2012 Civic Si Premium Audio Speakers versus Aftermarket Speakers
- Thread starter squiggy
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I'm sure the polks weigh a lot more with the magnet differences.
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You mean there is actually a magnet on the stock speaker?
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- #4
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I'd be surprised if they didn't? There are only a few examples of speakers I've ever seen which didn't use magnets. There are speakers called electrostatic speakers that don't use magnets... but they're like this -
http://www.martinlogan.com/learn/faq-electrostatic.php
http://www.martinlogan.com/learn/faq-electrostatic.php
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- #5
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lol nothing to see here... move along 
hey_mikey
Well-Known Member
i put the polk db6501 components in and i like em. took a few days to break in, but once they did, they sounded pretty good.
CivicCanuck
Well-Known Member
The stock speakers have a neodymium magnet, that's why it can be so small yet have high flux in the gap, it also uses a solid pole piece for higher BL than a vented pole, venting is done under the spider plateau. The Polk replacement uses a ferrite or 'mud' magnet, so it needs to be quite large in comparison.
A 4 inch x 3 inch solid neodymium magnet has enough force to lift one end of your civic off of the ground. 1200 pounds of pull:
http://www.ebay.ca/itm/Neodymium-Ma...942?pt=LH_DefaultDomain_0&hash=item53e735a83e
A 4 inch x 3 inch solid neodymium magnet has enough force to lift one end of your civic off of the ground. 1200 pounds of pull:
http://www.ebay.ca/itm/Neodymium-Ma...942?pt=LH_DefaultDomain_0&hash=item53e735a83e
CivicCanuck
Well-Known Member
Here's a small ( 3/8" x 1/2" ) neo cylinder magnet, pull force of 16.5 pounds, something like this could very well be used inside the steel return structure.
http://www.ebay.ca/itm/10-VERY-STRO...582?pt=LH_DefaultDomain_0&hash=item1c3194f796
http://www.ebay.ca/itm/10-VERY-STRO...582?pt=LH_DefaultDomain_0&hash=item1c3194f796
Mtaddi
Well-Known Member
Mtaddi
Well-Known Member
Did you just replace the speakers, or did you do any other amp/ head unit work?
Mtaddi
Well-Known Member
Does this mean someone should focus on speakers with neodymium magnets for better sound?
- Thread starter
- #14
I am working on replacing the rear speakers and head unit. I was trying to find a suitable free air sub that would fit...but that does not seem to be possible.
CivicCanuck
Well-Known Member
Not necessarily, there are many factors at play in making something sound good. For a given cone area, you can't make something louder unless you decrease it's bandwidth and/or increase it's linear excursion ( distance the cone travels in a linear fashion ) which also requires an increase in power, as a result of heavier parts ( longer voice coil, coil former ) means a decrease in sensitivity.
Many factors affect good sound, Klippel has designed a system that uses a laser to measure cone displacement, and compares that to the impedance curve, as well as varying power levels. The system is PC based, and can generate curves of suspension non-linearities, motor non-linearities including force variations vs. amperage through the coil, force variations vs. displacement, distortion products ( harmonics ) etc.
http://www.klippel.de/our-products/rd-system.html
The best speaker motor designs use shorting rings placed with precision to keep the inductance low, ( affects bandwidth and frequency response of coil in vs coil out) and also keep the magnetic center position in the gap from shifting under higher power levels. They also focus on heat management techniques, removing as much heat quickly out of the motor as possible.
The force acting on the cone is generated from the magnetic system and the wire forming the coil that pushes on the cone, the product is known as BL. The magnetic assembly ( magnet and steel top plate, bottom plate and pole - or cup as in a neo ring magnet structure ) is the "B" and the length of wire is the "L".
You want as tight a gap from the coil to the pole piece and top plate as practical, this increases force ( magnetic force falls off rapidly as distance is increased ) as well as it aids in thermal transfer of the heat generated in the coil to the pole and top plate. This also has a problem in that the suspension must be centered very accurately, otherwise the coil could rub.
