Speakers with no internal damping

[Krunok]

Absolutely no audible sign of cabinet resonance or "coloration".

IMHO you would need to carefully measure THD with stepped sine measurement to verify that.

What you can also do is play a loud sine sweep while having a glass of water on top of your speaker and your hand on it's side and see if you will see/feel any cabinet resonance.

 

[Roy_L]

I wrote "audible"... not "measurable"...

 

[Krunok]

I wrote "audible"... not "measurable"...

You did, but what is "audible" is pretty much undefined term when it comes to distortion. Measurable THD figure however can be put in some perspective.

 

[pozz]

Could anyone point to studies which contain information about internal cabinet pressure for a given output vs. frequency?

 

[Krunok]

Could anyone point to studies which contain information about internal cabinet pressure for a given output vs. frequency?

Internal pressure depends on amplitude of the driver's movement and is not directly related to the cabinet's resonant frequencies. Resonance will occur even at small pressure when driver plays at the resonant frequency of the cabinet.

 

[Roy_L]

Is price a reliable indicator of sound quality?

No, but it's an indication.
More commonly than not, a pricier driver will provide better performance than a cheaper one- subject to the law of diminishing return.

 

[pozz]

Internal pressure depends on amplitude of the driver's movement and is not directly related to the cabinet's resonant frequencies. Resonance will occur even at small pressure when driver plays at the resonant frequency of the cabinet.

I'm not referring to the cabinet's resonant frequency, but how internal pressure will change depending on what frequency is produced by the drivers. I'm most interested in knowing how it compares to steady state atmospheric pressure, how quickly that value can change and by what amount, just to understand what's happening inside the cabinet.

 

[Krunok]

No, but it's an indication.

So, price is not a reliable indicator but it is still an indication? Sounds confusing..

 

[Krunok]

I'm not referring to the cabinet's resonant frequency, but how internal pressure will change depending on what frequency is produced by the drivers. I'm most interested in knowing how it compares to steady state atmospheric pressure, how quickly that value can change and by what amount, just to understand what's happening inside the cabinet.

Heh, that doesn't seem to be related to the topic of internal damping. And also varies very much of the box design: transmission line, ported or closed box will not behave the same.

 

[pozz]

No, but it's an indication.
More commonly than not, a pricier driver will provide better performance than a cheaper one- subject to the law of diminishing return.

I'd mostly agree, but then I'd also consider that mass-produced drivers will be cheaper than boutique or custom jobs due to economies of scale.

 

[pozz]

Heh, that doesn't seem to be related to the topic of internal damping. And also varies very much of the box design: transmission line, ported or closed box will not behave the same.

... Damping will affect the amount of resonance depending on the amount of pressure the cabinet will have to withstand. And it goes without saying that enclosure type matters.

 

[Krunok]

... Damping will effect the amount of resonance depending on the amount of pressure the cabinet will have to withstand.

Pressure fluctuations are directly related to the frequency and amplitude being played and dumping is there to "dump" the amplitude of those pressure fluctuations. You still have to have cabinet sides that are solid enough not to accept the vibrations coming from the driver chassys as well as those that were not stopped by dumping. Compromises made here will directly affect the sound quality.

 

[Roy_L]

I'd mostly agree, but then I'd also consider that mass-produced drivers will be cheaper than boutique or custom jobs due to economies of scale.

I'm not necessarily talking about custom stuff. More like choosing between different drivers of the same manufacturer.
There are many factors that improve when climbing the model ladder within well known manufacturers, such as magnet size, drive excursion (travel) length, surround material properties etc. If we take woofers for example, this can be the difference between a woofer being able to produce a convincing kick-drum sound, and a woofer that will bottom and may be damaged from such an attempt.

 

[Juhazi]

Russell K. speakers seem to have rather thick walls compared to Harbeth etc. clones. Besides that they are bass-reflex designs, so there will not be high internal pressure at low freq. The internal perforated divider helps to tame resonances in midrange.

I found some tests of Red 50 and the woofer seems to have stamped steel frame. Cabinet resonances were not tested, but spl response shows excaggerated treble above 8khz, otherwise pretty good but typical for this size of speakers. Bigger speakers have much lower BR tuning, which is a good feature IMO.

https://www.tnt-audio.com/casse/russell_k_red50_e.html
https://www.hifitest.de/test/lautsprecher_stereo/russell_k-red_50_18450

 

[Roy_L]

So, price is not a reliable indicator but it is still an indication? Sounds confusing..

Like with cars. More expensive is not *always* better, but usually it is. Therefor it's an indication, i.e. a rule of thumb, but not a decisive, single factor.

 

[Krunok]

Like with cars. More expensive is not *always* better, but usually it is. Therefor it's an indication, i.e. a rule of thumb, but not a decisive, single factor.

I know what you are trying to say but I don't think car analogy works here as HiFi market is simply "screwed" so price/performance correlation is very often lost.

 

[Roy_L]

I know what you are trying to say but I don't think car analogy works here as HiFi market is simply "screwed" so price/performance correlation is very often lost.

I know, it's a worn-out discussion. And I'm not even talking about complete products, but strictly about drivers.
And the fact is, that within serious brands, more expensive drivers present better measurements, by thus presenting better potential (subject to proper implementation) for the final product.

 

[maty]

I found some tests of Red 50 and the woofer seems to have stamped steel frame. Cabinet resonances were not tested, but spl response shows excaggerated treble above 8khz,

https://www.hifitest.de/test/bildergalerie/lautsprecher_stereo/russell_k-red_50_18450/5

Spanish shop: € 900

Crossover: https://www.hifitest.de/images/testbilder/big/russell-k-red-50-lautsprecher-stereo-57166.jpg

 

[maty]

KEF Q100 (new)

https://www.audiosciencereview.com/...measurements-by-danny-richie.8840/post-222794

I can see one very little resonance about 700 Hz.

The coaxial speaker suspension is very rigid and it needs many hours (about 200 h). Without burning they sound squeaky -> a failure in sales for years. It is what the current market has, compulsive purchases predominate.

Well that, the improvement was substantial. Imagine with the Russell Red 50...

 

[Juhazi]

Maty obviously wants to state, that the impedance and phase flips around 230 and 980Hz most likely come from resonances of the midwoofer/cabinet. I agree, they are similar to many many other small speakers.

Harbeth 30.2

For comparison KEF LS50 which is smoooth!