if I have an amp with less 15W of power, what type of speaker would you recommend?

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Hi Jarthel,

It's tough to answer as we don't know what you like but in a nutshell:

If you like it loud, you will want to consider PA drivers. These are effecient and will give you lots of bang for the buck.

If you are a critical listener then you might consider HiFi drivers. These will not give as much sound but the reproduction may be a little truer.

The rated power of a speaker is not that important. Most will be able to handle more than the 15W you are considering but please keep in mind that a 15W amp can damage a 120 watt speaker if you attempt to squeeze too much from it and send it into clipping. (overdriving). Often it's better to have an amp that is rated higher than the speaker which allows you to get the maximum from that speaker without having to worry about overdriving the amp.
 
Cal Weldon said:


If you like it loud, you will want to consider PA drivers. These are effecient and will give you lots of bang for the buck.

If you are a critical listener then you might consider HiFi drivers. These will not give as much sound but the reproduction may be a little truer.


can you point me to manufacturer's link of PA and hifi drivers?

Thank you.
 
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For your tube amp you may want to look into full range drivers. Your amp will play well with them. There is a lot to choose from.

How big a speaker do you want?


FYI, if a speaker is rated at 120W, it does not "need" 120W. It's just that it should be able to take 120W without blowing up.

With 40 watts of tube power, you have plenty of choices. Efficient speakers will be welcome, but need to be bigger to get the same bass as low efficiency speakers.
 
joker6211 said:
hi, since the topics on 15 watt tube amplifier. i would like to ask whether my 8watts stereo to work with a 60watts bookself speaker, would damage the speaker.please advise
Because of the general behaviour of tube amps when they clip (they do not provide the harsh treble noise that solid state amplifiers do), there is generally less chance of your amplifier 'breaking' you speaker (specifically your tweeter) when it is overdriven.
The 60w rating is how much continuous power the voice-coils of the speaker will handle (by handle, I mean before they reach a temperature which will start melting the glue holding the VC in place). You can still break your speaker by feeding it a signal that will cause it to push the voice-coil out of the magent asseblmy far enough to casue it damage.
If you are always turing the sound above half-way to listen to music then your speakers probably are not sensitive enough for your amplifier - but that is a generalisation...
 
I'm probably going to come off sounding harsh, but I don't mean to; simply looking for clarification.

Here is what I have so far -

- You have a 15 watt amp
- you'd like a 40-watt amp, but think only exotic people use them
- you saw some 120 watt speakers in a store
- and you want to know what speakers to use with your 15 watt amp

but I'm losing the thread; I don't see the connection between these diverse events.

First, define 'amp' and define 'speakers'. That is, what is your application; stereo, mono, movies, musical instrument amp, Public Address amp?

On general principle, you can use any speakers you want with your amp. Though some modern stereo/HiFi speakers do have a minimum power requirement, usually about 20 to 30 watts; most don't, but some do.

Second, 'exotic' people don't use 40 watt amps, but they do use tube amps because they like the sound. Again, an amplifier is an amplifier. If you'd like to build a tube amp and you think you will like the sound of a tube amp, then that is all there is to it. Connect any speakers that will handle the power.

Which brings us to power, as others have already told you, a speaker power rating is the power limit. A 100 watt speaker can sustain 100 watts of music. But it can work just as well on 50 watts or 25 watts. As long as the specific speaker doesn't have a minimum power requirement, you can do what you want. Usually sealed cabinets have minimum power rating, bass reflex or ported cabinets usually don't.

As to the assertion that low powered amps are dangerous for speakers, I'm here to tell you it is never the low powered amp that blows the speaker, it is ALWAY the guy running the Volume Control. To destroy speakers with a low powered amp, the volume has to be ridiculously, insanely, and unnecessarily high.

Now, most speakers have a continuous power rating and a peak power rating. It is not unusual to see 100 watts continuous/200 watts peak (or short term) power. It is possible to use 100 watt speaker on a 200 watt amp; may people do it, as long as you don't get too carried away. You can still play loud music, but if you reach into the ridiculously loud (as in wild drunken party loud) range, you are risking your speakers. But again, many people enjoy loud music on amps that are twice the power rating of their speakers. They get by with it because, loud as they might get, they still maintain a reasonable level of sanity when it comes to their Volume Control.

