Active amplification for DIY two-way question.

[WonkyDonkey]

I'm planning a build of a large, high efficiency active two-way speaker. I had assumed I'd buy a couple of Hypex FA122 (or FA123 - future-proof option!) and the remote kit, as even 50W @ 8 Ohm is enough for stratospheric listening levels. I only need two digital inputs and one analogue balanced input, so job done and many boxes done away with.

However, my pair of Topping PA5s are ample for the task in both number of channels and power. I had recently considered swapping out my NAD C658 for a MiniDSP SHD and it now registers on the radar again. The SHD can implement the necessary crossovers, response EQ and then globally Dirac Live the whole in-room result. It also fulfils the role of streamer.

Does this mean it simply boils down to a case of which is the better (easier?) platform for the crossover design? I had a pair of MiniDSP PWR-ICE125 in the past and the interface of that was certainly easy enough, but interested in insight from anybody who has used either/both or just spotted something obvious I'm missing.

Thanks in advance.

Russ

 

[abdo123]

You can’t go wrong with either option, but honestly unless you’re dealing with horns i would just try to do a passive crossover and edit externally with EQ as required.

 

[sergeauckland]

Whilst I agree with adbo above that either will be fine, I can't agree that a passive crossover is better or easier, even with EQ. If you're going to use DSP for EQ, and why would you do it an other way, then you might as well use the DSP for an active crossover, and get far more accurate and repeatable results. Apart from the power loss in a passive crossover, which I agree is trivial, the advantages of a DSP-based active crossover are:-
1) Much higher slopes at the crossover, 48dB/octave is easy to achieve. This improves distortion, both harmonic and intermod.
2) Choice of different types of crossover, L-R, Chebychev, Butterworth, etc.
3) Instant choice of crossover frequencies, and you can slide the crossover point about for best effect.
4) Time alignment if you're concerned about this.
5) LF rolloff if you're going to use one or more subwoofers.
6) EQ without using a separate unit.

I wouldn't hesitate to go active, the advantages are just too many, especially if you already have four channels of amplification.

S.

 

[WonkyDonkey]

Whilst I agree with adbo above that either will be fine, I can't agree that a passive crossover is better or easier, even with EQ. If you're going to use DSP for EQ, and why would you do it an other way, then you might as well use the DSP for an active crossover, and get far more accurate and repeatable results. Apart from the power loss in a passive crossover, which I agree is trivial, the advantages of a DSP-based active crossover are:-
1) Much higher slopes at the crossover, 48dB/octave is easy to achieve. This improves distortion, both harmonic and intermod.
2) Choice of different types of crossover, L-R, Chebychev, Butterworth, etc.
3) Instant choice of crossover frequencies, and you can slide the crossover point about for best effect.
4) Time alignment if you're concerned about this.
5) LF rolloff if you're going to use one or more subwoofers.
6) EQ without using a separate unit.

I wouldn't hesitate to go active, the advantages are just too many, especially if you already have four channels of amplification.

S.

Exactly that. All of it. Anybody why has implemented bass management in a 2.1 (or more) system with room EQ can already hear the manifest benefits of active crossovers and amplification.

I have built passive speakers in the past and modified a few DIY and commercial crossovers with varying success it should be said! On the other hand, all of the DSP/Active stuff I messed with has always ended up exceeding expectations, occasionally glitchy firmware or non-family friendly operation notwithstanding.

Russ

 

[WonkyDonkey]

You can’t go wrong with either option, but honestly unless you’re dealing with horns i would just try to do a passive crossover and edit externally with EQ as required.

I am very much dealing with horns in this case. 18 Sound 15W750 in a 175L/6 cu ft ported box crossing at circa 800hz to a 18 Sound XT1464 horn - tweeter to be decided.

To be fair, even in an active 6.5" two way with waveguide I did with the PWR-ICE125s, I was staggered how easy it was to hear tiny adjustments in delay increments.

Russ