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Aes820 05-13-2005 02:26 AM

If the speakers that you have are 8 ohm speakers, they will need to be rated at at least 200 watts each.
If so, yes.
But it really does depend on the specs of the speakers.

Ozduck 05-13-2005 03:17 AM

well it damage the speakers if they arnt the right specs.. even if just testing them starting like at a low volume??

airborne50caliber 05-13-2005 09:48 AM

if the impedance matching is way off, things might get damaged independant of the operating level.

Sacto-Grrrl 05-13-2005 01:51 PM

Feedback and Monitors
 
Hello boys and girls,
First post here - hope I'm not screwing it up.

I'm in my first band; I sing lead and play rythm guitar. We have a bass player who also sings backup, and a drummer, and we play rock/pop-punk. I've never known anything about sound equipment before, but have recently purchased a bunch of stuff and I'm learning.

Here's my questions-
1.) I have a Yamaha EMX5000 combo mixer/pa and a pair of Yamaha S115V (15") main speakers. 500 watts or 1,000 watts bridged power. We will only run 2 vocal mic's through them. Should be plenty powerful for local bar gigs, I hope. But, in practice, I STILL can't hear my vocals. So I'm considering a monitor. I guess it makes the most sense to get the Yamaha 15" monitor, right? Any thoughts on that?? In that case, I guess I will have to bridge the 2 mains, right? How is that done? Through a basic speaker cable?

2.) Are there some basic principles for setting up the stage sound equipment that helps avoid feedback?

I know this is all probably very elementary to most of you. I appreciate your help! Rock on~

moaner 05-13-2005 02:56 PM

trust me, speaking in intelligble english has already but you in the top 5% of newbies.

[QUOTE]1.) I have a Yamaha EMX5000 combo mixer/pa and a pair of Yamaha S115V (15") main speakers. 500 watts or 1,000 watts bridged power. We will only run 2 vocal mic's through them. Should be plenty powerful for local bar gigs, I hope. But, in practice, I STILL can't hear my vocals. So I'm considering a monitor. I guess it makes the most sense to get the Yamaha 15" monitor, right? Any thoughts on that?? In that case, I guess I will have to bridge the 2 mains, right? How is that done? Through a basic speaker cable? [/QUOTE]

15" monitor would be great, but a little unnecessary if you're only putting vocals through it- a !2" one would do you fine.

Bridging the amp (if it is explicitly possible) would be done with a switch on the amp. but since you could pick up a powered 12" monitor for not too much more than a high end 15" passive, i'd advise doing that.

Aes820 05-14-2005 02:17 AM

Sacto-Grrrl:
Welcome to the forums.
First off; 2x500 watts should be plenty enough. Very suitable for pub gigs.
But, of course, while on stage with the rest of a band, if may be difficult to hear yourself. And, in that case monitors might be a good idea.

Even tho it is possible to split your PA to handle both main mix and monitoring systems. I am enclined to advise against it. Because doing so will reduce the poweroutput of your main speakers and will prevent you from making use of the stereo dynamics.

Instead, purchase yourself a powered speaker. Something like this:
[url]http://www.peavey.com/products/browse.cfm/action/detail/item/91259/number/00392610/cat/98/begin/1/112PM%3F+Floor+Monitor.cfm[/url]
Run this off one of the Aux send outputs on your PA.
And because it is self powered you wont have to worry about the loadings off your PA, or bridging.
It defiantely makes it easier.

Aes820 05-14-2005 02:28 AM

Steve:

1. It wont be 'twice as loud' per-se. Although it will be considerably louder.
Because of the extra speaker area and increase in power. You may have an increase in loudness of about 6dB.
And although 6dB may not sound like much in words, it may very well sound like a lot when you are standing infront of it.

(for it to be 'twice as loud' there'll need to be an increase by about 12dB)

With this +6dB increase in mind. You may find that you'll be able to reach similar volumes as you used to have while the level meter on your PA was reaching 0dB (with just the two speakers). But now with the level meter reaching around -6dB.
So, think about how loud your setup was when the level meter was up at 0dB. With the extra speakers on, it may be that loud while the level meter is at -6dB.

2. Those 4 core Speakon connectors are for use in larger PA setups where you [B]biamp[/B] the speakers. That is you have a seperate amplifier for the high frequencies and the low frequencies.
Those outputs on the back of your speakers are just for the parrallel connection on additional speakers. Your speakers cannot be biamped.

You can just use a meter or so 2 core cable, with the NL2FC connectors. For each speakers. Like you have shown in your diagram.
There will be no need to replace those long speakers cables of yours.

How you have drawn the diagram is spot on correct. :)

aussiegnr 05-14-2005 03:18 AM

Hey there guys,
Just recently posted a question to Chris aka Aes820, but ill also send it here in case others can help aswell or learn from stuff im going through.
I have:
1. Powered mixer with 2 x 400w @ 4 ohm or 2 x 200w @ 8 ohm.. and
2. i currently have 2 x 200w rms @ 8ohm loud speaker cabinets connected...
and i use the PA to connect mic and semi accoustic guitar..and play with a drummer, and a lead guitarist who uses his own amp.

