ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
In the seventies and eighties there was a quest for more and more powerful amplifiers and I wonder at what point in a home environment does power become over-kill? Was this power quest mostly for marketing purposes and to “beat” the competition?
One does need to be an electrical engineer to understand that even a 15 watt amplifier can easily power a tweeter and quite possibly a mid-range with satisfactory results. Although more power is desirable to power 12” woofers to give a rich bass sound.
Fine, I get that.
It is also important to mate the amplifier with the appropriate speakers. We all know that.
My “little” 25 watt Beomaster 2400.2 does a very respectable job powering S75 speakers, which on paper is probably a stretch for it. Perhaps it would be better if the amplifier “loafed” and didn’t have to work as hard, and thus producing more accurate sound reproduction.
I also have little doubt that if I was so foolish as to mate the Beomaster 2400.2 with the MC120.2 speakers that the BM would run out of steam and a very unhappy combination that would make.
But why was the Beomaster 8000 with its 150 watts necessary? Later followed by powered speakers.
I have been interested in M100 or M150 speakers for some time due to their super high quality sound reproduction and I have no doubt that I would favor them over the S75’s I currently have, however the woofers are similar in size, why would a M150 12” woofer be better than a S75 12” woofer? Seems like a fair question.
Moving along this train of thought, I have super power hungry Linn Isobaric speakers which have an assortment of tweeters and mid-ranges, BUT the woofer is an 8” so why do they require a minimum of 100 watts?
The Linns have more speakers than most and produce a very, very accurate sound, but I don’t see why they need so much more power than say the S75’s.
All the electronic manufacturers built ever increasing powerful amplifiers along with ever larger power demanding speakers, was there a real reason for this?
Jeff
Beogram 4000, Beogram 4002, Beogram 4004, Beogram 8000, Beogram 8002, Beogram 1602. Beogram 4500 CD player, B&O CDX player, Beocord 4500, Beocord 5000 T4716, Beocord 5000 T4716, Beocord 5000 T4716, Beocord 8004, Beocord 9000, Beomaster 1000, Beomaster 1600, Beomaster 2400.2, Beomaster 2400.2, Beomaster 4400, Beomaster 4500, Beolab 5000, Beomaster 5000, BeoCenter 9000. BeoSound Century, S-45.2, S-45.2, S-75, S-75, M-75, M-100, MC 120.2 speakers; B&O Illuminated Sign (with crown & red logo). B&O grey & black Illuminated Sign, B&O black Plexiglas dealer sign, B&O ash tray, B&O (Orrefors) dealer award vase, B&O Beotime Clock. Navy blue B&O baseball cap, B&O T-shirt X2, B&O black ball point pen, B&O Retail Management Binder
Your BM2400 is perfectly capable of powering the S75, and indeed the MC120s as well. Most music at normal listening volumes uses about 1W. The problem you have is that at high volumes, small amplifiers tend to have higher distortion and the distortion may be the problem as far as the speakers are concerned. Equally, the problem with Isobariks is that they are notoriously difficult to drive and the impedance drops very low at certain points of their frequency range. This drws large amounts of current and it is this that most smaller amps cannot handle. They will tend to overheat and burn components. A perfect amplifier will increase power output linearly as the impedance decreases - most amplifiers will follow the line till about 4-6 Ohms and then tail off - the Beolab 5000 manual has some nice power delivery charts to see how it does.
Peter
On the power requirements - most is bluster - but some speakers are notoriously inefficient due to the complex crossovers which sap power so need more powerful amplifiers to deliver the same pressure of sound. Equally drive units can have different impedances so not every 12" driver is exactly the same.
The Beomaster 2400.2 is one of my favourite amplifiers and it is perfectly capable, as you said Peter, in handling the S75 speakers.
I have very low tolerance for sound distortion and would be most unhappy if distortion was present with my use of the BM 2400, which it isn’t, even under a high demand load.
There is much in print about matching amplifiers to speakers, but I rather think that if it sounds good to the user, than it is a good match. Also room size, speaker placement, and furnishings make a considerable difference in speaker selection.
Case in point, two similar amplifiers, the Beomaster 2400.2 and Beomaster 4500, the latter powers S45.2 speakers brilliantly, in part because they are on a hardwood floor and in a small space, whereas the Beomaster 2400.2 has to contend with a large carpeted room with very large scale furniture and benefits from the more powerful S75 speakers.
In regard to the inefficient Linn Isobaric speakers, thank you Peter for pointing the finger at the overly complicated crossover network, which makes perfect sense.