Calling audio nerds

[Tom]

Ok,

Been playing around with the Behringer Ultradrive and have come across something. Work with 2 tops and 1 sub, just for reference

When listen to songs, you can tell that the bass is that slightly slower. So I decided to add a delay to the tops to try and equal things out. So far I am at 10ms and sounds a lot tighter. 10milliseconds is not much but when you listen to a song, you can really tell the difference.


Why is there such a delay??? I know the sub has a larger driver but surley in a gig situation, the bass would be quite far behind the speaker tops, which would then make the music, sound off.


Can anyone help or explain. Bit baffled. :(

[spin mobile disco]

It is called being out of phase. Mackie tops for example have phase correction circuitry to stop this from happening. And DB sub-15's have a 180 degree phase correction switch. The mackie website has an interesting comment on this.

[Tom]

Strange.

I have the Mackies setup from 110hz up to 18khz so all the bass is coming from the DB Sub which is 35hz to 110hz. The sub is in phase and so are the Mackies so everything is setup correctly.

[nigelwright7557]

Ok,


Can anyone help or explain. Bit baffled. :(


If your system has crossovers then they add phase delays.

If your system is using different amps for tops and bass then they could be 180 degrees out of phase depending on the design of the amps and make.

Active speakers also have phase delays through the filter circuitry.


Personally I wont entertain crossovers, I use a 4 by 12 inch cab in association with a 18 inch bass cab with no crossover.
The bass cab doesnt need a crossover coz it rejects high frequencies on the impedance curve. A speaker is after all an inductor and rejects higher frequencies.

[Tom]

The Behringer Ultradrive is my crossover.

All my speakers are active. All speakers are in phase on the crossover and also on the back of the sub. The mackies do not have this function on the rear panel so I would say that they are in phase permanently.

I also took the woofer out of the sub to check the cables are on the right posts, which they are so I think I have covered everything phase wise.

I know if the mackies were out of phase with eachother then they would be cancelling each other out and sounding toilet. But they are ok.

You wont use crossover???

So you just let all the freqiencies of the 4x12 and the 1x18 crossover with each other. :eek:

[nigelwright7557]

You wont use crossover???

So you just let all the freqiencies of the 4x12 and the 1x18 crossover with each other. :eek:

Yes, sounds great, loads of bass yet still plenty of highs from the 4 by 10 inch speakers. The 10 inch speakers are full range.

The bass speakers impedance goes up greatly above 2.5KHz so automatically rejects high frequencies.

I woudl seriously suggest reading a spec for a speaker and you will be horrified at the frequency reponse and teh wide range of impedances over the frequency range it is specced for.

[Tom]

Just any old speaker or my speakers???

If you are on about self build then I am already designing plans. I am getting SPL levels the same as JBL, Martin and D&B. Not so much Void and FK1 as they use hornloaded systems which is where I am still learning.

I know the specs for my speakers so have setup the crossover to the specs provided by the manufacture

[A1DL]

If your system has crossovers then they add phase delays.

A crossover will add group delay representing the transit time for the signal to pass through the device. What's the problem though Nigel? The audibility threshold of delay varies by less than 2ms throughout the spectrum audible to the human ear and the delay introduced by the DSP will by equal at all outputs.



Personally I wont entertain crossovers, I use a 4 by 12 inch cab in association with a 18 inch bass cab with no crossover.
The bass cab doesnt need a crossover coz it rejects high frequencies on the impedance curve. A speaker is after all an inductor and rejects higher frequencies.

That's why your system sounds awful. Nothing to do with delays introduced into the signal path, the simple fact that you are sending the same full range signal into all the the amps/cabs with (supposedly) different purposes.

[nigelwright7557]

That's why your system sounds awful. Nothing to do with delays introduced into the signal path, the simple fact that you are sending the same full range signal into all the the amps/cabs with (supposedly) different purposes.

But it doesnt sound awful !

The bass is very strong with good mids and highs too.

I also have a 6 way tweeter box that doesnt need a crossover.
With the full range 4 by 10 cab I get good highs anyway.

[A1DL]

Just any old speaker or my speakers???

If you are on about self build then I am already designing plans. I am getting SPL levels the same as JBL, Martin and D&B. Not so much Void and FK1 as they use hornloaded systems which is where I am still learning.

I know the specs for my speakers so have setup the crossover to the specs provided by the manufacture

Which series' for each manufacturer are you looking at, Tom?

I'm surprised you put JBL and d&b in the same bracket - JBL are well known for being inefficient and power hungry, esp. SRX (although they sound nice) whilst d&b are noted for being incredibly efficient.

For example our new d&b Q7 (reflex) tops go 3db louder than the (hornloaded) Void Stasys 3 MkII boxes with 30º more H dispertion

[Danieleastwood.com]

There is a problem with that setup Nigel.

Without a cross-over, all your speakers are getting more frequencies to deal with than they were designed to re-produce. Yes speakers only audiably produce what they can, but they will still try to reproduce the frequencies they cant!!! They can get quite hot like this.

