I’m sorry to burden you all with what might seem another silly question about Amp’s & Speakers, but because I’ve only been doing discos seriously since July, I still have a lot to learn.
The Amp & speakers I have been using so far is a Stageline 400w (120w RMS @ 8ohm) with AXL speakers. (These were sold to me as 150w RMS, but after looking at AXL’s web site, I’m not so sure now they may only be 100w RMS)
That aside I’ve been very happy with their performance, but just lately I’ve found that with doing larger groups, the Amp has had its clip lights on nearly all the time. (Although the Amp has never got hot, with just warm air being blown out by the fan even after 4 hours of pushing it hard)
Not wanting it to shut down half way through the night, I decided to get a bigger Amp & speakers as soon as money would allow.
After collecting money from Christmas presents I had just enough to get ether the new Amp or Speakers (not both at the moment money is still very tight)
Being happy with the Stageline Amp for the price I decided to get a larger one, that way if the 400w Amp did decide to shut down I could use the larger one on reduced volume. (I know putting 250w RMS through 100w to 150w RMS speakers would have to be done carefully) This is where I found out Stageline is now Prosound, and I could get a 1000w Amp at a very good price. (I know some of you are saying, “why bother with this budget range rubbish & you only get what you pay for”) but as I have already stated money is tight, if it wasn’t I would spending thousands not hundreds on equipment.
OK, OK, I know I’m waffling on a bit, but please bear with me I’m almost there!
Last night I had the chance to try the two Amps out at a venue (didn’t want the people next door banging on the walls by trying it too loud at home)
I connected the 1000w amp to the speakers & turned it up gently, “wow” it sounded so much better a much nicer base & top end. The worrying thing was the peak lights were coming on at only 2/3 volume & it didn’t sound that loud. (It didn’t sound as loud as it did on the 400w Amp)
So I tried connecting one speaker through the 400w Amp & one through the 1000w Amp. After adjusting them both so the volume was about the same on both speakers (no DB meter to say they were exactly the same, but they sounded about the same) The peak light on the 1000w Amp was flashing with every beat of the music, where the 400w Amp still had plenty to give.
OK now I have finally got to the questions!

Is this normal?

Is it because I’m using low wattage speakers causing the Amp to peak early?

Will this get a lot better when I get the new speakers? (I’m looking at 300w RMS 8ohm, the Amp should be 250w RMS at 8ohm)

Or is it a faulty Amp and I should take it back ASAP?

Sorry it’s a bit long winded but any help would be appreciated.

To early for me to even think about it!!!

This has been discussed several times before .

If you have 150W loudspeakers you will only get 150W from them, regardless of whether your amp is 150W or 1000W. Just because your Amp was 1000W doesn't magically mean that you will get more than 150W safe handling from your speakers.

Doing this was VERY RISKY and I wouldn't recommend anybody attempting to connect 150W speakers to a 1000W amp, you could have blown them both just by switching on the Amp (Surge).

Keeping the volume at a steady 150W is almost impossible to do, play something with heavy bass passages (New Order - Blue Monday for example) and the output from the amp could peak at three times it's current output for a few seconds during the bass passage without any physical adjustment of the volume control on the mixer. This is why it's advisable to have speakers rated above that of your amplifier to allow for bass and transient peaks (A 1000W RMS Amp can easily produce peaks of upto 1500W for a few milliseconds during loud music intervals!!!).

From your description (luckily for you) I can only assume that the Amplifier had some sort of V/I limiting or intelligent speaker protection which could sense the current being drawn by the speakers and limit the output of the Amplifier when the speakers began to overload - hence why the peak lights illuminated earlier than they would with a pair of 1200W speakers connected. Either that or the speaker drivers have already been damaged and the impedance of them has dropped to a point where the Amplifiers protection / limiting circuitry activated.

Is this normal? - you shouldn't even be attempting to connect very low wattaged speakers I belive you found the speakers to be actually 100W rms??)

Will this get a lot better when I get the new speakers? (I’m looking at 300w RMS 8ohm, the Amp should be 250w RMS at 8ohm) Read the other threads regarding this - and make sure that your speakers are rated ABOVE the power output of your amplifier - for example if you have an amp which delivers 300W at 8ohm - then connect 350 or 400W 8 ohm speakers to it!!!

Or is it a faulty Amp and I should take it back ASAP? Very unlikely - connecting 100W speakers to a 500W or 1000W amp is a stupid thing to attempt!