Recently i posted that the vocals still werent that loud..or that i had to really crank the levels up close to max to reach acceptable vocal levels in comparison to drums and electric guitar. And got Chris to listen to it (i live in the same city and gave him a test listen), so i could atleast know if there was a problem.. thankfully its all good, ie. as loud as it should be. Thanks again for that Chris, i appreciate the time u took to help out ;)

So BASICALLY I WANT MY SYSTEM TO BE LOUDER (eg vocals so i dont have to strain and be able to hear myself) WITHOUT GETTING EVEN CLOSE TO MAX...

So what ill most likely do is keep what i have already, and get myself 2 more 200rms @ 8ohm speakers, and connect them so i have 2 loudspeakers on L and 2 on R..... this will essentially make me use all the power of my amp, ie. each side will have 400w rms @ 4ohm.
Heres a pic to explains what i have in mind:
[url]http://s25.yousendit.com/d.aspx?id=35M0N70PYJVEU2G64LGN31FHCV[/url]
As the pic suggests, the cool thing about this is that if infact we decide to gig (currently just havin fun jamming but wanting good sound quality), i could even hook up an active/powered monitor speaker to the preamped connection.

A couple of questions:
1. Will this new setup i want (2 extra speakers as the pic shows) mean approx twice as loud how i can get it now? im hoping to be able to get it a bit louder than how we have it now, but at a comfortable level, without even getting close to the clipping light...

2. The only drawback to a system like this one i want (as in the pic) is the weight of it all (4 speakers instead of 2). Thankfully the school i work and jam at has good storage facilities for me so its not that bad. But..is there anywhere one can get single 400w rms @ 4ohm speaker cabinets (with both subwoofer and horn in the one cabinet)??ive only seen one on the net after extensive searching, and that was just a subwoofer.. itd make things so much easier if i could use 2 x 400w rms @ 4ohm speaker cabinets.... meaning just 2 speakers instead of the 4 im currently gonna do.

I was actually thinking of getting a single 800w rms speaker (sub and horn) if they exist, and just bridge it, so that id have only one mother of a speaker to carry round..
But for possible future gigging this one speaker approach probably wouldnt work too well.. guess id be better to half it and have a speaker on each side.. which again is why id love 400w rms @ 4 ohm speakers :)

My Initial goal (and i guess it still stands today) was to get a POWERFUL System, so that vocals could be heard clear and loud over the drums and lead guitar, and to be able to do this very comfortably (using bout 1/2 - 3/4 of max of system), but with the SMALLEST, LEAST amount of equipment. Maybe i need to pay abit more, but money isnt a great issue.. providing its not too much ;)

well thats about it.. any help would be great, and im hoping someone learns from my stuff aswell... after about 2 months of researching this PA stuff.. it is beginning to make good sense. And thanks again to chris and the rest of the helpful guys on this forum.
take care peeps,
steve ;)

aussiegnr 05-14-2005 03:41 AM

[QUOTE=Aes820]Steve:

1. It wont be 'twice as loud' per-se. Although it will be considerably louder.
Because of the extra speaker area and increase in power. You may have an increase in loudness of about 6dB.
And although 6dB may not sound like much in words, it may very well sound like a lot when you are standing infront of it.

(for it to be 'twice as loud' there'll need to be an increase by about 12dB)

With this +6dB increase in mind. You may find that you'll be able to reach similar volumes as you used to have while the level meter on your PA was reaching 0dB (with just the two speakers). But now with the level meter reaching around -6dB.
So, think about how loud your setup was when the level meter was up at 0dB. With the extra speakers on, it may be that loud while the level meter is at -6dB.

2. Those 4 core Speakon connectors are for use in larger PA setups where you [B]biamp[/B] the speakers. That is you have a seperate amplifier for the high frequencies and the low frequencies.
Those outputs on the back of your speakers are just for the parrallel connection on additional speakers. Your speakers cannot be biamped.

You can just use a meter or so 2 core cable, with the NL2FC connectors. For each speakers. Like you have shown in your diagram.
There will be no need to replace those long speakers cables of yours.

How you have drawn the diagram is spot on correct. :)[/QUOTE]


Hey chris, thanks for the quick reply hahah well that post u replyed to was bit fkd up cause i accidently (in the middle of finishing and editing) pressed the submit before id finished.. so i just deleted it an sent the finished version :)
Still thanks for the help.. great to hear i can use the NL2FC cables :) and just buy some shorter ones of the same kind ;)
And thanks for explaining the volumes of sound and ofcourse the confirmation of the pic ;)

Quick one on the Volume levels..u say to be twice as loud id need an extra 12db...
So whats more important for greater volume, db or watts??
these speakers i have are 96 dB@1watt/1metre.. well thats the SPL says, whatever that means..
If i happened to find some 200w rms cabinets with higher dbs.. thatd be better for volume right??
Ive noticed alot of active or powered speakers having high dbs eg 126db
IS that why these little speakers are so fkn loud hahah
Ill probably get one for a monitor oneday.

