Cheers Mikee

Will go have a look and play

the speakers don't sound damaged (thankfully)

Vinnie

RTFM

Read the flipping manual

THe mixer (Citronic CDM10:4) has an output of 0 dBu (775mV rms)
The amp has input of 0dBu (1.0 V rms
The mixer doesn't have switchable output settings.


PS this is all beyond me

Vinnie

There is a small amount of mismatch between the Amp and speakers, although it is opposite to what would overload the Amp.

For instance, your Citronic will produce signal beyond its rated 775mv but in doing so will introduce more distortion into the signal chain. It is always a good idea to make sure that all of your audio components are matched. For example, A 775mv output from mixer should ideally be plugged into an amp with a 775mv input sensitivity.

775mv ratings are often the standard, although 1.2v is commonly used on US manufactured equipment.

The above is purely for advice, since I don't think its causing your described problem, although it may account for a slight loss of quality when approaching the Amplifiers rated power levels.

How about your bass control on the mixer?. A high bass setting can cause the amp to clip at lower power levels. Try reducing the bass on the mixer eq to see if this makes any difference.

The more obvious advice is to turn your amp controls upto 80 or 90% of their travel and then lower the volume from your mixer. My guess is that your mixer output is clipping, and driving large amounts of distortion into your amp.

Cheers guys - have been going through the manual for details.

will have a play with the kit tonight as I am not giging.

Am I right in my assumption that the rms of the speakers is 250W from the 500W program & 1000W peak figures as I can't find a rms figure anywhere in the manual for the speakers

Vinnie

There is a maths formula to work out watts figures accurately, but the rule of thumb is that Program is twice the continuous rating of RMS.

Ignore any peak or PMPO ratings, as this is the absolute maximum rating that the speaker withstood in the testing lab before it destructed.

Cheers Chris

Checking through some of the stuff you guys have suggested I think I may have been panicing a bit - fortunately the clipping (red) led light hasn't been lighting up but I have been running at the top of the amber ones.

The amp has a limiter to stop the output sending a clip signal, as I mentioned before it also has a low cut filter to remove ultra-low frequency which I have now switched on.

Following Mikee's advice and turning the amp volumes right up, I can take the master volume up to 7 with the line volume up to 10 (max) without the amp clipping. (I have disconnected the speakers to avoid damage (both to them and my ears)

On the upgrade side the amp runs
300W rms @ 8ohms per channel (stereo)
475W rms @ 4ohms per channel (stereo)
650W rms @ 2ohms per channel (stereo)

The speakers as I mentioned run at 500Wpower / 4ohms 1000W peak
(how do these guys get away with not putting rms ratings on their literature)

I was kind of thinking of just linking another pair of the samefrom the speaker backs?

Vinnie

PS would a pair of 500W rms 4ohm speakers be a bad combo with the amp running at 475W @ 4ohm?

Cheers

Vinnie

Occasional peaks into the red, where the clip light illuminates briefly during loud music bursts are not considered a problem. Providing that the light isn't a continuously lit beacon, then don't worry about it!.

Oh dear. After reading the posts in this topic, I am now concerned about my setup. The rating of my speakers, below, are actually PEAK ratings and have no program or rms figures on them.

2x Skytec 12" 200W speakers (8 Ohms)
2x Skytec (2x12" drivers) 300w speakers (8 Ohms)

I run them with 2 speakers per channel.

The amp.....

SoundLAB G097M Amp

...has the following rating....

Stereo 650w @ 4 Ohms
400w @ 8 Ohms
Mono Bridged 1000w @ 8 Ohms

Is my assumption that my speakers are actually very weak and are being heavily over driven by the amp a correct one? I always ensure that no clipping occurs during use and have kept the amp volume fairly low, (although the mixer has been pushed a bit), but with bigger gigs fast approaching I'm going to need to increase the volume somewhat.
I've just had to turn down a gig because I felt I didn't have sufficient power.

I have a second question. I have been looking into buying some Peavey Messenger Pro 15's (2x full range & 2x bass bins). These speakers are rated at 4 Ohms.
If I buy them, would my current amp be sufficient to run them without fear of damage?

Thanks in advance for your help.

