PKN evaluation results

This is true lev, but and a big but, people assume roots music is all about low dirty bass... loud bass yes low no.... why do i say this....... you only have to look at at how the roots guys set up and listen to hear that alot of the sub content is 50 to 80hz...... not 30 to 50hz. yes some tunes do drop down to 30hz but most are not that low..... dub drops lower i agree, but even still alot of the power used is in the 50 to 80hz region..... if i compare roots to dance based music (dnb, dubstep,house) the important area is 90 to 150hz, but the music content in all most all tracks drops to 40hz and in some 30hz.... is this maybe an issue with the amps, working great at some frequency's and not others. To run 4 1850's from this amp and smoke 4 a side is some going. The cabs in question were being run 35hz to 90hz very flat response no big peak around the 60 to 80hz region like roots music......

bee wrote: This is true lev, but and a big but, people assume roots music is all about low dirty bass... loud bass yes low no.... why do i say this....... you only have to look at at how the roots guys set up and listen to hear that alot of the sub content is 50 to 80hz...... not 30 to 50hz. yes some tunes do drop down to 30hz but most are not that low..... dub drops lower i agree, but even still alot of the power used is in the 50 to 80hz region..... if i compare roots to dance based music (dnb, dubstep,house) the important area is 90 to 150hz, but the music content in all most all tracks drops to 40hz and in some 30hz.... is this maybe an issue with the amps, working great at some frequency's and not others. To run 4 1850's from this amp and smoke 4 a side is some going. The cabs in question were being run 35hz to 90hz very flat response no big peak around the 60 to 80hz region like roots music......

Have seen PL9/K10 run 4x PD1850s per side on hard Roots all night, and not blow any drivers. So would suspect the PD1850 not being right for Cubo, more than anything else there, as apparently the PKN doesn't output anymore power if used in 2.66 or 2 ohm mode.

Bee, you need to get out to more Roots gigs, GP soundoffs are not the gigs to hear Roots sounds that are firing on all cylinders" .

Have at least 100 tracks in my collection, that I've run through software Spectrum Analyzer, and they have peaks downto 35Hz. Won't even mention Iration Steppers tracks, where sub peaks more often in the 30-50hz region, than anywhere else.

When the chance comes up, go hear WSP, and see what it's like to have huge amounts of 35-50hz thrown at you from 8x scoops.

i have lev , just saying the way the pre amps, lms etc get set up to boost the frequency's around 60 to 80 for roots/ reggae/ dub etc, is very different to dance, which is very different to live music. All this does is put very different stresses on the amps. The cubo loaded with the 1850's are the nuts, the 4 drivers blew after we turned off, basically over heated, they were run over and beyond what they should of been :ohmy: ..... one thing to note I would never swap an amp for another with out re eq'ing the system as every amp sounds different to the next and will naturally change what we hear.....

bee wrote: i have lev , just saying the way the pre amps, lms etc get set up to boost the frequency's around 60 to 80 for roots/ reggae/ dub etc, is very different to dance, which is very different to live music. All this does is put very different stresses on the amps. The cubo loaded with the 1850's are the nuts, the 4 drivers blew after we turned off, basically over heated, they were run over and beyond what they should of been :ohmy: ..... one thing to note I would never swap an amp for another with out re eq'ing the system as every amp sounds different to the next and will naturally change what we hear.....

Don't know any Roots people who would be boosting the 60-80hz. I'm sure you didn't Tippa or Ligwa doing that. :lol:

Scoops naturally excel in this area, and some engineers actually cut 1-2db off those freqs, to even the system.

All the people I know "and rate", would be boosting 40-55hz.

Which is why many like the AH Mixwizard WZ3 series, as the low eq sweeps from 32hz up.

lol true lev you got me thats what i ment to say....... what i was trying to say is the way i set up rigs is very different for different styles of music. So why and how should this (as we know it does) effect whats going on inside the amps..... how can an amp have plenty of power left and still blow 4 1850's yet not have enough power to drive 2 drivers...... dont forget lev i got shot down for saying that a 10k amp was driving two drivers just off clip...... yes yes maths say its not possible, so my ears eyes are wrong...... no they were not, so why does a driver in a scoop act very differently to all other cabs.... and what is the actual effect on the amp... has any one done any very advanced testing on a scoop vs another type of cab in regards to electicaly whats going on.... we all know there are far more efficient / louder flatter response etc cabs than a scoop, but no other cabs sounds like a scoop. Yes a scoop colours the sound which gives then there unique sound and the world would be a worse off with out the scoop.... people reading this will think ive got that amp or same spec amp and it drives my cabs fine, they are louder than a scoop and more efficient, the roots guys dont no what they are doing.... this is so not true..... what we need to no is what effect the scoop has on an amp and driver and why.....

