4 0hms

[deltaforce]

how much harder does an amp have to work at 4ohms compared to 8 ohms

reason i ask is i have a warrior da-1300 watt amp
and a set of 250 watt class-d's

i have just brought another set of the class -d's 250 watt

will this match ok

thanks

[deltaforce]

oh yea also as i will be connecting the cabs from one to the other
do i have to change the mode setting on the back of the amp to parallel
or do i leave it in stereo
thanks again

[Excalibur]

how much harder does an amp have to work at 4ohms compared to 8 ohms

reason i ask is i have a warrior da-1300 watt amp
and a set of 250 watt class-d's

i have just brought another set of the class -d's 250 watt

will this match ok

thanks
No probs at all. In some ways it's a free sound upgrade, cos you get extra drivers to move the air, and etxra power to move it with.


oh yea also as i will be connecting the cabs from one to the other
do i have to change the mode setting on the back of the amp to parallel
or do i leave it in stereo
thanks again

Stereo's absolutely fine.

[NKR]

The amp will run happilly at both loads and sounds like you have linked everything up correctly. No need to adjust your amp as my Yorkshire friend said.
More air movement is good, which is why I like to have 4 cabs going for medium sized rooms. You don't have to spank it as hard, so you should actually be doing your amp and cabs a favour.

[deltaforce]

thanks for that guys
also could you explain what the mode switch is for then
bridge, stereo, and parallel,

also there is a sensitivity switch on the back
the options are 1.44v, 1.0v or 0.775v
the manual don't really explain what the different settings are for
thanks

[Excalibur]

thanks for that guys
also could you explain what the mode switch is for then
bridge, stereo, and parallel,
Stereo, two separate channels, two separate volume controls
Parallel, left hand channel is fed to both sides, left hand volume control only, but still two channels. Often used for driving subs, especially if the mixer sub output is mono, which it often is.
Bridge. Right, now we're in advanced territory. :( :( This adds both channels into one, usually connected to different terminals ( which is why you normally need a special cable for this) . If you know what you're doing, it can be an excellent way of powering subs. If you don't know what you're doing, it's an excellent way of blowing something up.


also there is a sensitivity switch on the back
the options are 1.44v, 1.0v or 0.775v
the manual don't really explain what the different settings are for
thanks

Exactly what it says on the tin. Low numbers mean you only need small signals to achieve full rated output. Some mixers ( Denon for one) have different outputs. If you're running a high output from your mixer into a low input on your amp, it should light the clip lights very easily. Too easily, cos you're running too much signal into the amp. Conversely, if your mixer has a low output, and the amp is on high, you'll struggle to get the volume. Matched, or thereabouts is best.

[deltaforce]

cheers Excalibur valuable info
i was at a gig and noticed the amp was clipping slightly
when i got home realized the mode switch had been moved i generally
keep it at in the middle at 1.0v

[Tom]

I'm not sure on how much harder the amp will be pushed but if I am correct, because there is less or a resistance, more power can be transferred from the amp to the speaker. Just don't go under 4ohm.

Amp will get warmer as more power is being generated.

[Excalibur]

Stereo, two separate channels, two separate volume controls
Parallel, left hand channel is fed to both sides, left hand volume control only, but still two channels. Often used for driving subs, especially if the mixer sub output is mono, which it often is.
Bridge. Right, now we're in advanced territory. :( :( This adds both channels into one, usually connected to different terminals ( which is why you normally need a special cable for this) . If you know what you're doing, it can be an excellent way of powering subs. If you don't know what you're doing, it's an excellent way of blowing something up.
.

Hold the front page, I think I'm slightly wrong here. Both volume controls operate, it appears. :o :o :o :o

[ppentertainments]

Hold the front page, I think I'm slightly wrong here. Both volume controls operate, it appears. :o :o :o :o
Not like you to be wrong Peter :D :D :D :p

[Excalibur]

Not like you to be wrong Peter :D :D :D :p

I'll try not to let it happen again. ;)

[Corabar Steve]

Hold the front page, I think I'm slightly wrong here. Both volume controls operate, it appears. :o :o :o :o
That may depend on make & model of the amp.

[markdj60]

Stereo, two separate channels, two separate volume controls
Parallel, left hand channel is fed to both sides, left hand volume control only, but still two channels. Often used for driving subs, especially if the mixer sub output is mono, which it often is.
Bridge. Right, now we're in advanced territory. :( :( This adds both channels into one, usually connected to different terminals ( which is why you normally need a special cable for this) . If you know what you're doing, it can be an excellent way of powering subs. If you don't know what you're doing, it's an excellent way of blowing something up.


