Underperforming PA....

[yorks5stringer]

The current band PA is an HK Lucas 600, 400 watts into a 15" speaker sub and 150 watts each into 2 X8 " speakers. It's heavy to roll around, the 1 sub gets in the way and for only vocals I thought some self powered cabs would be less hassle and a more powerful answer.

The Proel Flash 12HA's I've bought actually seem quieter with a MP3 into my desk even though they are rated at 500 watts each, as you are told not to run it with the clipping light on constantly.

I've read reviews of the Proels and they seem highly regarded and are not cheap: are my ears deceiving me?

PS and to cap it all, when first switched on they are quite noisy too....

Edited March 14, 2011 by yorks5stringer

[icastle]

[quote name='yorks5stringer' post='1162335' date='Mar 14 2011, 08:38 PM']The current band PA is an HK Lucas 600, 400 watts into a 15" speaker sub and 150 watts each into 2 X8 " speakers. It's heavy to roll around, the 1 sub gets in the way and for only vocals I thought some self powered cabs would be less hassle and a more powerful answer.

The Proel Flash 12HA's I've bought actually seem quieter with a MP3 into my desk even though they are rated at 500 watts each, as you are told not to run it with the clipping light on constantly.

I've read reviews of the Proels and they seem highly regarded and are not cheap: are my ears deceiving me?

PS and to cap it all, when first switched on they are quite noisy too....[/quote]

That would depend on how Proel have defined their '500W'.
If they've done it 'Behringer style' then in real terms those cabs are probably about 120W each.

[yorks5stringer]

"Continous 500 watts, peak 960 watts" These are not cheap, c £600 each!

[PVTele]

[quote name='icastle' post='1162402' date='Mar 14 2011, 09:21 PM']That would depend on how Proel have defined their '500W'.
If they've done it 'Behringer style' then in real terms those cabs are probably about 120W each.[/quote]
Don't exaggerate

The Behringer B215D powered cab is rated at 550 Behringer watts (peak power in other words) and 345W RMS.

Having said that, I do wish manufacturers in general (not just Behringer) would quote power as RMS into 4 ohms, and into 8 ohms, and then we'd all know where we stood

Edited March 14, 2011 by PVTele

[icastle]

[quote name='yorks5stringer' post='1162415' date='Mar 14 2011, 09:26 PM']"Continous 500 watts, peak 960 watts" These are not cheap, c £600 each![/quote]

Ouch - that's expensive!
Those figures don't really mean anything though as we have no idea what criteria they have used to make the measurements.
As they were £600 each then I'd be inclined to get in touch with the retailer and explain you aren't happy with the quality of them.

I have to say that I've not seen Proel kit being used anywhere before, it's mostly Peavey, JBL, EV and HK kit around here.

[icastle]

[quote name='PVTele' post='1162426' date='Mar 14 2011, 09:35 PM']Don't exaggerate

The Behringer B215D powered cab is rated at 550 Behringer watts (peak power in other words) and 345W RMS.

Having said that, I do wish manufacturers in general (not just Behringer) would quote power as RMS into 4 ohms, and into 8 ohms, and then we'd all know where we stood [/quote]

It was just a number off the top of my head , but yes, I totally agree that it's about time manufacturers worked to a single standard so that like for like comparisons can be made.

I think ours is the only industry where a standard measurement hasn't been adopted!

[Phil Starr]

The Proels ought to be OK, as you say they have reviewed extremely well. They use well rated Celestion drivers and claim a peak output of 128dB. The cdx1-1731 compression driver gives 110dB @ 1W and handles 75W giving 128dB which matches the Proel claim well enough. Proel say the amp is 400+100W 'continuous' and I'd use a 100W with this horn driver so the ratings probably are 'RMS' The bass driver looks like the TN1230 which will 'only' give 124dB at 400W however.

The Celestion drivers don't have particularly good excursion so low frequencies might be limited at very high power.

The HK's aren't bad speakers but the Proels ought to be louder. The only possible explanation I could guess at is that the lack of a bass bin is leaving you a little short here or that the flat response of the Proels is making them subjectively quieter. Alternatively the limit Leds may be coming in too soon.

I've just re read your post. The noise when you switch on shouldn't happen. It may indicate some instability in the system which is eating up power. If they are under warranty get it checked out.

Good Luck

[Thurbs]

Do you have a crossover? Passive or Active?

