Dynamic Headroom

VOLKS · « **on:** 12 Sep 2011, 08:10 pm »

Hi James,
By chance do you know what the Dynamic Headroom is on the 14BSST2?

James Tanner · « **Reply #1 on:** 12 Sep 2011, 08:26 pm »

Hi Volks,

It is about 3dB but you have to be careful with this specification as we feel it is better to provide a lot of power supply reserve so the waveform is well within the operating range of the power supply rails as opposed to a power supply that allows more swing but may have more difficulty controlling the voltage and current demands of the load due to fluctuations in signal level.

james

VOLKS · « **Reply #2 on:** 12 Sep 2011, 09:02 pm »

ok thanks James..........3dB? ok good.....is Dynamic Headroom a measurment that fluctuates or does it stay steady?

James Tanner · « **Reply #3 on:** 12 Sep 2011, 10:34 pm »

Quote from: VOLKS on 12 Sep 2011, 09:02 pm

ok thanks James..........3dB? ok good.....is Dynamic Headroom a measurment that fluctuates or does it stay steady?

I assume it is a window but I will ask engineering.

James

VOLKS · « **Reply #4 on:** 13 Sep 2011, 01:25 am »

sounds good James.

amblin · « **Reply #5 on:** 13 Sep 2011, 01:50 pm »

Sorry that i jumped into the discussion

But there's also the limits of the speakers --- Especially when talking about the 14B , as James said, 3dB dynamic headroom, so that's 200, even 400+ instantaneous bursts of coil kicking watts , not many speakers/units out there can handle such huge spikes of power input without suffering from dynamic compression. So the voice coils would be knocked out of their normal linear movements , beyond their region of magnetic flux thus fails to respond and track the incoming signals any more .

So there's the problem, we always want more, more power, higher damping factor, more 'headroom', but can our speaker units handle all the hard core butt kicking awesomeness? Is there a place somewhere yin and yang finds their peaceful harmony？Or, we all locked in the eternal struggle of more power, bigger boxes?

SoundGame · « **Reply #6 on:** 13 Sep 2011, 02:58 pm »

For those less technically versed:
Definition: Dynamic Headroom refers to the ability of a receiver or amplifier to output power at a significantly higher level than normal for short periods to accommodate musical peaks or extreme sound effects in films. This specification is important in home theater, where extreme changes in volume occur during the course of a film. Dynamic Headroom is measured in Decibels. If a receiver/amplifier has the ability to double is power output for a brief period to accommodate the conditions described above, it would have a Dynamic Headroom of 3db. zSB(3,3)

SoundGame · « **Reply #7 on:** 13 Sep 2011, 03:05 pm »

Quote from: amblin on 13 Sep 2011, 01:50 pm

Sorry that i jumped into the discussion

But there's also the limits of the speakers --- Especially when talking about the 14B , as James said, 3dB dynamic headroom, so that's 200, even 400+ instantaneous bursts of coil kicking watts...

Ambin - by definition of a 3dB dynamic headroom, the 14B should be able to provide an increase of about 600 watts / channel - so a total of 1200w + 1200w of instantaneous and very short duration power output. So yes, I'd agree that not many speakers could handle that - especially when some of those using 14B amps are not even using speakers rated to handle the nominal RMS power output of 600w + 600w.

An additional question here would be is the 3db D.H. apply to both 4ohm or 8ohm loads. If 4 ohm, would that then make it 1800w + 1800w power delivery?

SoundGame · « **Reply #8 on:** 13 Sep 2011, 03:12 pm »

Quote from: VOLKS on 12 Sep 2011, 08:10 pm

Hi James,
By chance do you know what the Dynamic Headroom is on the 14BSST2?

Volks - could you question be due to McIntosh posting Dynamic Headroom specs for their amplifiers? e.g.

