Let's Seperate Myth From Fact....
01-18-2010, 10:31 AM
#161
yeah, you said under 150hz in a door will sound bad, and I have to disagree as well. As far as resonance, i have a stock door with 6.5" crossed at 50hz that has no resonace until I hit about 22/35 on the volume control with typical music...clapton, jackson, police etc...so either you have a very rattle prone door or a very poor install. While we're on it, Tim Bailie's shop, Hz'emall, have done multiple 9" Morel bass drivers in doors with no specific enclosure, but very well installed, and given the cost and level of the install, I'll assume they don't sound bad.
01-18-2010, 10:56 AM
#162
0 Watt CAFz'r
Join Date: Jan 2010
Posts: 32
Yeah, used wrong words. "glass fibres" would be the better way to put it.
"In physics, damping is any effect that tends to reduce the amplitude of oscillations in an oscillatory system, particularly the harmonic oscillator."
So if you absorb then at the rear of the enclosure, doesnt it serve that exact purpose?
If you were to re-read that quoted line again to keep it fresh then consider.... If you want to stop the oscillation inside the enclosure of a speaker, then just don't use the speaker. That is direct way to have instantaneous damping. If you wanted better results, try amps with higher damping factors. If you want even better results, try using an enclosure that doesnt flex at all when air pressure is applied to it.
Enclosures that resonate do lend themselves to "quality" sound.
To above, if you have a capable midbass solution, theres no way to make it sound good if you're using the thin sheet metal with "damping" as an enclosure.
Go try and argue on any home audio forum, "lets make enclosures out of 22 gauge metal and line it with dampening material and forget about bracing it, thats the dampener's job."
Myth: Dampening is the replacement for a proper enclosure.
"In physics, damping is any effect that tends to reduce the amplitude of oscillations in an oscillatory system, particularly the harmonic oscillator."
So if you absorb then at the rear of the enclosure, doesnt it serve that exact purpose?
If you were to re-read that quoted line again to keep it fresh then consider.... If you want to stop the oscillation inside the enclosure of a speaker, then just don't use the speaker. That is direct way to have instantaneous damping. If you wanted better results, try amps with higher damping factors. If you want even better results, try using an enclosure that doesnt flex at all when air pressure is applied to it.
Enclosures that resonate do lend themselves to "quality" sound.
To above, if you have a capable midbass solution, theres no way to make it sound good if you're using the thin sheet metal with "damping" as an enclosure.
Go try and argue on any home audio forum, "lets make enclosures out of 22 gauge metal and line it with dampening material and forget about bracing it, thats the dampener's job."
Myth: Dampening is the replacement for a proper enclosure.
Last edited by matt5112; 01-18-2010 at 04:25 PM.
01-18-2010, 01:03 PM
#163
Yankee
Join Date: Oct 2003
Posts: 3,599
Yeah, used wrong words. "glass fibres" would be the better way to put it.
"In physics, damping is any effect that tends to reduce the amplitude of oscillations in an oscillatory system, particularly the harmonic oscillator."
So if you absorb then at the rear of the enclosure, doesnt it serve that exact purpose?
If you were to re-read that quoted line again to keep it fresh then consider.... If you want to stop the oscillation inside the enclosure of a speaker, then just don't use the speaker. That is direct way to have instantaneous damping. If you wanted better results, try amps with higher damping factors. If you want even better results, try using an enclosure that doesnt flex at all when air pressure is applied to it.
Enclosures that resonate do lend themselves to "quality" sound.
To above, if you have a capable midbass solution, there's no way to make it sound good if you're using the thin sheet metal with "damping" as an enclosure.
Go try and argue on any home audio forum, "lets make enclosures out of 22 gauge metal and line it with dampening material and forget about bracing it, thats the dampener's job."
Myth: Dampening is the replacement for a proper enclosure.
"In physics, damping is any effect that tends to reduce the amplitude of oscillations in an oscillatory system, particularly the harmonic oscillator."
So if you absorb then at the rear of the enclosure, doesnt it serve that exact purpose?
If you were to re-read that quoted line again to keep it fresh then consider.... If you want to stop the oscillation inside the enclosure of a speaker, then just don't use the speaker. That is direct way to have instantaneous damping. If you wanted better results, try amps with higher damping factors. If you want even better results, try using an enclosure that doesnt flex at all when air pressure is applied to it.
Enclosures that resonate do lend themselves to "quality" sound.
To above, if you have a capable midbass solution, there's no way to make it sound good if you're using the thin sheet metal with "damping" as an enclosure.