I was actually thinking of getting 2 powered speakers to replace my passive cabinet speakers, but thatd defeat the purpose of my powered mixer hehe..
which leads to the following question..
Would an option be to simply buy a mixer (not powered) + 2 powered speakers (300w with 120+db each).. i guess the only drawback to that would be ultimate future flexibility and having to use a few power outputs.. instead of the one im using now.. ie. just to power the powered mixer. Would this option be louder with a smaller package..if u know what i mean??

anyways dinners ready hehe.. talk later thanks again,
steve :)

PainKiller8191 05-14-2005 04:43 AM

[QUOTE=Aes820]^ It'll ruin it after time. It is normally fine to run vocals through a guitar amp. But after a while, (about 9 months or so) your amp will sound like crap.
As in, dont use your 'good' amp.

The range of frequencies of the human voice, and the levels of the vocal mic constantly overdriving the input stages of the guitar amp, does eventually take its toll.

For those in bands who are a bit strapped for cash and cant afford a proper PA. Just go to a second hand store and buy an old cheap guitar amp. Use that until you can afford something more permanent.[/QUOTE]

i hate my dad so much....hes like ya were gonna need a mic and an amp for a speech....now i dont have any speakers or cabs or anything i just have a 65w guitar amp, i use my mics for recording with headphones....

and also, my guitar amp is blown because we used it as a mic amp a couple times against my approval....so now he's saying well i payed for it its my amp so im gonna use it......now im taking off and he has no clue how to set anything up i hope he breaks everything

Aes820 05-14-2005 04:52 AM

That '96 dB@1watt/1metre' thing describes the speakers efficiency. For passise speakers, like yours, you'd expect anything under 100dB@1w/1m. Although the more the better. Those speaker you've got are very good speakers for what they are.
And I think you'd be hard pressed to find more efficient ones.

Those two powered speakers that I have got have an efficiency of 126dB.
Because, of course, they are active and they are internally biamped.

They are 300 watt speakers each. Although 220 of those watts are for the sub driver, and 80 watts are for the tweeter. So, that's what i mean by biamped. One 220 watt amp just for the sub, and one 80 watt amp, just for the tweeter. But 300 watts all up.

And, heh, you've heard how loud they are, for just little speakers they pack a mean punch. If anyone does ever want to buy some powered speakers for monitors or even FOH speakers. They are a great option.

How loud you'll actually be counts on a lot of things, not just the watts, but also the amount of speaker area you've got, the efficiency of the speakers and of course the natural acoustics of the room you are in.

I would normally tell people that 2x200 watts would be more than enough for jamming with a band. It is unfortunate that you don't feel as if it is enough for you. I hope others who are looking at PAs are not in a similar situation as what you, are and are let down if I tell tham that thier setup would be enough and they find that it isn't.

If you go off the "10 watts per person" rule, which I guess is an industry standard. You'd would think that a total output of 400 watts from your PA would be enough for a room with 40 people in it.

But, even tho powered speakers are good, you don't have much room for upgradability with them. It's totally up to you because it is your money, but just see how you go with those extra two speakers for your setup. It may very well be plenty loud enough.

Then, perhaps if you do later buy some powered speakers you could use them just for practising on their own. And add them onto your bigger PA for gigs. Just an option, i guess.

moaner 05-14-2005 05:29 AM

[QUOTE=PainKiller8191]i hate my dad so much....hes like ya were gonna need a mic and an amp for a speech....now i dont have any speakers or cabs or anything i just have a 65w guitar amp, i use my mics for recording with headphones....

and also, my guitar amp is blown because we used it as a mic amp a couple times against my approval....so now he's saying well i payed for it its my amp so im gonna use it......now im taking off and he has no clue how to set anything up i hope he breaks everything[/QUOTE]

its unlikely that putting a mic through it twice would blow a guitar amp, realistically.

PainKiller8191 05-14-2005 05:53 AM

noo theyve done it like fifty million times....i had just realized it damages it a couple weeks ago when my speaker blew

aussiegnr 05-17-2005 07:02 AM

[QUOTE=Aes820]That '96 dB@1watt/1metre' thing describes the speakers efficiency. For passise speakers, like yours, you'd expect anything under 100dB@1w/1m. Although the more the better. Those speaker you've got are very good speakers for what they are.
And I think you'd be hard pressed to find more efficient ones.

Those two powered speakers that I have got have an efficiency of 126dB.
Because, of course, they are active and they are internally biamped.

They are 300 watt speakers each. Although 220 of those watts are for the sub driver, and 80 watts are for the tweeter. So, that's what i mean by biamped. One 220 watt amp just for the sub, and one 80 watt amp, just for the tweeter. But 300 watts all up.

And, heh, you've heard how loud they are, for just little speakers they pack a mean punch. If anyone does ever want to buy some powered speakers for monitors or even FOH speakers. They are a great option.

How loud you'll actually be counts on a lot of things, not just the watts, but also the amount of speaker area you've got, the efficiency of the speakers and of course the natural acoustics of the room you are in.

I would normally tell people that 2x200 watts would be more than enough for jamming with a band. It is unfortunate that you don't feel as if it is enough for you. I hope others who are looking at PAs are not in a similar situation as what you, are and are let down if I tell tham that thier setup would be enough and they find that it isn't.