MC 1.2KW = 2 db
MC 501 = 1.8 db
MC 402 = 2.1 db

tim92gts · « **Reply #9 on:** 13 Sep 2011, 05:09 pm »

i'd also be interested to know how the clipping indication relates to headroom use.
i've had the occasional flash on the 14BSST2 channels powering my bass drivers on the PMC BB5is.
Sounded great but i backed off a fraction just in case.
i hope you're not going to tell me that means i'm feeding 4 x 1200W into the speakers!
Tim

James Tanner · « **Reply #10 on:** 13 Sep 2011, 05:23 pm »

Quote from: tim92gts on 13 Sep 2011, 05:09 pm

i'd also be interested to know how the clipping indication relates to headroom use.
i've had the occasional flash on the 14BSST2 channels powering my bass drivers on the PMC BB5is.
Sounded great but i backed off a fraction just in case.
i hope you're not going to tell me that means i'm feeding 4 x 1200W into the speakers!
Tim

Hi Tim,

Yes the clipping indicators monitor both the instantaneous voltage and current draw and will flash RED if the load attempts to draw more than the amplifier can supply The occassional RED flicker is not an issue but if it is pulsing RED with every beat you will be destroying your speakers.

james

Dandy · « **Reply #11 on:** 13 Sep 2011, 06:39 pm »

I imagine the headroom on the 14B prior to the transformer upgrade would be different than the newer ones that have those new transformers.

1oldguy · « **Reply #12 on:** 13 Sep 2011, 09:39 pm »

So in other words .....There is a thing of having too much power?

Correct me if I'm wrong.

PRELUDE · « **Reply #13 on:** 13 Sep 2011, 10:11 pm »

Quote from: 1oldguy on 13 Sep 2011, 09:39 pm

So in other words .....There is a thing of having too much power?

Correct me if I'm wrong.

Well,Why waste?For me if you are serious,I would never go below 200w for each speaker but it would be a very wise way if you choose your speakers first then get the right power for it.

amblin · « **Reply #14 on:** 14 Sep 2011, 01:46 am »

Quote from: 1oldguy on 13 Sep 2011, 09:39 pm

So in other words .....There is a thing of having too much power?

Correct me if I'm wrong.

I imagine it'd be very difficult to 'damage' a speaker using 'too much' power, but if there's indeed too much of it, all those expensive watts would be converted into useless heat.

It's abit like buying one of those mad black edition Mercedes SL65 AMGs, 670hp and 738lb-ft of Earth reversing torque, impressive, but that's too much, the awesome, expensive power and torque would either be limited by the traction control and if you switch off TC ---- useless heat and endless tyre spin.

VOLKS · « **Reply #15 on:** 14 Sep 2011, 04:13 am »

Quote from: SoundGame on 13 Sep 2011, 03:12 pm

Volks - could you question be due to McIntosh posting Dynamic Headroom specs for their amplifiers? e.g.

MC 1.2KW = 2 db
MC 501 = 1.8 db
MC 402 = 2.1 db

Hi SoundGame.......No...........a good friend of mine has 2 14BSST2's running bridge mono into his Maggies and asked me to ask James here on the fourm.

1oldguy · « **Reply #16 on:** 14 Sep 2011, 11:14 am »

Quote from: amblin on 14 Sep 2011, 01:46 am

I imagine it'd be very difficult to 'damage' a speaker using 'too much' power, but if there's indeed too much of it, all those expensive watts would be converted into useless heat.

It's abit like buying one of those mad black edition Mercedes SL65 AMGs, 670hp and 738lb-ft of Earth reversing torque, impressive, but that's too much, the awesome, expensive power and torque would either be limited by the traction control and if you switch off TC ---- useless heat and endless tyre spin.

Thanks for your sensible reply.

James Tanner · « **Reply #17 on:** 14 Sep 2011, 11:23 am »

Remember though that transient material in music can require much more instantaneous power than average power so larger amplifiers may be needed more than you would think given the speakers average requirements.

James

James Tanner · « **Reply #18 on:** 14 Sep 2011, 11:26 am »

Quote from: VOLKS on 14 Sep 2011, 04:13 am

Hi SoundGame.......No...........a good friend of mine has 2 14BSST2's running bridge mono into his Maggies and asked me to ask James here on the fourm.

Hi Volks

The 14B can not be bridged as it is already a Series configured amplifier. How does your friend have them hooked up? I am worried he may be doing some serious damage

James

VOLKS · « **Reply #19 on:** 14 Sep 2011, 02:00 pm »

Sorry James my error.He has his Maggies Bi Amped.