Speaker power.What rating should speakers be in relation to Amp power?

[sparks68]

Probably a dumb arse question ,but I would sooner ask a silly question once rather than live in ignorance.

So , Speaker power rating .Is there a rule of thumb as to what power speakers should be in relation to Amp power ? Is there a rule of thumb ,eg speakers should be 20% higher rated than amp power output ,should it be equal watt for watt ,I'm sure there must be some kind of formula reguarding this?

Anyone got any links to an answer to this question,or indeed an answer ?

 

[BigH]

No formula as far as I know. I would be more concerned with the minimum amps power rating rather than the max. For example get a an amp. that can drive your speakers without distortion. Lots of clean undistorted power is better than lower distorted sound. You have to watch out for Ohms as well, some amps are not good as low Ohms, if speakers dip down below 4 Ohms I would be careful with your amp. choice.

 

[sparks68]

Thanks for the reply .

Amp already chosen (too hastilly I'm begining to think) Marantz pm 6004 , rated 45w 8ohm . Mainly listened to (but not exclusively ) at low volume .I live in a thin walled terrace house and am respectfull of my nieghbours . I did have a Pioneer 35w amp running Pioneer 70w speakers . I kept the speakers but have found the sound to be "Thin" very clear and detailed ,but "Thin" (best word I can think of) .So now looking to replace the speakers and would like to get it right . My last purchases were 20+ years ago and I've long since forgotten what I learned doing my research back then . It all seems to have got far more technical these days ........

 

[BigH]

Thanks for the reply .

Amp already chosen (too hastilly I'm begining to think) Marantz pm 6004 , rated 45w 8ohm . Mainly listened to (but not exclusively ) at low volume .I live in a thin walled terrace house and am respectfull of my nieghbours . I did have a Pioneer 35w amp running Pioneer 70w speakers . I kept the speakers but have found the sound to be "Thin" very clear and detailed ,but "Thin" (best word I can think of) .So now looking to replace the speakers and would like to get it right . My last purchases were 20+ years ago and I've long since forgotten what I learned doing my research back then . It all seems to have got far more technical these days ........

The Marantz is OK from what I have read but I would get some speakers that are fairly sensitive and avoid ones that go below 4 Ohms and that requires more power. What sort of budget do you have?

 

[Deleted member 108165]

Nothing wrong with the amp, I used to own one myself. Personally I would look at the speakers as the prime suspects. Are the speakers you're using the Pioneers? And are these 20+ years old? Reason I ask is when I had my PM6004 I initially connected them to some old Kenwood speakers from a similar age system - they too sounded carp. Saw the light and bought a pair of MA BX2's, these were great but it all depends on what sounds good to your ears. However, it seems that most of the newer breed of amps don't sound brilliant unless they're given a bit of welly, within reason of course as I have nice neighbours too. Have you tried the amp with the source direct "off" and twiddle with the tone controls a little? Or try backing the speakers a little closer to the rear wall.

 

[sparks68]

I had it in mind to go for 8 ohm rated speakers .Thats what the Pioneer's are. Plus I read they are a good choice?

Budget laughable,maybe £300 . I have a brand new set of MA BX2s sat here.I need to get them returned and refunded to pay for the next ones . They did'nt cut it.No where near the detail of the pioneers.They lack hi trebble,detail and meat in the bass. Nowhere near as open sounding as the pioneers (I think thats the term) Def sounded kind flat compared to the pioneers. But they are a much larger and 3 way. I don't mind used speakers as far as buying goes .

 

[Deleted member 108165]

If the BX2's are brand new then they will sound carp at first but will get better after as little as 10-15hrs of use. I once spend nearly a grand on a set of speakers and they sounded awful when they arrived, but after 12hrs of use they just got better and better. Be patient, it may be your friend on this occasion.

 

[Overdose]

Budget laughable,maybe £300 . I have a brand new set of MA BX2s sat here.

Perhaps some research and a careful purchase of some second hand speakers would be the best idea.

Better bang for buck and better value retention if you need to sell on in the future.

 

[sparks68]

Doug

Yes they are brand new. Back in the box at the min . I did speak to the shop about the sound,they to said they woud improve in time ,but it would only be the bass that improved not the high end ,which is just not there ? Well compared to the pioneers that is ,I can only think that is because they are three way ?

I have played around with treble n bass settings ,direct in etc but just can't get them to produce the high end detail.High hat cymbols just sound flat with them as do all high treble sounds. The pioneers bring out everything.One track (I forget which) has someone very gently using a brush on a cymbol ,on the pioneers you can pretty much hear each individual strand of the brush as it makes contact.The bX2s lump it all together as one sound ,more like a small cloth bag of coins being gently tapped down. I have been comparing them back to back ,having both sets connected to the A-B outputs and switching between the two.

But for all the praise of the Pioneers they have lost the body and richness in the base and mid with the Marantz .I was wondering if that was to do with the power relationship to the amp. They were connected to a 35w output them beind 70w , now connected to 45w I wondered if that was the problem ,some sort of power mismatch .Which is why I asked the question in the beginning of the thread about the power relationship between the two and matching them.

