please help with amp choice
- Thread starter johnnie2k7
- Live activity
- Replies 8
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- Thread Starter
- #2
no one has any advice???
revrider1
5,000+ posts
Hmmm...
why not get a mono amp?
Are they Dual 4ohm subs?
Are they Dual 4ohm subs?
- Thread Starter
- #4
ive thought about it but since the subs are 4 OHM's and i use a 2 channel amp i can wire each sub in parralel and make it a 2 ohm load for the amp.
- Thread Starter
- #6
yea im thinking of going with the kicker zx850.2, but i wont be able to fit a 4 cube enclosure in my trunk
revrider1
5,000+ posts
Hmmm...
if you must choose between those get the 850.2, but if you want them to get loud 4cf ported
- Thread Starter
- #8
thank you all,im going to buy the kicker zx850.2 amp. im not really interested with ported, i just want clean, tight bass, thanks though
don't think porting means you will lose quality. read from dd website
DD PORT DESIGN INFORMATION
WHY GO PORTED?
Efficiency is the easiest one word reason for choosing ported over a sealed box. Everything is better with a little efficiency sprinkled on it. Ask any motor builder what they would do to a motor if it were theirs and they'd say turbo charge it! What does turbo charging do for an engine? It raises the efficiency. Why not apply this same thing to your audio system. Making the most out of the air space you have for a subwoofer enclosure, is the first step in raising the efficiency of your system. This means that you will utilize this space in the most efficient manner possible.
Designing a ported a.k.a. vented enclosure will not only give you added output, but can give you more low-frequency extension. This means louder and lower! Since the speaker system is the least efficient part of the whole audio chain, would it not make sense to make it as efficient as possible? Of coarse it does.
MORE SOUND, BETTER BASS
(back to top)
This is why venting is basically free output, and free sound quality. Local shops tell you that a small sealed box is the best way to go? Hit up your local hi-end home audio store and find out how many of those $20,000.00 pairs of speakers are sealed designs. You won't find many. Think efficiency as you read up in the DD tutorial section, this will help you clear all of that smoke out of your eyes that most car audio manufacturers have been pumping all along.
HOW DOES A PORT WORK
(back to top)
Think of a box port not as a vent in the terms of a venting path for air to travel into and out of a box, but rather as extra cone area that is propagating acoustic energy from the enclosure to the cabin. The air in a port is fixed; it is trapped within the confines of the port walls. When the cone moves there is a corresponding change to the pressure in the box, that pressure change then causes the trapped air in the port to move either forward or backward. It moves as a solid unit, just like a speaker cone does. When you build a properly vented enclosure, its kind of like a two for one special! Since the port is essentially another woofer!
MORE RADIATING AREA
(back to top)
A passive radiator and a vented port work on the same theory. When a port mass moves back and forth, a pressure wave (sound wave) is sent into the cabin. The larger the port, the larger the radiating area is that creates the pressure. Tuning a port is tuning the mass of the trapped air in the port to the air mass in the box volume.
For all out no holds barred SPL efficiency, rule of thumb is the larger the box, the higher the output. The larger the box, the larger the ports can be for a given frequency tuning range. There is no substitute for cubic inches. Drivers like our 9500 series can achieve high efficiency in moderate sized vented enclosures (3 to 4 cubic feet) but will continue to increase in output with increase in volume and port size. Multiple drivers in such enclosures can yield a frightening amount of output and should be used with caution.
THE RIGHT PORT AREA, THE DD PORT
(back to top)
Most modeling programs that simulate box responses were written for home audio use. They are not suited for high output systems. The port area defaults are inadequate. The port area must be commensurate with cone area. If the port velocity gets too high, the port no longer functions as a port, you end up with a leaky sealed box, double bad.
Lets say we have a 12 inch speaker in a box, roughly 100 sqin of surface area. Many programs and manufacturer sites will suggest a 4" diameter port for a 12" vented box. A 4" diameter port has about 12 sqin of area. This is about an 8-1 ratio of cone area to port area. If the 12 inch cone moves 0.25", the port must move 2.0". It can handle this, but when the cone is moving 1.0", the port must move 8 inches! Now you've got a leaky sealed box.
