Hello everyone,
I want to add an ambient rear-firing dome tweeter to a pair of 3-way speakers to observe the effects.
The system is powered by a Hypex FA253. I will use the 100W inbuilt tweeter amplifier to power both the front-firing LT3.2 Planar ribbon plus the new rear-firing ND16FA6 dome.
I am aware that the filters and slopes (DSP) for the front tweeter will inherently be applied to this ambient tweeter (being connected to the same processing). However, I intend only to use the rear-firing dome from ~8Khz and up (I am after ambience / highest octaves only). I might add a 3.3 µF cap for a 1st order roll-off at 8000hz to the ND16FA6?
What are your thoughts on this? I would appreciate any help on how to wire this up; I want to ensure the load to the amp is stable, the impendence stays happy etc.
Thank you kindly.
Vance
I want to add an ambient rear-firing dome tweeter to a pair of 3-way speakers to observe the effects.
The system is powered by a Hypex FA253. I will use the 100W inbuilt tweeter amplifier to power both the front-firing LT3.2 Planar ribbon plus the new rear-firing ND16FA6 dome.
I am aware that the filters and slopes (DSP) for the front tweeter will inherently be applied to this ambient tweeter (being connected to the same processing). However, I intend only to use the rear-firing dome from ~8Khz and up (I am after ambience / highest octaves only). I might add a 3.3 µF cap for a 1st order roll-off at 8000hz to the ND16FA6?
What are your thoughts on this? I would appreciate any help on how to wire this up; I want to ensure the load to the amp is stable, the impendence stays happy etc.
Thank you kindly.
Vance
I'd use the rear tweeter at least an octave lower. And if your speakers are near the wall, you probably should think about putting the ambient tweeter on top of the speaker, pointing towards the ceiling.
No, use instead a voltage divider because that won't change the xo frequency attenuating the rear (top?) tweeter.
I did the same thing a few years back added rear tweeters to my floor standers. I found the level needed to be be way less than the front tweeters so addition of a series resistor became necessary. I also added a phase switch as a number of commercial designs have the rear tweeters out of phase. In phase it improved imaging, out of phase wider ambiance. Worth doing if speakers are near a wall, out in the room much less effect.
Have a look at Boxsim free speaker modeling software by Visaton. It allows you to position drivers on any side of the cabinet and it compute the response in all directions. For the best response I have found that the tweeters need to be back to back as close a possible and a wide baffle allows using the rear firing tweeter to lower frequencies. If you have a narrow cabinet with some depth to it, the rear tweeter will send some energy around the cabinet and cause some peaks and dips in the forward response. I recall the Hypex is happy with 4 ohm loads.
Here is an example of two back to back 3" BleisMa midrange speakers on a half meter wide baffle modeled in boxsim. The baffle is 9 cm thick, as this was set by the depth of the midrange cup enclosures.
The first pic shows the configuration.
The second pic shows the response black: summed output blue: front driver contribution red: rear driver contribution.
The third pic shows the horizontal dispersion with frequency. The system is omnidirectional up to about 2 kHz.
You should be able to model you system and add the rear firing tweeter.
Here is an example of two back to back 3" BleisMa midrange speakers on a half meter wide baffle modeled in boxsim. The baffle is 9 cm thick, as this was set by the depth of the midrange cup enclosures.
The first pic shows the configuration.
The second pic shows the response black: summed output blue: front driver contribution red: rear driver contribution.
The third pic shows the horizontal dispersion with frequency. The system is omnidirectional up to about 2 kHz.
You should be able to model you system and add the rear firing tweeter.