The 12 Best Professional Sound Speakers?

[Phil Starr]

Just thought other people might like watching this. The auto translation is hilariously out in places but you can easily follow so I guess it is functional. The opinions may be surprising but evidence is given so it is genuine food for thought and for UK purchasers might point you in new directions. Who would feature in your top 12?

 

 

Edited Wednesday at 14:37 by Phil Starr

[Dan Dare]

These YouTube "best of" vid's are almost always AI generated rubbish, complete with robot voice-over. I've no doubt they simply parrot manufacturers' sales literature.

[stevie]

I'm not a fan of "Best of" videos either, but this there was a lot of detail in this that more technically inclined buyers might appreciate - not the usual mindless waffle. Shame about the voiceover and AI translation, but the content is much better than the usual fare.

[Phil Starr]

17 hours ago, stevie said:

I'm not a fan of "Best of" videos either, but this there was a lot of detail in this that more technically inclined buyers might appreciate - not the usual mindless waffle. Shame about the voiceover and AI translation, but the content is much better than the usual fare.

Yes, that's what I thought. Lot's of details about which amplifier modules were being used and some about the drivers installed too. I started watching over a coffee break and ended up watching it through. He's not shy of saying where measurements disagree with manufacturers specs either. It's good to be sceptical but cynicism can't replace an open mind

[Stub Mandrel]

The protection in the EV speaker made me think of the inverter drive I use on one of my lathes. It models the thermal performance of the motor and reduces power to avoid overheating which actually means you can abuse the motor safely (e.g. running it slow which means reduced airflow and more heating) .

 

Applying such a model to class d amps/speakers should be easy and effective.

[Chienmortbb]

4 hours ago, Stub Mandrel said:

The protection in the EV speaker made me think of the inverter drive I use on one of my lathes. It models the thermal performance of the motor and reduces power to avoid overheating which actually means you can abuse the motor safely (e.g. running it slow which means reduced airflow and more heating) .

 

Applying such a model to class d amps/speakers should be easy and effective.

I think this is a bit of manufacturer's marketing speak. All reputable Class D amps have several protection features built in and if you add DSP you can add more to suit the drivers. No manufacturer is going to use an amp that could really overpower a driver, and as far as I know, it is amp failure that powered speakers suffer from mostly*.

 

* They may have improved, but the original Mackie Thump speakers, as well as many others, used a chip based Class D amp that they advertised as well over 1000 watts. Add the Thump name and no DSP and these little 2-300watts chip amps fried like eggs on a black car in the midday sun. Behringer also used these chip amps but rated them much more modestly. 

[Phil Starr]

4 hours ago, Stub Mandrel said:

The protection in the EV speaker made me think of the inverter drive I use on one of my lathes. It models the thermal performance of the motor and reduces power to avoid overheating which actually means you can abuse the motor safely (e.g. running it slow which means reduced airflow and more heating) .

 

Applying such a model to class d amps/speakers should be easy and effective.

The latest iteration of the RCF 9 series are already using dynamic management of excursion and I think it will rapidly become standard to use extremely high power amps across the range with Dsp controlled management of the amp to allow best performance of the drivers but keeping well within their performance envelope for increased reliability in the face of abuse from their owners

[Bill Fitzmaurice]

The only method of driver protection that really works is limiting the voltage output of the amp. It's SOP in touring pro-sound. The voltage is limited so that neither the driver Pe nor Xmax is exceeded. Outboard DSP can incorporate it, as can onboard. Whether or not a given powered speaker has it or not you can probably determine from the owner's manual. If it has it they'll say so. If they don't say so it likely does not. 

[Stub Mandrel]

2 hours ago, Chienmortbb said:

I think this is a bit of manufacturer's marketing speak. All reputable Class D amps have several protection features built in and if you add DSP you can add more to suit the drivers. No manufacturer is going to use an amp that could really overpower a driver, and as far as I know, it is amp failure that powered speakers suffer from mostly*.

 

* They may have improved, but the original Mackie Thump speakers, as well as many others, used a chip based Class D amp that they advertised as well over 1000 watts. Add the Thump name and no DSP and these little 2-300watts chip amps fried like eggs on a black car in the midday sun. Behringer also used these chip amps but rated them much more modestly. 

