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<blockquote data-quote="Immacomputer" data-source="post: 3083557" data-attributes="member: 570419">The transfer function is only a scaler when all other things remain constant. You&#039;re going to be off when the enclosures take up different amounts of space in the vehicle. The transfer function of the vehicle is also dependent one the mass of air in the environment and not just the interior dimensions of the vehicle. Also, where you place the port, sub, and enclosure will all have a large effect on the actual FR. Another big factor in the transfer function is the natural resonance of the chassis and body of the car. This will also change when the different subs and enclosures are weighing down the car differently.Theoretical graphs are useful but are to be taken with a grain of salt. They&#039;re also small signal parameters that will shift greatly when high power is applied. Just because there is a power input section does not mean it&#039;s adjusting for those parameter shifts due to losses in the EMF, suspension, or the coil heating up.One of the most useful of the graphs is group delay and I didn&#039;t see you taking that into consideration at all.I do believe in modeling subs before randomly designing an enclosure for them but you really need to be careful. At low volumes my IDQ in my room sounds exactly how it models up. When I crank the volume though, the low end begins to fade and the upper frequencies get boosted. My av12 in my car is the exact opposite. At high volumes, higher bass frequencies get a cut while the low end gets exaggerated. This is something that modeling programs cannot tell you.</blockquote>

[QUOTE="Immacomputer, post: 3083557, member: 570419"] The transfer function is only a scaler when all other things remain constant. You're going to be off when the enclosures take up different amounts of space in the vehicle. The transfer function of the vehicle is also dependent one the mass of air in the environment and not just the interior dimensions of the vehicle. Also, where you place the port, sub, and enclosure will all have a large effect on the actual FR. Another big factor in the transfer function is the natural resonance of the chassis and body of the car. This will also change when the different subs and enclosures are weighing down the car differently. Theoretical graphs are useful but are to be taken with a grain of salt. They're also small signal parameters that will shift greatly when high power is applied. Just because there is a power input section does not mean it's adjusting for those parameter shifts due to losses in the EMF, suspension, or the coil heating up. One of the most useful of the graphs is group delay and I didn't see you taking that into consideration at all. I do believe in modeling subs before randomly designing an enclosure for them but you really need to be careful. At low volumes my IDQ in my room sounds exactly how it models up. When I crank the volume though, the low end begins to fade and the upper frequencies get boosted. My av12 in my car is the exact opposite. At high volumes, higher bass frequencies get a cut while the low end gets exaggerated. This is something that modeling programs cannot tell you. [/QUOTE]

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