Exactly what it says on the tin. Low numbers mean you only need small signals to achieve full rated output. Some mixers ( Denon for one) have different outputs. If you're running a high output from your mixer into a low input on your amp, it should light the clip lights very easily. Too easily, cos you're running too much signal into the amp. Conversely, if your mixer has a low output, and the amp is on high, you'll struggle to get the volume. Matched, or thereabouts is best.

How do you no if your mixer has a low or high output? im being thick again i think :confused:

[Corabar Steve]

How do you no if your mixer has a low or high output? im being thick again i think :confused:
What Peter is refering to is mixers that enable 2 different levels of output.

If you look on page 9 of this PDF http://www.denondj.com/Assets/DImages/Products/Manuals/f1160bc969bf42e0bc5e90b6600c5207.pdf?ts=071443 you'll see 2 switches between the Master (XLR) output & the Unbalanced (Phono) output.

The one on the left that says Att -10dB OFF ON is the one that switches between the 2 levels (& boy does it make a difference!)

[Excalibur]

What Peter is refering to is mixers that enable 2 different levels of output.

If you look on page 9 of this PDF http://www.denondj.com/Assets/DImages/Products/Manuals/f1160bc969bf42e0bc5e90b6600c5207.pdf?ts=071443 you'll see 2 switches between the Master (XLR) output & the Unbalanced (Phono) output.

The one on the left that says Att -10dB OFF ON is the one that switches between the 2 levels (& boy does it make a difference!)

Thanks Steve, clearer than my explanation.

[Squelch]

how much harder does an amp have to work at 4ohms compared to 8 ohms

reason i ask is i have a warrior da-1300 watt amp
and a set of 250 watt class-d's

i have just brought another set of the class -d's 250 watt

will this match ok

thanks

Personally boys I wouldn’t put those speakers on a 650 w rms per channel amp.Two 8 ohm speakers in parallel the amp sees 4 ohms so no probs there. The speakers are ratted at 250 watt (rms i hope and not music power) so the 2 of them in parallel Could handle 500 watts rms(rms = 0.707 of the peek power I think, its about 25 years since i was at college!)so they have got the possibility of being over powered by 150 watts rms or 75 watts rms each and that’s a lot of power!!The same thing has happened to a dj friend on NYE...so be careful .I would nearly always rate my speakers higher than my amp because of the peek power the speakers have to handle just to be on the safe side
But I’m no sound engineer just a sparky and that’s what I was taught
but I prob am wrong......

[Excalibur]

Personally boys I wouldn’t put those speakers on a 650 w rms per channel amp.Two 8 ohm speakers in parallel the amp sees 4 ohms so no probs there. The speakers are ratted at 250 watt (rms i hope and not music power) so the 2 of them in parallel Could handle 500 watts rms(rms = 0.707 of the peek power I think, its about 25 years since i was at college!)so they have got the possibility of being over powered by 150 watts rms or 75 watts rms each and that’s a lot of power!!The same thing has happened to a dj friend on NYE...so be careful .I would nearly always rate my speakers higher than my amp because of the peek power the speakers have to handle just to be on the safe side
But I’m no sound engineer just a sparky and that’s what I was taught
but I prob am wrong......

No right, no wrong, just different opinions. Peavey for instance recommend using an amp rated twice the RMS value of you cabs.


Here's a thread about it.
http://www.forum.mobilediscodirectory.co.uk/showthread.php?t=10463&highlight=amplifier+speaker

Contentious
http://www.forum.mobilediscodirectory.co.uk/showthread.php?t=10291&highlight=amplifier+speaker

Happy reading. :D

[CRAZY K]

Peavey for instance recommend using an amp rated twice the RMS value of you cabs.


:D

:confused:

I visited big C ( Corby Headquarters ) five years ago and was told no problem using XR800F---500 watts rms a side into 4 ohms--- was ok with two pro 15s and two pro subs---overall about 1000 watts rms handling--- these all came to the the Yorkshire Speaker fest last year.;)

Before Xmas I bought the UL15s 500watts rms a side ohms and during a conversation with Peaveys own Techo at the dealers premises was given the thumbs up using the XR8600 ---600 watts rms a side into 4ohms.

I guess as long as you keep out of red light areas ( no I dont mean Hull )
there should be no problems whatever your set up--

No doubt someone will disagree--I can only say 5 years down the line I have had no issues with fried or blown speakers:D :D :D

CRAZY K