[xgsjx]

It does sound like there's a fault with them. Take them back to where you got them.
If they're less than 6 months old, ask for either a replacement or refund. Over 6 months & they'll maybe try to repair them 1st. If out of warranty, you're still covered for 6 years under the sale of goods act against faulty parts.

[thinman]

Just a thought - you said they "seem quieter". Is it a perception thing, i.e. they're less harsh, maybe less middy that the HKs?

Try having a fiddle with the E.Q. If you're just driving them with vocals they shouldn't be too challenged. I've got a pair of db Technologies Operas 415 which are quite similar in spec and it takes a fair bit to get the limiter light to come on - have never done it with vocals alone.

[yorks5stringer]

[quote name='thinman' post='1163584' date='Mar 15 2011, 07:57 PM']Just a thought - you said they "seem quieter". Is it a perception thing, i.e. they're less harsh, maybe less middy that the HKs?

Try having a fiddle with the E.Q. If you're just driving them with vocals they shouldn't be too challenged. I've got a pair of db Technologies Operas 415 which are quite similar in spec and it takes a fair bit to get the limiter light to come on - have never done it with vocals alone.[/quote]


No, it's not a perception thing...if I plug via the Mixer into the Mic In on the Speakers then there is plenty of power but the clip light comes on with the gain on at 9 oclock (zero is at 6 oclock)

If I plug into the Line In, they are about half the volume and no louder than my Hi Fi even on full gain. Both with an MP3 track which rattles the other PA

This is coupled with a buzz when first switched on which does not go by pressing ground loop switches or swapping to different mains circuits.

Gigged with them last night, plenty of power when into Mic In but clip light on as above. Have tried fiddling with EQ's but surely I should be going into the Line In and getting adequate volume: the Mic In is really too sensitive( hence the early clipping)?

Could'nt get to the back of the pub to listen last night as the cordless bass thing was on the blink!

Edited March 20, 2011 by yorks5stringer

[thinman]

OK - assuming that you have a pair of them, are you saying that both are equally bad? It would be a bit odd (though not impossible) for both to have the same fault so I'm thinking what could be common to both.

Could there be a problem with the signal being sent to them (though I'm not sure what would cause them to be both quiet AND cause the clipping light to come on). E.g. phantom power creeping in somehow?

Another thought, is the mains supply to them both OK - have you tried anything else in the maims supply to confirm it's OK?

[yorks5stringer]

[quote name='thinman' post='1170135' date='Mar 20 2011, 10:13 PM']OK - assuming that you have a pair of them, are you saying that both are equally bad? It would be a bit odd (though not impossible) for both to have the same fault so I'm thinking what could be common to both.

Could there be a problem with the signal being sent to them (though I'm not sure what would cause them to be both quiet AND cause the clipping light to come on). E.g. phantom power creeping in somehow?

Another thought, is the mains supply to them both OK - have you tried anything else in the maims supply to confirm it's OK?[/quote]

Both have the hum, even with nothing connected but tried them at another house and it was the same.

Have tried different leads too. Yes it is a Behringer mixer but it is fine with the HK system. Oh, and phantom power is off too!

[Phil Starr]

[quote name='yorks5stringer' post='1170112' date='Mar 20 2011, 09:53 PM']No, it's not a perception thing...if I plug via the Mixer into the Mic In on the Speakers then there is plenty of power but the clip light comes on with the gain on at 9 oclock (zero is at 6 oclock)

If I plug into the Line In, they are about half the volume and no louder than my Hi Fi even on full gain. Both with an MP3 track which rattles the other PA

This is coupled with a buzz when first switched on which does not go by pressing ground loop switches or swapping to different mains circuits.

Gigged with them last night, plenty of power when into Mic In but clip light on as above. Have tried fiddling with EQ's but surely I should be going into the Line In and getting adequate volume: the Mic In is really too sensitive( hence the early clipping)?

Could'nt get to the back of the pub to listen last night as the cordless bass thing was on the blink![/quote]
OK I think we may be confusing gain with power. The position of the volume control is irrelevant, it doesn't matter if the volume control is at 9 o'clock or 3.30. You may just be dealing with a mismatch between your mixer and your new speakers. Let's say your mixer gives out 100mV, the mic input is expecting 1mV and the line input 1000mV. This means your mixer is swamping the mic input unless it is turned right down. When you transfer the output to the line input the 100mV aren't enough to drive the amp to its full capacity. You can't get full output.