Go try and argue on any home audio forum, "lets make enclosures out of 22 gauge metal and line it with dampening material and forget about bracing it, thats the dampener's job."
Myth: Dampening is the replacement for a proper enclosure.
So if your point is to say building custom built enclosures should sound better than what a car provides i would also tend to agree though I think that the utter disregard for the reality of car audio or cost control (converting your car into a series of custom enclosures) is a little expensive.
now onto the acoustics, the oscillatory system is the cars sheet metal. From the speakers point of view NO absorbtion has occurred (simply a minimized resonance of the enclosure) so the dynamat has not done anything to improve the sound, it has only done something to prevent harm to the sound. A proper enclosure (car or home) needs to address rigidity, damping, absorption, diffraction, reflection, proper volume and venting. So investigate and use all the tools available to minimize distortion to the front and back wave of the driver.
Enclosures that affect the sound or are tuned enclosures are fairly common (Sonus Faber, Harbeth, the BBC designs) but they tend to colour the sound. A rigid properly damped enclosure tends to produce a more neutral result (Wilson). I seem to recall at least 2 manufactures using metal for their home audio enclosures (Krell and YG) BTW.
01-18-2010, 01:34 PM
#164
0 Watt CAFz'r
Join Date: Jan 2010
Posts: 32
I agree with your myth bust, dynamat is not a fix all it is a tool in the tool bag.
So if your point is to say building custom built enclosures should sound better than what a car provides i would also tend to agree though I think that the utter disregard for the reality of car audio or cost control (converting your car into a series of custom enclosures) is a little expensive.
now onto the acoustics, the oscillatory system is the cars sheet metal. From the speakers point of view NO absorbtion has occurred (simply a minimized resonance of the enclosure) so the dynamat has not done anything to improve the sound, it has only done something to prevent harm to the sound. A proper enclosure (car or home) needs to address rigidity, damping, absorption, diffraction, reflection, proper volume and venting. So investigate and use all the tools available to minimize distortion to the front and back wave of the driver.
Enclosures that affect the sound or are tuned enclosures are fairly common (Sonus Faber, Harbeth, the BBC designs) but they tend to colour the sound. A rigid properly damped enclosure tends to produce a more neutral result (Wilson). I seem to recall at least 2 manufactures using metal for their home audio enclosures (Krell and YG) BTW.
So if your point is to say building custom built enclosures should sound better than what a car provides i would also tend to agree though I think that the utter disregard for the reality of car audio or cost control (converting your car into a series of custom enclosures) is a little expensive.
now onto the acoustics, the oscillatory system is the cars sheet metal. From the speakers point of view NO absorbtion has occurred (simply a minimized resonance of the enclosure) so the dynamat has not done anything to improve the sound, it has only done something to prevent harm to the sound. A proper enclosure (car or home) needs to address rigidity, damping, absorption, diffraction, reflection, proper volume and venting. So investigate and use all the tools available to minimize distortion to the front and back wave of the driver.
Enclosures that affect the sound or are tuned enclosures are fairly common (Sonus Faber, Harbeth, the BBC designs) but they tend to colour the sound. A rigid properly damped enclosure tends to produce a more neutral result (Wilson). I seem to recall at least 2 manufactures using metal for their home audio enclosures (Krell and YG) BTW.
Consider the cost to dynamat two doors versus the cost of a simple MDF enclosure and some fiberglass and paint for your door skin. They're not far from each other unless you're paying someone else to install the second option.
Only the midrange needs to address internal reflections seeing as the other drivers shouldn't be playing in a range where that is a concern. Even thats easy to solve by having no surface parallel to the cone and some glass fibre fill on the back wall.
Last edited by matt5112; 01-18-2010 at 04:25 PM.
01-18-2010, 02:54 PM
#165
Administrator
Join Date: Feb 2006
Posts: 16,855
Real IB = 4 x Vas and a perfect seal.
Its difficult to get either in a car and as such, no one has a real IB and thus has phase issues and defeats the purpose of the IB in the first place.
Using the door as an IB? thats impossible. Unless of course you're mounting say a 2" widerange driver in your door. See above ratio of 4 x Vas. And thats just the minimum of whats considered "worth it" a TRUE IB is 10 x Vas of all the drivers using the enclosure.
What kind of driver are you using?? Or... just how small do you think a door cavity is?Personally, for midbass, I will take a well damped IB door install than a typically undersized enclosure any day.
01-18-2010, 04:31 PM
#167
0 Watt CAFz'r
Join Date: Jan 2010
Posts: 32
