I need some advice, JBL DD66000，Beolab 50 or KEF Blade One Meta?

[sarumbear]

Objectively? Sensitivity.

Why would low sensitivity is a trade off when amplifier power is abundant? A 70W stereo amplifier will produce more than 100dB at a 3m listening position, with two speakers away from the walls. Source

Subjectively, people have described the bass of the M2 as having faster attack and impact with the Salon2 being a cleaner sound (narrower baffle-> less diffraction).

Shootout between JBL M2 and Revel Salon 2

A blind listening test was organized and reported on AVS Forum. It ran this weekend and here are the results: http://www.avsforum.com/forum/89-speakers/2907816-speaker-shootout-two-most-accurate-well-reviewed-speakers-ever-made-12.html#post54628832 There are the details of tracks on the...

www.audiosciencereview.com

Can also see Amir’s comments about the 4367 which is a passive version of the M2 with a smaller horn.

I read the thread. Some people have mentioned the fact that each speaker interacts differently to a room. I think that was the case in their tests. I have auditioned both speakers in my own room and I have not felt M2 as having a faster attack. It simply had the typically brash West Coast sound.

 

[dickman]

And what about the JBL M2 have you considered them?

Basically because of the aesthetic design of the M2 and the semi-obligatory M2 Crown amplifier with fan noise, the M2 is perfect in terms of sound alone, but the square, dark shape is unacceptable in a living room.

 

[GXAlan]

Why would low sensitivity is a trade off when amplifier power is abundant?

You have asked me what trade-offs existed. I have provided an example of an objective consideration. Cosmetics is another.

The original poster mentioned 4m not 3m listening, and THX reference is 85 dB averages with peaks of 105dB. Hitting 105dB is very different when you have 86 vs 92 dB.

Do you need to listen that loud? Is it healthy to listen that loud? All trade-offs to consider.

It simply had the typically brash West Coast sound.

Sounds like your sighted bias influenced your listening experience, knowing the brand, and seeing the industrial cosmetics.

I'd love to see how the JBL M2 has the same sound signature as the classic "West Coast" sound that's seen in the classics such as the JBL 4311 which defined West Coast sound and is generally replicated by the JBL 18Ti hinting at a consistent target curve at the time.

 

[sarumbear]

I have provided an example of an objective consideration. Cosmetics is another.

Do you think cosmetics is an objective criteria?

The original poster mentioned 4m not 3m listening,

For medium sized rooms, THX recommends ~10 foot viewing distance from the screen. That is roughly 3 metres, hence my choice.

Hitting 105dB is very different when you have 86 vs 92 dB.

According to this calculator in order to hit 115dBSPL at 4m with one M2 you need a 3000W amplifier and with two M2 you need a 2x800W amplifier. That is what THX spec. correlates to.

and THX reference is 85 dB averages with peaks of 105dB. Hitting 105dB is very different when you have 86 vs 92 dB.

Do you need to listen that loud? Is it healthy to listen that loud? All trade-offs to consider.

No you should ignore THX and shouldn't listen that loud! See my view on listening levels on HTs: How loud is loud, how to measure it? Is THX calibration bad for your health?

This is why I do not see the 6dB less sensitivity of Salon2 as an objective short coming. It is just a parameter of the speaker.

 

[azzy_mazzy]

the 105dB peak and 85dB average is an old standard, Dolby in their latest documents recommends lower calibration "The target SPL can range from 79 dB to 82 dB SPL(C) at the central listening position, depending on the room size, when driven with pink noise with an RMS level of ---20 decibels relative to full scale (dBFS)."

while its ridiculously fun to listen loud you have to take precautions

 

[GXAlan]

Do you think cosmetics is an objective criteria?

We are going in circles without offering much help to the original poster and question.

Yes, there are objective elements of cosmetics.

The M2 is black. The Salon2 is piano black or mahogany.

The M2 has an exposed horn and front ports when the fabric grill is used. The Salon2 has a fabric grill that covers the drivers.

When the fabric grill is removed, the M2 has all black drivers. The Salon has silver drivers against a black surface.

This is why I do not see the 6dB less sensitivity of Salon2 as an objective short coming. It is just a parameter of the speaker.

That’s great.