The actual RMS values of your speakers are as follows:-

Skytec 12" 200W - 125W RMS (200W Peak)
Skytec 2x 12" 300W - 175W RMS (300W Peak)

Total (both speakers connected) :- 300W RMS @ 4 Ohms

Amp Power:- 650W RMS @ 4 Ohms

Yep, you have some potential problems here, with the Amp actually being capable of delivering more than twice the RMS power of the speaker ratings. Even if you take into account the Peak figures of the speakers there is still a 150W difference. You will have to excercise quite a bit of care not to overdrive them.

Always compare RMS figures of speakers to RMS figures of Amplifiers, ignore the peak, maximum and PMPO figures they are meaningless in this industry and are just used to make things look better than they really are.

The Speakers you have are not really suitable for the Amplifier, I would upgrade as soon as finances allow.

Thanks Chris. You've comfirmed my worst suspicions.

Do you think my amp could cope with 4 peavey pro 15's, with each cab running at 250w continuous at 4 Ohms?

Don't want to go and blow more money on some more unsuitable speakers.

Cheers.

Even with 2x 250W RMS Cabs you are still treading a fine line, although certainly not anywhere near the risk you are running with the Skytec's. If you feel that you can excercise a little control with regard volume levels and not drive the Amp into clipping then you should be okay with 2x Peaveys per channel, or invest in a compressor - limiter and physically set it so that you can never clip the amp.

Ultimately I would be more comfortable with 2x 300W or 2x 350W cabs running from a 650W Amp which results in speakers which are neither underpowered nor overdriven, however you'll probably be okay with the Peaveys - just keep that red clip light OFF (as indeed you should with any Amp / Speaker combination).

As far as the Soundlab goes, well they are good Amps and use MOSFET transistors, as well as being fully protected, so you shouldn't run into any issues with that.

Chris, you are indeed a true gent and scholar.

Yet again I bow down with gratitude for your help.


Thanks again.

just read through all these and noticed a few comments about amps clipping - isn't this sometimes due to the signal from the mixer being too high and overloading the amps input ? and isn't the PFL meter here to help you measure this and reduce it if necessary? I thought the PFL was there to help you present the highest cleanest signal to your amp and that sending a distorted signal from your mixer to your amp can damage your speakers as well ...not sure where I got this from and could be wrong so any comments most welcome...

Cheers Chris - thems lights are pretty though!

Having read through this topic, I am amazed at how little some of you guys will settle for .. the rules are simple .. you just can't get a square peg to fit in a round hole!! If ya want to play bigger rooms .. get some power for goodness sake. As for the latest comments about Peavey Messengers, They have a passive x-over built into the subs and this does NOT alter the impedance of the rig at all. Therefore, if you link the mid/tops to the subs using the high-out on the subs, the rig still only imparts a 4ohm resistance back to the amp (not 2 ohms as you may think). These cabs are very conservatively rated by Peavey and the Black widow drivers in the subs alone will easily handle 500 watts each without melting the voice coils! I think 650 watts a channel to the MEssengers will result in a lovely crisp sound .. just be sureto use some decent processing at pre-amp or they have a tendency to sound all mid-range. You should all check the "slew rate" of power amps too as a poor response from this will result in major losses of power to heat if driven hard. This gives the impression (correctly) that high volumes cannoit be achieved as the night progresses (not what you want at all). I myself messed with loads of different configurations before settling for JBL concert Subs (1200 watts per cab @4ohms) These are driven by the excvellent Audiohead amp 1200x1200 @4ohms . Mid toip is taken care of by an awesome pair of Peavey Hysis4's (700watts RMS per cab) driven by Studiomaster 800x800 @4ohms. I use a Electrovoice x over to control the subs, and a 30 band equaliser to make sure the whole lot stays in check.

Hi and welcome to the forum heretochill,it would be nice if perhaps you could give us a little intro into who you are in the new member section, See you know what you are talking about and also saw you were asking for a gig in another section of the forum so we need to know a little more about you. Regards Chris S. Sorry to take this off topic guys

Hi Guys this is my first post so hopefully nobody will say "read all the other messages on this topic!"

I have inherited an InterM R300 amp - 2 channels with "stereo" or "bridged mono" and the minimum impedance is stated as 4 Ohms/channel for Stereo or 8 Ohms bridged.

I also got 2 x RCL LPA EM1260 400 Watt 8 Ohm speakers.

The main purpose will be for large family gatherings of 80 - 90 people. My wife has lots of sisters (sorry, all spoken for!). Obviously we rent fair sized rooms for such a number and I wondered if someone could advise:

a) Is the amp/speaker combination suitable?

b) How should I use the amp - Stereo or Bridged Mono?

c) Any other suggestions or comments?

