Mixing sealed and vented enclosures

[ohthexcitement 10+ year member]

I know, generally, sealed for SQ, vented for SPL and/or low-end. What is the general consensus regarding the use of both for good SQ and low-end (and versatility w/ different music styles). I'm working with 6 small subs wired to separate amps.

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[audioholic 5,000+ posts]

Bad idea. The different frequency responses will cause an irratic over-all response, which is not a good recipe for SQ. The subwoofer plays the smallest portion of the freq spectrum of any speaker in your system, why do you think you need to splt that freq band even further? Building a sub system that plays flat from 20-80hz shuld be pretty simple. Dont over complicate the situation.

Its not an original idea. In fact, id venture to say most car audio enthusiasts have had the same epiphany at some point early in their hobby career. Its a common misconception that running different subs, different enclosure sizes/types/alignments, or different power ranges will somehow equate to better over all performance.

 

[FootlongSam 10+ year member]

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif I must admit that rather than asking, I just did it.. Fail on my part. Well said audioholic

 

[Rashaddd 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif I must admit that rather than asking, I just did it.. Fail on my part. Well said audioholic

Please refer to this guy's thread for tips on what not to do, ever.

 

[ohthexcitement 10+ year member]

Bad idea. The different frequency responses will cause an irratic over-all response, which is not a good recipe for SQ. The subwoofer plays the smallest portion of the freq spectrum of any speaker in your system, why do you think you need to splt that freq band even further? Building a sub system that plays flat from 20-80hz shuld be pretty simple. Dont over complicate the situation.
Its not an original idea. In fact, id venture to say most car audio enthusiasts have had the same epiphany at some point early in their hobby career. Its a common misconception that running different subs, different enclosure sizes/types/alignments, or different power ranges will somehow equate to better over all performance.

I wouldn't necessarily call it missconception in this case, as I've phisically tested both enclosures back to back with this particular sub. Perhaps I should've been politically correct in the first post in that I was refering to actual volume and not frequencies. My fault, for sure. Same sub in both enclosures (tuned properly), I like the sound of the vented enclosure @ lower volumes (flat-out more loudness). However, @ higher levels of volume, there is a distinct difference in the 'control'/accuracy of the sealed sub, where the vented sounds a bit 'flabby'/uncontrolled. My less-experienced (in this field) mind tells me that, having 6 of them, I can get both the low-volume loudness and tighter high-volume sound by mixing [properly-tuned] enclosures. Sort of like "twincharging" in the automotive performance field, if you're familliar with the term.

I appreciate the input, regardless.

 

[ohthexcitement 10+ year member]

Please refer to this guy's thread for tips on what not to do, ever.

lol Pos. or neg, an example is an example, right?...

 

[mokedaddy 5,000+ posts]

It will not work like you think it will but it sounds like you already have your mind made up. Give it a try and let us know what you think since that is really the most important thing.

 

[audioholic 5,000+ posts]

I wouldn't necessarily call it missconception in this case, as I've phisically tested both enclosures back to back with this particular sub. Perhaps I should've been politically correct in the first post in that I was refering to actual volume and not frequencies. My fault, for sure. Same sub in both enclosures (tuned properly), I like the sound of the vented enclosure @ lower volumes (flat-out more loudness). However, @ higher levels of volume, there is a distinct difference in the 'control'/accuracy of the sealed sub, where the vented sounds a bit 'flabby'/uncontrolled. My less-experienced (in this field) mind tells me that, having 6 of them, I can get both the low-volume loudness and tighter high-volume sound by mixing [properly-tuned] enclosures. Sort of like "twincharging" in the automotive performance field, if you're familliar with the term.
I appreciate the input, regardless.

Of course you wouldn't call it a misconception, you have learned to yet. You will. And yes, I tried it in my early years, thought I had the exception to the rule too, just like everyone else.
But as is so often true, as said above, you've already decided its a good idea and seem to just mostly be looking for positive reinforcement to proceed with your plan.

 

[ohthexcitement 10+ year member]

It will not work like you think it will but it sounds like you already have your mind made up. Give it a try and let us know what you think since that is really the most important thing.