The hum and noise the mixer put out will have a fixed component which is unaffected by the position of the volume controls on the mixer, especially the hum. Let us say it is 1/10th of a mV. When you were driving your old amp the hum wasn't noticeable as it was only a thousandth of the signal. Into the much more sensitive mic input it is now a 1/10th of the signal and you hear it all the time. A little test you can do is to set it up for maximum hum and then turn off the mains to the mixer, but not to the amp. It should keep going for a second or two but the hum will magically disappear.

Another problem is that the mic input is probably 300ohms or low impedance and the mixer may be designed to match a high impedance input.

Alex Claber has an article on this site [url="http://basschat.co.uk/index.php?showtopic=3730"]http://basschat.co.uk/index.php?showtopic=3730[/url] which might be worth reading.

There's a number of things you could do, borrow another mixer with a higher output and see if the problem goes away. You can buy booster pre amps which will give you a little extra gain so you can match the line input. One cheap way of doing that might be to buy a simple little stereo mixer or even a graphic with a bit of gain to go between mixer and amp. If the Behringer is like the one I used to use then you might find one of the other line outputs or the control room output is a better match for your speakers.

Let us know how you get on

[yorks5stringer]

[quote name='Phil Starr' post='1170348' date='Mar 21 2011, 08:57 AM']OK I think we may be confusing gain with power. The position of the volume control is irrelevant, it doesn't matter if the volume control is at 9 o'clock or 3.30. You may just be dealing with a mismatch between your mixer and your new speakers. Let's say your mixer gives out 100mV, the mic input is expecting 1mV and the line input 1000mV. This means your mixer is swamping the mic input unless it is turned right down. When you transfer the output to the line input the 100mV aren't enough to drive the amp to its full capacity. You can't get full output.

The hum and noise the mixer put out will have a fixed component which is unaffected by the position of the volume controls on the mixer, especially the hum. Let us say it is 1/10th of a mV. When you were driving your old amp the hum wasn't noticeable as it was only a thousandth of the signal. Into the much more sensitive mic input it is now a 1/10th of the signal and you hear it all the time. A little test you can do is to set it up for maximum hum and then turn off the mains to the mixer, but not to the amp. It should keep going for a second or two but the hum will magically disappear.

Another problem is that the mic input is probably 300ohms or low impedance and the mixer may be designed to match a high impedance input.

Alex Claber has an article on this site [url="http://basschat.co.uk/index.php?showtopic=3730"]http://basschat.co.uk/index.php?showtopic=3730[/url] which might be worth reading.

There's a number of things you could do, borrow another mixer with a higher output and see if the problem goes away. You can buy booster pre amps which will give you a little extra gain so you can match the line input. One cheap way of doing that might be to buy a simple little stereo mixer or even a graphic with a bit of gain to go between mixer and amp. If the Behringer is like the one I used to use then you might find one of the other line outputs or the control room output is a better match for your speakers.

Let us know how you get on[/quote]


Right, can u/s what you say about gain and am going to try different outputs now. However the humm/buzz I get is there with nothing connected other than the mains power leads to the Speakers and starts when I switch them on , irrespective of volume or no volume and have tried them at another house and they do the same....!

[icastle]

[quote name='yorks5stringer' post='1170755' date='Mar 21 2011, 03:09 PM']Right, can u/s what you say about gain and am going to try different outputs now. However the humm/buzz I get is there with nothing connected other than the mains power leads to the Speakers and starts when I switch them on , irrespective of volume or no volume and have tried them at another house and they do the same....![/quote]

Well if the hum/buzz is there even when the volume is turned fully down then perhaps it could be a 'mechanical' failure.

With that in mind and without hearing the noise, my first guess would be that it has to be poor quality/faulty or damaged transformers within the cabs.
If they get damaged then the windings can vibrate at 50Hz which will sound like a buzz - especially noticeable in an enclosure designed to throw as much sound out as it can possibly manage to.

The other 'mechanical thing' that can do it is a badly routed piece of cable getting clipped by a cooling fan (if your cabs use them that is!) - I've known PC's make a hell of a racket when this has happened.

[yorks5stringer]

These speakers have no fans........literally and metaphorically!

Have checked out the speaker specs....