Thanks in advance for any help.

Haggis

run the amp in stereo......

Thanks for the fast resposne .....

If I added two more 8 Ohm speakers that would let me get more out of the speakers as long as I run them in stereo?

I think!!

Is that right?

Haggis

think of it this way.

your amp is infact two mono amps in one box.

each mono amp can work at 4 or 8 ohms....

if you use one channel eg the left speaker connection with one speaker you will be running an 8 ohm load...

add the other speaker to the right channel for stereo...

ok now the teky bit

two 8 ohm speakers on one channel would be 4 ohm load...

you could infact run 4 speaker if they are all 8 ohm ones.....

now for bridging, to keep it simple when you bridge your two mono amps to Make one big mono amp , you get more power but lose the ability to run 4 ohms or two speakers in your case....

keep it stereo... and run 2 or 4 speakers......

hello i am totaly new just setting up my equipment read all about ohms law fweeeee il give it a miss and just ask the question

i have
gemeni xpm 1200 amp
ohm rw 5 350w 8 ohms speakers

are these ok .or am i under running them or over running the speakers
i oviously can turndown the power on each channel from the amp.

thank u for any help

thank u very much for your reply good news tell me mate i wanting a setup for karaoke .would base binns add to quality for karaoke or mostly for disco again thank u for the reply















;

0

i wouldnt bother with bass bins at a karaoke

Behringer makes great value and rugged amps and speakers for the price you pay.

The Behringer amps are clones of the QSC RMX series. And having heard them both theres not much difference in the sound quality.
Except QSC has the repuation, great reliability, great service and offers replacable modules, but is twice the price than the Behringer.

As for powering most speakers always use amps with rms 1.5-2 times the rms of the speakers. Then there is less chance of clipping the amp, as clipping amp = fried speakers.
And very high quality pro drivers like Precision Devices can take 4 times the rms rating of the driver, as they got special heatsinks and very large voicecoils of around 5 inch.

Both Behringer and QSC amps feature a clip limiter which reduces clipping, and has saved my speakers from burning out when it went into clip once;but that was only soft clip[clip light blinking on amps]. Dunno if the clip limiter will protect against hard continous clipping[ clip light on continouslly] though.


Nothing wrong with under powering speakers EXCEPT if you clip the amp[and it doesn't have clip limiter etc] or you not set the external compressor/limiter correctly, then goodbye speakers.

So an amp which is 1.5-2 times the rating of your speakers rms gives more headroom [as bass mostly uses up amp power until it clips].
So that using an amp 1.5- 2 times the power of your speakers means you can get more out of the speakers including better bass before it clips.

Some very good advice in here. I'm looking at investing in a PA system. My DJ setup already consists of over £2K of kit, so whilst i want to maintain quality in my PA, i don't want to be daft in my spending - out of money now!

I like many many others in this thread looking at the Peavey Messenger Pro's. 2 15" tops and 2 15" subs with inbuilt high pass filters for £250 each pair is appealing. (One person mentioned they had blackwidow drivers, i was under the impression only the UL series featured these?) Rated at 250 watts continuous each; what amp wattage should i be looking at? I've looked at the Behringer EP 2500 and it looks decent and cheap £189!!! Also Yamaha amps seem high quality and reliable for the price. Crown and QSC are overpriced for me.

The mackie SRM450'S tempted me, but for £900, a pair of full range speakers, subs and a powerfull amp seems to offer more versatility and longevity.

Bare in mind i am a club/dance music DJ, and most of my events are 18th Birtdays/Student nights where high volume is a must for long periods. Good clarity, volume/bass, along with reliability and affordability are a must - so any advice is much appreciated!

I have been runnin a pair of peavey hisys 2 powerd warrior is1000 they sound pretty dam good and never had the clipin light on altho you could use the amp as a hair dryer at the end of the night (if i had any )ive got 2 of these amps and they both get pretty hot! (only ever use 1)
So maybe i should use 1 for each channel?
Also ive been offerd a pair of hi sys 4's but got to go 80 miles to get em question is are they good better worse than my hy sys 2's?
I don't no any one thats got any,any ideas chaps?
I tryed to do my profile so you no more about me n it did'nt work where do I go to do it ? Cheers Stevie

Hi guys this is my first post!i've been reading all the info it may be an old one but i've had an audiohead ah2400 amp for 18 months and its been great!Im running 4 ev zx5 speakers and i've just up graded to an audiohead ah4000.These amps may be cheap but they are reliable and sound great.
In conjunction with the above i use 2 ev sba 760 powered subs,cheap amp dear speakers but what a great sound!
Any views would be appreciated.Nice to be a member of a good chat room!!

