# Sealed enclosures in door cavities =decreased output?



## reverendgreg71 (7 mo ago)

I have built a set of doors panels for my 1991 Mazda Miata.
14mm birch(recycled)
Total volume of .12 cu/ft each
I am installing a pair of Kenwood coax in each door, as proof of concept. Upgrading to serious 6.5"mids in future 
Today after watching a YouTube video, several comments stated that enclosed door speakers need to breath and the output will be diminished. 
Did I just waste a bunch of time, on a very heavy upgrade?


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## Grinder (Dec 18, 2016)

Unfortunately, yes, that is very likely to be the case. A small sealed airspace presents in this case (i.e., to a speaker designed for essentially free-air operation) an unnecessary and undesirably firm acoustic suspension in addition to the speaker's already sufficiently firm mechanical suspension. This will tend to limit potential cone movement, which will tend to limit potential bass/midbass output.

I have first-hand experience with this sort of thing, having learned the hard way by building first a boombox and then satellite speakers using 6.5" car audio coaxials in small sealed airspaces.


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## hella356 (Dec 11, 2016)

I'm running a pair of Anarchy 704 (one on each door) in 0.26cf sealed boxes. They don't lack for output. These are suited for small sealed boxes, apparently can run well in quite a bit smaller boxes than I'm using. Far better midbass performance than any door IB driver I've used. Not all drivers like a small sealed box, though. It's likely that one of your Kenwood coax per door will sound better than two.


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## lithium (Oct 29, 2008)

You can model the drivers you intend to use to compare the response (output). Regardless of that, the benefits of an enclosure outway the cons of IB door installs anyways. Issues like rattles for example. 

Another point to understand is that a small enclosure causes the low end to roll of quicker than a larger enclosure. But we run midbass drivers with a high pass filter anyways. Meaning that you might not be loosing that much low end compared to IB if you're running a standard ~80Hz HPF. 

Now that you have the enclosures built it just a matter of finding a good driver to use in that airspace. If you have the depth something like the peerless sls 6.5 might work well.


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## reverendgreg71 (7 mo ago)

hella356 said:


> I'm running a pair of Anarchy 704 (one on each door) in 0.26cf sealed boxes. They don't lack for output. These are suited for small sealed boxes, apparently can run well in quite a bit smaller boxes than I'm using. Far better midbass performance than any door IB driver I've used. Not all drivers like a small sealed box, though. It's likely that one of your Kenwood coax per door will sound better than two.


Will be changing out to a set of Dayton GF-180-4 mids, once everything is working properly. 
The coax are what I had, and this vehicle only had oem provisions for a 6.5 at your ankles, and a pair of 2"x3" in each seat.


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## Jroo (May 24, 2006)

I think I know the video op watched. A well known box builder on you tube. Basically
Unless the speaker is designed for sealed, he or anyone could hurt the performance of that driver. I am pretty sure the speakers he is using are not like 704s in this thread that are. He has good content around sub. I’ve heard those baffles before and they hurt the sound. If you search on here, you will see that back in the day some used them but always said you have to cut the backs or bottoms out.


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## Sounds_Insane (8 mo ago)

reverendgreg71 said:


> Will be changing out to a set of Dayton GF-180-4 mids, once everything is working properly.


Don't believe everything you read on the internet. 
That being said, those Daytons have a Qts that would work in a sealed enclosure, and not well in a free air build, so you should be fine.


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## hella356 (Dec 11, 2016)

Yeah, the key point is that most midbass drivers are meant to be run infinite baffle, the large door volume functioning as something of a very oversized box that doesn't interact much with the backwave, if at all. I wouldn't expect them to sound good in a box. But some drivers (like the 704) work great in smallish sealed boxes. Those are the type to look for when deciding what to put in your enclosures. First thing to do is determine what drivers will physically fit in the boxes, most likely mounting depth will be the key measurement.


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## reverendgreg71 (7 mo ago)

hella356 said:


> Yeah, the key point is that most midbass drivers are meant to be run infinite baffle, the large door volume functioning as something of a very oversized box that doesn't interact much with the backwave,
> 
> 
> Sounds_Insane said:
> ...


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## Jroo (May 24, 2006)

I was also thinking. Back in the day when I first saw these, they didn’t market them for sound improvement. Correct if I am wrong they were for speaker protection in the door from things like water etc.


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## LBaudio (Jan 9, 2009)

My opinion is that midbass enclosures are beneficial if and only when they are executed properly. Too small sealed enclosures usually bring more negatives and bunch of problems than positives.


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