Nominal sensitivity:

Line input +4 dbu (line level at max)
mic input from -5dbu to -35 dbu

Mixer specs are:

max output level +28 dbu

But a Shure 58 microphone plugged straight into the mic-in ( no mixer) causes the clip light to come in a low volumes whereas plugged into the line -in there is almost no volume or clipping. Surely ( no pun) a system like this should be designed to take an industry standard mic without clipping?

[Phil Starr]

It doesn't sound right for it to buzz/hum with nothing connected. Is the hum coming out of the speaker or is it coming from something inside the cab. I've had poorly made transformers be really quite noisy especially when you first switch them on.


It is fine for your mic to be able to overload the system. You'd want to be able to get the full wattage out of even a low output mic so the 'hotter' mic's would be able to overload the amp. you just have to turn down.

[icastle]

[quote name='yorks5stringer' post='1170838' date='Mar 21 2011, 04:26 PM']These speakers have no fans........literally and metaphorically!

Have checked out the speaker specs....

Nominal sensitivity:

Line input +4 dbu (line level at max)
mic input from -5dbu to -35 dbu

Mixer specs are:

max output level +28 dbu

But a Shure 58 microphone plugged straight into the mic-in ( no mixer) causes the clip light to come in a low volumes whereas plugged into the line -in there is almost no volume or clipping. Surely ( no pun) a system like this should be designed to take an industry standard mic without clipping?[/quote]

According to the Shure website, a bog standard SM58 is -54.5 dbu.
The other industry favourite, the SM57 is also -54.5 dbu.

[mrtcat]

This may not be the most helpful input but if it were me I'd be taking them back to the dealer and looking at having them replaced. It may be a bad batch or it may be that they're not up to the job either way powered speakers are meant to make life simpler so I wouldn't settle for poor quality. Especially when they clearly weren't cheap and there's some good kit out there.

[xgsjx]

+1

Take them back. Why are you wasting your time?

[yorks5stringer]

[quote name='xgsjx' post='1171462' date='Mar 21 2011, 10:41 PM']+1

Take them back. Why are you wasting your time?[/quote]


......because that is the one thing (time) I have, however have made the decision for them to go back: but it's not as simple as marching into a shop as they were got for me as a favour. But as people are saying, clearly there is something wrong with them.

Thanks to all for their input and advice!

[Phil Starr]

The HK Lucas speakers are also highly rated and though I can't find specs for your system which seems to be discontinued I cetainly wouldn't expect the Proels to be any louder,

However there does seem to be something wrong here, it probably is time to get back to the dealer.

[Bankai]

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[Moo]

There may be a confusion of a couple of different issues here.

1st,- Gain, and levels.
The 'line level' input of the speakers will be expecting a LINE LEVEL signal from another piece of pro audio equipment with a signal of approximately 1.737 volts also commonly known as +4dbu.
MP3 players do not produce this level from the headphone output and typically produce 100mV into 16-32 ohm earbud type headphones. It is normal for MP3 players to be quiet, and need a lot of gain boost when plugged into a line level input. Some pieces of equipment bypass the gain setting for line level inputs, because they are expecting the input to the line level socket to be Line level.

The XLR input: Does this allow you to switch between line level and Mic level?
It should be at line level (+4db or 1.7 volts) when plugged into a mixer.
A normal setting for the gain for a vocal mic should be around 30db gain for a normal singer. This is normally at the 12 o'clock position on the gain knob.
If you do not have a switch on the input to choose between Mic or line level, then it will be necessary to turn the gain to zero, and adjust the output of the mixer so that it is not high enough to clip the input of the speaker.

2. The Humming:
Does the speaker hum when nothing is plugged into it? If yes then the unit is faulty. This could be caused by a design fault, a manufacturing fault, or damage. Whichever means its not your fault, and you are entitled to be refunded. I would be wary about using a unit with a possible earth problem because it could electrocute the user.

If the speaker hums only when the mixer is plugged in, there could be a number of causes:
If you are connecting Mixer and speaker with jacks: Is the input balanced? Is the output of the mixer balanced? I have had a humming problem when an unbalanced jack output from a mixer was connected with a balanced TRS cable to an amp. The output and input need to be both either balanced or unbalanced to eliminate that problem.
If you are connecting the mixer to the speaker with XLR: Then the XLR input of the speaker needs to be switched to Line Level.
If you are connecting to a mic level input, it will be expecting 1-10mv level, but will be receiving 1.7volts level, and will noticeably amplify any tiny background noise or hum which is normal for any mixer to produce.

Hope this helps and is not too confusing.
Moo.