Sub placement

charlysays wrote: Elliot Thompson wrote: When the SPL increases, we (Humans) become more conscientious on the midrange frequencies. The intelligence of the music is lost when the Bass and Treble overrides the Midrange at high sound pressure levels. The above method is known as the smiley face equalisation method. Using such a method will also be problematic for Dance Music that offers any means of vocals and/or percussion.   Larger sound systems use Double Eighteen Inch Reflex Subs. Only small sound systems will focus on Single Eighteen Inch Reflex Subs. The logic behind each method is based on transport when using quantity.   Larger sounds systems will use two Double Eighteens for one top minimum. So it is not surprising you are not getting enough bass using, three Single Eighteen Reflex bins to two Full-range tops.   You need understand how the frequencies work on the type of music you are reinforcing from a dB standpoint. I would suggest finding someone reinforcing the same type of music as yourself, utilising a larger sound system than yours, in order to get a better understanding what is needed to get the job done properly while, achieving the fidelity you are seeking.   When a loudspeaker system offers a frequency response of shall we say 40 Hz – 100 Hz (-10 dB @ 40Hz) it means, you need 10 decibels of amplitude @ 40 Hz to equate the same amount of SPL @ 100 Hz (100 Hz being 0 dB).   The above passage means if you are feeding the loudspeaker system 1000 watts @ 100 Hz, you are going to require 10,000 watts @ 40 Hz to achieve the same SPL.   Those who study the fundamentals on how everything works together as a team, usually achieve the frequency response, the sound pressure level in addition to, the fidelity they are seeking. Those who find themselves constantly damaging speakers, living off of heavy equalisation and, still looking for that special magic black box in order to achieve great Fidelity, tend to become perplexed on why they are not achieving a sound which is pleasing to the ear.   Best Regards,   I see what you're saying, however it doesn't explain why MP415 tops will have trouble with midrange running at moderate SPL (their response graph looks pretty smooth from 90hz up to 18khz) so much so that you advocate that I only run one pair of JBL reflex subs with these tops, like a typical disco setup.

As I mentioned in a previous reply...

Elliot Thompson wrote: Your JBL Speaker System is a Two-way configuration. Like most Two-way full range loudspeakers, midrange is not the priority. Two-way full range loudspeakers focus on bass and treble. They work well for Weddings and Corporate events where very loud is not a priority. However, for Raves, you need to have a dedicated midrange driver. This is why the more expensive full range loudspeaker systems always offer an extra driver or two solely for midrange.

You are lacking midrange. This precisly why I said...

Elliot Thompson wrote: Those who fall into the above category usually tend to become perplexed on why they are not achieving a sound which is pleasing to the ear while others are not facing the same issues. The answer is quite obvious... focusing only on one thing and disregarding everything else.

Once I start quoting myself, we have come full circle.

Best Regards,

Hemisphere wrote: I think there are some crossed wires here - it seems like you're not actually taking in any of what Elliott is saying beyond "your midrange won't be good enough", which may or may not be correct, depends how much you care about intelligibility of the midrange, and how satisfied you are with it already. I don't think he said at any point that it won't be loud enough. If it's good enough for you now then maybe it'll be good enough with more of the same, but the louder the system gets, the worse the midrange quality will seem to be, simply because it's louder, and that's where the ear is most sensitive. Let's say you have some 2nd harmonic distortion at -20dB, well if your mids are playing 100dB that 2nd harmonic distortion will be 80dB and that's really not going to be so bothersome, but if they're playing 125dB then your distortion is raised to 105dB, etc, and that may creep into the realms of unacceptability for some people. Generally speaking, and especially with budget boxes, two way designs have more distortion in the midrange to begin with, so it's something to think about, but like I said, if midrange intelligibility really doesn't even register as a concern for you right now, another 6dB from doubling up your midtops probably won't be an issue.

Thanks for the post hemisphere, finally getting some clarity.
I fully acknowledge the mid range clarity issue point which elliot is making (providing it's not harsh it doesn't offend me anywhere near as much as not having trouser flapping bass, same goes for most ravers) but to suggest that using these MP415 tops with a couple of MP418 subs (or any number of MP418 subs up to six for that matter- i tried it) will work "very well" when playing jungle and dub, yet not be satisfactory when used with some cubo subs which will actually play low enough to reproduce the bass in jungle seems crazy and goes against all the results of the open air field testing I've done.