It may sound "good" and I without hearing it, I cant comment on that. All I'm saying is, a crossover can vastly improve system performance, Protect drivers, and reduce the strain on your amplifier as you won't be needing to drive it as hard to get the same effect.

[nigelwright7557]

There is a problem with that setup Nigel.

Without a cross-over, all your speakers are getting more frequencies to deal with than they were designed to re-produce. Yes speakers only audiably produce what they can, but they will still try to reproduce the frequencies they cant!!! They can get quite hot like this.

It may sound "good" and I without hearing it, I cant comment on that. All I'm saying is, a crossover can vastly improve system performance, Protect drivers, and reduce the strain on your amplifier as you won't be needing to drive it as hard to get the same effect.

The 10 inch speakers are full range anyway.

The bass speaker works upto 2.5KHz and the impedance rises massively above that frequency so it takes very little power from the amp above 2.5KHz.

[Tom]

A1DL - I was basing my figures around the SRX series actually.

I am getting same figures as the Q-sub but not able to use a low powered sub than what d&b use. If I am correct, d&b use b&c speakers which is what I have been using to get my figures aswell. Still trying out different drivers so not got my mind on what brand to use.

I know about the d&b speakers. There is a new thread on sp which is rather interesting to read. I don't know how they can get that much output from a 200 rms or driver. lol. I just think its over processed imo.

[Danieleastwood.com]

Fair enough, I suppose it keeps it simple with fewer links in the chain.:)

[A1DL]

I know about the d&b speakers. There is a new thread on sp which is rather interesting to read. I don't know how they can get that much output from a 200 rms or driver.

The D12 does some very clever stuff... and so it should for what it costs.

[Tom]

The D12 does some very clever stuff... and so it should for what it costs.

Yeah. lol. Would love to know whats going on. :D:D:D

[sleah]

The problem I see with the Behringer Ultradrive is the fact it is Behringer.

Not the best reputation amounst sound engineers.......:D

Sorry can't help other than that.
:coat::run::taxi:

Nigel,
I understand what you're saying about your 10's & 18's not having crossovers, but I'm not sure about the tweeters?
A tweeter can easily be destroyed by sending low frequecies to it.
Are you using peizos? I think they can take it as they are a totally different technology.
I used to use home build (well cobbled together:D) 15's loaded with piezos and no crossovers and they were pretty bomb-proof, until I seriously overdrove them:o
Personally I don't like the sound a piezo tweeter makes, but that's just my preference.

[Tom]

The problem I see with the Behringer Ultradrive is the fact it is Behringer.

Not the best reputation amounst sound engineers.......:D

Sorry can't help other than that.
:coat::run::taxi:



Brand snobbery comes to mind.

I agree that Behringer are not the best brand but a lot of people on the SP forums, who do know a lot about audio and how it works do recommend this unitfor its price to peformance. If I could afford other units I would get them but as I am quite new to the pro audio stuff, I am still learning.

I have other Behringer equipment and for the price, its not bad. Nothing I have from them has ever broken and dont expect it to either.

[Solitaire Events Ltd]

Brand snobbery comes to mind.



Why use Mackies then?

[A1DL]

Tom's right, the DCX2496 seems to have gained a reputation as being one of the better products from the Behringer stable, representing good value for money and allowing users whom otherwise could not afford a DSP, a reasonable entry level processor.

Sure, it's no DP226, but it costs about a tenth of the XTA, so what do you expect.

[A1DL]

Why use Mackies then?

I suppose they're not as immediatley obvious to the untrained eye as Uli's shiny silver gear. :p

[Tom]

Why use Mackies then?

I use Mackies as they are light weight cabs and have the power for my needs. I use my car for transportation to and from gigs, so I need small, light speakers that will fit in car with other equipment.

Mackies fitted the bill within my price range. RCF were too much and other brands I looked at were passive, which I am not ready for yet untill I get myself a van.

[sleah]

Brand snobbery comes to mind.

I agree that Behringer are not the best brand but a lot of people on the SP forums, who do know a lot about audio and how it works do recommend this unitfor its price to peformance. If I could afford other units I would get them but as I am quite new to the pro audio stuff, I am still learning.

I have other Behringer equipment and for the price, its not bad. Nothing I have from them has ever broken and dont expect it to either.

I actually agree 100%:D
It was nothing to do with brand snobbery, not from me anyway. Although it certainly is from some quarters.......
I just know that Behringer kit isn't nearly as good as Mr Behringer likes to think and have us believe, but as you say, darn good value for what it does!
It may be the problems being experienced are inherent with any 'budget' gear, or maybe not:confused: I don't know enough about them:(

[Larry B Entertainment]

I have been using Behringer equipment for years and have noticed that the gear is improving. The backline is still not quite there but the outboard units are very good for what they cost. The new line of mixers are fantastic in my opinion.
We use Mackie speakers with a behringer feedback destroyer at work with no problems at all.