What are the advantages of separately powering your tweeters?

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What are the advantages of separately powering your tweeters?

Postby paul666 » Thu Jul 11, 2019 8:57 pm

I’ve been looking at HYPEX NCxxx amplifiers and some of them give you the option to drive the tweeters via an amplifier that is powered from the main amplifiers power supply or at least that’s what I think is going on.

What are the advantages/disadvantages of doing this?

It’s not a ‘free’ option in that if taken it’s not possible to fit the rear channels to what is intended to be a multi-channel amplifier.


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Re: What are the advantages of separately powering your tweeters?

Postby mojo » Fri Jul 12, 2019 12:48 am

It's probably going to help if you provide a link to an example of what you mean.

As far as I'm aware, the NCxxx products are all mono amplifier modules in one configuration or another. I've got a pair of NC500 based monoblocks and they have no facility to separately amplify a tweeter channel.

Are you sure you are not thinking of the Hypex Fusion amps, which come in various multi-amp modules and are designed for use in active speaker systems - where of course a separate channel for the tweeter would be essential?

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Re: What are the advantages of separately powering your tweeters?

Postby paul666 » Fri Jul 12, 2019 2:01 am


It's hard to demonstrate as it's configure the amp how you would like it.

If you go here https://www.kjfaudio.com/product/ma-01-flexible-amplifier/#slot-1 and configure (half-way down the page) slot 1 and 2 with say NC250 you can configure slot 3 or 4 with:

The NC100HF is a single channel 100W (into 4 Ohm) add-on module. It is designed to be used as an additional power amplifier channel for the higher frequency audio band. It is directly powered from the NCxxxMP modules and one can be chosen per NC***MP chosen. You are choosing 2 of these modules for this slot.

To try and describe what I'm looking at.

The amp has 4 slots into which hypex NCxxx amps can go.

So Slots 1-3 = NC250
Slot 4 = NC252

Gives me 5 channels.

But there is also this tweeter option, however it which would cost me a slot so the NC252 (rear channels) would have to go.
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Re: What are the advantages of separately powering your tweeters?

Postby Ianmac » Fri Jul 12, 2019 6:15 am

Walking through the Hypex options these days is not simple.
Their product range has expanded and they seem to have separated their DIY options from their OEM options sold to other manufacturers which is their mainstream business.
The ability to house 3 amps on one board has been avaiable for years with their original class D amps, the Ucd series ( eg Ucd 36MP) and these formed the basis of their PLATE AMPS used primarily to build DIY active speakers. The original plate amps were a combination of their DSP modules (digital signal processing) and Ucd. The DSP section allowed one to digitally divide the input signal into 3 frequency band components to directly drive a Bass Mid and Tweeter directly - making Active speakers. The ability to house the amps on one board and select gain and power gave one the ability to select the best amp for the job ( driving speakers directly requires much less amp power which decreases from bass to mid to tweeter 120 W ,80 W and 40W being typical for large floorstanders.)
This system is still there but the amps are now upgraded to N Core performance standards, and the old Plate amps replaced by the Fusion series. These are available for DIY in a variety of formats , 2way ,3 way and various power options. The ability to add a tweeter module to the 2 way systems exists using the NC100HF. (NB this amp has a lower gain than the others so I am assuming it is used with a Hypex DSP module which is part of the Fusion)

Is the KjF option a plate amp minus the DSP section so designed to allow people to easily Bi or Tri amp or use external analogue equalisers to provide the inputs for active speaker operation.

Mojo and I have both looked fairly closely at the Fusion amps and there is a very long thread on DIY audio on these amps. I gave up until Hypex produce a clear and concise set of instructions as to how one correctly lines up an active speakers set up in a domestic environment.I was also uncomfortable with the operation of the Fusion set up requiring a conversion of analoge inputs (Vinyl) to digital.
I still have a longing to build a set of actives and have been looking at analoge equalisers.
I hope this helps
Keep us posted as to how you progress.
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