Spendor BC3 power requirements

I am an old chap just looking for a pair of speakers.

I have recently downsized and sold my Tannoy Gold monitors, I also sold my separates and bought a Meridian 551 integrated amp rated at 55W/Ch into 8 Ohms, 100W/Ch into 4.

A chap recently offered me a lovely pair of Spendor BC3, these speakers are in in perfect condition, and all originals, cabs and tissues in perfect condition. Includes two original tweeters, a midrange driver and a pair of stands.

The owner manual says, the power rating is 75 watts peak programme but the owner mentioned that these speakers do require a high current amp and that they are not the easiest to drive.

I grew up with The Beatles, The Kinks, Led Zeppelin, Joe Cocker, etc., but now I listen to classical music exclusively at moderate volume levels.

I do not know the BC3’s sensitivity and I wonder if the BC3s will be a good choice for my Meridian.


lovely speakers If they’re the ones I’m thinking of I thought they were up near 90dB sensitivity but the impedance was quite low (daddy of and similar to the sp100)

The Meridian should be ok though and should be a good match for them.

82db sensitivity

There is docuumentation for the Spendor BCI, BCII and BCIII speakers at hifiengine but you need to join them (it’s free) Spendor BCIII Loudspeaker System Manual | HiFi Engine.

They give the sensitivity but it’s in unusual units: +2.5dB relative to 1 dyne/cm2/volt applied.

1 dyne/cm2 corresponds to 74dB, I believe. So the speaker sensitivity is 76.5dB/volt applied.

1 volt applied to an 8 ohm speaker will dissipate an eighth of a watt. So the speaker sensitivity needs to be increased by a factor of 8 (i.e. 9dB) get it into units of dB/W. That corresponds to a sensitivity of 85.5dB/W.

That’s a plausible number, if a little insensitive, but a 55W amp should be able to drive a speaker like that to about 102dB which should be more than loud enough for classical music at moderate volumes.

This is unsurprising really. The BCIII dates from a time when a 50W/ch domestic amp was a BIG amp.

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pick a number, any number

We could try telephoning them (Nutfield Ridge 2554) but it’s probably not worth it over 3dB :grin:.

EDIT: Actually, reading the fine print in Gregg’s article explains it

… our test signal developing a weighted output of 82.5dBa (85dB unweighted) …


Forgive the obvious - any chance said chap could just bring them round to you for a listen? Numbers are dandy, but don’t tell you if you will enjoy the combo at a subjective level, and unfortunately the subjective bit is the bit that matters…

Speaking from my own POV, Meridian + Spendor is a double dose of pipe’n’slippers sonically, but could definitely ‘aid restful sleep’… :wink:

No, fat chance, he lives in Colorado and I live in Florida. Very interesting points of view, I now have the feeling that the combination BC3-Meridian 551 will leave a lot to be desired, why take the chance?

Where’s your commitment / sense of adventure man ?

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If you feel that then it very probably will. There’s a good deal of subjectivity in our appreciation of audio and a niggling worry that ‘something’s not right’ can easily stop us enjoying a combination that others would think sounds fine .It’s one of the reasons why we’re not all listening to the same system :+1:.

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There are plenty of happy Spendor owners out there.
I had a pair (not this model) for a few years and liked them, sold them on to another forum member with a mainly jazz based music collection who enjoyed them for many years.
All some years ago but would have thought that Spendor would be pretty good with classical music.

Ask this question on a different forum and you will get a very different answer.
I don’t now what ‘offered’ means but if they are cheap then go for it, you can always move them on if they don’t work.

As Graeme points out, a BIG factor in the equation.

Some random bloke on the internet who has never heard the speakers and amp thought the combination might not sound good so you just give up on the speakers. FFS. Get a grip man.

I’ve heard the bc1 and sp100 and wouldn’t describe them as pipe n slippers, the more recent ones are ATC levels of dull but the sp100 really impressed.

Just by the way !
For you guys in the UK, I have a friend who inherited a pair of these and wants to sell them. So if anyone is interested drop me a PM.


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The answer is that you need more power than the specs imply. Not excessive but not valve amps from the period. As a base, maybe 50 watts of solid state.
They have a reputation amongst Spendor owners as being power hungry but the amps we have now are a lot more powerful than they generally had when these speakers came out.
You might well be OK with the Meridian.


Informative opening post - welcome. :grinning:

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I have owned a pair of BC1’s since 1973, driven by a 303/33 combination. The cabinets are bass - reflex I believe, a small port below the main driver. They are quite sensitive and the 303 appears to drive them well enough. I was considering a pair of BC 3’s but there was strong suggestions that the 303 would not cope - they needed more power.

I then bought a 405 and the difference is remarkable, with much tighter and lower bass - they sounded like different speakers altogether.

If the 405 makes such a marked difference compared to the 303, with the BC1’s given their low power rating, I suggest, a 100 wpc, such that the 405 has, is more appropriate than what your Meridian delivers.

A bit late to the party, but that is my two pennies worth.

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