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Floorstanding speakers - thin versus fat

Cereal Killer said:
Have a look at the new Kerr Acoustics K102
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The K102 doesn't seem to appear on the Kerr Acoustics website, but if it shares the same physical scale as the K100, it's off the top of my "hernia scale". It weighs in at 78 kilos!

I simply wouldn't be able to move it...
 
The K102 has 2x 12" VOLT radial drivers and is slightly taller and deeper. A proper speaker!! ;) think it comes in around 90kg each!!

Check it out on there Facebook page!
 
tuga said:
Isn't the latter one of the Achilles' heels of a TL (because of the long group delay)?
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A true transmission line is supposed to rolloff somewhere between a sealed box and a ported box (i.e. 3rd order). The faster the rolloff the worse the transient response.
Of course some of the smaller PMCs are not true transmission lines.
 
Someone mentioned bass quality, as if it is a singular dimension. I think not. To me, bass (f<200Hz) has four critical components, in no particularly order of importance:

(1) Extension - how low can it go. Whilst reaching 20Hz might be a goal, it is not necessary. 40Hz is plenty to reproduce most of the fundamental notes of acoustic instruments. In any case, the room and its inherent LF gain must be taken into consideration for actual in-room extension.

(2) Transient - how quickly notes can start and stop. Some might relish trouser-flapping bass, but I like mine crispy. It's no secret that I'm very partial to sealed loudspeaker systems.

(3) Impact - it's the difference between hearing and feeling. Real bass is visceral, and this is where there is no replacement for displacement. Coincidentally, most of the bass gravitas that we all love occurs in the mid-bass from 80Hz to 120Hz.

(4) Tonality - how evenly spread are the room modes/nodes so certain notes don't go missing and others become dominant. This is exceedingly difficult to get right in an unsympathetic room, and will frustrate even the most expensive hifi and its fervent owner, but is absolutely essential to tuneful bass.

So, in conclusion, the loudspeaker size and design matter, and so does the room.
 
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tuga said:
The whole fundamentals range in the PMC frequency response is shelved-down by around 5dB, I would expect it to sound "lean" and "bright":

3tXRqDp.jpg
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This is because they're intended to be used off-axis, so the blue line in the left graph, which looks not too bad. No idea under what circumstances these measurements were taken, but that huge bass hump looks like a room mode or positioning problem. Take that out, use the blue line and that's not bad at all.
 
James said:
Pick the one with the biggest woofer. There's no replacement for displacement. I'm now a firm fan of classically proportioned loudspeakers that are wider than they are deep.
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One has a bigger woofer, but then the other probably has a greater surface area across its pair of smaller woofers.
 
sunbeamgls said:
This is because they're intended to be used off-axis, so the blue line in the left graph, which looks not too bad. No idea under what circumstances these measurements were taken, but that huge bass hump looks like a room mode or positioning problem. Take that out, use the blue line and that's not bad at all.
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Not too bad for £12k? No thanks.
 
James said:
Someone mentioned bass quality, as if it is a singular dimension. I think not. To me, bass (f<200Hz) has four critical components, in no particularly order of importance:

(1) Extension - how low can it go. Whilst reaching 20Hz might be a goal, it is not necessary. 40Hz is plenty to reproduce most of the fundamental notes of acoustic instruments. In any case, the room and its inherent LF gain must be taken into consideration for actual in-room extension.

(2) Transient - how quickly notes can start and stop. Some might relish trouser-flapping bass, but I like mine crispy. It's no secret that I'm very partial to sealed loudspeaker systems.

(3) Impact - it's the difference between hearing and feeling. Real bass is visceral, and this is where there is no replacement for displacement. Coincidentally, most of the bass gravitas that we all love occurs in the mid-bass from 80Hz to 120Hz.

(4) Tonality - how evenly spread are the room modes/nodes so certain notes don't go missing and others become dominant. This is exceedingly difficult to get right in an unsympathetic room, and will frustrate even the most expensive hifi and its fervent owner.

So, in conclusion, the loudspeaker size and design matter, and so does the room.
Click to expand...

When I read tonality I thought that you were going to talk about the opposite of "one-note" bass that one gets with bad bass-reflex designs.

There is also floor-bounce cancellation. Some designs (woofer arrays in some standmounts) deal with it better than others.
 
tuga said:
When I read tonality I thought that you were going to talk about the opposite of "one-note" bass that one gets with bad bass-reflex designs.
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I've made a wee addition to my post. One-note bass is a product of both loudspeaker and the room.
 
Warszawa said:
I'm not really au fait with measurements but do they not fare better in the Hi-fi Critic measurements I posted?
https://pmc-speakers.com/sites/default/files/attachments/HiFi Critic fact.12 Review_0.pdf
"On the straight ahead formation ideally employed for listening, the response is almost flat to 16kHz (+/-2dB)."
"Frequency response Very good: see graphs and in-room off- axis response"
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Toe-in is important not only for producing sharper phantom images but also because it reduces side-wall interaction.
In those measurements the balance is still tilting upwards from bass to treble, even in the 30° off-axis curve (blue), which will give an overall "thin"/"bright" balance:

vrTXUth.png
 
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