay is minimised and the Amplitude also ends up being the same?:
- Is it transient response?
- Phase delay?
- Something else?


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## EFMax (Jun 25, 2018)

Gosh... loads of stuff written here some of which is not 100% accurate.

At the end of the day, it all comes down to match your speakers to a correctly designed box.

Both sealed and ported boxes can be designed to do amazing things... I read here people saying what a ported box can and cannot do... If transient response is what you are after and you want to hold on to low bass and you want loud bass, then you have to find a balance and find a driver that is designed for an Infinite Baffle equation and then design a good ported box for it... this should give you the punch you need at around 60Hz and also be able to get to grips with stuff around 35Hz-45Hz and yet not freak out at the stuff around or below 25Hz.. It is not impossible but much research has to be done in advance but when it comes together you will be surprised and happy.


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## Redliner99 (Mar 26, 2018)

SPLEclipse said:


> You are referring to phase delay, which is the difference in phase angles between frequencies without taking into account the angle of the rate of change of the phase difference. There will always be phase delay between differing frequencies when looking at the audible spectrum because wavelengths are different. At lower frequencies you might only be 20 degrees through a phase rotation while a higher frequency is already through several cycles, so several hundred degrees of phase rotation.
> 
> As for your last statement Fourier disagrees. The time and frequency domain are intrinsically tied together, although it's possible to measure just one or the other independently (for example with non-periodic pink noise).
> 
> ...


So excuse me ignorance. I'm learning a lot every day on here. A lot of what has been said in this thread is way over my head. Can you dumb down your thoughts of 10 vs 12 sealed vs ported? And what you use and why?


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## EFMax (Jun 25, 2018)

Redliner99 said:


> . Can you dumb down your thoughts of 10 vs 12 sealed vs ported? And what you use and why?


Simplistically... most people think you go sealed for tight punch controlled bass... .. many people think a ported box goes low and loud... .. and some even like bandpass boxes..

Bottom line, find yourself a good bass box designer - not just someone who has downloaded a free bit of software and thinks overnight that they are an expert in box designs.

A good designer can make the right speaker in the right box perform very well.. there are so many variables in each equation that no one size fits all applications and when you change "x" you need to know why and what to expect in advance.

So for example.. in my box, I have two 15" speakers. I am greedy, I wanted clean loud bass that plays low and is so tight you could cut yourself on it. I could have gone for a single 15" in the same size box but by going for two I have increased the power handling and reduced the group delay and hence increased the tightness of the bass (drum tracks sound amazing through these speakers).

To get this I accepted that my box would be big. I did not need it to play above 80Hz nor below 20Hz but at 20Hz it had to be in control and not farting all over the place. I actually have mine on an 18dB slope at 63hz and that works well in my car.

My box is not conventional.. it, like all of my designs, is a box with three chambers - in the two outer chambers are the speakers, they are ported into the inner chamber which itself is then ported to the outer chamber. The inner ports are small enough to make the box behave like a sealed box on either side of the tuned frequency, which does not have to be mega low... the centre chamber behaves like a bandpass box and collectively, the box is a ported box.. so effectively I get the low and slow group delay of a sealed box.. I get the lows of a bandpass box and the efficiency and loudness of a ported box. BUT this, because of its size, is not for everyone as a 7cuft box is not small and at 220ibs is not light.

.. and you must filter in cabin gain (transfer function) with comes in around 50Hz-70Hz and has a massive impact on performance.. used correctly in your calculations, you can effectively reduce the need to tune your box too low.

SO... with respect to your original questions. 

Output is subjective and directly related to the amps power vs the load you give it plus the quantity of speakers or cone area being employed. 

If you ask, do 2x 10 in a ported box being given a 100w sound louder than a single 12 in a sealed box being given 100w... then all other things being equal the answer is probably yes.. 

If you ask which will sound better, then this comes down to the box designed assuming that the 10's and the 12 are of the same make and brand.

Your car will have an impact on all of this so again, there is no one answer to fit all the equations and you may well have to waste a bit of money to get your answer.

