Is My Amp Too Powerful For My System?

[sicktrick 0]

Hi im so glad i stumbled apon this site.

Ive been Hobby DJing for a few years now doing friends and family events with the occasional pub nights.

 

But i have never fully know the limit of my sytem and mainly if my amp is too powerful for my speakers so i only ever run the amp just over half about 25db, here is the set up.

 

AMP.

Peavey 2600

Power Output: 4 ohms 900w RMS / 1800w program per channel

Power Output: 8 ohms 550w RMS / 1100w program per channel

 

SPEAKERS

Pair of Wharfedale evp x15

Continuous 300W /Music 600W / Peak 1200W power handling

 

Single Sub evp x18

ontinuous 600W / Music 1200W / Peak 2400W power handling

 

The sub runs in line with one of the evp x15.

 

So what i want to know is can i crank the amp and not worry?

 

Many thanks

 

 

[vokf 0]

Hi, welcome to the forum!

If you fancy providing a better intro - there is a special topic area;

http://www.dj-forum.co.uk/index.php?showforum=13

 

 

Ok-

Wharfdales are 300WRMS at 8Ohms

Sub evp x18 is 600WRMS at 4Ohms

 

Stick to RMS, its a safer and more accurate measure than Peak.

 

The main problem is that the amp will be seeing 8Ohms when connected directly to 1 evp x15, so the full 550WRMS is availble, and so quite a bit of potential to blow the poor evp!.

 

The other channel will see 2.7 Ohms, the amp can run down to 2 Ohms, so you should be ok regarding amp overloading.

Ok - the power will be shared between the sub and the other evp x15.

Sub will see about 666WRMS, the X15 will see about 333WRMS.

 

To you - this can be a problem - you can't set the gain levels on the amp the same!

At 100% on both, the single X15 will see 550W - probably "bang". The channel with combined sub+x15 will be slightly over therotical max.

 

So, with this in mind - you're ok, but obviously its a bit of a beast to work with.

 

Jason

Edited February 18, 2010 by vokf

[MintyDave 0]

Hello sicktrick and welcome to the forum, hope you find some usefull info

 

In a nutshell no, its better to have some head room rather than being under powered but you should always be carefull not to push things too hard. You would be safe running the amp at its maximum if you are carefull, which some say you should do anyway and keeping your mixer master level down. also you dont always get 100% of the specified power.

 

With your speaker configuration you may have some issues with the sub and 1 top cab connected on one side. The sub i think is 4ohm and the top cab 8ohm which if i think would give you a total impedance of 2.6ohms (I stand to be corrected if im wrong) which will not be good for your amp if it specifies a minimum impedance of 4ohms

 

The way round this would be to have the sub on one channel and the tops in parallel on the other chanel (4ohm + 4 ohm = happy amp). You would lose some stereo imaging but would get you by for now.

 

Peavey subs used to have a specially designed crossover so that the amp would see 4ohms regardless of what was plugged into the top so i would check your sub manual to see if it has something simular.

 

Also 600w and 300w do not make 900w, you would only have 2 times the value of the lowest powered speaker - 600w

 

This is my understanding from what i was told and i may need correcting but i think im on the right path.

 

There are some very clever people on here who would be able to tell you more and im sure they wll be along soon.

 

 

best wishes

Dave

 

edit: see just as i was typing, Jason was posting.....and im not even considering making any smart ass sarcastic remark about the words Clever and Jason appearing together in one post! That would be wrong

Edited February 18, 2010 by MintyDave

[vokf 0]

edit: see just as i was typing, Jason was posting.....and im not even considering making any smart ass sarcastic remark about the words Clever and Jason appearing together in one post! That would be wrong

 

:Thumbup:

 

Lol! My post required lots of google fu Dave, not really my area of expertise. If I knew all the above, then I'd be Clever. Currently just feeling old!

 

Internet is painfully slow as Carmen is uploading pictures to Photobox.

So you must type very slowly!!! lol!

 

[MintyDave 0]

Ok i found the impedance calculator too, i actually knew the equation this time but needed proof.

 

Im running xp sp3 on a pentium 4 with 256 mb ram (rimm based motherboard) - i started my reply before sicktrick even registered!

 

Back to topic

 

Hopes this helps sicktrick, keep posting and dont forget to do an intro.

[sicktrick 0]

Thanks guys at least i know where i stand i have been thinking of updating my speakers for awhile so i think i may go down that road very soon.. look out for a what speaker post!

 

the sub does have a high pass output for that satelite speaker.

 

got a gig tonight so i will have a play

[sicktrick 0]

so when i get round to buying a new speaker system its best to get the cabs and the subs with the same power rating and operating at either 8 or 4 ohms not mixing the ohms?

 

so i would be looking for somthing like

 

400 watt rms cab and sub combo at 4 ohms.

 

giving me 100 watt headroom!

[MintyDave 0]

so when i get round to buying a new speaker system its best to get the cabs and the subs with the same power rating and operating at either 8 or 4 ohms not mixing the ohms?

