Speakers

[geoffers 0]

Hi I bought all of my gear second hand in the summer and they guy I bought it from did not know what size the speakers are. They are big speakers with tweeters include in the case and they have a good sound, I have been using them with 200 watt amp.I want to buy a new amp and keep my other as a back up. I would like to buy a bigger amp as I always seem to have my amp close to full power.

 

Is there any way of working out the power of the speakers from thier measurement ?

 

Also I am not very technicaly minded and I do not understand the difference between ohms and watss per channel.

 

Please could some one give some advice ? http://www.dj-forum.co.uk/html//emoticons/thanks.gif

[orbitdisco 0]

Can you remove the drivers from one of the cabs and post on here what they are? I'm sure then someone can help - there is no direct correlation between speaker diameter and the power handling - eg a 15" driver could have an RMS power rating of anything between 100W an 1KW depending on the manufacturer...

[geoffers 0]

http://www.dj-forum.co.uk/html//emoticons/wallbash.gif sorry I was being very thick not thinking to remove one of the speakers to find the size. okay I have removed the large round speaker and its 150 w 8 and a sign whick I am assuming means ohms. there are three tweeters and another horn

does this mean my speakers are 150 watts ? if so does this mean the largest amp I can use is 150 watts per channel ?

 

All advice gratefully recieved !

 

 

[otronics 0]

150 watts is correct if it says it is and yes that will be 8 ohms.

 

You can use your 200w amp with these speakers fine as you have seen as I expect it produces 100w per channel (200/2 = 100w per chan)

 

As already stated, this is most likely 150 RMS (root mean square) which is the 'normal power' you speakers can produce.

 

I would say do not use anything more that 150w per channel amp for these speakers (ie/ 300w amp) as there is a tiny chance they could blow if the amp is full and used frequently.

 

Ideally, for example, you would want a 500w amp into 600w speakers (ie/ 250 watts per channel into 300w speakers)

 

There are many factors that we could go over here - ie/ you could get a 500w per chan amp going into a 300w speaker with the volume turned down on the amp and you should be fine but the main rule is to have the speakers about twice as powerful as the amp.

 

Hope that all makes sense!

 

Saying that, I use 300w per chan. into 300w speakers so 600w in all and no probs yet.

 

 

[Gary 0]

QUOTE (otronics @ Dec 5 2005, 04:02 PM)

Ideally, for example, you would want a 500w amp into 600w speakers (ie/ 250 watts per channel into 300w speakers)

I'd add a little something to this.

 

I totally agree with the idea of only sending 500watts (8ohms) into a 600watt (8ohm) speaker...

 

However...if you were to get that 500watts from a 500watt amp, you'll be slogging the poor amp too hard and the likelihood of it failing and maybe taking the speakers with it, is a concern. A bit like driving a car at 100mph when its top speed is only 100mph at tops.

 

So, if choosing to send 500watts into a 600watt speaker, I'd suggest using a 800 watt (8 ohms) amp, or higher - running with its front panel attenuator (volume control) turned down to half etc.

 

Therefore, with your 150rms speakers (8ohm) consider an amplifier of 300watts per side, turned down a fair way.

[ChrisPointon 0]

QUOTE

So, if choosing to send 500watts into a 600watt speaker, I'd suggest using a 800 watt (8 ohms) amp, or higher - running with its front panel attenuator (volume control) turned down to half etc.

 

Or Buy a Compressor - Limiter which is a good idea because it is a little more likely to stop loud passages and peaks during loud songs than just solely trusting the front panel controls.

 

[norty303 0]

I'd also point out that the rating you're looking at is for the woofer driver on it's own. Depending on whether they're piezo bullets/horns or proper compression drivers you're looking at a rating of around 250w - 300w rms for the whole cab at 8ohms.

 

I'd recommend using an amp of between 200w/ch at 8R and 450w/ch at 8R.

 

If you plan on boosting bass frequencies then you need to be careful. I'm not a fan of using amps with attenuators turned down. I prefer to run them all the way up and reduce the gain somewhere back in the signal chain. This removes the possibility of someone unexpectedly turning up the amp.

 

Providing you don't clip the amp and the drivers are of reasonable quality you should be fine running 450w into those cabs all night. Just listen for any unexpected sounds or distortion from the cone.

 

 

Also worth bearing in mind is that the difference between 200w and 400w is only 3db (actually slightly less once power compression is taken into account) so you don't get a whole load more out of them with a bigger amp anyway. However the bigger amp will make the top and bottom end sound nicer due to being able to deal with transients in the music more effectively.