Personally, for the music you say you like, I would be tempted to go for 2x 10 in a sealed box with a strong amp or a single 12 in a ported box if amp power is a little shy.


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## Redliner99 (Mar 26, 2018)

EFMax said:


> Simplistically... most people think you go sealed for tight punch controlled bass... .. many people think a ported box goes low and loud... .. and some even like bandpass boxes..
> 
> Bottom line, find yourself a good bass box designer - not just someone who has downloaded a free bit of software and thinks overnight that they are an expert in box designs.
> 
> ...


So let me ask you this if an 8" and 18" will perform the same in ported and in sealed in every way except volume and out put why wouldn't everyone use huge subs IF they had the power for it?


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## Red Saber (Jul 5, 2018)

Redliner99 said:


> So let me ask you this if an 8" and 18" will perform the same in ported and in sealed in every way except volume and out put why wouldn't everyone use huge subs IF they had the power for it?


That’s very simple. Space


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## EFMax (Jun 25, 2018)

Redliner99 said:


> So let me ask you this if an 8" and 18" will perform the same in ported and in sealed in every way except volume and out put why wouldn't everyone use huge subs IF they had the power for it?


Of course and 8" and an 18" cannot perform the same.. logic says so and physics says so.. but I have made boxes with an 8 and even a 6" speaker that can drop bass.. but an 18 will drop bass better, lower and louder but you need more space to do it.. and more power to do it with.

.. also ported boxes do not perform like sealed boxes as they both do the same job but in different ways but what I often see is people mismatch their boxes with their speakers... speaker manufacturers will make suggestions for what is the most appropriate box for their particular speaker - I see myself as a bit like a remap for a car.. car makers make good engines but a good remap can do amazing things for the same well made engine..


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## Redliner99 (Mar 26, 2018)

EFMax said:


> Of course and 8" and an 18" cannot perform the same.. logic says so and physics says so.. but I have made boxes with an 8 and even a 6" speaker that can drop bass.. but an 18 will drop bass better, lower and louder but you need more space to do it.. and more power to do it with.
> 
> .. also ported boxes do not perform like sealed boxes as they both do the same job but in different ways but what I often see is people mismatch their boxes with their speakers... speaker manufacturers will make suggestions for what is the most appropriate box for their particular speaker - I see myself as a bit like a remap for a car.. car makers make good engines but a good remap can do amazing things for the same well made engine..


This makes complete sense but what I haven't seen is someone say I would go ported for this reason or sealed for this reason and here is why? I have heard the same 2 10" w3 jl subs I have in my ported box with specs straight from JL and 2 10" w3 in a sealed box with specs straight from JL. How do I know the specs are from them I built both boxes and talked to the same guy at JL. They don't even remotely sound the same not even in the slightest. Mind you this was their recommendations of specs I went off of.


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## EFMax (Jun 25, 2018)

Redliner99 said:


> This makes complete sense but what I haven't seen is someone say I would go ported for this reason or sealed for this reason and here is why? I have heard the same 2 10" w3 jl subs I have in my ported box with specs straight from JL and 2 10" w3 in a sealed box with specs straight from JL. How do I know the specs are from them I built both boxes and talked to the same guy at JL. They don't even remotely sound the same not even in the slightest. Mind you this was their recommendations of specs I went off of.


 At the end of the day, what we want to listen to is the music, not the speakers. I will always argue that a well designed box lets you listen to the music playing at its recorded best.. so if you give me a speaker that was engineered for a sealed box (Qts of around 0.7ish) and allow me a free reign to design the optimum box for that speaker AND you do the same for a speaker engineered for a ported box and give me the same freedom... both boxes will sound the same because both are optimised for their job... so put both boxes in the same room and play them the same music.. if I have done my job good - you hear the music, not the speaker box or what type of box it is - it should just be quality bass. 

In the past when I designed speakers for nightclubs and studios this is what the customer expected - they wanted to hear the music... so when you hear people talking about this box is best and that box is better - I silently smile to myself with amusement.