The reason why it sounded better when you connected the Speakers to a larger amplifier is due to the reason mentioned earlier - in that a 120W amplifier is NOT really suitable for anything more than home bedroom use - which is the Market the Prosound is aimed for!. If the peak leds light then there is not enough power for your application - plain and simple!. When your amp peaks you are probably sending 10% distortion through your speakers making the sound terrible.

So I’ll take it from your reply Chris, that I should wait until I get the new speakers before using the 1000w Amp again? (Only joking, I wasn’t thinking of using it again until I get the new speakers, I was just a bit concerned in case it was a problem with the Amp) it may take some time before I afford the new speakers.
Ok so my wrist has been severely slapped for trying it, but it’s not quite as bad as your reply makes it look. I wasn’t connecting a 1000w RMS Amp to 100w RMS speaker’s it was actually a 250w RMS Amp to 100w RMS speakers.
The Amp is 1000w max at 4ohm
2 x 400w RMS at 4ohm
2 x 250w RMS at 8ohm
The speakers I have been looking at are
8ohm 300w RMS
8ohm 600w max
will these be ok or should I go for
8ohm 400w RMS
8ohm 800w max

Another slap on the way....


Quit using MAXIMUM figures for anything other than refering to boy racer In Car Enterainment Systems or those cheap PC speakers you bought from that car boot sale. My car will do 120 mph - Downhill with a strong wind behind it , it doesn't mean that it will do it CONTINUOUSLY or EASILY and the same applies to Speaker and Amplifiers. Always quote RMS figures and use the same philosophy when BUYING equipment

Maximum wattage figures are impractical, and often not worth the paper they are printed on. They are also used by salespeople to boost the sales of cheap inferior products which are not suitable for D.J'ing in the first place!. If it can't stand up on its own RMS figures - then it isn't worth buying.

If you quote another MAXIMUM figure again - i'll send Paula around to put a bat up your nightdress....Grrrrrr

It's also worth considering that sound levels are linear and based on the complexities of the Human Ear. Buying a 300W amplifier doesn't mean that it will sound exactly twice as loud as a 150W amplifier - the human ear simply doesn't work that way!. So ultimately a slightly larger amp may not sound much louder, just that there is more headroom and the sound is so much cleaner and sharper than the smaller amplifier.

Buy as large as your budget will allow. A 2x 400W or 2x 500w system is adequate for most venues and certainly a vast improvement on what you have now!.

Wow ! A speaker connected to an amp that is TEN times too powerful, as stated it doesn't matter what equipment you have it will only sound like 100w system because of the final link. I would leave the 1kw amp at home until you have enough dosh to invest some money into some half decent speakers, but remember 'You Get What You Pay For'

All amps vary of course, except those cheap Taiwan/hong kong ones that are the same amp with 1 of 8 different makers badges on them!

Some cheaper amps simply use the "last" red LED on their input meters as the "Clip" light, in which case, I would be looking at how much output I was pushing out from the mixer (and any equaliser) eg: The master output controller, the input gains on the channel thats playing, and especially the very often guilty, Bass, mid and hi/treble controls on each channel of the mixer (if fitted).

Ignore people who tell you that its ideal to push double the amount of power into speakers eg: run a 400 watt amp into a 200 watt speaker, with all sorts of poor excuses about "nominal input levels"...such people are usually the same ones who can tell you 10 cheap places who can re~cone blown speaker drivers...Hmmmmm

Just be really careful until your speaker wattages are safely over what your amp can push into them.

As Chris said, certain sounds can easily put way too much signal through the mixer and into the speakers, eg deep bass, dropping a mic, whistling feedback (thru mic)...also, be aware that electronically originated sounds eg:synths have no "variance" in their waveform (when you look close enough). This lack of variances, which "real" instruments naturally produce, dont allow speakers any "rest", so a synth tune at say 500watts could blow speakers,(given time) which a tune with "real" instruments at 500watts, wouldnt.

My C-Audio amps are 500w each channel at 8ohms. I then add two JBL TR125's series speakers to them rated at 2205w 8 ohms. I have plenty of times cranked the power right up to the top. With no clipping or any distortion to the speakers.

So having an amp more powerfull then speakers works fine. Also you notice better sound, more headroom and obverall better performance from the speakers.

My speakers are over four years old now, and I have always used my C-Audio amp on them and never had to recone of a burnt out top end!