 

[Absolute]

There is nothing wrong with insane bass?

Hah, probably not
I was thinking about how said system would be built. For me a single bass array with 60+ cm of porous absorbers in the back, a double bass array or distributed subs to even the response over multiple seats would be a sane way of building a bass system in a cinema room.

Smashing a huge sub in a corner is not, even if the sub itself is insane

 

[sarumbear]

Smashing a huge sub in a corner is not, even if the sub itself is insane

Unless you treat the room.

 

[Absolute]

Unless you treat the room.

Extremely ineffective for multiple seats and likely the most expensive way if you take real-estate cost into consideration, but you can always add more subs down the line.

 

[sarumbear]

Extremely ineffective for multiple seats and likely the most expensive way if you take real-estate cost into consideration, but you can always add more subs down the line.

I respectfully disagree. Multiple subwoofers also take space.

In my HT room, I have five Helmholtz resonators, three in the false ceiling and two in a false wall that encloses the LCR, two subs & two heights (all in-wall speakers). The lost space is just 18cm shortening of the room depth. However, I have almost no room modes that affect the FR.

 

[Absolute]

I respectfully disagree. Multiple subwoofers also take space.

In my HT room, I have five Helmholtz resonators, three in the false ceiling and two in a false wall that encloses the LCR, two subs & two heights (all in-wall speakers). The lost space is just 18cm shortening of the room depth. However, I have almost no room modes that affect the FR.

Multiple subs certainly do take space, although easy to build into the wall in a sba or dba type of configuration. Your solution of including the resonators in the walls and ceiling sounds clever and something I'd recommend, but in my opinion still ineffective or at least very difficult to get similar results.

If you have frequency response of several positions and can show them at three different heights I would love to see it. Curious how effective treatment in the bass can be

 

[sarumbear]

Multiple subs certainly do take space, although easy to build into the wall in a sba or dba type of configuration. Your solution of including the resonators in the walls and ceiling sounds clever and something I'd recommend, but in my opinion still ineffective or at least very difficult to get similar results.

If you have frequency response of several positions and can show them at three different heights I would love to see it. Curious how effective treatment in the bass can be

As you know each room mode (standing wave) is fixed in frequency. They stay at that frequency where ever you are in the room. The only thing that changes is their amplitude. If you place a Helmholtz resonator near to the point where the amplitude is at its highest, i.e. where the wave is at its peak than you can null that peak, effectively cancelling that room mode. As there are multiple room modes in a room, you can apply the same concept to other room modes and cancel them as well.

A room has many room modes but not all of them are prominent. In my room I started with three resonators that cancelled three major modes and later I added two more to cancel two more modes. What I have now is a room where the RT60 doesn't change more than around a third in the 20-200Hz range. That is reflected with a +3dB / -4dB level variation in a pink noise FFT. Trinnov equalises that remaining variation out. Without the resonators the variation was +10 dB / -12dB. That would made the power amplifiers and speakers to work very hard causing distortion potentially.

 

[Absolute]

As you know each room mode (standing wave) is fixed in frequency. They stay at that frequency where ever you are in the room. The only thing that changes is their amplitude. If you place a Helmholtz resonator near to the point where the amplitude is at its highest, i.e. where the wave is at its peak than you can null that peak, effectively cancelling that room mode. As there are multiple room modes in a room, you can apply the same concept to other room modes and cancel them as well.

A room has many room modes but not all of them are prominent. In my room I started with three resonators that cancelled three major modes and later I added two more to cancel two more modes. What I have now is a room where the RT60 doesn't change more than around a third in the 20-200Hz range. That is reflected with a +3dB / -4dB level variation in a pink noise FFT. Trinnov equalises that remaining variation out. Without the resonators the variation was +10 dB / -12dB. That would made the power amplifiers and speakers to work very hard causing distortion potentially.

Those numbers, are they for the listening position or a number of points in space? It's interesting because I'm curious whether or not you can come close to the spatial average of multiple subs located in different places with resonators alone. I doubt it because I imagine the size of the resonators are too small relative to the walls.
Happy to be wrong, though.

 

[sarumbear]

Those numbers, are they for the listening position or a number of points in space? It's interesting because I'm curious whether or not you can come close to the spatial average of multiple subs located in different places with resonators alone. I doubt it because I imagine the size of the resonators are too small relative to the walls.
Happy to be wrong, though.