I can't tell if I answered your question, because I'm not really sure what the question is, but hopefully, in all this, there is at least part of an answer somewhere.

Steve/BlueWizard
 
Everything that BlueWizard said is very true. And with a 15 watt amplifier, one of your main concerns is the speaker's sensitivity rating, measured in dB/watt (decibels per watt). Another somewhat important concern is impedence, although this depends on the specific amplifier being used, and the application it's being used for.

Yes, loudspeaker drivers geared toward the professional market, specifically for touring or fixed sound applications, are generally much more sensitive than those geared toward the consumer market. However, as with many things, there's always going to be trade-offs and sacrifices. This is what loudspeakers, and audio in general, is all about. You must choose what you need to sacrifice and how much of it to give away, in order to obtain what you want to work the way you want it to.

However, your choices certainly are NOT limited to pro audio by any means. There are a plethora of highly sensitive loudspeaker drivers out there, especially full-range (which also have many trade-offs of their own) that offer good sound, geared towards consumers and the DIY market.

As previously mentioned, in order to provide you with further assistance, a little more information is required from you. Also, is the 15 watt amplifier actually a tube amp? I'm not so sure that was ever stated in your post, and other people that replied just assumed it. Going by your statement regarding tube amplifiers requiring 'exotic' speakers, I'm actually thinking that your 15 watt amplifier isn't a tube amplifier. Is it a chip amp? Some other topology?

What kind of amplifier are we actually talking about here?
What's your budget?
What will this system primarily be used for?
What else will it be used for?
Any size requirements?
How concerned are you about looks?
What do you like?
What do you listen to?
How do you listen to it?
What kind of room is this going in?
Any other speakers or things you have previously owned that you can comment opinions on? What have you found that you've liked or not liked? In other words, is there any specific thing or type of sound or characteristics you're after or would like these speakers to have?

...Could go on and on, but those are the first few things that come to mind. Let us know, and perhaps a good amount of people will be able to provide you with a lot of good information, and a large number of suggestions regarding loudspeakers and other things. So, please inform us. :)

~ Brandin
 
Hi,
the amp power is turned into acoustic watts by the speaker.

In my view the next important specification after low distortion (incl frequency response) is the max SPL that can be reproduced i.e. the acoustic watts.

For a 15W amplifier I would suggest a speaker with near 90db/2.8V/m. or higher sensitivity.

15W is approximately 12dbW. Add that to 90db/2.8V/m speakers and the result is max SPL of 102db/m
At 2.5m listening distance and a pair of speakers the max SPL at the listening position will be about 5db lower or about 97db.
With crest to average music of 20db the average level will be about 77db. This is a bit louder than conversation.

If you like loud then increase the speaker sensitivity above that 90db/2.8v/m guide figure. Try 94db sensitivity or even 98db. What about 105db/2.8v/m? Now that would be capable of being LOUD, Max SPL approx 112db. Even allowing crest to average of 30db gives an average level of 82db (well above conversation). All this from just 15W and most of the time using just a few hundred milliWatts.
 
Just to clarify something in regard to speaker power handling.
If a speaker is rated at 40w, it should handle typical power available from speech or music from a 40w amp, not the RMS power.

It is safer to have a higher rating on the amp, and use the volume control wisely. Many tweeters are fried due to the harmonics generated when clipping occurs.

I think Andrew summed up your requirements, go for 90+ dB/w. My choice would be in a full range, with bass helper.

Geoff.
 
Re: JPW gold monitor

joker6211 said:
Hi AndrewT
I think is about 86db/w
That sounds familiar.
Now add 12dbW (15W) and you get 98db/m
subtract about 5db for listening distance and a pair feeding the room leaving about 93db @ the listening position.
Now subtract 20db for a crest to average ratio in normal music and you are left with 73db when the volume is cranked right up and the signal is just starting to clip.

This is very low level listening.

The maximum of 93db at the listening position is the potential problem. I suggest this be increased by at least 5db and preferably 10db. A loud/realistic freak would be aiming for 110db at the listening position. I heard a school "African drumming band" just recently. How I wish my stereo could reproduce that at realistic levels. The kids' playing was superb! My stereo is not.
 
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