Update on the situation!
I have 3 amps at the moment.
1. Matrix 300w, which is putting out 2 X 80W RMS at 8ohm
2. Stage line 400w, which is putting out 2 X 120W RMS at 8ohm
3. Prosound 1000w, which is putting out 2 X 250W RMS at 8 ohm

These figures are what are listed on the paperwork that came with each Amp; I have only put the 8ohm figures because the speakers are 8ohm.

I have now conducted a few tests using different speakers all rated just above the advertised outputs of these Amps.

Using the same track of music through a mixer that has its output marked in dB, with the Amps volume turned up to Max.
Turning the output from the mixer up slowly, the Matrix & the Stageline Amps just started to peak at zero dB.
BUT the Prosound Amp was peaking at –25db & by the time the mixer was at –20db the peak lights were full on.
Using the same 300w RMS speakers on all three Amps to the point where the peak lights were just starting to flash produced the following results (please bare in mind I didn’t have a dB meter so they are going just by ear)
The Stageline 400w Amp was the loudest, followed by the Matrix, as I would have expected. BUT the Prosound was bar far the quietest of all three. Unfortunately I can’t take it back because when putting it into my flight case, the Amp case managed to get some nasty scratches on it.
Now I wouldn’t normally put the name of another supplier on this forum because I wouldn’t want to upset Chris ‘P’ & I know he has a business to run.
BUT in this case I will, because I don’t want anyone else to fall into the same trap of thinking that these budget priced Amps are good for the price, because they are not (in fact they are rubbish so don’t buy them)
That’s the last time I get anything from EDITED - RULES ARE RULES - PLEASE DON'T LINK TO RIVAL SUPPLIERS EVEN IF YOU ARE MAKING A COMPLAINT AGAINST THEM

That’ll be something Chris has added to stop people putting other Suppliers on his web site.

I wonder if the "forbidden words" checker is set to swap any references of other suppliers, to "CSL"...

If so, such auto~replacements work very well with members accidently recommending other DJ supply outlets eg"I just bought a great cd~deck from ^other suppliers Ltd^".

If it is an "Auto replace" routine running, then at least its prevented the "other supplier" from taking Chris to task over liable....

DJ Sounds - Why have you got two aliases on this forum?? your I.P address is identical to that of JACKWABBITS.

Explanation please - before both aliases get banned!!!.

Father & son,
Son a little bit keyboard shy.

Fair enough, I see the subtle "rabbit - related" link in the surnames. Of course you can see why this would initially look suspicious.

You frightened him off a little when he first posted this thread Chris, but he still wanted to let you know his findings i.e. the Amp was not worth half what he paid. So as soon as he pays back all he owes he’ll probably be coming your way, he likes spending more than he earns.

Not half as shocked as I was when I saw the original post!. Thats my 4th nervous breakdown today we've had other problems & issues during the night which made me a little jumpy . But No Harm done - but the linking rules still applies even when members wish to slate a competitor!. Otherwise it can appear embarrassing for all parties, as you found.

Connecting an amp to speakers that have a lowe rating (As recommended by the speakers own manufactuer, remember) is simply living in "The Danger Zone"...like driving everywhere without using top gear, and having the rev counter permenantly in the red...and thats too risky for those who have gigs several nights in a row, with no wish or time for 3rd party re~coning.

Ive no doubt that the sound is punchier when a speaker is driven past its advertised/manufacturer recommended figures, but the safety margin for pushing the wrong button, dropping the mic, a faulty/crackling lead, adding effects (some are very bad for "pushed" systems), is reduced considerably.

Its like my PC, if I just used it for games, I would consider over~clocking that too. However, as I use my PC for business, I cant afford to apply "max power magazine" style suggestions to it.

Im afraid I disagree with most of you, It is by far better to have am amp more powerfull then the speakers, becuase I dont kno about you guys but I always run my amps at about 1/2 and never even consider putting them above 3/4. And when you take into account that the volume controls are not in any way linear (eg u put amp to 1/4 u get a small amount of power put when u turn it to half it is far more than double power etc etc.) It is particularly important to have extra power when the amp is driving bass speakers, because the extra power will give added depth to the bass, on full range speakers It will also add a lot of clarity as soon as the amp starts tunning high the frequencies start dropping off.

Nobody is disputing the advantages of having a bigger System than you require - just that it is better (safer) to have a matched Amp and Speaker pair, rather than overloading the speakers.

I agree that it is better to have a louder system than you need, so both the Amplifier and Speakers will not be running close to capacity.