You also make the assumption that just because JL Audio make and sell speakers that they actually know what they are talking about.. Back in 1996 I had a right ding-dong with a techie guy from JL and in the end, he conceded that I did know what I was talking about and when challenged back then to make a better box than JL with a JL speaker, I did.

Many speaker manufacturers make great speakers based on computer modelling... but the computer can only go so far and when you have an "ear" for sounds/notes/frequencies and have made 00's of mistakes like I have, from those mistakes comes a lot of wisdom and it is the sort of wisdom that a computer cannot model.. think of it like this - you guys are all familiar with car re-mapping (chipping).. car makers could make their cars already re-mapped but they want to please the many, not just a few, so their cars are made within smart guidelines so as to not cause problems and speaker makers - box makers do the same, but there are guys out there who take what the speaker maker has given you and make it better.

For those of us that can measure your Thiele Small parameters, we never get the same results as the speaker maker cos they go by an average of what they do and we go by each individually tested speaker.. I often find speaker parameters that are more than 5% out and I work to a tolerance of 1.5%.


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## Holmz (Jul 12, 2017)

Redliner99 said:


> This makes complete sense but what I haven't seen is someone say I would go ported for this reason or sealed for this reason and here is why? I have heard the same 2 10" w3 jl subs I have in my ported box with specs straight from JL and 2 10" w3 in a sealed box with specs straight from JL. How do I know the specs are from them I built both boxes and talked to the same guy at JL. They don't even remotely sound the same not even in the slightest. Mind you this was their recommendations of specs I went off of.


If they do not sound the same, then they are not the same.
Group delay and EQ flatness are 2 leading reasons for this

If one can correct both box designs, then would they sound the same?

And if they would sound the same, then which box should be chosen if one is going to correct them anyhow?
Or
Which is better without correction? (The third question's answer is sealed: sealed)


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## Holmz (Jul 12, 2017)

EFMax said:


> At the end of the day, what we want to listen to is the music, not the speakers. I will always argue that a well designed box lets you listen to the music playing at its recorded best.. so if you give me a speaker that was engineered for a sealed box (low Qts) and allow me a free reign to design the optimum box for that speaker AND you do the same for a speaker engineered for a ported box and give me the same freedom... both boxes will sound the same because both are optimised for their job... so put both boxes in the same room and play them the same music.. if I have done my job good - you hear the music, not the speaker box or what type of box it is - it should just be quality bass.
> ...


^Close^...
The optimised boxes will be optimal in a system without any other corrections. (EQ and Group delay).
(Maybe an IB has the flattest EQ and least GD?)


However if a corrected "speaker & box" exactly replicated the input signal, then that would be, by definition... "perfect".


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## Red Saber (Jul 5, 2018)

One last thing to add. 
Recommend specs are always to small. Nobody wants to hear a sealed 12 really needs 2 cubes or more


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## JCsAudio (Jun 16, 2014)

EFMax said:


> I will always argue that a well designed box lets you listen to the music playing at its recorded best.. so if you give me a speaker that was engineered for a sealed box (low Qts)


EFMax, I think you meant high Qts (total Q of driver of .5 and above) for a sealed box right? A lower qts works best in a ported box, typically. Just trying to get the facts straight.


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## Grinder (Dec 18, 2016)

Red Saber said:


> One last thing to add.
> Recommend specs are always to small. Nobody wants to hear a sealed 12 really needs 2 cubes or more


No. Not always.

Nowadays, power is cheap; and not everyone has room for 2 cubes or more.

Hoffman's Iron Law:
GlassWolf's Pages


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## Red Saber (Jul 5, 2018)

Power won’t drop F3. 
That’s what I’m saying. Retailers won’t sell as many if they give proper specs.


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## Grinder (Dec 18, 2016)

Red Saber said:


> Power won’t drop F3.
> That’s what I’m saying. Retailers won’t sell as many if they give proper specs.


Sure, but it's a matter of trade-offs. There is no ideal. Fact is, we all draw the line somewhere, based on our budget, tastes and/or priorities. Most of us want trunk/cabin space AND a subwoofer; and nowadays we can have both.

There are lots of 12" subs that will work quite well, for mobile audio SQ purposes, in less than 2 sealed cubes.


