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<blockquote data-quote="Canaan" data-source="post: 7459772" data-attributes="member: 566706">***I only read the title of this post....none of the replies***IMHO...building an enclosure based on the manufacturer&#039;s &quot;spec-box&quot; is boarder-line CRAP.Yes, building a &#039;manu-spec-box&#039; can be a good place to start, but from my time in the 12v world...many mainstream lines recommend a box that will be LOUD in a demo room.&nbsp; Thus, increasing sales due to the loudness around 50-60hz.&nbsp; (If you have ever spent any real time in a reasonably sized demo-room in a shop w/ the average joe, you will see that LOUD SALES!!!!)&nbsp; Hell, if you look at most &quot;good&quot; prebuilt boxes....most are tuned in the 40-45hz range.&nbsp; Thus, with most common subs tend to peak in the 50-60hz range, reinforcing peaks of most sound rooms and making even crap sub systems &#039;sound&#039; louder.Forget the &#039;manu-spec-boxes&#039; in vehicle, unless you have a large SUV and like peaky bass w/ spotty low-end response.&nbsp; (AKA...PROBOX brand crap)Your enclosure is 80% of your sound when it comes to subwoofer design.Design your enclosure around your vehicle&#039;s acoustics and your sub&#039;s parameters.Otherwise, everything is just hit and miss.Edit:Also...ported/vented box tuning (aka HELMHOLTZ RESONANCE) can mean next to nothing in a vehicle environment.&quot;Tuning&quot; is just a number derived from math based on driver&#039;s T/S parameters in a ported/vented enclosure in an perfectly open environment. (AKA...anechoic chamber)Helmholtz Resonance is (simplified as) the point at which a given driver&#039;s impedance is at it greatest in a given environment and enclosure.Even if your enclosure is &#039;tuned&#039; to a given freq, if you simply change the environment of the forward chamber (vehicle cabin) you totally change the resonance of the subwoofer, aswell as the response.For example, if you have ever listened to a simple sealed subwoofer enclosure in a single cab truck you have likely noticed that the bass is FAR louder when windows are rolled down.Just rolling the windows down in this case turns the cabin of the truck into the forward chamber of a 4th-order bandpass (in horribly simplified terms).&nbsp; Thus the Helmholtz resonance of the drivers shifts.&nbsp; And given that...in principle the forward chamber of the 4th order has become larger.&nbsp; And thus the &#039;tuning&#039; has become lower.That is basically why low freq. response is FAR more prominent when your simply roll down the windows of your single cab truck.This is a VERY basic representation of what can happen due to driver and enclosure design in any given vehicle.Their is no PERFECT enclosure.Only an enclosure that fits your personal preference with a given driver.</blockquote>

[QUOTE="Canaan, post: 7459772, member: 566706"] ***I only read the title of this post....none of the replies*** IMHO...building an enclosure based on the manufacturer's "spec-box" is boarder-line CRAP. Yes, building a 'manu-spec-box' can be a good place to start, but from my time in the 12v world...many mainstream lines recommend a box that will be LOUD in a demo room. Thus, increasing sales due to the loudness around 50-60hz. (If you have ever spent any real time in a reasonably sized demo-room in a shop w/ the average joe, you will see that LOUD SALES!!!!) Hell, if you look at most "good" prebuilt boxes....most are tuned in the 40-45hz range. Thus, with most common subs tend to peak in the 50-60hz range, reinforcing peaks of most sound rooms and making even crap sub systems 'sound' louder. Forget the 'manu-spec-boxes' in vehicle, unless you have a large SUV and like peaky bass w/ spotty low-end response. (AKA...PROBOX brand crap) Your enclosure is 80% of your sound when it comes to subwoofer design. Design your enclosure around your vehicle's acoustics and your sub's parameters. Otherwise, everything is just hit and miss. Edit: Also...ported/vented box tuning (aka HELMHOLTZ RESONANCE) can mean next to nothing in a vehicle environment. "Tuning" is just a number derived from math based on driver's T/S parameters in a ported/vented enclosure in an perfectly open environment. (AKA...anechoic chamber) Helmholtz Resonance is (simplified as) the point at which a given driver's impedance is at it greatest in a given environment and enclosure. Even if your enclosure is 'tuned' to a given freq, if you simply change the environment of the forward chamber (vehicle cabin) you totally change the resonance of the subwoofer, aswell as the response. For example, if you have ever listened to a simple sealed subwoofer enclosure in a single cab truck you have likely noticed that the bass is FAR louder when windows are rolled down. Just rolling the windows down in this case turns the cabin of the truck into the forward chamber of a 4th-order bandpass (in horribly simplified terms). Thus the Helmholtz resonance of the drivers shifts. And given that...in principle the forward chamber of the 4th order has become larger. And thus the 'tuning' has become lower. That is basically why low freq. response is FAR more prominent when your simply roll down the windows of your single cab truck. This is a VERY basic representation of what can happen due to driver and enclosure design in any given vehicle. Their is no PERFECT enclosure. Only an enclosure that fits your personal preference with a given driver. [/QUOTE]

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