I'm thinking of protection that predicts an overheat and reduces output power marginally rather than cutting out.

[Bill Fitzmaurice]

Thermal protection only applies to the amp. 

[Chienmortbb]

2 hours ago, Phil Starr said:

The latest iteration of the RCF 9 series are already using dynamic management of excursion and I think it will rapidly become standard to use extremely high power amps across the range with Dsp controlled management of the amp to allow best performance of the drivers but keeping well within their performance envelope for increased reliability in the face of abuse from their owners

I assume that as they also make the drivers, they know the variations in specifications. Taking the that knowledge allows you to protect the drivers, limiting them to the minimum specs. You might also have some sort of dynamic impedance measurement to check the actual voice coil temperature, avoiding the worst effects of power or thermal compression.

[Bill Fitzmaurice]

That is a possibility, impedance rises with temperature, but it would take a very sophisticated DSP to incorporate that feature. 

[Chienmortbb]

1 hour ago, Bill Fitzmaurice said:

That is a possibility, impedance rises with temperature, but it would take a very sophisticated DSP to incorporate that feature. 

Which makes me think that they are limiting to the driver minimum specs.

[Stub Mandrel]

8 minutes ago, Chienmortbb said:

Which makes me think that they are limiting to the driver minimum specs.

 

It's not that difficult. 

 

You have a model that reflects the rate of cooling at the current ambient temperature, and the rate of heating at any given power level. Knowing that you can predict the net temperature change over any period.

[Phil Starr]

10 hours ago, Chienmortbb said:

Which makes me think that they are limiting to the driver minimum specs.

Did you mean maximum?

 

I don't think that there is any magic about speaker protection. Excluding manufacturing faults, which thankfully seem to be very rare, there are only two ways in whicvh a drive unit will fail. Over excursion leading to mechanical failure and over heating. There is just one complication, if the coil spends time outside the magnetic gap then it can't dissipate heat into the magnet so that there can be a special situation where over excursion and heating combine, but all of this is very predictable. For years folklore or perhaps more politely 'rule of thumb' has allowed musicians to match speakers and amps. In the 60's most of us would allow for speakers to have twice the power rating of an amp if we wanted reliability. As high temperature materials were introduced most of us now would now expect to be able to use double that power and match the amp and speaker power. In PA however well trained engineers have pretty much always gone for amps that were twice the power of the speakers. That way they could manage the peak excursion and overheating issues because they had a basic understanding of the duty cycles and frequencies they were pushing into the speakers to get extra peak sound output without distortion from the amps. It all depended upon skill levels and experience but the advent of active speakers and now DSP has brought that to all of us. 

 

As @Stub Mandrel has said we can predict the heating/cooling of any part of the speaker from the testing done during the design phase and knowledge of the power going from the amp and the ambient temperature. You can also predict the position/excursion of the coil from knowledge of the frequency and power level , that's what the speaker modelling software does to predict frequency response. Temperature rise and excursion are entierly predictable for any given speaker. With the amp and speaker built into the box and DSP 'knowing' power and frequency levels you can afford to use higher power amps to get higher sound levels with the DSP taking sure to dynamically limit the power if things go outside of the parameters of the drive units. DSP is doing what the sound engineers were doing in big professional PA's for decades past, and class D amps are so cheap that putting big amps in small speakers is cheaper than building 5 different PA amps for every different speaker model. At the moment I'll guess that there are no sensors for ambient temperature in most base level systems used by semi pro bands. From the advertising I don't think RCF for exampe do this. What they do have however is a proxy for ambient temperature: the amplifier monitors it's own temperature as there is overheating protection built into the amp. If the ambient temperature rises the cooling on the amp is challenged and the temperature there will rise in proportion to the rise in the voice coil again this is all predictable. Obviously a sensor on the speaker itself would give an extra layer of protection.

 

I found it really interesting to know which amp modules were being used inside these boxes and it's fairly easy to track the design decisions being made generally from these videos. I think it is fabulous that we can buy speakers that manage themselves in ways that allow bands to use more of the available output of the drive units. This sort of thing is already starting to spread to budget cabs and I suspect it will be moving to bass guitar combo's fairly soon.