Hello all,

Could anyone explain to me the difference(s) if any with running Beovox's against Beolabs off a unit such as Boemaster 5500/6500/7000.

I appreciate that with a Beomaster amp unit you can run passive speakers off of it - but what (if any) are the differences of say, using a pair of active speakers over a pair of passives when they are not strictly needed.

What, for example, happens if you are using say, Beosystem 7000 with active speakers such as Beolab Penta's? Which amp is being utilized in this set-up - the beosystem's amp, or the Penta's amps - or both?

Many thanks,

Michael 

 

In a 7000 system with Pentalab 2 or 3s, you use the pre-amp in the 7000 and the power amp in the Penta. The power amp in the Penta is quite a bit more powerful that that in the 7000. The 5500 is a bit different as it has no Powerlink sockets so you use Speakerlink which uses the power amplifier of the 5500. However it is used into a very high resistive load which reduces the output to essentially line level so the power amplifier in the Penta is again used.

It's worth noting that the BeoLab Penta isn't actually an active speaker - it's a powered speaker with conventional passive crossover circuitry. All the speaker drivers are driven by one amplifier.

Hi there

We've had similar threads on this subject before, and the real issue is the amplifier in the 5500/6500/7000 Beomasters not really poweful enough to handle the Beovox Pentas at anything other than moderate listening volumes. The amp in the 5000 (which I own) is considerably better, but still doesn't really do the job with the Beovox Pentas (which I also own).

If you're using the 5500/6500/7000 series Beomasters, I'd go for the Beolab Pentas. There's a reason for the 150w amp under each speaker, and that is that the speaker itself really needs more grunt than 55w possible from that series of Beomasters.

If you want a B&O amp to power some Beovox Pentas, I would recommend the 6000 or 8000 (both of which I own) as more than capable.

Personally I do not buy into the argument that you need 150 watts to drive a 150watt speaker!  The ratings on the speakers are input levels and a bit like 0-60 times for a car - pretty meaningless if one car is geared for the next gear change at 59mph and another at 62mph!

Check the sensitivity (or power at a consistent level of dB) in the specifications (sadly modern B&O catalogues have less and less data) and you can then obtain an idea of the sound pressure level for a given input . power requirements. The nominal power rating that the speaker will accept does not tell you what you need to know.

I have used an old Beomaster 900 (2x 6 watt) to drive a pair of 4 legged Beovox 5000 (50w) very sucessfully (the later's sensititvy is listed at just 2.2w - low compared to the 5w of a M100 (100w) - or P50 (50w))

Brian

I almost agree, although there is more to it than sensitivity!

For example, a good PA speaker will have a sensitivity greater than 100dB/1w/1m. For example, a pair of Nexo PS15s have a sensitivity of 102dB/1w/1m, yet require a fiendishly capable amplifier to produce a good sound (hence why even the 3400 watt amp I commonly use to drive PS15s struggles like there's no tomorrow at very high SPLs).

The same kind of goes for hifi speakers. Just because it produces more sound per watt doesn't mean it's easier to drive, especially at high volumes.

Cheers guys,

All getting a bit technical for a mere simpleton such as myself, but i getting the idea of what the consensus is on the matter.

Many thanks to everyone,

Michael R.

Xseries:

Personally I do not buy into the argument that you need 150 watts to drive a 150watt speaker!  The ratings on the speakers are input levels and a bit like 0-60 times for a car - pretty meaningless if one car is geared for the next gear change at 59mph and another at 62mph!

Check the sensitivity (or power at a consistent level of dB) in the specifications (sadly modern B&O catalogues have less and less data) and you can then obtain an idea of the sound pressure level for a given input . power requirements. The nominal power rating that the speaker will accept does not tell you what you need to know.

I have used an old Beomaster 900 (2x 6 watt) to drive a pair of 4 legged Beovox 5000 (50w) very sucessfully (the later's sensititvy is listed at just 2.2w - low compared to the 5w of a M100 (100w) - or P50 (50w))

Brian

Brian

If the numbers are meaningless then let's throw them out of the window. I happen to have a Beomaster 5000 and have tried using it with my Beovox Pentas and I personally don't think it is up to the job of powering them. I also own a Beomaster 6000 and a Beomaster 8000. These amps can drive the Beovox Pentas all day long, with the 8000 edging it IMO. Rather than trashing what I have said, perhaps you could go and have a listen for yourself to these amps with the same source and the Beovox Pentas first. 

I don't think numbers are meaningless but I do think that you have to listen for yourself. Interestingly, Beovox Pentas are actually reasonably sensitive at  2.5W but I agree with John that my lower powered amplifiers don't seem up to the job of really driving them.

The Beomaster 900 mentioned, although low powered by modern standards, was really rather a nice amplifier and the 5000s were very efficient. The Beomaster 2400 always surprised me with the amount of power it could deliver, though it could get quite hot!! In those days, a B&O watt of power was usually an under estimate! 

Certainly. Numbers aren't 'meaningless', but the ones you see in catalogues etc... usually are as they're A) very limited and B) often skewed by marketing departments. Generally, high-end professional audio companies are the only ones who seem to represent their products correctly with specifications. B&O have generally been very good at it!

I have the Beomaster 7000 and Beolab Penta MK2. When I rebuilt my filters in the Pentas I also connected them directly to the Beomaster amplifier just to compare the amplifier in the Beomaster to the built in Penta-amplifier. I must say that it was a big difference to the Penta amplifier advantage. Besides the obvious lack of power in the Beomaster the sound quality was also very different. The Penta amplifiers delivers the music in a more convincing way. More details and more dynamics, and the music also felt easier to listen to through the Penta amplifiers.

The Pentas may be a speaker wich seems easy to drive in the aspect of power/dB -ratio but they seem to sound better with more power. Look at the set ups here at the forum with 2x500w ICE-pwer on the passsive Pentas. Of course the result is "in te ear of he listner" but I am convinced that the Penta speakers need a lot of power to perform as they should.

The more power you can feed the Pentas with, -the better, this is of course true for most speakers but I think it is more obvious on the Pentas than many other speakers.

Turbo:

The more power you can feed the Pentas with, -the better, this is of course true for most speakers but I think it is more obvious on the Pentas than many other speakers.

Spot on Jens! The Penta is a difficult speaker to drive, and here at least, power = control :)