Crown xti 2 noise?

[oLjud]

Hi,
Im looking to buy a new amp with built in dsp/xover and found Crown Xti. The plan is to use the amp for a BMS 4550 CD w/ horn, sensitivity about 110 dB. Will there be a noise floor issue if used in home environment?

The amp has a stated:
s/n 100 dBA
Voltage gain 30.5 dB or 32.9 (depending of model)
max input signal +22 dBu

I'll probably need to lower the sensitivity to match the B&C 15tbx100 (97 dB)...

thanks in advance!

let me know if the thread should be moved!

Best regards
Mikael

 

[conanski]

Yes you will have a 10-15dB level adjustment to make depending upon EQ and that will help a lot, but be sure to also use balanced interconnects to the amp as well.

 

[oLjud]

My preamp only have unbalanced outputs, will a rca-XLR be as good?

Tried minidsp 2x8HD and Anaview amp-modules but never got it noise free.

 

[conanski]

You need something to convert those unbalanced outputs to balanced.

 

[oLjud]

Thanks!

 

[GeorgK]

You need something to convert those unbalanced outputs to balanced.

If you do not need long cable from the processor to the power amp I would leave the connections unbalanced. If there is no danger for hum pickup or ground loops I consider this unnecessary.

 

[oLjud]

The cables will be max 1 m long, probably shorter.

 

[rdf]

The amp has a stated:
s/n 100 dBA

That's at rated power using a forgiving weighting curve. The lowest power model is 250 (or more?) watts per channel into 8 ohms. Best guess is the noise into the room will be at least in the high/mid 30 decibels at one meter, likely more depending contribution of source electronics, tweeter frequency response and how generous A-weighting is towards that 100 dB S/N figure.

 

[GeorgK]

The cables will be max 1 m long, probably shorter.

If so, I would not bother using balanced connections.

 

[conanski]

If he wants the lowest noise floor possible he needs a real balanced interconnect system.

 

[GeorgK]

Where should noise come from with just one meter of cable lenght? This is a line-level signal with low output impedance.
Interference will not occur. And I would not expect a ground loop when wiring is done correctly.

 

[conanski]

Where should noise come from with just one meter of cable lenght? This is a line-level signal with low output impedance.
Interference will not occur. And I would not expect a ground loop when wiring is done correctly.

Induced noise from an external source is not the problem here, it is the noise floor of all the equipment in the signal chain that gets amplified along the way and becomes a very obvious "hiss" when the tweeter in use has something like 110db sensitivity. A balanced interconnect system(cable and preamp) by function of it's design cancels any signal(like noise floor hiss) common on both + and - signal lines.

 

[GeorgK]

Of course, if you have a balanced source, keep it balanced.
But a noise signal that is already present will not be cancelled by a balanced interconnection, that's why I said it's possibly not worth the effort to convert an unbalanced source, if not by really expensive audio transformers... And additional noise will probably not be induced.

The question was, as I understood, about the noise floor the XTi...

Well I never tried this, let alone in a home environment, but I would consider that the Crown is a quite big amplifier capable of delivering at least 500W or so (depending on the model), which really is a lot and probably far more than a 1" compression driver will ever need at home. Maybe too high for hiss-free home use. And it has a built-in DSP. Noise level and overall performance will not be better than the DSP permits. If I would have to make the decision for myself I would look for a supplier that gives me a chance to try it out before buying.

Regarding the Anaview, I would not put a Class D amp into a HF path, but maybe I'm just old-fashioned