If you go off the "10 watts per person" rule, which I guess is an industry standard. You'd would think that a total output of 400 watts from your PA would be enough for a room with 40 people in it.

But, even tho powered speakers are good, you don't have much room for upgradability with them. It's totally up to you because it is your money, but just see how you go with those extra two speakers for your setup. It may very well be plenty loud enough.

Then, perhaps if you do later buy some powered speakers you could use them just for practising on their own. And add them onto your bigger PA for gigs. Just an option, i guess.[/QUOTE]

Hey there peeps,

Thanks for the info chris.. that biamp stuff was something i didnt quite understand, since lately ive been looking and researching on Powered Speakers. I will definitely get one bit further down the line for a monitor.. thatd be a great use for it… after listening to the one u had, im sold 

Well as u guys may know, ive gotta powered mixer with 2x400w @ 4ohm or 2x200w @ 8ohms. Been using 2x 200w rms @ 8ohm FOH speakers which for us was just not quite loud enough. Well id have to use most of its power to get the level that we need…

So what i was gonna do was buy 2 more of the same speakers, and add one of these 200w rms @ 8ohm speaker on each side (in parallel), meaning id have 400w rms @ 4ohm on each side… using the full capacity of the powered mixer (2x 400w @ 4 ohm) rather than the 2 x 200w @ 8ohm im currently using. But thatd mean 4 x 18.5kg speakers to carry around... tough on the arms.. plus a couple more speakon cables id have to buy.. other part of town ahhahah
Well, its still an option…

But get this… been doing about a week research looking for 4ohm speakers, so that I could get heaps of power, and only need 2 loud speakers all up. Finally found some in Australia.. :

Samson RS215 2x15 350watt Speaker Enclosure
RS215
Power Rating (@ 8Ω): 350 Watts RMS, 600 Watts Program
Nominal Impedance: 4 Ohms
Frequency Response: 35 Hz – 20 kHz ± 3 dB
Sensitivity: 101 dB SPL @ 1W/1m
MAX SPL: 128dB
LF Driver: 2 x 15-inch heavy-duty driver
HF Driver: 1-inch exit, 44mm Mylar diaphragm compression driver
Protection: Internal overload Lamp on HF driver
Weight: 80 lbs. 36.32 kg
Price $530.00 Australian

My option is to either get the 4 x 200w rms @ 8ohm speakers (400w on each side) as mentioned at top, or get these 2 x 350wrms @ 4ohm speakers. The weight will be the same, but having 2 instead of 4 will be easier… me thinks 

Also, these Samson 350w @ 4ohm speakers have a higher SPL or 101db @ 1w/1m compared to the 8ohm speakers I currently have which have 96db @1w/1m.

So basically its either the 2 x 400w rms (4 x 200w @ 8ohm speakers) at 96db @ 1w/1m….
Or 2 x 350w rms (2 x 350w @ 4ohm speakers) at 101db @ 1w/1m….

Im not asking anyone to make a decision for me, but id like to know what u guys think…
ie. Which would be the best way to go… also which would be loudest.. does the extra 5db make a difference…

And finally.. this is probably a silly question..and one I should have asked to begin with.. but chris… will it be ok for me to simply connect the 2 x 350w 4ohm speakers in my amp….. the same as I did with the 8ohm speakers…. ie. Is a parallel connection (2 x 8ohm speakers) the only way one must achieve the 4ohms?? Yeah silly question hahaha

Well finally like to say.. first sorta gig will be this Thursday.. and im **** scared hahaha im a teacher at this school.. atleast its not infront of an audience as such… its at expo night.. meaning all these activties will be goin on in our gym… but me and my half assed band will be on stage doing about 5 numbers hahah

Heres the set list (all covers) in no particular order:
Patience
Kockin on Heavens Door
Have U ever Seen the Rain
Kashmir
Civil War
Stairway To Heaven..
Funny thing is that I know the words to only 2 of these songs.. ill be reading the words off a sheet for rest hahaha how professional ;)

Btw we did a sound check today..and fkn amazing sound.. the reverb is amazing.. don’t need any on the mix 

Take care,
steve

Aes820 05-17-2005 05:13 PM

Getting some 4 ohm speakers is another good option for you.

They have 2x15" speakers in them. So they will be very bulky. And maybe difficult to transport. Check out their physical dimensions, and see how you go.

The difference in performance between the two 8 ohm cabinets compared to the one 4 ohm cabinet may only be very minimimal. May not be noticeable at all.
I think the main factor you'll have to take into consideration here is the ease of transorting your rig.
Have a think about it, but if it were me I would be more inclined to go for the seperate 8 ohm cabinets. At least you can mount two of them up onto stands, something that you may not be able to do with the 2x15 4 ohmers.

But good luck with the gig this thursday.

aussiegnr 05-17-2005 06:36 PM

Yeah youre right chris.. thats my biggest factor... having the power i need.. but together with the ease of transporting.

