QuestionHi there, hope someone can help with this dilemma…?
I am on the brink of upgrading my inadequate factory system with the following equipment:-
Tweeters - Infinity Kappa 10.9T - 50w RMS - 2ohm
Mid-Range - Audison Voce AV3.0 - 50w RMS - 4ohm
Bass - Audison Voce AV6.5 - 100w RMS - 4ohm
with a single DVC Type’R’ sub in a sealed enclosure.
My dilemma is: –
1.) I wanted to simplify the amplification with a 4 channel amp (4x100wRMS) with 2 channels going to the bass and the other 2 channels divided between the tweets and mids (50w + 50w = 100w), but the tweets are 2ohm and the mids are 4ohm AND also how could the gain be set separately for the tweets and the mids, if both are driven by the same channel – I can not see a way around it, which ever way a 4 channel amp could be deployed creates an incompatibility issue of either the wattage difference or the impedance ..???
Is the only option to have 3 separate - 2channel amps – each dedicated to its own pair of speakers, or is there a workable option with a multi-channel amp.?
2.) If separate amps are used – are certain amps better for tweeters and certain amps for bass – or does it not matter which amp drives which specific speaker frequency range ?
Lastly:-
3.) The Audison Voce mid-range drivers and mid-bass drivers do not come with cross-overs – would the built-in cross-overs in the amplifier be sufficient, or how much difference would there be if separate out-board cross-overs were used?
(I want the Infinity 10.9T tweeters because of their frequency range 3,500-35,000Hz (harmonics and overtones, etc) – and this is why I am not choosing the ‘audison component set’…)
Can’t wait to hear your replies and overall general concensus – and I hope this is of interest to others also.
Best regards,
Simon
AnswerHi Simon,
For your first issue, I am unaware of any devices that would let you set the gain differently between the two sets of speakers. The fact that they're a DIFFERENT impedance doesn't matter; what does matter is what the overall impedance presented to the amplifier would be. If you hook them up in series, you'll be providing the amp with 6ohms. The amp will no doubt be able to handle it, but its output level will be drastically decreased by it. If you hook them up in parallel, then you'll be presenting the amp with 2.4hohms. As long as you have an amp that can do 2 ohm stable, that might be just fine. But you're still left with the gain issue. Wattage differences mean nothing -- there's a chance you'd be able to find a gain level that works for both sets of speakers, but it's also possible you may not and your only real option is another amplifier.
For your second issue, there aren't really amps that're better per se, but keep in mind, you don't need nearly as much power to cleanly power smaller speakers -- moving small cones is not a lot of work, so you could maybe get a 4 channel amp for the midrange and bass speakers, and then a much smaller 2 channel to run the tweets separately.
For your third issue, generally, a decent high-pass filter in the amp might help, but with the frequency range STARTING at 3500Hz, you might find no amplifier will reasonably attenuate that high.
Another option for the mid speakers is just wiring in a capacitor into the circuit to attenuate the lower frequencies you don't want going to the mids. At 4ohms, a ~33microfarad capacitor should attenuate everything below ~3200Hz (It's not a straight dropoff, though; it would be a linear line heading downward that would reach complete attenuation around 400Hz.)