I'm new here, so please forgive me for jumping in with a couple of points I noticed needed clarification through this thread:
(Don't wish to appear a know-all!)

Speaker impedances:
The impedance figure represents the speaker's restriction, or resistance, to current flow. The higher the number, the higher the resistance.

Therefore, two speakers connected in parallel will halve the resistance.

2 X 8 ohm speakers connected in parallel have a total load of 4 ohms.
4 X 8 ohm speakers connected in parallel have a total load of 2 ohms.
2 X 4 ohm speakers connected in parallel have a total load of 2 ohms.
1 X 8 & 1 X 4 ohm speaker in parallel have an impedance of 2.66 ohms.
3 X 8 ohm speakers also present 2.66 ohms.
I think that's covered most permutations........ :-)
(Trust me, I know about these things!)

Bridging an amp is a slightly more complicated affair, as you double the voltage available to the load. I'll try and explain this concept as simply as I can for the non-techs:

The minimum load an amp can handle is dictated by the current it can supply without damaging itself.
Let's assume you have an amp with a minimum load rating of 4 ohms:
If you bridge the amp into an 8 ohm load, the amp is then capable of providing double the single channel 4 ohm power into the 8 ohm load. However, the amp will see this 8 ohm load as a 4 ohm load by virtue of the double current provided in response to the double voltage.

To load a bridged amp with a 4 ohm speaker stack would cause the same current to flow as if you had connected a 2 ohm load to each channel - few amps can stand this without emitting some smoke, unless designed specifically for 2 ohm loads!

RMS power output confusion:
Thankfully, music rarely consists of steady amplitude sine waves, and is rather more variable than this in real life, which is why a 500W amp can be used with a 300W speaker and it can still survive unless you habitually push the amp way past the distortion point. Not recommended, however.

This brings me on to amp ratings:
RMS power rating is OK, but it needs some qualification. Check the distortion present when the amp is delivering this output. Decent amps will have an RMS rating measured at a very low distortion, such as 0.001%. Bear in mind, though, that at high volumes 10% distortion is not particularly noticeable but under these conditions the amp's output can be 50 - 100% higher than at the lower distortion figure.

Also beware this trick being used to glorify a weaker amp, by listing an RMS figure, albeit at a high distortion figure, which they might forget to include....

That's it for now - thanks for your patience!

Edit:
Did anyone spot the deliberate mistake??! (I've fixed it now.)

Hi People

I was just having a read through all this topic and hope you dont mind me adding a bit of advice, as being in a band the best speakers to use out there i would recommend would be Adlib Audio.

They are british made and sound awesome.

I used to have Peavey's years ago, I have had the Eurosys, Hysis, DTH Systems and UL series, Main problem with Peavey now people get fooled into the Program Power ratings that they use, which is their own rating not an offical wattage rating.

The problem also is that the new version of the Black Widow Speakers just dont stand up to the old design, the new Kevlar these use just doesnt take the power.

We went onto Adlibs after years of Peavey problems and that, we decided to see the light and spend the money and decent gear,

Have a look www.adlibaudio.co.uk

If you dont believe how good they are we used them last year at the DJ north show outside and they were immense, plus you can have a tour round the factory and try them before you by them in a real demo room.

Some of you may not of heard of Adlib but honestly its top quality stuff

must admit... adlib aint bad at all!

Hi all How many people use the Speakers with amps built in, are they any good - apart from the obvious that if amp or speaker blow then you lose both.

The reason for me asking is I run a Numark Amp with 4 speakers and am looking to increase the power as some of the halls I play in our massive and the pub I currently do regularly is getting busier and even though current gear can handle it, would like some extra power just in case. And on speaking to my local DJ shop they suggested a larger amp and speakers but also suggetsed 2 300w speakers (with amps built in) - but is it worth it?

Plenty of discussion recently on the forum in respect of the advice which you seek.

I would carry out a simple search which covers all of the opinions which you require.

