High sensitivity drivers

[Dr_jitsu]

I was just reading some info over at the "Data bass" site, and it seems to apply to the 18.T. The Cliffs' Notes version is that big woofers don't necessarily require high wattage. That would explain why the dual 18 inch subs sound so good (according to everyone who has actually heard them).

" Bass myth # 8. Big woofers require big amps

Often times larger drivers require less amplification, that’s sort of the idea. The concept that bigger woofers need more power is not always true and plays into a major misconception common in car audio. What you should consider is the efficiency of the subwoofer. Efficiency will literally tell you how much acoustic output you will get given a discrete amount of power. If the driver is bigger, has a larger motor and has a higher sensitivity, there is no mystery about it, you are going to get more SPL with the same amplifier provided the impedance is similar. Sensitivity is most easily achieved by a weight reduction usually from the cone surround and voice coil. Sensitivity is often a tradeoff for xmax.

However there are many larger drivers that don’t have ultra high sensitivity. A good pro audio subwoofer may have 6 to 10dB higher sensitivity over an average high excursion car audio subwoofer making them very capable with quite a bit less power, at least for their frequency range which is usually above 40Hz. Likewise, SPL drivers ironically enough don’t need much power! Let me repeat. True SPL drivers ironically enough don’t need much power! That’s because they are used in the higher frequency range and generally have great sensitivity numbers. They need this in order to get the excursion and ultimately SPL. High sensitivity and lots of power means lots of SPL provided the driver is still reasonably linear and does not break. It’s important you know the TSP’s of the driver you buy, otherwise it could be the wrong driver for you! "

[edgebsl]

Good find!

A good indicator of how driver size or surface area relates to driver efficiency is to go to Parts Express or another website and look at a line of woofers. Often you will find as you go up the line the larger drivers get a little more efficient. For example an 18" Driver may be 2db more efficient than the 15" version of the same woofer. Meaning that the smaller driver would require much more power. If there is a 3db difference in efficiency then it would take double the output power to get to a desired level, assuming both drivers were still within limits.

This may not be always the case depending on how the manufacturer has designed it's lineup, but you'll see that often.

I was just reading some info over at the "Data bass" site, and it seems to apply to the 18.T. The Cliffs' Notes version is that big woofers don't necessarily require high wattage. That would explain why the dual 18 inch subs sound so good (according to everyone who has actually heard them).

" Bass myth # 8. Big woofers require big amps

Often times larger drivers require less amplification, that’s sort of the idea. The concept that bigger woofers need more power is not always true and plays into a major misconception common in car audio. What you should consider is the efficiency of the subwoofer. Efficiency will literally tell you how much acoustic output you will get given a discrete amount of power. If the driver is bigger, has a larger motor and has a higher sensitivity, there is no mystery about it, you are going to get more SPL with the same amplifier provided the impedance is similar. Sensitivity is most easily achieved by a weight reduction usually from the cone surround and voice coil. Sensitivity is often a tradeoff for xmax.

However there are many larger drivers that don’t have ultra high sensitivity. A good pro audio subwoofer may have 6 to 10dB higher sensitivity over an average high excursion car audio subwoofer making them very capable with quite a bit less power, at least for their frequency range which is usually above 40Hz. Likewise, SPL drivers ironically enough don’t need much power! Let me repeat. True SPL drivers ironically enough don’t need much power! That’s because they are used in the higher frequency range and generally have great sensitivity numbers. They need this in order to get the excursion and ultimately SPL. High sensitivity and lots of power means lots of SPL provided the driver is still reasonably linear and does not break. It’s important you know the TSP’s of the driver you buy, otherwise it could be the wrong driver for you! "

[craigsub]

The whole issue of drivers is pretty complex. There are a lot of electrical and mechanical parameters to consider when designing a bass reproducing system, or subwoofer.

The size of the enclosure, the Thiel/Small parameters, the available amp power ... they all become part of the equation.

We work with our OEM's on all issues before making a design decision.

We also spend considerable time listening to the subwoofers before signing off on the design.

Rather than focus on one single parameter, we look for balance. Our drivers are long throw, but others are longer.

But there is no longer throw driver than our that is closer than 6 dB as sensitive as is our driver.

Most drivers that are over 95 dB sensitive, as ours are, have an X-Max below 10 mm and an Fs over 30 Hz.

Those two specs are listed on our site now, in an effort, and with cooperation from our OEM, to dispel this myth that we use an "off the shelf pro audio driver that is high Fs and low X-Max".

There are those who make this claim about our drivers, and these guys are just plain guessing.

Go look at our user reviews - we have been compared to Epik, eD, Acoustic Elegance, Rythmik, Hsu, SVS, Velodyne, Danley ... the list goes on.

We always do well, and over time, we will continue to become better known for delivering really good products at real world prices.

It's quite clear that our biggest detractors have never even HEARD our products.

[myc52002]

From my layman's perspective when I was originally considering the CS 18.2 before it was even released last summer I shared with Craig one of my concerns was my previous experience years (10-15) ago with an 18" driver that I was not impressed with at all and had always just felt one couldn't design a great 18" sub regardless of how great one might perform in a pro setting for it's intended use. That 18" driver was an off the shelf unit ( I think it was even an Emminence driver) and while being promoted to be used for sub duty its specs did not nearly represent what they needed to be in order to perform like an 18.2. Reading the above information just solidifies what my current experience has been with my (3) 18.2 It is a superbly calculated design that just blows your socks off. That is more than enough to dis-spell any rumor of an off the shelf driver in my mind. If you have not heard one of these, then you just can't say otherwise.