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## Grinder (Dec 18, 2016)

FWIW, I would just like to point out that, for better or worse, this happens to be a thread in which the OP is asking for answers to questions that have been asked and answered in this forum many times before. 

...which is why (apart from the fact that I'm certainly no expert) I simply posted links to some of those threads. 

...and (presumably) why so many of our experts haven't bothered to contribute to this thread.


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## P0234 (Jul 5, 2018)

I'm sure there are some _really_ amazing box builders here that can defy physics but the reality is smaller drivers play higher notes more easily. A lot of punch in rock is in the bass to midbass range. Great example is The Cars - Let's Go. Smaller drivers playing the upper range of what is sub bass and probably into midbass is what makes the sort of punch I love. 

Sure if I want to make my doors into swiss cheese I can have a bunch of midbass drivers and an 18 in a 10 cu ft box and it will sound great. But that doesn't work for me and its why I run smaller drivers.


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## EFMax (Jun 25, 2018)

V8toilet said:


> EFMax, I think you meant high Qts (total Q of driver of .5 and above) for a sealed box right? A lower qts works best in a ported box, typically. Just trying to get the facts straight.


Thank you... thinking too far ahead but yes around 0.707 is what the maths say we should chase after... thanks for the correction and I will edit to reflect.. cheers


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## fastlane (Apr 6, 2009)

P0234 said:


> I'm sure there are some _really_ amazing box builders here that can defy physics but the reality is smaller drivers play higher notes more easily. A lot of punch in rock is in the bass to midbass range. Great example is The Cars - Let's Go. Smaller drivers playing the upper range of what is sub bass and probably into midbass is what makes the sort of punch I love. .


Depends on what you define as higher notes. By your definition I would again disagree. 

I have a set of speakers comprising of dual TD6M drivers crossed over to a CD/waveguide and a set comprising of a single TD15M crossed over to same cd/waveguide. 

The TD6's definitely don't have more punch in the sub bass/midbass as you claim and don't play these notes more easily. There is a point where the 15's breakup sooner than the 6's, but it's long after the frequency your are referring to.

Yes, all drivers behave differently and this won't always be the case, but blanket statements don't help anyone when searching for answers.


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## fastlane (Apr 6, 2009)

Red Saber said:


> One last thing to add.
> Recommend specs are always to small. Nobody wants to hear a sealed 12 really needs 2 cubes or more


Not necessarily. Smaller boxes require more power for the same output (albeit at a small low frequency expense). I have tried multiple configs in my home theater. Honestly, most of the time you are splitting hairs with box design. A db here or there, or a roll off a couple hz sooner is hardly going to be realized, especially in an environment such as a vehicle.

If I had a car, IB would definitely be at the top of the list. For sheer output a ported box is really tough to beat. To reach the same output in a sealed config you either need considerably more power or more drivers. No way around it. 

I miss my ported setup in the theater but I am a sucker for single digit reference level bass, and the only way to get there is with a sealed setup. That required multiple large drivers however (ten 18's) and a crap load of power (10,000 watts on tap).


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## Red Saber (Jul 5, 2018)

We can agree on one thing. There is always give and take.


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## Alrojoca (Oct 5, 2012)

Ported, needs more space bigger box, can be louder, better have a good DSP with many EQ bands for the sub channels, it is harder to tune.

Sealed is way easier to tune, and gives the sense of more accuracy or tends to be more musical, at first some may think the sound or bass is dry.

Ported boxes besides playing a bit louder tend to be boomy, again if tuned for SQ they can match the sealed box sound.

And yes it is a preference, if you care about SQ, go with a sealed one, if you want spl listen to hip hop and want to shake and boom more, the ported one is for you.


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## Alrojoca (Oct 5, 2012)

I had a good ported 8", and no dsp. It gave me fatigue, headaches. Switched to a sealed and shallow 10, lacked output but I got used to it, and it got more points in SQ competition


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## Red Saber (Jul 5, 2018)

My last sub was a beefy ported 8. It scored pretty good also. Tbh after the tune they sound the same as the current sealed 12


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