Hey chris do u know of any sites to calculate approx loudness of speakers based only on SPL and Max DB and Wattage (not taking the surface area or venue into consideration).
I mean its gonna probably be minimal difference, but would a set of 4 x 200w rms @ 8ohm speakers (each with SPL of 96db 1w/1m dont know the max) be louder than 2 x 350w rms @ 4ohm speakers (each with SPL of 101db 1w/1m and max of round 128)???
Will that extra 5db make some kinda good difference??

Id much rather only 2 set of speakers in terms of transport, but as u say..the samsons are at 2 x 15" which means pretty much the same size.
I have seen some other 350w rms @ 4 ohm cabinets with only the one 15" woofer included, but they cost a bit more.. thatd be great for transport. Still have to suss it out a bit.

The advantage of the 4 x 200w 8ohm speakers i guess is.. that i can position those speakers better.. in many ways etc... as well they have a 5 year warranty.

Still weighing it all up.. but the db is a factor at the moment.. as the 4ohm speakers ive seen so far have a db spl around the 101 mark..and max of 128

back to work,
thanks again chris,
cheers,
steve

Kosta 05-17-2005 07:10 PM

Ok, so, I do vocals in a metal/hardcore/math rock/shoegaze band (yes, we actually do mix all of that). I.. scream.

Anyway, I don't have a big budget. But, I need some active monitor speakers for my vocal amplification. Something that's about as loud as the guitars. Or even a bit louder. I don't know what amp our guitarist uses, but it's an average sized amp - far from the size of a practice amp.

What would be a fairly good budget priced active monitor. Let's say... a 100 watt one. Or 150?

Aes820 05-17-2005 07:28 PM

The way that the efficiency of speakers are noted is somewhat misleading for 4 ohm speakers.
This 1 watt / 1 meter thing is an idustry standard measurement, used for the testing the efficiency of all loudspeakers.
However this is usually taken in reference to 1 watt being equal to 2.83 volts.
But. With 4 ohm speakers, seing as they have only half the impedence of 8 ohm speakers, they require less voltage to do the same thing.
So 2.83 volts through a 4 ohm speaker would infact be equal to 2 watts (that's a +3dB difference).

Now, in english.

To compare the efficiency between the 96dB 8ohm speaker with the 101dB 4ohm speakers, you'll have to take into consideration the difference in ohms between the two, by deducting 3dB off the efficiency of the 4 ohm speaker.

Therefore that one 4 ohm speaker compared to the two 8 ohm speakers will have a difference in efficiency of only 2dB. Not 5dB.
But, that's not all that bad news.
Given that these 4 ohm speakers 2dB are more efficient. They will go about as loud while pumping out 100 watts as what those two 8 ohm speakers would while pumping out about 160 watts.
They will require less power to seem just as loud as the less efficient speakers would.

If you can cope with the fact that they will be harder to transport around, these more efficient speaker cabinets would be a good buy.

As for any actual equations for figuring this all out, I don't know of any, sorry.
But I did find this:
[url]http://www.electrosound.com/Speaker_Facts/v5no8.htm[/url]
It explains it technically but in good detail.

Nicko_Shmicko 05-17-2005 07:35 PM

Has anyone heard of wharfedale PA gear?

Aes820 05-17-2005 07:45 PM

[QUOTE=Kosta]Ok, so, I do vocals in a metal/hardcore/math rock/shoegaze band (yes, we actually do mix all of that). I.. scream.

Anyway, I don't have a big budget. But, I need some active monitor speakers for my vocal amplification. Something that's about as loud as the guitars. Or even a bit louder. I don't know what amp our guitarist uses, but it's an average sized amp - far from the size of a practice amp.

What would be a fairly good budget priced active monitor. Let's say... a 100 watt one. Or 150?[/QUOTE]
A couple of these would probably do the job.
[url=http://www.peavey.com/products/browse.cfm/action/detail/item/91259/number/00392610/cat/98/begin/1/112PM%3F+Floor+Monitor.cfm]Link[/url]

But, even tho active speakers make it easy, they arn't usually budget priced.
Those Peavey ones arn't exactally huge, but if you point them righ tat your face they'll be right.

But if you can afford a few extra dollars, you should definately look into these ones:
[url]http://www.questaudio.net/prod_qsa200.shtml[/url]

I havn't heard much about wharfedale gear, sorry.

Nicko_Shmicko 05-17-2005 07:51 PM

[QUOTE=Aes820]

I havn't heard much about wharfedale gear, sorry.[/QUOTE]

Its pretty cheap...like cheaper than behringer cheap so i just want to know what its like

aussiegnr 05-18-2005 03:00 AM

Thanks for that Chris.. thats link u put up was awesome :)
Should have read something like this before purchasing the speakers i got.
The db efficiency is the thing i found most interesting.. and now im beginning to understand it.

I guess it means if i put out around 350w rms through my 8ohm speakers (sensitivity of 96db @ 1m/1w) and 350w rms though my 4ohm speakers (sensitivity of 101d @ 1m/1w - which as u say equates to round 2db extra efficiency) , the 4ohm speakers would be somewhat louder at this wattage.

