Klipsch SUB-12 Subwoofer (1 Viewer)

[BraveHeart123]

If pro amps are so cheap in terms of watts per dollar, why are they not prefered over home amps like rotel, nad, emotiva, adcom, etc?? Is there any downside to it that I am missing??
Also, is it 2 ohms stable??
Can I use it with my RF-82 II??

 

[Robert_J]

Those sound better. How much better? It depends on the amp. Plus the pro amps have fans that are loud and rarely have the proper home theater connectors. I use RCA to 1/4" mono phono plugs to connect my Behringer.
I think it is 2 ohm stable. Check the specs.
Probably.

 

[BraveHeart123]

Crown states all its ohm and power ratings at 1 kHz.....what does it mean?? I will be mainly using it for sub at 80 hz and below. Does it mean all those power ratings hold true at 1 khz only??
What does these numbers mean? I've taken from Onkyo TX-NR809 specs. Crown input sensitivity is 1.4 Vrms.

Input Sensitivity and Impedance (Unbalance)
200 mV/47 kΩ (LINE)
2.5 mV/47 kΩ (PHONO MM)
Rated RCA Output Level and Impedance
200 mV/470 Ω (PRE OUT)
Maximum RCA Output Level and Impedance
4.6 V/470 Ω (PRE OUT)

Also, would it be able to run RF-82 II?? coz later I plan to buy Klipsch SW-115, which would be available by June 2012 in Pakistan and I will move my mains on crown.

 

[Robert_J]

It's easier on the power supply to reproduce a 1khz tone rather than a 20hz tone. Behringer does the same with their EP-4000/EP-2500. It's rated at 1,250w @ 2 ohms when reproducing a 1khz tone. At 20hz, it can only push 800w @ 2 ohms. If you are using it as a sub amp, it will do about 2/3 the 1khz rating.
The Onkyo can push 4.6 volts from it's pre-amp outputs. That's more than enough for my Behringer so I'm sure the it will work for the Crown.
Yes, it will easily drive your RF-82's.

 

[BraveHeart123]

The Onkyo can push 4.6 volts from it's pre-amp outputs. That's more than enough for my Behringer so I'm sure the it will work for the Crown.

Onkyo is listing peak voltage, whereas Crown is listing rms voltage............. confused

 

[BraveHeart123]

The Onkyo can push 4.6 volts from it's pre-amp outputs. That's more than enough for my Behringer so I'm sure the it will work for the Crown.

I hooked up Crown XLS1000. The input signal from Onkyo 809 is not strong enough. I had to dial the gain knob to its maximum to get some output from the DIY sub, but it still is very weak. Um using rca inputs. I get only the first LED from the bottom on front panel to light up. That means the signal strength is way too low. I even tried raising the sub level to +5 on avr, still the response is very weak.
Am I doing something wrong here???

 

[Mike Thomass]

i am by far no expert.
i do know that if you have your mains set to large, you wont get anything out of your subs in some cases.
check your settings on your mains and change them to small if they arent already
again, robert is the man, and im just an amateur, but the first thing i figured out was to set the mains to small
i hope this helps!

 

[BraveHeart123]

and im just an amateur

No offence mains are set to small....In fact this is not the problem. It has everything to do with input sensitivity of crown amp. It requires minimum 1.4 Vrms to perform at its best. Onkyo is feeding 0.2 Vrms through its pre, which is way too low for crown.
Robert....um crying out loud....help me.

 

[Mike Thomass]

no offense taken.
i only know a couple simple things, small.large is one of them.
hopefully robert can solve the problem.
he will be around im sure

 

[BraveHeart123]

The Onkyo can push 4.6 volts from it's pre-amp outputs. That's more than enough for my Behringer so I'm sure the it will work for the Crown.

I hooked up Crown XLS1000. The input signal from Onkyo 809 is not strong enough. I had to dial the gain knob to its maximum to get some output from the DIY sub, but it still is very weak. Um using rca inputs. I get only the first LED from the bottom on front panel to light up. That means the signal strength is way too low. I even tried raising the sub level to +5 on avr, still the response is very weak.
4.6 V is the peak value Onkyo is using. Whereas 1.4V is the rms input value Crown is stating. Anyway, the signal is way too weak. I even tried running the amp in bridged mono which gives 1100 watts at 4 ohms, still to no avail.
What wrong am i doin here??

 

[Robert_J]

I get only the first LED from the bottom on front panel to light up. That means the signal strength is way too low.

On my Behringer, when first light starts to flash then it is already too loud for my wife. I've had both the lights on and it was at concert levels.
Have you measured the voltage of the receiver's sub out?

 

[BraveHeart123]

I've gone through an article by Wayne A. Pflughaupt on measuring AVR's ouput voltage. Will check it using the procedure he mentioned and post my findings here.

 

[hachuelo]

Hi everybody I'm new on this forum and I'm reading this interesting (and old) thread and I got a couple of quick questions to Robert: How can I add the BFD to the chain? Do I have to connect it between the receiver LFE output and the LFE input of the sub? If that so what cable should I use? Thanks in advance.