Miami Joe

Situation...I am sort of acting as DJ at a Christmas Party and am using mixer software on my laptop plugged in (using RCA audio cables) to either:
A- a "stand alone" stereo Amplifier rated at 250 Watts (Radio Shack Optimus brand)
...or, option B....
B- an integrated receiver...one with like 5 channels @ 100 watts per channel.

I am only using 2 "dj" speakers rated at 100watts each. There is no adjustment for sound on the amp other than volume (ie... treble and bass) like there is on a receiver. The room size is not that big...its a restaurant's party room but is bigger than a 2 car garage size. Can I use the receiver, and won't it sound better than just this amp?
Is the receiver going to be rated at 250 watts per speaker when I only use the two speakers? or still at the same 100 watts per channel/speaker?
Any thoughts or direction would be greatly appreciated

palebluedot

You are better off using the receiver. There are some receivers that increase the amperage for the "stereo" section when in 2 channel mode but most don't. So you are going to be running 100 watts at 2 channels but for your room size that is plenty of power.

If you have the means I would run 5 speakers around the room and run the receiver in 5 channel stereo mode)if it has it).

Miami Joe

Sounds cool and I was thinking of that last night... however, I generated more questions such as:

1. What "mode" would I set the receiver in... maybe use some DSP's (like I have on my Yamaha RXV992 surround receiver...like stadium, disco, etc) and see what sounds best?

2. If I have the two speakers already, I guess I'll need 2-3 more full range (20-20000Hz) speakers which can handle 100 watts? (I'll prob. go just with 2 extra speakers)

3. If placement of each speaker is on the corners of the room, with the speakers pointing toward an imaginary center of the room, will there be more interference with a microphone? (I think mic's tend to throw off more feedback when in front of a speaker)

4. How does the receiver process the stereo sound (ie going from one speaker to another and back & forth) with 4 speakers without having Dolby Digital media (ie...using stereo MP3's)?

This is sounding better and better, each time I think of it... and maybe I should use a Dolby Prologic II capable receiver. I just wish all my MP3's were in Dolby Digital surround.
(by the way, I am using MixVibes Pro DJ mixing software...it is awesome)...and thanks again.

palebluedot

I wouldn't use any DSP modes because the room is goinf to provide enough ambient reverd, but give it a few a try, just keep in mind that the sound will change some as people fill the room up.

On my receiver I have a 5-channel stereo mode that esseltially send a full range stereo signal to the left and right fronts, a full range stereo signal to the left and right rears, and it sums the left and right for the center speaker.

In your case you could get by with four speakers and most receivers have this "5-channel" stereo mode.


Using the microphone shouldn't be a problem. What are you using to plug the mic in?

audrey

I'd go w/ the PA Amp; no question. Many receivers were simply not designed for this kind of use. But as long as you keep the volume levels moderate the risk of damage to the receiver or speakers seems minimal. Plus, i simply wouldn't want to take the risk of dragging my receiver around--accidents do happen.

However, I would NOT recommend using the 5 speaker setup mentioned above. Many receivers were simply not designed to deliver their full power rating w/ all 5 channels simultaneously---especially if it is a fairly low-end model. At best, this is a risky, proposition.

palebluedot

I agree with you on the use of a low-end receiver however I have not had any problem running my reciever in 5-channel mode for hours and hours at a time and I have done this many time.

The only reason I suggested the receiver was it wouldn't connect a laptop directly to a pa amp. However if you can use a mixing board in between then a pa amp would work as well.

edclem

I second the vote for using a PA.
Professional sound equipment is designed to run virtually wide open for hours on end. Receivers more often than not, really aren't.

I also wouldn't worry too much about the power rating of the speakers. As long as the power is clean (you're not hearing distortion), you're not likely to damage the speakers. Just because an amplifier is rated at 250 Wpc doesn't mean that it's outputting that level. It just means (assuming that it's an honest rating) that it can output that much power.

To answer your last question, assuming the receiver has discrete amplifier stages, you are not going to get 250 wpc out of it....you'll still just get 100 (or maybe very slightly more) wpc.

audrey

I run mine all the time as well. But w/ 5.1 sound from a DVD, typically all 5 channels are not driven to the same level all the time; in a PA setup all 5 channels will be in use most of the time. If Joe has a receiver that shares a power transformer across all (or even some) of the channels (not uncommon) there's some risk of over heating or clipping or both.

Miami Joe

To continue/add information...
The receiver that I've got is a Sears purchase: JVC $299 DD & DTS Audio Video receiver with a few DSP's with 500watts total and I think 100 W.P.Channel. So I guess it is somewhat lowend however, my other Yamaha RXV992 with just DD cost me about twice that much a few years ago, so maybe technology (and components used to make them) are cheaper.

The mic. can be attached to a small 2 channel "physical" Gemini mixer, and then I can also attach the Laptop to its channel 1.

The makeup of the party... should last from about 2pm until 8pm, starting out at "medium throttle" from a music media stand point and as the folks get more liquored-up the dance floor should be "jumpin-jumpin"... Then it could get somewhat loud, and I'd say louder than you'd listen to any DVD movie. So maybe the people will provide diflection of much of the sound. Its a cash bar so that's why I'm hessitant to invite y'all, since we DVD-Talkies love our DVD and other bargains, (and I haven't found any online coupon codes to work at that bar.)

Amp... Would only be able to do 2 speakers off the amp @ 125 per spkr @ 8 ohms, I think, otherwise if I do 4 speakers off the amp which I think i can do, I would only be sending 62.5 watts to each (100W 8ohm) speaker... again I think thats right... (250 watts Div. by 4).

I'm going to play with it in the spare bedroom tonight and see how it sounds... I feel like the music will "sound" better coming out of the receiver, but power-wise maybe the amp is the better choice... hmmmmm.
THanks Again!

jumbojp

It really isn't the wattage that is a factor as much as the current.

If you draw too much current for too long from that receiver it will fry.

That being said I for one think as long as the speakers are 8 ohm and you hook them up in Dolby Surround, 5 channel stereo, or whatever mode it is called on your receiver where the fronts and surrounds get equal power you will be fine.

Keep an eye on the receivers temp by touching the top every few minutes and especially after a "bassy" song.

BUT: (had to edit cause I just thought of this, duh!)

If you are really worried about it hook the extra amp to the "Tape Loop" output on your receiver and power 2 of the speakers using that amp

Miami Joe

Thanks again... I'll try it