So in that term, id rather get the 2 x 4ohm samson speakers, but as u say.. i now need to weigh up the transporting of cabinet issue...ill sort that out soon hahah

Oh..and one snag.. just checked the specs of the Samson 4 Ohm Speakers again.. heres what it says:
Power Rating (at 8ohm): 350 Watts RMS, 600 Watts Program
Nominal Impedance: 4 Ohms
Frequency Response: 35 Hz – 20 kHz ± 3 dB
Sensitivity: 101 dB SPL @ 1W/1m
MAX SPL: 128dB
LF Driver: 2 x 15-inch heavy-duty driver
HF Driver: 1-inch exit, 44mm Mylar diaphragm
compression driver
Protection: Internal overload Lamp on HF driver

THe problem i have is what it says at the Power Rating.. ie. says at 8ohms 350w rms. But it says impedance at 4ohms.
I initially thought it meant 350rms at 4ohms.... but now im pretty sure that the 350w rms is at 8ohm.... what do u think chris??
I wonder what rms the speakers are at 4ohm?? ive emailed the site about this.. hoping they get back to me soon.

well im off to do some more research... thanks again for that link ;)
cheers,
steve

Aes820 05-18-2005 04:38 PM

[QUOTE=aussiegnr]
I initially thought it meant 350rms at 4ohms.... but now im pretty sure that the 350w rms is at 8ohm.... what do u think chris??
I wonder what rms the speakers are at 4ohm?? ive emailed the site about this.. hoping they get back to me soon.
[/QUOTE]
That's a good question. I can't think of anything to explain that just now. Perhaps wait till the manufactures get back to you.

aussiegnr 05-19-2005 06:21 AM

Yeah ill do that.. just checkin out some other speakers.
Ive come to realisation (well i did recently anyways) that my powered mixer is all i need.. ie. probably the cheapest powered amp with that much power.. giving the 2 x 400w @ 4ohms.... hence all i need to do now is find the correct speakers.
After lookin at that great Speaker links chris sent a few posts ago, im not only searchin for the 4ohm amps, but also taking a note of the db.

Jeez i hope my questions are helping other people out... or i hope chris answering my questions helps people out hahah
well i have another couple for you chris, if u dont mind :)
I just saw some speakers and it has the following spec regarding db:
Sensitivity: 98dB 1 Watt / 1 Meter.
Maximum Output SPL at 1 Meter: 120dB Continous 126dB Peak.

I thought Sensitivity was what the speakers Continuous db was...
Whats the difference... are there any good links on these.. ill have a search for some now.. and see what i can find.. if i get a good one..ill send it in.. its the least i can do with all the help uve been doing.

btw.. i finally overcame my fear.... we gigged first time ever.. was first time ive ever sang in front of more than 2 people.. same with the guitarist and drummer. This was at my school.. infront of my teacher peers.. and students.. 'tough crowd' ahhahah well i have to say although we didnt do our best, due to not getting sound exactly right, some tuning issues, and the drummer goin bit too fast occasionally (i love using the drummer as a scapegoat ahhah), but we did rock :) We didnt get to talk to many people during or after because it was getting late 8pm and most where ready to leave this expo function... but we did get some good feedback, but tommorrow will be the d day.. kinda.. its back to school..and talk will get around bout our performance.. ****..now im nervous hahah nah.. i loved it.. thats the important thing..
We just did covers: Have u ever seen the rain, Knockin on heavens door, Patience, Civil War, Kashmir, Stairway to heaven, Jack n Diane.. and TNT..
Funny how i couldnt sleep the night before.. i was so **** nervous..but prior to the show..when i thought id be most nervous.. i gradually pumped myself up.. did a good warmup with vocals in the music room 20mins prior, then hit the stage in the gym...
so yeah.. the rambling is over... im a quite a shy guy.. and public speaking has been my biggest fear all my life....so jeez im so **** proud of myself (if i can say so myself) and my bandmates for doing this... just makes me wanna do it more. Makes me also wanna get a better sound system even more so... new speakers, plus a monitor would be great.. cant wait.
as u can tell..im pumped... probably wont be able to sleep tnight cause i still have all the energy rush from our first ever gig ;)
cheers,
steve

Aes820 05-19-2005 04:49 PM

Congratulations. For a first gig, I'm sure it went well.

The continuous power output of an amplifier would be rated in watts, RMS. This is like the [B]average[/B] power output of an amp.
Because music is always changing, and the audio wave contains many variations in intensity. The power output of an amp is not always consistant.
So, this continuous power output is the average of what the amp will pump out under normal working conditions.
Those speakers will be able to produce a maximum level of 120dB under these conditions while receiving their maximum rated RMS watts.

Peak power is the absolute maximum amount of power that an amp can output. However this peak may only be for fraction of a second. This peak level would be the upper limit of your amplifers performance.
Speakers can peak to, but with speakers, this peak limit describes the absolute maximum amount of power the speaker can receive before damage will occour.

