Speakerplans.com Homepage
Forum Home Forum Home > General > Newbie Discussion
  New Posts New Posts RSS Feed - a load of newbie questions + martin audio Q's
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

a load of newbie questions + martin audio Q's

 Post Reply Post Reply Page  <12
Author
Message
teeth View Drop Down
Young Croc
Young Croc
Avatar

Joined: 05 July 2021
Status: Offline
Points: 561
Post Options Post Options   Thanks (0) Thanks(0)   Quote teeth Quote  Post ReplyReply Direct Link To This Post Posted: 06 July 2021 at 6:43pm
thanks. i'd like to ask how you know if you are clipping, do you just mean the amp LEDs? so basically don't run the amp at max level?
Back to Top
cravings View Drop Down
Old Croc
Old Croc
Avatar

Joined: 30 January 2007
Location: Ireland
Status: Offline
Points: 7441
Post Options Post Options   Thanks (0) Thanks(0)   Quote cravings Quote  Post ReplyReply Direct Link To This Post Posted: 06 July 2021 at 6:46pm
clip indicators (yep, lights) at any stage really should be avoided. on mixers, processors / crossovers etc, and amps most importantly.
Back to Top
toastyghost View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 09 January 2007
Location: Manchester
Status: Offline
Points: 10920
Post Options Post Options   Thanks (0) Thanks(0)   Quote toastyghost Quote  Post ReplyReply Direct Link To This Post Posted: 06 July 2021 at 8:46pm
Originally posted by cravings cravings wrote:

clip indicators (yep, lights) at any stage really should be avoided. on mixers, processors / crossovers etc, and amps most importantly.


That can most easily be avoided with a bit of planning and maths to set proper gain structure. It also helps to avoid audible noise. Check out the stuff from SynAudCon’s YouTube channel, as a first point.

Since you asked for books; the Yamaha Sound Reinforcement Handbook can be found easily and is a good introduction despite its age. The next one that should be on your reading list is Don Davis and Eugene Patronis JR’s Sound System Engineering aka the yellow bible.

Bear in mind that even the heaviest/most compressed dance music is going to demand 12 dB peaks at points. That means 16 times the average drive level, since +3 dB output needs a doubling of input power to the speaker (assuming ruler flat sensitivity, which is almost never the case).

So suddenly your amp that clips at say 400 Watts of output is only good for an average level of 25 Watts without clipping or limiting/compression to prevent clip. The F12 has a published sensitivity of 97 dB with 2.83V input, which for an 8 ohm box is equivalent to 1 Watt at 1 metre.

Take that doubling of output for +3 dB, and you’re at 111 dB average at 1 metre. Not many people listen that far away, and the box can be assumed to be a simple point source with -6 dB SPL per doubling of distance. Let’s say it’s a small party of 200 people, that likely means most listeners are 5-10m away. We’re now down to a window of 97 dB to 91 dB average - and this is the level on-axis to the speaker!

Most listeners are off-axis in real life, but if you’re aiming the speakers well they’re going to be within the -6 dB coverage angle points. Let’s split the difference, and say they’re mostly -3 dB from on-axis. Take that off the numbers above, and then check if you’re happy with that average level.

And we aren’t including subs here, which will typically need about 20-30 dB more level capability than the mains to sound balanced for dance music.
Back to Top
Bams View Drop Down
Young Croc
Young Croc


Joined: 08 April 2009
Status: Offline
Points: 622
Post Options Post Options   Thanks (0) Thanks(0)   Quote Bams Quote  Post ReplyReply Direct Link To This Post Posted: 06 July 2021 at 9:24pm
To put it in other words, when used in a small setting with a small crowd near the speakers it isn’t a problem to use a “smaller” amp. But when used in anger you will be happy with the headroom which now is needed. 
Back to Top
teeth View Drop Down
Young Croc
Young Croc
Avatar

Joined: 05 July 2021
Status: Offline
Points: 561
Post Options Post Options   Thanks (0) Thanks(0)   Quote teeth Quote  Post ReplyReply Direct Link To This Post Posted: 10 July 2021 at 9:55am
thanks for all your advice ppl. i really appreciate it.

i've been experimenting. i have a pair of EV ELX115's here also, and i'm thinking about using these in parallel with the martins for a bit of low end (don't have a sub yet)

they will of course be underpowered but really don't need to go very loud.

what's the best way to do this?

both martins in parallel off one side of the amp, EV's off the other side
pro: volume control of each pair of speakers
con: amp is "imbalanced" (is that a thing? i assume CH1 and CH2 are linked in some way)
OR
one of each off each side in parallel
pro: easy stereo - no need to think about putting things in mono, "balanced" CH1 CH2 of the amp.
con: no volume control of speakers, some kind of wattage mismatch?

:)
Back to Top
doller View Drop Down
Young Croc
Young Croc


Joined: 19 July 2014
Location: japan
Status: Offline
Points: 509
Post Options Post Options   Thanks (0) Thanks(0)   Quote doller Quote  Post ReplyReply Direct Link To This Post Posted: 10 July 2021 at 12:41pm
The volume nob on your amp isn't really a volume knob. It is an input signal attenuator. So if you set it to -10db and the boost your input signal to much it will still clip the amp. You need to read up on that. 
It isn't best to run two different speaker boxes side by side. They have different phase characteristics. They might cancel each other out. If you want to know what I mean put your martins next to each other run one plus minis as normal and the other one minus plus ie switch polarity. you will maybe hear a drop in volume. This is because they are out of phase. Maybe it's ok but I would think that you will get some cancelation at some frequency's. Best to get a sub of some kind.
Back to Top
doller View Drop Down
Young Croc
Young Croc


Joined: 19 July 2014
Location: japan
Status: Offline
Points: 509
Post Options Post Options   Thanks (0) Thanks(0)   Quote doller Quote  Post ReplyReply Direct Link To This Post Posted: 10 July 2021 at 12:45pm
Oh! it is perfectly fine to run sub on one channel and high on another the amp channels are separate not linked unless you put it into bridge or parallel mode, 
Back to Top
Earplug View Drop Down
Old Croc
Old Croc


Joined: 03 January 2012
Location: Europe
Status: Offline
Points: 7199
Post Options Post Options   Thanks (0) Thanks(0)   Quote Earplug Quote  Post ReplyReply Direct Link To This Post Posted: 10 July 2021 at 12:45pm
From the specs, the EV's don't seem to go much lower than the Martin's, but adding a couple more speakers can't hurt.

I'd start by putting one of each per side and take a listen. See if you like the combination.  Smile


Earplugs Are For Wimps!
Back to Top
 Post Reply Post Reply Page  <12

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.078 seconds.