Have you read my response to audioholic (I ask as I had to clarify something)? I'm a composito finatico (fibres), and an anal planner (laugh it up //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif ) on top of it. Trial and error is fun and all, but I wouldn't just jump in the lake with this @ the cost of my time and the supplies. I respect the opinions of those with more experience than I on any given topic. However, I've much more interest in 'why's' than I do in just making a run for it with an opinion. If any of you can offer why it will sound different in the cabin than what my ears are telling me, I would greatly appreciate it. I know that it may sound like it, but the mind isn't 'set' on either way at this point. I truely am collecting the what's and why's here.

 

[ohthexcitement 10+ year member]

Of course you wouldn't call it a misconception, you have learned to yet. You will. And yes, I tried it in my early years, thought I had the exception to the rule too, just like everyone else.
But as is so often true, as said above, you've already decided its a good idea and seem to just mostly be looking for positive reinforcement to proceed with your plan.

Contrary to your opinion, and how I made it sound in post1, vague reinforcement, neither pos. or neg. is what I want. Physics behind it would be great.

 

[audioholic 5,000+ posts]

Have you read my response to audioholic (I ask as I had to clarify something)? I'm a composito finatico (fibres), and an anal planner (laugh it up //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif ) on top of it. Trial and error is fun and all, but I wouldn't just jump in the lake with this @ the cost of my time and the supplies. I respect the opinions of those with more experience than I on any given topic. However, I've much more interest in 'why's' than I do in just making a run for it with an opinion. If any of you can offer why it will sound different in the cabin than what my ears are telling me, I would greatly appreciate it. I know that it may sound like it, but the mind isn't 'set' on either way at this point. I truely am collecting the what's and why's here.

I already explained why, pretty much. When you have two systems running the same frequency band, but not identical systems, they will display dissimilar response curves. So instead of reinforcing each other linearly, as would identical setups, it will get irractic and unpredictable response characterisitics. Some frequencies will be reinforced, some will have cancellation. Over all output to your ears will sound louder generally speaking, as you simply have more cone area for displacement. But if you listen to the system critically, you will notice some notes will be much louder than others, when they should sound the same, for example.
You seem to be correcting yourself to say you are after output, not SQ, but then describe a situation where you want a certain type of sound for the low end, and a certain type of sound for the upper bass. These would be aspect in the SQ realm, not the SPL arena.

You say your ported system sounds muddy on the top end. Who is to say the 'tightness' you hear in the sealed system will overpower the sloppy sound from the ported, and give an over all pleasing sound? It wont.

Subbass is primarily intended to reinforce the front stage, not dominate it or compete with it. IMO you need a better midbass setup in your front stage, and quit expecting your subwoofers to play midbass. Trying to over complicate your substage to attempt to play midbass well, as well as subbass, is just not the right direction to head in.

 

[mokedaddy 5,000+ posts]

Just because you plan something doesnt mean it will work. //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

Also just because something works in theory does not mean it will work in the real world. So explaining the physics behind the concept will not help.

As said you can go ahead and try it, its not anything I havent seen before...

 

[Immacomputer 10+ year member]

Different enclosures means different transfer functions. Different transfer functions means different frequency response, different phase response, different group delays, and difference in tonality. All those differences can lead to a degradation of sound quality. It will probably still have decent output but will not be as capable as having all the subs in the same enclosure specs to keep the transfer functions as close to each other as possible.

If your ported setups don't handle themselves at high volumes, lower the tuning frequency and lower the enclosure volume. That should help give the subs more composure at higher volume levels.

 

[ohthexcitement 10+ year member]

I already explained why, pretty much. When you have two systems running the same frequency band, but not identical systems, they will display dissimilar response curves. So instead of reinforcing each other linearly, as would identical setups, it will get irractic and unpredictable response characterisitics. Some frequencies will be reinforced, some will have cancellation. Over all output to your ears will sound louder generally speaking, as you simply have more cone area for displacement. But if you listen to the system critically, you will notice some notes will be much louder than others, when they should sound the same, for example.

So the sound would reach the ears in cluster**** fashion.

You seem to be correcting yourself to say you are after output, not SQ, but then describe a situation where you want a certain type of sound for the low end, and a certain type of sound for the upper bass. These would be aspect in the SQ realm, not the SPL arena.

I'm not looking for different 'types' of sound. To again clarify, I'm refering to differences in DB per actual volume, not frequencies. It's all about SQ regardless of where the volume knob is. The SQ of the vented enclosure was great at low volume. It simply provided more quality DB than the sealed at low volume. The sealed enclosure provided greater SQ at high volume, and plenty of DB. I figured a little of both would be great, but you did bring-up a good point below...