Ray, can you give the exact details of all the components in the chain that were used at the controversial amp shootout.

Need to know speaker cables lengths and cross sectional area, any EQ settings and if cabs were alone or had others around them.

I know djk doesn’t believe in DF but I do and we have had this argument for years. If a roots guy brought 30 meters of 2.5mm cable this could explain why amps like the PL380 clipped earlier than other amps. Maybe you had a low DF all round and the amp was struggling to keep things in check.

When we did the amp shootout with the 8 quake bins we used very short cables as it was a 2 ohm load on each side of the amps under test. I learnt a lot from that day. For one, some of the amps that played really loud, even louder than the Inf 8 had limiters that made the sound useable to me. The sound was a garbled mess at times. If the limiters had better attack and release settings or was of a different character then that amp would have been amazing. You could tell it had great control, it was just the limiter that let it down.

I spent a long time on the limiter on the Inf 8 V2. It works more like the ultra maximiser on the waves platinum bundle. This will raise the average RMS content by a considerable level. You can hear this when you really start to push the amp. You will notice the transients like the kick start to get quieter in relation to the longer sustained notes.

I really think limiter designs play a big part in how loud you perceive an amp to be. This will not show up on a bench power test or by people who have an allergic reaction to clip lights though. Different EQ settings can also upset some amps. I’m just trying to make sense of all this hence asking for the details of all the components used at your amp shootout.

Lewis’s bench test of the Inf 8 V2 didn’t show up high distortion levels. In fact if I remember correctly he said the distortion was no higher than the best amps he has ever tested. So I’m sceptical of the higher distortion = louder with the Inf 8 V2.

I would definitely agree that limiting behaviour could be a major factor here. If the limiter is indeed behaving as a fast acting compressor then that would certainly explain why it would sound louder when run to it's limits.

Another factor is how the limiter is triggered, whether it's just on level or on distortion.

I think the limiter on the PKN probably has a relatively long release time and you won't get that compression of the music signal and raising of the RMS level.

At the weekend I had a chance to open up my PKNs running 4 Stasys X, 1 bin off each channel of an XE6000.

Music was Drum and Bass.
I had a very good power supply stable at 245V.
I also had a hand held spectrum analyzer & SPL Meter.

I had no problem pushing the Stasys X hard enough to get the heat sinks on the back of the cabs nice and warm.
Bellow 50hz performance was fantastic with the whole venue rattling to the point where light fixtures injected from the walls.

The amp temperature was very well behaved staying in and around 50c - 60c range.
I feel I could have pushed the amp harder without running out of thermal headroom.

However I did notice one interesting thing. Two times during the night the DJ dropped a tune where the bass note corresponded to a speaker impedance of less than 4ohms, the amp was seeing 3.5ohms, at this point the amps temperature started to raise and if I had two or three tunes like this in a row I may have had to decrees the volume a little.

I wonder if the scoops you where using have a point where the impedance drops below 4ohms at a frequency where a lot of roots bass content is?

Under theses circumstance an amp that can delivery its maximum load into a lower impedance might have an edge.


Any how, I still remain very impressed with the performance of my amps and I will not be swapping them out any time soon.
Sol

Rog Mogale wrote: Ray, can you give the exact details of all the components in the chain that were used at the controversial amp shootout.

Need to know speaker cables lengths and cross sectional area, any EQ settings and if cabs were alone or had others around them.

Some very, very valid points there Rog.

Will pass questions to Ren & Tweeter Box, as it was their systems running the tests that day, and they were at the "control towers" during testing.

Speaker Sol wrote: At the weekend I had a chance to open up my PKNs running 4 Stasys X, 1 bin off each channel of an XE6000.

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However I did notice one interesting thing. Two times during the night the DJ dropped a tune where the bass note corresponded to a speaker impedance of less than 4ohms, the amp was seeing 3.5ohms, at this point the amps temperature started to raise and if I had two or three tunes like this in a row I may have had to decrees the volume a little.

I wonder if the scoops you where using have a point where the impedance drops below 4ohms at a frequency where a lot of roots bass content is?

Under theses circumstance an amp that can delivery its maximum load into a lower impedance might have an edge.

Very relevant. Some Roots Reggae/Dub tracks have peaks in the 35-45hz area, some even have continuous bass material 40-45hz, and some have actual 40-50hz sinewaves. The music is designed to be played on Overbuilt torroidial amplifiers, so would require extremely strong lightweight amp, to cope with whole night's worth of this torture.

Would suggest from seeing how certain amplifiers deal with 2x 8ohm scoops per channel (without actual measurements), that at some notes, the impedance will drop below 4 ohms per channel,