You need more port area for a clean sounding, high output system. The DD port formula is this: 16 sqin of port area per cubic foot of box volume. The port should be 16 inches long. Remember, the port is tuned to the box volume, not the sub(s).
This formula was derived from 1000s of hours of in-car testing and 1000s of installs. It works. It takes into account the need for increasing port area for increasing cone area. When combined with our DD subwoofer box requirements, you'll end up with the perfect match.
DD PORT DESIGN INFORMATION
WHY GO PORTED?
Efficiency is the easiest one word reason for choosing ported over a sealed box. Everything is better with a little efficiency sprinkled on it. Ask any motor builder what they would do to a motor if it were theirs and they'd say turbo charge it! What does turbo charging do for an engine? It raises the efficiency. Why not apply this same thing to your audio system. Making the most out of the air space you have for a subwoofer enclosure, is the first step in raising the efficiency of your system. This means that you will utilize this space in the most efficient manner possible.
Designing a ported a.k.a. vented enclosure will not only give you added output, but can give you more low-frequency extension. This means louder and lower! Since the speaker system is the least efficient part of the whole audio chain, would it not make sense to make it as efficient as possible? Of coarse it does.
MORE SOUND, BETTER BASS
(back to top)
This is why venting is basically free output, and free sound quality. Local shops tell you that a small sealed box is the best way to go? Hit up your local hi-end home audio store and find out how many of those $20,000.00 pairs of speakers are sealed designs. You won't find many. Think efficiency as you read up in the DD tutorial section, this will help you clear all of that smoke out of your eyes that most car audio manufacturers have been pumping all along.
HOW DOES A PORT WORK
(back to top)
Think of a box port not as a vent in the terms of a venting path for air to travel into and out of a box, but rather as extra cone area that is propagating acoustic energy from the enclosure to the cabin. The air in a port is fixed; it is trapped within the confines of the port walls. When the cone moves there is a corresponding change to the pressure in the box, that pressure change then causes the trapped air in the port to move either forward or backward. It moves as a solid unit, just like a speaker cone does. When you build a properly vented enclosure, its kind of like a two for one special! Since the port is essentially another woofer!
MORE RADIATING AREA
(back to top)
A passive radiator and a vented port work on the same theory. When a port mass moves back and forth, a pressure wave (sound wave) is sent into the cabin. The larger the port, the larger the radiating area is that creates the pressure. Tuning a port is tuning the mass of the trapped air in the port to the air mass in the box volume.
For all out no holds barred SPL efficiency, rule of thumb is the larger the box, the higher the output. The larger the box, the larger the ports can be for a given frequency tuning range. There is no substitute for cubic inches. Drivers like our 9500 series can achieve high efficiency in moderate sized vented enclosures (3 to 4 cubic feet) but will continue to increase in output with increase in volume and port size. Multiple drivers in such enclosures can yield a frightening amount of output and should be used with caution.
THE RIGHT PORT AREA, THE DD PORT
(back to top)
Most modeling programs that simulate box responses were written for home audio use. They are not suited for high output systems. The port area defaults are inadequate. The port area must be commensurate with cone area. If the port velocity gets too high, the port no longer functions as a port, you end up with a leaky sealed box, double bad.
Lets say we have a 12 inch speaker in a box, roughly 100 sqin of surface area. Many programs and manufacturer sites will suggest a 4" diameter port for a 12" vented box. A 4" diameter port has about 12 sqin of area. This is about an 8-1 ratio of cone area to port area. If the 12 inch cone moves 0.25", the port must move 2.0". It can handle this, but when the cone is moving 1.0", the port must move 8 inches! Now you've got a leaky sealed box.
You need more port area for a clean sounding, high output system. The DD port formula is this: 16 sqin of port area per cubic foot of box volume. The port should be 16 inches long. Remember, the port is tuned to the box volume, not the sub(s).
This formula was derived from 1000s of hours of in-car testing and 1000s of installs. It works. It takes into account the need for increasing port area for increasing cone area. When combined with our DD subwoofer box requirements, you'll end up with the perfect match.
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