Aluminum vs copper coils: Aluminum is lighter, so you can pack more wire length in the gap ( increasing L ) without a penalty in weight. With an edgewound ribbon coil ( either aluminum or copper ) you can pack the conductors tighter than a comparable round wire coil, again increasing "L" and can run a tighter gap. Some very expensive compression drivers use a copper clad aluminum edgewound coil, this increases the conductivity and making connections are easier than with aluminum, but increases the cost over aluminum. From a manufacturing standpoint the most expensive is CCAW, then aluminum, and the cheapest is copper. Edgewound ribbon wire is more expensive than round wound.
Cone material selection: cones should ideally be infinitely stiff, lightweight, waterproof, ( for some applications this is very important ) easy to adhere to, and well damped. ( non-resonant ) Currently the best cone material out there for most applications that meets all of those demands is a composite Rohacell foam with carbon fiber, fiberglass, or kevlar skins.
Voice coil diameter choice: the coil should be sized for the long term power handling, the larger the coil the more heat it can shed ( larger surface area ) but this also has to be balanced with the weight of the coil and the former it's wound on to maximize the bandwidth. Larger coils require more magnet volume than smaller coils to generate the same B in the gap.
All of these design choices are aided by FEMM magnetic modelling software, FEA analysis of the cone, surround etc.
Some of the companies that use Klippel meaurement:
http://www.klippel.de/company/customers.html
Many factors affect good sound, Klippel has designed a system that uses a laser to measure cone displacement, and compares that to the impedance curve, as well as varying power levels. The system is PC based, and can generate curves of suspension non-linearities, motor non-linearities including force variations vs. amperage through the coil, force variations vs. displacement, distortion products ( harmonics ) etc.
http://www.klippel.de/our-products/rd-system.html
The best speaker motor designs use shorting rings placed with precision to keep the inductance low, ( affects bandwidth and frequency response of coil in vs coil out) and also keep the magnetic center position in the gap from shifting under higher power levels. They also focus on heat management techniques, removing as much heat quickly out of the motor as possible.
The force acting on the cone is generated from the magnetic system and the wire forming the coil that pushes on the cone, the product is known as BL. The magnetic assembly ( magnet and steel top plate, bottom plate and pole - or cup as in a neo ring magnet structure ) is the "B" and the length of wire is the "L".
You want as tight a gap from the coil to the pole piece and top plate as practical, this increases force ( magnetic force falls off rapidly as distance is increased ) as well as it aids in thermal transfer of the heat generated in the coil to the pole and top plate. This also has a problem in that the suspension must be centered very accurately, otherwise the coil could rub.
Aluminum vs copper coils: Aluminum is lighter, so you can pack more wire length in the gap ( increasing L ) without a penalty in weight. With an edgewound ribbon coil ( either aluminum or copper ) you can pack the conductors tighter than a comparable round wire coil, again increasing "L" and can run a tighter gap. Some very expensive compression drivers use a copper clad aluminum edgewound coil, this increases the conductivity and making connections are easier than with aluminum, but increases the cost over aluminum. From a manufacturing standpoint the most expensive is CCAW, then aluminum, and the cheapest is copper. Edgewound ribbon wire is more expensive than round wound.
Cone material selection: cones should ideally be infinitely stiff, lightweight, waterproof, ( for some applications this is very important ) easy to adhere to, and well damped. ( non-resonant ) Currently the best cone material out there for most applications that meets all of those demands is a composite Rohacell foam with carbon fiber, fiberglass, or kevlar skins.
Voice coil diameter choice: the coil should be sized for the long term power handling, the larger the coil the more heat it can shed ( larger surface area ) but this also has to be balanced with the weight of the coil and the former it's wound on to maximize the bandwidth. Larger coils require more magnet volume than smaller coils to generate the same B in the gap.
All of these design choices are aided by FEMM magnetic modelling software, FEA analysis of the cone, surround etc.
Some of the companies that use Klippel meaurement:
http://www.klippel.de/company/customers.html
CivicCanuck
Well-Known Member
I would concentrate on supplementing the low end, and leave the stock rear speakers in the deck.
- Thread starter
- #17
I am still debating on the sub solution. I don't really like giant boxes and tend to value my trunk space. Plus, I don't need it to be super loud. Just well balance.
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- #20