Lab Gruppen IPD series loadlibrary speaker presets

Andy Turner

Freshman
Mar 31, 2016
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Copenhagen, Denmark
I read somewhere that there is a substantial difference between the original d&b amp presets and Lab Gruppen IDP amp presets for d&b Q series subs. I have heard both and noticed a lot more output on the Q subs on a Lab IDP than on a d&b D12 amp.

While making presets for my d&b speakers on a Powersoft amp I noticed this difference and wonder if boosting 4-5db in the 37Hz area, as they do in the Lab IPD preset -will be safe long term and what about SPL? The Q sub is tuned about 41-44 Hz if I recall correctly so boosting below that seems a little strange?

Below is a readout from the d&b and Lab amps. Guess which is the Lab :0)

Cheers, Andy

D&B_Q_presets LAB IPD VS D&B D12.jpg
 
Andy,

I'm honestly not sure about this, but I know from creating my subwoofer presets that it can by very tempting to create a preset with a boost below tuning frequency to get more extension. It doesn't actually work super will in my experience, and usually get best results when making up gain at the tuning frequency. That is one explanation of what's going on - trying to make a flatter FR and then using HP to control excursion. It's not the worst way to go.

The other option, and where I would actually put my money, is that that peak is for the cold, small signal tuning frequency. I bet that at lower levels the IPD makes more sense, but once the ports choke a little and the VC heats up, I'd put my money on the d&b preset making more sense.

I can't wait to hear what Alexander says, though!
 
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Hi Chaps,

Not having much luck finding out the specific reason for this, but I believe Max has guessed the most likely reason...

"The other option, and where I would actually put my money, is that that peak is for the cold, small signal tuning frequency. I bet that at lower levels the IPD makes more sense"

For questions on any newer presets and updates moving forward I will be able to answer these questions more accurately, to give you a bit of insight we are trying to focus more on building exact clones of other manufacturer presets now.

My apologies I could not give you more information here!

- Alexander Lane
 
Hello Alexander from Lab Gruppen. Any chance that a copy and paste function will be added to the IPD editing software? Also is there a way to un-"black box" the ready made speaker files so that we can see the DSP choices made and adjust them to our applications?
 
Not really interested in any sort of secret sauce but always curious as to the choices people made that got them to a particular solution. Case in point is the IPD preset for the JBL SRX712 speakers. Clearly very different from the stock JBL settings, very boom & sizzle sounding as if they were made to sound good in a car stereo or for a bad party DJ. I'd be curious to see what they did. I don't need a transfer function to tell me its very wrong for any application I might have. If the same sorts of choices were made for D&B and other speakers I'd suspect it was time to turn a new team loose on working up these settings.
 
I have had luck asking Powersoft for unlocked presets - but transscribing filter- settings between different dsp models will not necessarily give you a precise copy. I didn’t check to see if the limiter settings from Powersoft was open. I believe d&b uses ‘dynamic’ eq with their limiters and to my knowledge IDP series dsp does not offer that functionality. Again I would think that copying limiter setting would be very difficult and time consuming. I doubt Powersoft or Lab made that effort in their presets.
 
Thank you Alexander for sharing :). I must admit that I have never heard of anyone using Lab.gruppen presets having problems related to limiters. What I meant was that in the case of d&b that the original amps will give more SPL due to the heavy engineered limiters including e.g. Dynamic eq.
 
Thank you Alexander for sharing :). I must admit that I have never heard of anyone using Lab.gruppen presets having problems related to limiters. What I meant was that in the case of d&b that the original amps will give more SPL due to the heavy engineered limiters including e.g. Dynamic eq.
There are several FOH techs that have used GR as a master buss comp... myself included.
 
What I meant was that in the case of d&b that the original amps will give more SPL due to the heavy engineered limiters including e.g. Dynamic eq.

Limiters work differently depending on how they are designed. There are literally a dozen ways to implement protective limiting and when those limiters are in the amp, you can't really change the "how".

As for getting more SPL... No, it doesn't really work like that. You'll get *maybe* a couple dB more output, short term, but once the voice coils heat up you're into power compression at the loudspeaker and throwing more voltage/current at it will not produce anything but more heat.

If you are routinely running a system to the ragged edge, you need a system capable of greater SPL. We call that "enough rig for the gig."
 
Limiters work differently depending on how they are designed. There are literally a dozen ways to implement protective limiting and when those limiters are in the amp, you can't really change the "how".

As for getting more SPL... No, it doesn't really work like that. You'll get *maybe* a couple dB more output, short term, but once the voice coils heat up you're into power compression at the loudspeaker and throwing more voltage/current at it will not produce anything but more heat.

If you are routinely running a system to the ragged edge, you need a system capable of greater SPL. We call that "enough rig for the gig."
I beg to differ a little bit here. Depending on how the system is designed, you can definitely get more SPL out of a box with clever limiting. Is it ever realistically more than a 3-6 dB? No. But with the right limiting you can definitely get a box that keeps giving and sounds great even several dB into limit. d&b in particular do a fantastic job of this, and while the ultimate limiting factors are excursion and thermal dissipation, by carefully limiting just what causes the system to reach those limits rather than just compressing or reducing the entire system gain you can indeed get a system to keep going that few extra dB. And while 6dB isn't a huge number, when it would take doubling an 8 box array to get the same increase, it can make an enormous difference in getting "enough rig for the gig".
 
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