If you consider the fact that everytime you add 3dB you double the power, and there is a 6dB difference in those speakers rated continous to peak rated power handelings.
If, for example, those speakers are rated to handle a maximum of 400 watts continous. Then they will be able to handle an absolute maximum peak of 1600 watts.
This figure can help while shopping for a suitable poweramp for the speakers.
But, If all this doesn't sound too clear. It need not be worried about too much.
The majority of small PA users may not need to know all this.

aussiegnr 05-19-2005 06:47 PM

That makes sense.. got the pic how db rating of speakers relates to max watts ;)
Its getting clearer and clearer which is great.
Ok.. one more thing.. so what does the Sensitivity mean then, ie. : Sensitivity: 98dB 1 Watt / 1 Meter.
This i the the way most specs are shown in regards to specs and speakers..
Alot dont show the continuous spl and max spl.. but rather just the Sensitivity SPL.

well.. back to work..
thanks again chris..
talk soon,
steve

Aes820 05-19-2005 07:00 PM

That "98dB 1 Watt / 1 Meter" thing describes the speakers efficiency.
It is an idustry standard of measurement to guage the peformance of a speaker.
It tells you how good that speaker is at converting an electrical signal into acoustic energy.
And, obviously, the higher the better.

It is a measurement of the sound created by a speaker when it is fed a 2.83 volt signal (equal to 1 watt through an 8 ohm speaker) at a distance of 1 meter.

But. Take note that 2.83 volts through a 4 ohm speaker is equal to 2 watts. So the efficiency of a 4 ohm speaker is always going to be 3dB higher than an 8 ohm counterpart. And when comparing them to each other you must deduct 3dB off the rating of the 4 ohm speaker.

aussiegnr 05-19-2005 09:32 PM

Cool all makes sense... great stuff.
Now just to tie things up one more question: so in terms of db.. is sensitivity spl the thing to look for, ie. that 98db 1w/1m thing....
rather than the Maximum Output SPL at 1 Meter eg. 120dB Continous 126dB Peak??

ie. im thinking that the sensitivity spl or effieciencty, will generally mean a higher continuous or peak.. is this right???

Basically am i right in saying, in terms of checking the effieciency or db rating, all i should look at is Sensitivity SPL?? I do remember u saying if comapared to 2 speakers of the same wattage, if one has sensitiviy of 96db 1w/1m and the other has 99db 1w/1m, that at the same wattage (from the amp) the second speaker would be twice as loud.... or another way to put it... the second speaker can reach the same loudness with half of the wattage used for the 1st speaker??? is this right... well hope so.. if so.. then im getting clearer about it all :)

have a great day chris, and the rest of ya,
steve ;)

Aes820 05-19-2005 10:43 PM

Yeah. When speaker shopping the thing to take note of most is the speaker efficiency.
It is that, combined with the power handeling of the speaker, that the maximum SPL figures are derived from.
But, with highly efficient speakers, comes an equally high price tag.

But, yes, you seem to have a correct understanding of the concepts with speaker efficiency. But the majority of PA buyers need not know this, although it is handy for those who want the best stuff regardless of the price tag.

aussiegnr 05-20-2005 03:13 AM

Excellent stuff chris :) Thanks for all ure help dude.. yeah itll definately help me out :)
Im gonna go to Better music tommorrow.. may well purchase some speakers.
Just recently found another 4ohm speaker, but in this case..its only a single 15" rather than the 2 x 15" of that previous 4ohm samson speaker i spoke about.

These are the speakers:
[url]http://www.musicianswarehouse.com.au/default.aspx?Pg=21&ProductCode=HPS154X[/url]

they are peak audio speakers, ... comes in 8ohm(HPS-154X) and 4ohms (HPS-154XA) .. and initially got info that these were 300w rms at 4ohms, but after emailing the peakaudio site, they told me this model has infact been upgraded to 400w rms at 4ohms.. perfect.. well im happy with 350 - 400w rms at 4ohms.
But fact that its a regular sized speaker box makes it even better...
And even better is the fact that they are sold in canberra at Better music and Pro Audio.. so ill check them out tommorrow..and any other 4ohm speakers they have.
The only thing ill check also is the db efficiency ;)

One thing i kinda find unusual though... ive seen this on a number of sites selling speakers... when there is the same speaker cabinet that lets say is 300w rms, and it comes in either 8ohm or 4ohm... but are the same price or slightly different...
id think, considering that the 4ohm allows for much more power use of an amp like mine
that itd be much more expensive...

anyways.. have a good weekend peeps
steve :)

moaner 05-20-2005 03:29 AM

[QUOTE]id think, considering that the 4ohm allows for much more power use of an amp like mine
that itd be much more expensive... [/QUOTE]

I would too, since lower impedance speakers certaintly used to be harder to make.