 

[sparks68]

I have no problem picking up seconed hand if anyone has any ideas on what may suit .The only problem there is hearing them.Its been great having the luxury of auditioning the BX2s at home,being an internet purchase they can get returned .Well worth the £10 postage fee ,far better than getting stuck with something I don't like .

 

[Deleted member 108165]

I would appear that the Pioneer set-up must have had far better synergy than the Marantz/BX2 pairing. How much was the Pioneer kit when you bought it all those years ago?

Where are you based?

 

[sparks68]

I bought Pioneer amp,Twin casette and speakers circa 1988 , all bought as seperates new and I spent £6-650 in total .

For my sins I live in Wolverhampton .

 

[Anderson]

In the world of proaudio you're looking at amps that deliver twice as much power than the speakers can regularly handle. How that translates for home audio I don't know.

 

[Deleted member 108165]

I bought Pioneer amp,Twin casette and speakers circa 1988 , all bought as seperates new and I spent £6-650 in total .

For my sins I live in Wolverhampton .

That was quite a sum in '88, in todays money that would be over £1200, and dare I say the Pioneer could probably be the better amp if only on price alone.

I only asked about your locale as I have some boxed-up BX5's and RX2's that I never got around to selling - if you lived a little closer, (I'm in Essex), then you'd be welcome to give them a spin, just to see if any of the MA range would do it for you.

Others have suggested different speakers so probably a good idea to find a dealer with a PM6005 in stock and a list of speakers to audition until you find the match you are looking for, or failing that take your own amp along. If you can try to audition the BX2 as well and use this as the control sample.

 

[robg1976]

Hi hope this helps

Try not to worry to much about manufactures ratings....

the powere of an Amp is only relevant to what load (speaker) it is driving.....

To give you an idea. A car battery is 12v... 8 AAA batterys in your remote for your tv is also 12 v but try starting your car with 8 AAA batterys. a 2liter engine in a bus will be slow in a MINI will be quick it is what they are driving the other end of your speaker cable.... So ohms and sensitivity in DB is very relevant

So a 8 ohm speaker with a DB of 90 is very easy load to drive but 4 ohm 86 DB very hard load and would need more watts from the amp.

this also comes down to power supply in the amp, its more complicated than this but i hope this sheds some light

for example a speaker of 100w rating will be fine with an amp of lets say 40w to 150w.

another tip is better an AMP with to much power than to little as the low power amp will at full power start distortion and clipping then will damage your speaker

hope this helps

 

[robg1976]

another thing forgot mention your amp will be fine and drive most speakers in that budget, the marantz very capable amp

most modern speakers are around 6 to 8 ohm and 87db to 91 Db all be fine with your amp

 

[sparks68]

Doug, the amp at the time was fairly good.Looking inside when cleaning it recently though shows minimum amount of components ,very sparse by todays standards.If memory serves me well it was the penultiment model in its class at the time,just one more powerful model above it .The class above was "Non switching " which I just could'nt stretch to.

I have to say I'm not down on BX2's they have a good sound ,just nowhere near as good as the pioneers. To my ears on certain tracks sounds appear( to my ears) to come from out of the ceiling esp some high treble .The BX2's only seem to give a sound that falls 2-3 feet short of the ceiling height ,the pioneers also do disappear ,totally . I don't have the vocabulary to explain what I mean in Hifi terms I'm afraid.

I think given my budget I'm going to have to look seconed hand to gain an improvement . As you recommend, go to a shop see what I like and then look around for used.

Many thanks for the offer of hearing your spare speakers.

 

[sparks68]

Thanks for the input Rob. Hi volume is not a problem for me be it Marantz or old Pioneer the volume control rarely reaches 10 oclock ,gotta be mindful of the neighbours don't ya know ! Ha

 

[davedotco]

Speaker power ratings are not straightforward and rarely comparable from one model to another. Do you measure at a specific frequency, in the midband, the bass? How about a wideband signal, white noise, pink noise? Over what bandwidth?

The most useful rating is the range of power recommended for the speaker by the manufacturer, it gives a decent idea to the non-expert. If you use a little common sense you will realise that if you do not play too loud, have an average or smaller room, you can choose an amplifier towards the minimum recommended power. Similarly, if you play loud, in a bigger room then something around the top of the recommended range is appropriate.

Personally I take no notice of loudspeaker power ratings, any modern speaker will have a reasonable power rating. I am quite comfortable using very powerful amplifiers with speakers of quite modest ratings, use a bit of common sense and you will have no issues.

 

[robg1976]

no problem in short, you should be fine with most modern speakers, just let you know i have owned a marantz set up my 1st system was a pm4000 amp and 5004 cd player, i found the Monotor audio not a good match the marantz being very polite and ;ayed back, resulting in the monitor audio which are very honest speakers not adding any character to the sound. i had a set wharfedale diamonds with the marantz sounded great, i have an Arcam Rotel systerm now with monitor audio S1 now so im a monitor audio fan but not with marantz

 

[MeanandGreen]

Power ratings on speakers is pretty much meaningless. It's a rough guide for recommended amplifier power.

impedance/ohms is the figure you have to match, so an 8 ohm amp requires 8 ohm speakers. Using a lower impedance speaker will be a struggle for the amp.