 

so i would be looking for somthing like

 

400 watt rms cab and sub combo at 4 ohms.

 

giving me 100 watt headroom!

 

Do you really need a new speaker system, are you happy with the wharfedales?. the ideal way to complete the setup making use of what you have is get another sub, a second amp and an active crossover.

 

the concept is that you output from your mixer to the crossover which seperates the frequencies and sends the bass to the amp with the subs connected and the mid high frequencies to the tops. Not really louder but a better overall quality sound as the speakers are not having to cope with a full range of frequencies and can work more efficiently

 

granted it means splashing out on a second poweramp, crossover and 2nd sub but you could just use 1 sub for now or even just pick up an amp and if you have a booth/monitor output on you mixer control the sub from that with the tops on the master outs, doing away with the crossover.

 

just a thought, hope it helps

 

 

just a thought

[sicktrick 0]

Been reading alot on the subject of ohms, amps speakers. :shocking:

Just to clarify a pair of 8 ohm speakers on the same channel will see 4 ohms. This means that you have to use the 4ohm rms rating of the amp and not the 8 ohm rating?

 

Seems i am not alone in trying to understand maths involved. I am really tempted to chop it all in for a pair of Mackie's plug an play got the money there. Seems to be a more user friendly option. I am going to speak to my local store for advice but always get the feeling that they never give you the full picture!

 

But could someone tell me with just my amp and not adding another

(although I do own an Alto macro2400)

 

What speakers would be ideal for my amp?

 

i.e cab and sub combo.

[superstardeejay 0]

a pair of 8 ohm speakers on the same channel will see 4 ohms. This means that you have to use the 4ohm rms rating of the amp and not the 8 ohm rating?

 

Yes, except of course that the 4-ohm watts-rating of the one channel will be split between both speakers, not delivered to each. So the speakers will get about the same as if you had one on each channel..in reality slightly less.

 

If you only have one pair of 8-ohm speakers, then dont stick them all on the one channel, put one on each and therefore run it at 8 ohms.

 

You can stick 2 on each channel if you get another pair, that way you have 4 speakers in total and you run the amp at 4 ohms in total.

 

 

 

 

 

 

[MintyDave 0]

 

 

What speakers would be ideal for my amp?

 

i.e cab and sub combo.

 

example

 

Peavey do a new version of the old eurosys set and you can get 2 15" 400w subs and 2 12"350w tops for about £1000.

 

subs

tops

 

the subs are 4ohm as are the tops but quoting peavey

Hi Pass output facility:-

We have equipped the EuroSys 115 and 118 with a high pass output socket. This provides a filtered output signal for operating a satellite enclosure with a minimum impedance of 4 ohms. The design of the crossover ensures the total load presented to the power amplifier is never less than a nominal 4ohms.

 

My set of hisys bins and tops are the same. My bins are 4ohm and the tops are 8ohm but the crossover design is the same as above so it works

 

if you want a deep bass sound, which i suspect your moshers will, you really need some bass bins unless you go higher end and really splash out.

 

regards

 

dave

 

PS i would get on to wharfedale and ask them about their crossovers first. have just looked at the manual for the subs but its a bit sparse.

Edited February 26, 2010 by MintyDave

[sicktrick 0]

 

Yeah i have seen better manuals for a kinda egg toy :lol2:

 

I have emailed Wharfedale be interesting to see if i get a response would be handy just to buy another sub.

 

although they weight a tonne and i wouldn't be able to fit another in my vw camper poor thing barley goes with me inside but it is 30 years old!

[sicktrick 0]

My set of hisys bins and tops are the same. My bins are 4ohm and the tops are 8ohm but the crossover design is the same as above so it works

 

Can i ask what power your speakers are and what amp you are using?

[MintyDave 0]

Can i ask what power your speakers are and what amp you are using?

 

all of my speakers are 350w (rms) and i use different configurations. The tops are 8 ohm and the bins 4 ohm.

The amps are

Kam kxr 1500 (450w at 8 ohm and 750w at 4 ohm).

kam kxr 2000 (670w at 8 ohm + 1000w at 4ohm)

 

main system which i use weekly is

2 x 350x hisys 2's - 8 ohm

1 x kam kxr 1500 (450w per side at 8ohm)

I run the amp flat out and am careful with mixer master levels

 

sometimes i use the following but not very often

2x 350w hisys 2's - 8 ohm

2x 350 bass bins - 4 ohm (use the internal crossover and the hi output facility)

1 kam kxr 2000 (1000w per side at 4ohm)

remember the peavey crossover gives a total load of 4ohm even with the 8 ohm tops plugged in

 

then if i really need to (never had to yet)

2 x 350w hisys 2's + Kam kxr 1500

2 x 350w bass bins + kam kxr 2000

both of which are fed by a peavey electronic crossover

 

I have headroom with my configuration.

 

if space is an issue you may find some bassbins with the speakers mounted on an angle so they are not so tall. 15" bins and 12" tops will save some space as opposed to 18" and 15"

 

Dave