aussiegnr 05-20-2005 04:55 AM

Yeah.. i still find it weird.. i mean.. when i first got into my PA research.. and finally began looking for a simple setup powered mixer... all powered mixers would advertise their output in 4ohm ratings (or their total bridged output).. so theyd look so promising etc... even though most cabinet speakers come with 8ohm impedance and only use half (or abit above) the 4ohm amp rating.
considering this.. i would think that itd make sense to have more 4ohm speakers available.. its taken me weeks of net search to find some 4ohm speakers that had an rms of 300-400w (at the 4ohm impedance).
I didnt know that 4ohm impedance speakers were harder to make.. maybe thats the reason they are harder to find... this and the fact that they allow for great power usage (louder volumes with a same sized speaker) makes me question the pricing of them...
either way.. im happy that they dont cost much extra hahaha what am i complaining about.. im just curious :)

devildriver421 05-21-2005 08:27 PM

alright right now my band is using this PA system for our singer. and soon we'll be putting our drummer through it, well his bass drum. [URL=http://www.musiciansfriend.com/srs7/fg=101/g=live/s=packaged/search/detail/base_pid/632200/]here[/URL]
now, its only 80 watts, and my guitar amp is 120, bassist has 120, and of course drummer is loud as hell. so we cant even hear the singer most of the time. hes gonna be upgrading soon. and we're wondering if we can replace just the speakers with something like [URL=http://www.carvin.com/products/single.php?ItemNumber=1230&CID=CLB]this[/URL]

not that exact model maybe, but something like that. could we do that, and then replace the mixer later? and will it be much louder with 150w or 300w speakers instead of 40w if we're still using an 80w mixer?

moaner 05-22-2005 06:17 AM

[QUOTE=devildriver421]alright right now my band is using this PA system for our singer. and soon we'll be putting our drummer through it, well his bass drum. [URL=http://www.musiciansfriend.com/srs7/fg=101/g=live/s=packaged/search/detail/base_pid/632200/]here[/URL]
now, its only 80 watts, and my guitar amp is 120, bassist has 120, and of course drummer is loud as hell. so we cant even hear the singer most of the time. hes gonna be upgrading soon. and we're wondering if we can replace just the speakers with something like [URL=http://www.carvin.com/products/single.php?ItemNumber=1230&CID=CLB]this[/URL]

not that exact model maybe, but something like that. could we do that, and then replace the mixer later? and will it be much louder with 150w or 300w speakers instead of 40w if we're still using an 80w mixer?[/QUOTE]

it will be no louder at all. Sorry guys- you just need a bigger system, full stop.

Aes820 05-22-2005 04:51 PM

Yep.
The actual power comes from the PA head.
The power rating of the speakers is merely an indication of how much power those speakers can safely handle. That is, those speakers can handle [B]up to [/B]300 watts.
You'd want to save up for a more powerful PA setup.

devildriver421 05-22-2005 05:45 PM

well my friend doesnt have the money for a whole PA system right now, so he wants to upgrade bit by bit.
whats the difference between actives and passives? because i found passives for $50 each, cheap yes, but 150w. so if he got those speakers could he still use the mixer he has now, and then get a 300w mixer later?
[URL=http://www.musiciansfriend.com/srs7/fg=101/g=live/s=speakers/search/detail/base_pid/609014/]here[/URL]

also, will the feedback start at a higher volume due to the louder speakers, or is that because of the mixer? so even though the speakers are nearly 4x as powerful, they wont be any louder at all? id think the 80w being pushed through the bigger and more powerful speakers would make it at least a little louder

Nicko_Shmicko 05-22-2005 06:25 PM

Active speakers have the amp built in to the speaker.

devildriver421 05-24-2005 01:13 PM

alright again sorry about all the questions, kinda new to this, and this forum is full of knowledge :thumb: anyway right now with the 80w mixer, could we just buy a 400w speaker and use only one, and then get a big mixer and another speaker? i mean 400w, its not like the mixer is gonna blow it, is it ok to run only one speaker. if not, could i use the 400w and the 40w speaker now? 40w each channel on the mixer

also, could he get the 400w speaker, then a 2x400w mixer, and only run one speaker? its a 800w bridged mixer, if that makes any difference. would that be ok, or would it be all 800w going into the one speaker?

aussiegnr 05-25-2005 04:11 AM

Hi there Devildriver..
well i have to be honest, i dont quite understand the question.. maybe cause im in a rush and didnt get much sleep,
Anyways.. i have a powered mixer rated at 2 x 400w rms each side.. its at 4 ohms, hence im bout to purchase 2 x 350 or 400w rms speakers at 4ohms impedance.
Personally.. id get either 2 of the same speakers, ie. a pair... or if i was to get a single speaker, id get a single powered (active) speaker of around 300w rms, and most powered speakers ive seen have great efficiency, ie. hi sensitiviy, at round 100db+ 1w/1m.

In fact, after i get my 2 x 350-400w rms speakers (which ill use for FOH, ie. facing audience), ill get a single 300w rms powered speaker as a monitor... itll make a big difference...

This probably wont help heaps, but i do know if i was to get only one speaker itd be a powered one..

cheers,
steve

devildriver421 05-25-2005 12:57 PM

actually yea that kind of helped...sorry ill be more clear though:
we have an 80w pa system, with an 80w mixer and two 40w speakers. its not loud enough, so we're gonna upgrade. he doesnt have the money for everything right now, so we're gonna upgrade in pieces. we want to get 2 400w speakers, and a 800w mixer(very very loud i know, but we're gonna be doing shows and micing drums and everything). so could we get one of the 400w speakers for now, run that with his 80w mixer, and then later get the other speaker and the 800w mixer?


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