hello, I am building a custom speakers into my wall and constrained for width..so I need small woofer with max performance
This is definitely one of the better small woofers out there for the money, but it's a bit difficult to work with due to its aluminum cone. Metal speaker cones tend to have high amounts of cone breakup at high frequencies, which needs to be compensated for in the crossover. This particular speaker has a moderate breakup at 7kHz (a 10dB peak), and a strong breakup at 11kHz (20dB peak).To take care of the breakup, a low crossover frequency, steep crossover slope, and/or notch filters are needed. At the very least, I'd say a 4th-order crossover at 2.5kHz would be needed, or a 2nd-order at 2kHz or less. For even better results, adding notch filters at 7kHz and 11kHz would help to get rid of the breakup. I've attached a link to a pre-made crossover that would work alright for this, but, as is always the case with pre-made crossovers, it won't be optimal for various reasons (it doesn't take into account the actual impedance of the speakers at the crossover point, it doesn't have a Zobel network, there are no notch filters for the breakups, and its crossover frequency and slope are only just acceptable for this speaker, considering the breakups). But, unless you have really good ears then you probably won't notice too many problems with it.Now, since you need to use a low crossover frequency, the selection of tweeters is fairly limited because the tweeter has to handle a relatively large amount of low frequency content. You'll need a tweeter that is physically quite large (1" or larger dome tweeter) with a low Fs. The Dayton DC28FS-8 would be alright for this, but really it's best used with a 2nd-order crossover point of 2.5kHz or higher. The Dayton RS28 would do a bit better, but it's only available in a 4 ohm version, which wouldn't work with the crossover I linked to (because it only works with 8 ohm tweeters), so a series resistor would have to be added to it to bring it up to 8 ohms so that it is compatible with the crossover (which would reduce its sensitivity, but that needs to be done anyways to match the tweeter's sensitivity to the woofer). Other options that would be ok, but still would not be optimal, are the Vifa XT25 and Vifa DX25. Again, they're best suited for about 2.5kHz or higher when doing 2nd-order, but 2kHz 2nd-order wouldn't be too bad. If a 4th-order crossover at 2kHz were used instead (or a 2.5kHz 2nd-order), then all of these tweeters would be very well-suited to this application, but that would require building the crossover yourself.Finally, you will need use resistors to compensate for the sensitivity difference between the tweeter and the woofer. To do this, you will need an L-pad, a series resistor, or both. In the case of the 4-ohm tweeters, you will absolutely need a series resistor of 4 ohms in order to bring the effective resistance up to 8ohms (as mentioned above). Doing so will reduce the tweeter's sensitivity by 6dB, which might be too much attenuation, in which case that tweeter wouldn't be suited for this application. If more than 6dB is needed then an L-pad can be added. For 8 ohm tweeters, all that would be needed is an L-pad. To determine the configuration of the L-pad, and the resistor values needed, search for an L-pad calculator online.
Date published: 2013-03-16