I suggest you read a bit about standing waves, i.e. room modes A standing wave is stationary in a room. Your position only changes what part of the wave you are positioned. The idea is to remove the standing waves so that there will be no room modes that affects the sound. This is a good source. Here are two calculators (calc1 & calc 2) that may give you an idea where the room modes are.

Walls do not enter the equation. As long as they are rigid room modes will appear in a room. The resonator is like a speaker driver, it oscillates at a certain frequency and that cancels the room mode at that frequency. A decent size resonator is a mechanical device with very high efficiency, unlike a subwoofer. They can cancel a standing wave much, much better than a subwoofer.

 

[voodooless]

Why not

I suggest you read a bit about standing waves, i.e. room modes A standing wave is stationary in a room. Your position only changes what part of the wave you are positioned. The idea is to remove the standing waves so that there will be no room modes that affects the sound. This is a good source. Here are two calculators (calc1 & calc 2) that may give you an idea where the room modes are.

Walls do not enter the equation. As long as they are rigid room modes will appear in a room. The resonator is like a speaker driver, it oscillates at a certain frequency and that cancels the room mode at that frequency. A decent size resonator is a mechanical device with very high efficiency, unlike a subwoofer. They can cancel a standing wave much, much better than a subwoofer.

A question: do the resonators also affect the nulls?

The space argument doesn't really fly, does it? With the same kind of volume your resonators occupy, one could also just have subs. One can also hide those behind a fake wall, or other spaces. You'd get more output, and also be able to get a smooth response. I think they are both valid solutions.

As to the question of the TS: what about a high-end Genelec setup? Surely 8361/8351 + W371A (LR) + 8361/8351 C + 8341 Surround should be on the list? Throw in a Digital output AVP, and you'll have a very nice system as well.

 

[Absolute]

I suggest you read a bit about standing waves, i.e. room modes A standing wave is stationary in a room. Your position only changes what part of the wave you are positioned. The idea is to remove the standing waves so that there will be no room modes that affects the sound. This is a good source. Here are two calculators (calc1 & calc 2) that may give you an idea where the room modes are.

Walls do not enter the equation. As long as they are rigid room modes will appear in a room. The resonator is like a speaker driver, it oscillates at a certain frequency and that cancels the room mode at that frequency. A decent size resonator is a mechanical device with very high efficiency, unlike a subwoofer. They can cancel a standing wave much, much better than a subwoofer.

I think I understand the standing wave build-up, how a resonator works and the distribution of room modes. But I think I fail to comprehend how small resonators relative to the walls/floor/ceiling can remove the standing waves between the whole length/width of the surfaces.
I imagine I would need quite the surface area covered with resonators if I wanted the effect to have similar results over a large area?

 

[sarumbear]

A question: do the resonators also affect the nulls?

They cancel the wave, hence every part of the wave is eliminated (reduced).

The space argument doesn't really fly, does it? With the same kind of volume your resonators occupy, one could also just have subs. One can also hide those behind a fake wall, or other spaces. You'd get more output, and also be able to get a smooth response. I think they are both valid solutions.

Naturally, in engineering often there are multiple ways to kill a cat However, being passive at least resonator solution is helping the planet

 

[sarumbear]

I think I understand the standing wave build-up, how a resonator works and the distribution of room modes. But I think I fail to comprehend how small resonators relative to the walls/floor/ceiling can remove the standing waves between the whole length/width of the surfaces.
I imagine I would need quite the surface area covered with resonators if I wanted the effect to have similar results over a large area?

First of all they are not small. We are talking about 10" wide 5m long tubes...

Secondly, surface area is not a criteria, room dimensions are.

 

[voodooless]

They cancel the wave, hence every part of the wave is eliminated (reduced).

I should foreseen this Great to know! I really need to test this out sometime!

Naturally, in engineering often there are multiple ways to kill a cat However, being passive at least resonator solution is helping the planet

I'm not sure how killing cats will save the planet, but okay

 

[sarumbear]

I'm not sure how killing cats will save the planet, but okay

Well the phrase is to skin a cat but I though if you skin a cat you will kill the animal so I modified the phrase.