How can I tell how high of a frequency a full range will reach? I want to use larger full ranges that can reach to lower frequencies, but I still want to be able to reach at least around 16-18k hz. So is the only real way to tell how well it can extend is by looking at the fr graph of the driver? I just don't want to sacrifice the high-end for better low-end. I've personally never heard a full-range driver but am planning on building my first DIY speaker with one and just wanted to know how the high-end compares with a dedicated tweeter.
It's amazing how good treble can sound on a full range driver. My 6.5" Fostex 168z (old style with whizzer) replaced an expensive Dynaudio dome tweeter (along with the rest of the speaker). That's not to say the treble from the Fostex is the best. It's a matter of personal preference.
The 8" Pioneer B20 and 12" Eminence 12LTA are larger and less capable of good treble. Fortunately, their treble rolls off nicely allowing for the use of a tweeter. Additionally, since the response is extended with these drivers (due to the use of a whizzer) the tweeter is only required to add treble above approximately 8kHz (or higher, depending on personal preference).
After all these years working with full range drivers I've come to think of tweeters as add ons much like a powered subwoofer. They are easy to integrate, enhance the sound and require little effort - in many cases just a simple capacitor.
The 8" Pioneer B20 and 12" Eminence 12LTA are larger and less capable of good treble. Fortunately, their treble rolls off nicely allowing for the use of a tweeter. Additionally, since the response is extended with these drivers (due to the use of a whizzer) the tweeter is only required to add treble above approximately 8kHz (or higher, depending on personal preference).
After all these years working with full range drivers I've come to think of tweeters as add ons much like a powered subwoofer. They are easy to integrate, enhance the sound and require little effort - in many cases just a simple capacitor.
A lot of dedicated tweeters don't go that high, and there's not much chance for a large FR driver, whizzer or not. It will beam rather badly in the treble, too.
It doesn't take too long before you start thinking about smaller "Full Range" drivers - i.e. 3-4", operating wide band from perhaps just below the low end of telephone band, supported by stereo woofers - call them what you want, they're 2-ways with lower crossovers than normally seen with small domes.
This being the Full Range forum, one should expect to see much support for this approach - for many of us doing this with the likes of smaller Fostex (FF85 / 105 WK), any of several by Mark Audio, TangBand, Fountek, Vifa, etc , the high-end extension is sufficient, and beaming not as much of an issue as it theoretically should be.
This being the Full Range forum, one should expect to see much support for this approach - for many of us doing this with the likes of smaller Fostex (FF85 / 105 WK), any of several by Mark Audio, TangBand, Fountek, Vifa, etc , the high-end extension is sufficient, and beaming not as much of an issue as it theoretically should be.
There are a number of 8" full range drivers that reach that high or better. Look at the factory frequency response graphs.
The second question to ask yourself is what type of enclosure you are willing to build? Many beginners put a horn spec driver with rising response in a BR or OB, and then can't understand why it's biting their ears off. Whatever driver you pick, put it in an appropriate enclosure.
The Seas FA22RCZ and Alpair 12P are a couple options off the top of my head. The alpair might be considered a 6" in an 8" frame, but still it's probably a good choice for a first project. Unfortunately, most of the moderate priced options in the Fostex line that have been discontinued in the last few years (FX200, FF225K, FE207). There's the F200A but it's not cheap.
Very generally IME, smaller drivers tend to sound sweeter, but larger drivers can have more realistic lifelike dynamics and cleaner bass. Pick your poison...
Alpair10.3 or 10P - by not striving for that last drop of sensitivity / dynamics as with the 12P, Mark was able to achieve wider overall bandwidth and extension at both ends- although to my ears, it's most striking in the bottom.
Eventually, your calculus should include rationalizing your expectations and prior experience - which are both more nebulous than printed specs and computer modeling
Eventually, your calculus should include rationalizing your expectations and prior experience - which are both more nebulous than printed specs and computer modeling
Thanks for the advice everyone. Chrisb I will have stereo subs to help the low end, but because they will be on the wall and not with the speakers I want the crossover to be as low as possible, so I'm shooting to get down to around 80-100hz. I'm looking at the Dayton PS220-8 now which supposedly extends to a high enough frequency and moves enough air to easily get down to 80hz or lower. And it has a nice sensitivity which is an added bonus, but not a big deal since I have 200 wpc with my McIntosh lol.
The Dayton PS220 is exactly the type of driver I was referring to when made the comment about putting a rising response driver in a simple BR etc. Note that the response at 4kHz is approximately 14db higher 😱 than it is at 400hz.
If you have no objections to 'impurity' a passive or active correction network can fix this and make it work, though effectively you lose some efficiency. As you say you have plenty of power so it should not be a problem.
Alternatively you could use any of a number of acoustic solutions: backhorn, front horn, hybrid back/front horn, or even a karlsonator or 'XKi'. It really looks to me it should be in a compound front/back horn.
If you have no objections to 'impurity' a passive or active correction network can fix this and make it work, though effectively you lose some efficiency. As you say you have plenty of power so it should not be a problem.
Alternatively you could use any of a number of acoustic solutions: backhorn, front horn, hybrid back/front horn, or even a karlsonator or 'XKi'. It really looks to me it should be in a compound front/back horn.
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A PS220 in a sealed box may be a candidate for the "foam doughnut" mod, in which the driver (or baffle) is covered by open-cell foam with a ~3" hole in the center leaving the hf cone exposed. This reduces the beaming effect as well as combating the rising response. I've done this with my guitar speaker and think it could possibly have a place in single driver hi-fi as well. The trick would be making sure the driver's surround doesn't touch the foam during large excursions.
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