You say your ported system sounds muddy on the top end. Who is to say the 'tightness' you hear in the sealed system will overpower the sloppy sound from the ported, and give an over all pleasing sound? It wont.

We're not talking all-out crap here. Just not as clean as the sealed. Regardless, valid point.

Subbass is primarily intended to reinforce the front stage, not dominate it or compete with it. IMO you need a better midbass setup in your front stage, and quit expecting your subwoofers to play midbass. Trying to over complicate your substage to attempt to play midbass well, as well as subbass, is just not the right direction to head in.

The subs in question, 6* ED 7kr.2's (2 down-firing under the dash, 4 beside the rear seats in the cab.), are intended herein as dual-purpose low-mid and sub. I am running Pioneer's TS-D720C's as comps, and they simply do not offer enough mid bass (despite well more than enough pwr), so I'll cross them a tad higher, then cross the front 7kr.2's a tad higher to take care of it. There will be a ridiculous amount of tuning involved, of course...

 

[ohthexcitement 10+ year member]

Just because you plan something doesnt mean it will work. //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

"If you don't know where you're going, you'll never get there"...

Also just because something works in theory does not mean it will work in the real world. So explaining the physics behind the concept will not help.

If I rested on 'theory', I don't believe I would be asking questions...My inquirey of the physics was not some spitefull way of saying "prove it". I simply wanted to know

As said you can go ahead and try it, its not anything I havent seen before...

I've seen it quite a few times myself. However, I hadn't tested the configuration personally prior to, and had no intention on pooring my time and resources into such a endeavor until all the facts were in.

 

[ohthexcitement 10+ year member]

Different enclosures means different transfer functions. Different transfer functions means different frequency response, different phase response, different group delays, and difference in tonality. All those differences can lead to a degradation of sound quality. It will probably still have decent output but will not be as capable as having all the subs in the same enclosure specs to keep the transfer functions as close to each other as possible.
If your ported setups don't handle themselves at high volumes, lower the tuning frequency and lower the enclosure volume. That should help give the subs more composure at higher volume levels.

And that, folks, is a hot bowl of positive. Thank you much for the education.

Thank you to you others as well for your time and efforts. I have more testing to do.

 

[mokedaddy 5,000+ posts]

I wasnt trying to dissuade you in any certain terms. There is always a learning curve when trying something new and this just happens to be a part many have gone through before.

The reason I was trying to avoid all the physics behind it, is that no matter what something looks on paper, the only way to know for sure is to try it. And like many things in science its not just black and white.

That is why I was saying that if you are curious you should try it out for yourself and see what the results are because they may differ for you than someone else.

You never know for sure and you may in fact like what you come up with.

 

[ohthexcitement 10+ year member]

I wasnt trying to dissuade you in any certain terms. There is always a learning curve when trying something new and this just happens to be a part many have gone through before.
The reason I was trying to avoid all the physics behind it, is that no matter what something looks on paper, the only way to know for sure is to try it. And like many things in science its not just black and white.

That is why I was saying that if you are curious you should try it out for yourself and see what the results are because they may differ for you than someone else.

You never know for sure and you may in fact like what you come up with.

I fully understand your point. I was just refering to the physics behind why it "wouldn't work" as some said, not how it could work on paper. I am a mechanical engineer, and sadly, could not answer this for myself (I lost a bit of knowlege over the years I guess). I was born into a situation where trial and error was all that I had, then ended up going to school to fix that. There are cases where equasions predict a different outcome than what actually ends up happening. However, the vast majority of physical questions out there can be, at the very least, ball-parked, and running a numbers is free (pending the knowlege of how, of course), whereas trial and error is not. Take into account all equatable variables, and you can get surprizingly close to reality //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[mokedaddy 5,000+ posts]

Take into account all equatable variables, and you can get surprizingly close to reality //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

And thats the biggest problem //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

There are so many variables when dealing with sound in a vehicle that it is nearly impossible to model with any certainty. Also your brain processes sound much differently than it looks on paper.

Cost is definitely a limiting factor for trail and error and so is time. Comprises usually must be made.

I understand the quest for what I term as sonic nirvana and have yet to perfect it. Not to mention my idea of this will most likely differ from yours. This is why I say you kinda have to just see what works for you since only you can decide when to call it quits.