A good example of this was Old Mcdougal, who thought that he could double the brightness of his lights whilst still using 40W bulbs . He replaced the 230V 40W bulbs in his house with 120V 40W versions from a man he met in the pub, who happened to work at the local fairground. Mcdougal bought 10 and went home chuffed, thinking he could double the brightness for the same amount of current. He replaced the lamps and switched on!. The result.....3 hours in A&E waiting for glass to be removed from his eye. Sometimes the most obvious risk taking way of getting around a problem is not always the best solution .

Why take risk's?. If your P.A is always clipping then, yes its time to upgrade, but when doing so, make sure that when you upgrade your amp, you upgrade your speakers too, so they will cope with the increase in power handling. If you upgrade your amp to 800W and your speakers are 200W, then that this just the equivalent of putting new seats in your 20 year old 200,000 mile Capri and expecting it to keep up with a Porsche' . If there was no risk to using 200W speakers on a 500W amp for example, then 500W speakers wouldn't exist.

If you require around 600W of power then its more comfortable, to use a 1200W P.A system to acheive it, running with both your amp and speakers at 50% of their maximum capacity. As you point out, a good P.A system is all about NOT straining or stressing any individual component. But a 200W speaker running at 600W is stressed! - at 3 times it's design capabilities, distortion is inevitable, as is overheating of the voice coil after long periods of sustained power.

When looking at speakers, bear in mind misleading specs. Is a common occurance to find figures which read like a science text book. An example...

250W RMS Continuous. 1% T.H.D @ 1khz

This is misleading, not the RMS figure but how its been derived. Many speakers are tested and designed on paper by design engineers, who probably have never done a disco in their lives. Often all testing is done in nice clean laboratories using ideal conditions, clean mains, top of the range class "A" amplifiers and more importantly a test signal, produced electronically at a single frequency by a signal generator. Real Music signals vary widely in the frequency range of 20hz - 20khz, the signal changes rapidly and there are peaks and troughs which look like King Kongs Heartbeat.

To test a speaker on a continuous never changing fixed frequency of 1kz (as above) would mean that either the RMS figure would drop or distortion at the RMS figure would increase beyond that stated (1%), when the speaker is fed with an ever changing frequency such as that found in music signals. For this reason, it is always advisable to take manufacturers ratings with a pinch of salt, and allow a little bit of a safety margin for the speaker when matching it to the RMS power of an amplifier.

I agree that you shouldnt turn the amps up to maximum...always keep something back..
I think what we are saying here is, that a comfortable, reliable system would be...for example...(all 8ohm gear)

A 300watt amp, with its attenuator (volume control) turned down to only offer 75% amplification, driving a 400watt speaker, will keep the audience happy, but not the local money~making DJ audio repair centre, who will never see you, to be able to tell you their "memories" of how they made Wembly stadium shake for 8 hours continuous, by using an 8million watt stack of amps, into a pair of 32ohm 50watt, car door speakers...

I agree with parts of what you've stated there, indeed, I think that I mentioned earlier on in the thread that computer generated sounds, such as a throbbing (steady Paula) synth, or indeed a test tone could more damage to a speaker than "manual" sounds eg: guitars, drums etc.

However, I would never recommend anyone slapping an amp onto lesser rated speakers in straightforward, rational, proven, max or RMS watts.

"Program" or "PMPO" can be as random (or contrived) as "The Lottery".

You've only got to take a look through a computer magazine to see PC speakers, with 3inch drivers, for a tenner, rated at 1500watts PMPO, but Im sure that they wouldnt fare that well if we connected those drivers to even a 50watt amp...not for a continuous program of music.

I'm obviously not saying that DJs and members who already have overpowering amps/underpowered speakers need to change anything, although adding a £110 limiter/compressor, would certainly be a good precaution on any sound system (it could stop a sudden mixer or lead fault, turning into a amp and/or speaker fault).

What (watt?) I am saying is that the best advice that the many new members can follow is to ensure that they get speakers which offer around 20~30% more RMS or Max wattage than their chosen amp, to maximize reliablity, and minimize embarrassing system failures.

All I can add is that Gary and Chris have many, many years experience... Gary especially knows his onions here.

I have found over the last few years, with the onslaught of bedroom djs, there are now many outlets selling equipment who cannot distinguish the needs of a bedroom dj to that of a professional mobile dj. More often than not, the staff in these outlets are working on commission and wouldnt know an ohm from a broom handle!

Advise on the forum is free and impartial - and is gained from years of experience. I know whose advice I would trust if I needed to!