Rob

Hi, been reading all this stuff on amps, I was wondering if any one can recomend Carlsbro amps, I'm looking to upgrade from my DAP Audio1600 to carlsbro powerline 2000,I like the look of it. also have matrix 1300 and gemini gxa1600. I run 2 discos and need quality amp with loads of power. Chris @ Revival disco services

Hi

I'm running a Soundlab 800 watt amp to two Pevey HiSys 2XT 350 watt speakers at 3/4 power, works fine, I now ask, if I was to add two more base bins, what should I add?

Are these any good, they seem to sell a lot of them on ebay Shytec cheap and cheerful

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...p;rd=1&rd=1


Then all I have to worry about is how to get it al in the car!

The auction is a bit deceptive because they are not 300w RMS, they are 300w max, 150W RMS. I've got a pair of these although I have taken out the high pass filters and use them with an active crossover and bi amped. Okay for smallish gigs up to 100 people as long as the venue isn't too big.

Cheers for that, I guess you get what you pay for, so any advice on a good set of bins, to add to my set up , anyone? Under £500 budget.

Hi fellow Dj,s
i have been in the buisness since i was 13 years old over the years i have used many different types of amps but to date nothing has matched for power and reliability the new C- Mark amps considering the value for money they represent. i know that you might dissagree but i have used everything fron valve amps to citronic, peavey, H & K, but these C-mark Are excellant value for money, i have the c mark 2650 and 2 of the c-mark 3000,s i have them connected to the peavey UL215H,s 2000 watt 4 ohm full range cabinets simular to the jbl jrx 125,s and the sound is unbeleivable, i know that mobile Dj aying is all about ease but if you havent tried these amps i dont think youll be dissapointed.
anyway rosco signing off for now keep the faith best of luck to you all.

always remember to ensure that ohms law applies to any sound system that you are building the more speakers you connect to 1 amp the lower the ohms rating,
power amps have much more sofisticated circuitry in them these days so ensure that your speakers can handle the max wattage output.

I know that separates sound best you cant beat a high end amp, speaker, and sub combination,
but for ease of use and setup you cant beat active speakers i run a mix and match dependent on the size of the venue i have 1 pair 10"150w, 2pairs 12"400w and a pair of 15"450w. combine this with a mixer with main and booth outputs you have an infinite range of control over power and volume allowing you to position speakers at all four corners of the dance floor reducing the need for deafening db levels at the buisness end, therefore less risk of tripping the power with the sound level meters that some venues use.
david

Guys,

Is there a rule of thumb in terms of How Much RMS = How Many People ?

For example what would be considered powerful enough for an event with 100 guests?

Thanks
Stace

I would like an answer to that question! Everybody has different experiences, and there's the factor of how efficient your speakers are, for example 200W rms speakers that have a Sensitivity of 100dB + are probably louder than 300W rms that have a sensitivity of 95db, i thinks is correct from what I've gathered.

My question, I'm thinking of buying 2tops 2subs 300RMS each, from class d,
I've seen this amp http://www.thomann.de/gb/t-amp_ta2400.htm which seems to the best choice so far.
It runs 2x 1200W/4 Ohm!

Speakers = 1400RMS
Amp = 2400RMS java script:emoticon(':ouch:', 'smid_56')


Giving me 1000RMS watts of head room,
Is it possible for this to work if i be careful?!

I was wondering, seems obvious if i turn the 2 knobs on the amp have way down it would only be able to push out a max of 1200W rms (halve the amps power)

All at 4ohm

Thanks Llyr

Short answer, no. Even with the level controls on the amp at half way, it is still possible to feed in a signal powerful enough for the amps to output full power.

You shouldn't use an amp that exceeds the power handling of the speakers without using a limiter.

Class D are not particularly efficient speakers and there is a strong possibility that you will overdrive them in order to produce the required volume level. That amp has the ability to cause damage to the speakers.

Thanks for your help,

a limiter would limit the signal coming from a mixer making it "impossible" for the amp to blow the speakers if set up correctly? Could you recommend a limiter?

This would match the system perfectly, 2x 700W
http://www.thomann.de/gb/tamp_ta1400_amplifier.htm
so no need for a limiter, but I could pay £20 more and get a amp with 1000 more watts (and need a limiter) Which would you go for?!

Looking for a pair of Active Speakers in the coming months, My passive Lumps are huge & heavy and the amp is also getting a bit worn.

Budget would be around £500-800 I would imagine, can anyone suggest a good place to start?

Cheers...