The higher the sensitivity rating of a speaker the more volume output you will get per watt of power.

It sounds like you preferred your old Pioneer set up, why change?

 

[sparks68]

It sounds like you preferred your old Pioneer set up, why change?

Very good question . After decorating which nesessitated emptying the room, I had a good look over my old stuff.Speakers are in aweful cosmetic condition, bumps n chips ,peeling vinyl covering. Amp is perfect ,I opened it and cleaned it when I put everything back in the room. The DVD player I used for cd playing has always been a pain; rubbish controls and picky on what it would and would'nt play .So I decided with winter coming and the prospect of being shut in again I would replace the cd player.After 20+ years I figured major advancements in audio should have been made so I started researching. Started reading on cd players which then led on to the DAC side of things. I've much music on the laptop so the USB port almost became a must to me. I did read a little about AV/Network and streamer units thinking I would hook up the Laptop directly.After some thought I backed that idea for the USB/CD player . Having made that choice my thoughts led to the amp. After reading all the bells n whistles techy stuff on the CD player I thought "whats the point in all that technology running through my old amp" so I started looking at amps .I always wanted a bit more power than the Pioneer had, after all "Bigger is better" right ? I could'nt quite justify the cost of a brand new Marantz 6005 Amp n figured the two year older 6004 would still be a giant leap ,having far more sophisticated and advance internals and obviously ought to pair well with the Marantz CD player . The CD got here first and got plugged into the old Pioneer stuff .Whilst very clear and detailed (now I think back) it sounded thin then. No problem I thought ,when the amp gets here n hooked up all will be well.......

Short answer: I was blinded by science and drugged up on reviewers hype and forgot its actually about the sound and the listening .

 

[Vladimir]

A lot of meaningless things in domestic hi-fi. In the pro world it is clear, the amplifier should be equal to twice the speaker power rating.

How do I choose the right amplifier power for my speaker system?
[*][font="Verdana, Arial, Helvetica, sans-serif"]Ideally you should pick an amplifier that can deliver power equal to twice the speaker's continuous IEC power rating. This means that a speaker with a "nominal impedance" of 8 ohms and a continuous IEC power rating of 350 watts will require an amplifier that can produce 700 watts into an 8 ohm load. For a stereo pair of speakers, the amplifier should be rated at 700 watts per channel into 8 ohms.[/font][/list]
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Source: JBL Pro FAQ

BTW, manufacturer's Recommended Amplifier Power and Speaker Power Rating are two different things.

 

[davedotco]

A lot of meaningless things in domestic hi-fi. In the pro world it is clear, the amplifier should be equal to twice the speaker power rating.

How do I choose the right amplifier power for my speaker system?

• Ideally you should pick an amplifier that can deliver power equal to twice the speaker's continuous IEC power rating. This means that a speaker with a "nominal impedance" of 8 ohms and a continuous IEC power rating of 350 watts will require an amplifier that can produce 700 watts into an 8 ohm load. For a stereo pair of speakers, the amplifier should be rated at 700 watts per channel into 8 ohms.

Source: JBL Pro FAQ

BTW, manufacturer's Recommended Amplifier Power and Speaker Power Rating are two different things.

Still not exactly cut and dried, even in the pro world and a complete nonsence when applied to hi-fi.

JBL measure the power handling using the IEC system, 'shaped' pink noise used to drive the speaker long term. This is pretty demanding and most hi-fi speaker systems would have very low power handling measured in this way. The distortion limit is not specified because it is different for speakers with different applications.

I doubt if any hi-fi speakers are tested in this may, maybe some B&W or PMC, but only those units with a non hi-fi, 'pro' application. Most manufactures just take the ratings from the driver manufacturer and use that and, frankly, it is as good as anything.

For many years they have relied on the fact that their products will be used to play recorded music, with a reasonable dynamic range, say 20db, in a domestic setup. Ie a 100wpc amplifier will have a peak power of around 140 watts, and with that dynamic range the maximun average power delivered by the amplifier will be 14watts. Any competent hi-fi speaker will handle that.

The problem arises when modern, heavily compressed bass heavy music is played on the same setup. In this case, with say a dynamic range of 6db, the maximum average power being delivered is around 70 watts, big difference. Note that in both cases the peak levels are the same.

Throw in the differences in speaker sensitivity, the ridiculous setup of amplifier volume controls (discussed elsewhere, at some length) and it is easy to see why power ratings are, in the case of speakers in particular, practically useless

 

[robg1976]

sorry so wrong. and not revelant. readf my previous post, so many factors, his 45 watt marantz will be plent for most hi-fi speakers. most are 6-8 ohm and 87 to 91 db, and will run fine with an amp of 30w to 150,

read my other post power in watts in not just factor power supply and other factors play a part. i have owned 40 watt nad amp that will drive speakers than a sony 200w amp