iNuke600DSP V Focux D6 for SP418

[Ringnut]

Does anyone have any views surrounding the advantages or otherwise of using a Focux D6 over the iNuke6000DSP when driving an SP418 in a relatively small enclosure - say 90-100 litres? I am trying to weigh up the advantages of going to the Focux over the disadvantage of not having a built-in DSP. My listening is mainly movies FWIW.

Thanks.

 

[mattkhan]

As far as I can see there are no comparable published specs available so any comparison will be based on guesswork, depending on who is doing the guesswork will determine whether it's an educated guess or not

I'll give you my take anyway and we'll see where that goes.

The 6000 is a pair of 3000 amp modules where that number is based on some unpublished burst/peak rating. They also give RMS ratings as 2.2kW into 4ohm. This benchmark shows it ~2kW per channel both driven at 4ohms on a 33% duty cycle at 1kHz & 1.8kW under the same conditions at 31Hz.

2 things I noted from that benchmark

* it is pulling a peak current of 80A in that 33% 4ohm 31Hz test, I don't see how this is applicable to a home setting so surely the sustainable peak power will be less at 1.8kW at home?
* the 33% duty cycle is used as "safe for pro use" whereas 12.5% would be "normal" for home use

In contrast, Focux publish a number based on a much shorter, higher frequency burst. Best guess, given that behringer don't publish where that 3000 number comes from, is that this number is equivalent to the 3000 number assigned to the inuke. On this basis, the focux (bridged 4ohm) gives 20% more power than an inuke 6000. If this is sustained down to the more onerous conditions the inuke has been benched at then you would get 2.1kW out of it on power draw alone.

Having said all that, the power you actually need is a function of the SPL you want to produce and the low end boost you need to apply to get there. I have neither the kit nor the experience to safely load test an amp/driver so I can only go by a WinISD model. Note I am a WinISD noob so this could be a Q of a little knowledge being dangerous.

My LT looks like this, i.e. it reaches +7dB at 10Hz.

+7dB is about 5x the power so lets conservatively assume the real power in the Focux is less than 1/2 the rated spec at 1.5kW and then divide that by 1/5 to account for the LT. This gets us down to 300W in WinISD, this gives me the following excursion chart. If I push this up toward 500W (equates to saying the focux can do 2.5kW) then I breach xmax.

 

[Ringnut]

Hi Mattkahn,

Thank you for the time taken to do that, really appreciated. The link highlights the need for some serious thought to the power supply so I'll probably spur off my cooker supply just to be sure.

In the case of a twin four ohm coil such as that used in a USC18 do you think there is much of an advantage in going for the 20% increase offered by the Focux considering you are losing DSP? On the other hand I note that the Focux THD is rated at 0.02 whereas the INuke comes out at a rather high 0.2. I believe you tried both, if so, what did you feel were the subjective differences may I ask?

 

[mattkhan]

I was thinking of adding a 20A feed for my power amps as well, surely can't hurt anyway

I only compared them on the Q15 & I couldn't tell the difference. Early listening tests of the D6 + SP4 combo are satisfying though I haven't really cranked it up yet (apart from a few goes at kung fu panda skadoosh to check my handling of the LFE channel was correct, I ran that at somewhere near reference and it handled it nicely as far as I could tell).

You can get a minidsp for DSP duties btw, ~£120 or so IIRC.

re the need for power... what sort of listening levels are you aiming at? do you know how much room gain you get and/or how much boost you need to apply? I think this is what drives the power requirement really.

The other thing I'd say is that, again on paper, the USC18 looks like it really needs EQ to tighten it up. The best way to do this is via a linkwitz transform (as it is a precise fit) which you can only approximate using the inuke (via peq + shelf filter). For that reason, if budget is not a concern, I would go with the minidsp approach myself so it's then a Q of just comparing the amps.

On the other hand I note that the Focux THD is rated at 0.02 whereas the INuke comes out at a rather high 0.2.

where did you see those THD ratings?

 

[scottthehat]

How about getting a dual 2 ohm driver and getting a cerwin vega cv5000 if you don't need DSP. Cheaper and more power.

 

[mattkhan]

How about getting a dual 2 ohm driver and getting a cerwin vega cv5000 if you don't need DSP. Cheaper and more power.

FWIW I haven't been able to find any statement of what spec CV are using to come up with the 5kW rating. Do you have that info?

I don't think it's cheaper btw either.

 

[scottthehat]

FWIW I haven't been able to find any statement of what spec CV are using to come up with the 5kW rating. Do you have that info?

I don't think it's cheaper btw either.

Sorry Matt I don't. How much is the focus the certain new is 700. My cv2800 runs my ass far better than my nu3000 did, that could only run one.

 

[Ringnut]

I was thinking of adding a 20A feed for my power amps as well, surely can't hurt anyway

where did you see those THD ratings?

The iNuke user guide

http://www.behringer.com/assets/NU6000DSP_NU3000DSP_NU1000DSP_M_EN.pdf

verses the Focux user guide

 

[mattkhan]

The iNuke user guide

http://www.behringer.com/assets/NU6000DSP_NU3000DSP_NU1000DSP_M_EN.pdf

verses the Focux user guide

I thought the focux one said 1%?

 

[Ringnut]

I thought the focux one said 1%?

Sorry, I was reading the 'typical' as opposed to 'full power' measurement. Yes, 1%. but still half as much as the 6000 though

 

[MemX]

The link highlights the need for some serious thought to the power supply so I'll probably spur off my cooker supply just to be sure.

Ooh, nice idea

What are the cooker supplies rated at?

I understand a ring main is usually 32amp.

 

[Jameskatie]

I think its only non UK people who have to worry about power supply