General Forum

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

Puncher — Thu, 31 Jan 2008 18:57:44 GMT

Magnet size depends entirely upon the magnet material - ferrites or rare earth (NdFeB). Also the ABR's may not work quite how you think - they do not necessarily follow the movement of the main driver, they are more akin to a tuned port in that they can extend the lower bass frequency responce by as much as an octave below the cutoff frequency of the actual driver (you shouldn't think of them as making the effective area of the main driver "bigger").

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

Alex — Thu, 31 Jan 2008 15:06:15 GMT

Haven't seen the transformer from a BL2, but the driver is definitely very impressive. The magnet other bits on the driver are much bigger than I thought they would be for a 9" unit.

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

Peter — Thu, 31 Jan 2008 14:45:54 GMT

Having taken one apart, the bit that impresses me is the transformer, which weighs a ton! That and the drive unit are serious bits of kit!

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

Alex — Thu, 31 Jan 2008 13:31:36 GMT

I actually think that's more to do with the ABRs, and not the driver on the front. The driver at the front actually seems very good, although the chassis seems a little spindly in comparison to other big subwoofer drivers. It's got a double spider though, which helps it act more like a 'perfect piston'.

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

Puncher — Wed, 30 Jan 2008 15:15:24 GMT

Alex:

Bear in mind though that the BeoLab 2 is servo controlled, meaning the amplifier compensates for any 'wrong' movements by the speaker cone which takes up quite a lot of power.

....... although if frequent reports of the BL2 being "slow" are true, then not as well as it could!

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

jooka — Wed, 30 Jan 2008 15:12:20 GMT

thanks alex.

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

Alex — Wed, 30 Jan 2008 15:01:06 GMT

I've also seen the same subwoofer quoted at 120 watts.

Most people think of watts as being a measure of 'how loud it'll go', which is *generally* wrong. What you want to look for there is the Max. SPL output. The BeoLab 2 is quoted at 109 dB (if memory serves) at 1m, and the Genelec is 108 dB, so the difference in total volume output is minimal.

Bear in mind though that the BeoLab 2 is servo controlled, meaning the amplifier compensates for any 'wrong' movements by the speaker cone which takes up quite a lot of power.

RE the actual wattage output, the 850 watts is not an 'overquote' (like when you see computer speakers rated in the thousands of watts), it really is around that figure. The ICEPower amplifiers are capable of huge outputs over prolonged periods despite their tiny size. The BeoLab 2 will take up quite a lot of power though, as it's much smaller than other subwoofers with the same total volume output down to the same frequencies.

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

Puncher — Wed, 30 Jan 2008 14:52:08 GMT

Just think - 850W is almost a single bar electric fire - imagine the energy being radiated - now imagine 850W of "music" power firing into your ears in a confined space! You would die!

It is a measure of "headroom", i.e. ability to handle huge transients. The only speakers that bang out that amount of power for real are sound reinforcement speakers in auditoriums / concert venues etc.

Re: comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

Beobird — Wed, 30 Jan 2008 14:42:32 GMT

There is a huge difference between RMS power and normal power. RMS is what a amplifier kan produce for a long time. Normal power is what a amplifier can produce for about 5 seconds.... But in the end a real 50 watt RMS subwoofer can blow your windows out and 20 watts are enough for normal listening and movie volumes . But 99% of the people on earth really think more watts = better, so the companies matches their specs on that...

comparing beolab 2 to non-bang & olufsen sub /techical stuff / advice needed

jooka — Wed, 30 Jan 2008 13:36:26 GMT

what's the deal here.

beolab 2 has 850 watts.

and when compared to for example genelec 7060 bp which has almost same features - has only 70 watt ampflier.

no need to convince me to buy beolab 2 cause i allready own it but i just want to know where does this 850 watts come from technically and how it's different than this "normal" 70 watt genelec subwoofer.

link for genelec sub: http://www.thomann.de/gb/genelec_7060_bp.htm