If the JBL tops are running at say 120db (typically don't run them any harder than -6db subtracted off their AES as I stated before) the jungle music is going to sound far better with the pleasing sub 50hz notes coming across strong and trouser flapping than dying off like a fart in the wind like they do with the small highly tuned JBL subs.


I and the majority of customers/ punters think the MP415s sound great- coming from using JBL JRX/ Soundfactor etc. Before they were discontinued they retailed at around £600 each- is that really a budget speaker? Seems a similar price point as two way martin blacklines. Considering that you can't even buy a pair of the MP415 (BMS 4540) comps for the price of a pair of new JRX... Seems a mid range speaker to me but IDK. If people think they're in the same ball park as JBL JRX I might get another pair cheap :)

Great explanation on the distortion... and thanks for finally clarifying that if I double up the tops I already have I get a worthwhile increase in SPL without increasing the proportion of the sound which is occupied by distortion, though with more and more pairs added I understand that the distortion may become unacceptable. I thought this was the case ( i know it is with subs from experience but wasn't sure re tops) but elliot wouldn't tell me lol, only to buy martin H3+ which are simply not feasible.

So is this mid range mud inevitable with all two way systems even when they're not run hard or would better speakers like the martin two ways be better in this respect? It doesn't bother me at the moment especially when I consider the extra unit weight/ cost/ depreciation associated with a pair of big 3 way speakers but my ear may become more discerning in time.










Edited by charlysays - 01 January 2018 at 8:06pm

Not inevitable with 2 ways. Depends on loads of factors like crossover point to horn, quality of drivers used, how low you run the crossover to sub, music program (lots of hard kick harmonics in the midbass won't be good ie), and obviously how hard you drive them.

Elliot Thompson wrote: Hemisphere wrote: I think there are some crossed wires here - it seems like you're not actually taking in any of what Elliott is saying beyond "your midrange won't be good enough", which may or may not be correct, depends how much you care about intelligibility of the midrange, and how satisfied you are with it already. I don't think he said at any point that it won't be loud enough. Exactly. This is why I said... Elliot Thompson wrote: You need understand how the frequencies work on the type of music you are reinforcing from a dB standpoint. I would suggest finding someone reinforcing the same type of music as yourself, utilising a larger sound system than yours, in order to get a better understanding what is needed to get the job done properly while, achieving the fidelity you are seeking. Charlysays has to literally hear a difference through a sound system other than his to get a better understanding for, explaining it to him is not getting the message across. Best Regards,

charlysays wrote: Elliot Thompson wrote: Hemisphere wrote: I think there are some crossed wires here - it seems like you're not actually taking in any of what Elliott is saying beyond "your midrange won't be good enough", which may or may not be correct, depends how much you care about intelligibility of the midrange, and how satisfied you are with it already. I don't think he said at any point that it won't be loud enough. Exactly. This is why I said... Elliot Thompson wrote: You need understand how the frequencies work on the type of music you are reinforcing from a dB standpoint. I would suggest finding someone reinforcing the same type of music as yourself, utilising a larger sound system than yours, in order to get a better understanding what is needed to get the job done properly while, achieving the fidelity you are seeking. Charlysays has to literally hear a difference through a sound system other than his to get a better understanding for, explaining it to him is not getting the message across. Best Regards,     I go to jungle nights in places like Corsica studios and go to various other underground nights, so I have heard a few systems (playing music and even particular songs which I'm familiar with) which are much more expensive than mine. I'm not overly impressed with those sounds. Often the Funktion 1 systems in Corsica studios get piercingly loud towards the end of the night though the bass is still satisfying.   One of the best systems I heard at a new years even party were what looked like four mini scoops, two kick bins and four two way 10" woofer 1" CD tops.   I would rather run my system such that the sense of loudness comes from the low sub region more than the mid range and top end, similar to how rog mogale suggests- +10 below 100hz. As long as the vocals are coming across intelligible and clear and there is some pleasant sparkle above that I prefer it when the low sub is very powerful.   I think another pair of better but compact tops may be a good upgrade. Something like the JBL SP212- double the power handing, larger compression driver and a very safe crossover point.

For modern dance music in a gig situation, it's actually common to have +20 to +40dB on the low end…