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KEF Q100 Speaker Review

aarons915

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You don't need to have same slope on the sub side and on the mains side. Sealed boxes generally sound better except they require larger volume to produce deep bass. if you handed over bass duties to sub no need to have port open anymore.

Are you using high pass for your mains or not?
You don't need to, but it's optimal if you want your subs and mains to blend properly. Of course everyone should try it both ways and do what sounds best to them, as mentioned I've done this and prefer to keep the ports open, YMMV.

Yes I mentioned twice now I use a 4th order high pass on the mains, with open ports.
 

wowo101

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spend the same, or a bit more to take an existing speaker as far as it will go
I see your point – will have to weigh cost for additional amplification and advantage in SQ against savings by doing Zvu‘s modest passive mod...
 

QMuse

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You don't need to, but it's optimal if you want your subs and mains to blend properly. Of course everyone should try it both ways and do what sounds best to them, as mentioned I've done this and prefer to keep the ports open, YMMV.

Yes I mentioned twice now I use a 4th order high pass on the mains, with open ports.
Sealed boxes have natural roll-of equal to 2nd order (nice article about that here) so no problem if you make it steeper with 4th order, and you will still get tighter upper bass with less distortion from mains.

But, of course, whatever rocks your boat is fine.
 

jtwrace

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I'm sure the Danny version would measure better.
Dave.
That is a might big bold claim as I'm probably more sure than you that it would not measure better if at all than what the stock version has.
 

aarons915

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Sealed boxes have natural roll-of equal to 2nd order (nice article about that here) so no problem if you make it steeper with 4th order, and you will still get tighter upper bass with less distortion from mains.

But, of course, whatever rocks your boat is fine.
I mostly agree with what you're saying, the THX spec was meant for sealed speakers, it's just that most speakers today are ported and designed to be ported so simply sealing the port isn't the same as a properly designed sealed speaker. Also, adding a 4th order high pass to a sealed speaker results in a 6th order rolloff which won't blend very well with a sub. The 2 best options are to use a 2nd order high pass and the seal the port or keep the port open and use a 4th order high pass, both with 4th order low passes on the sub/s. I think the 2nd option is best since you take advantage of the low distortion slightly above the port tuning frequency but I understand that most use receivers and only have a 2nd order high pass and for them I agree sealing the port is the better option.
 

dreite

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That is a might big bold claim as I'm probably more sure than you that it would not measure better if at all than what the stock version has.
No, I'm not positive on that. I give Danny some credit as a decent practitioner with some decent practical experience. The reason I think his modification would measure better is because the stock one is so basic/cheap. Any decent crossover designer should be able to better the stock design with a more refined network.

Danny has numerous other issues, but I think he's more than capable of parting together a simple crossover like this.

Dave.
 

maty

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Some time ago Zvu passed me the files of his measurements and I did a few simulations based on his proposal for a new filter.

* It is important to me that the tweeter uses a first-rate filter and thus take advantage of the best quality of the components. With Miflex KPCU-01 0.022uF (22 nF in the image) 600Vdc as bypass cap.

* The other restriction was to keep the original woofer air coil.

KEF-Q100-LSPCAD-maty.png


With one or two filters at 1.4 kHz and 1.7 kHz ... with minimum phase PEQ + rePhase...


Proposed by Zvu



I was waiting for Danny Richie to make his own filter. I suspected that the two would be second order.

In doubt, I have not yet purchased the Jantzen Superior Z-cap as its value changes depending on the chosen filter: 3.9 uF, 5.6 uF or...
 

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jtwrace

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No, I'm not positive on that. I give Danny some credit as a decent practitioner with some decent practical experience. The reason I think his modification would measure better is because the stock one is so basic/cheap. Any decent crossover designer should be able to better the stock design with a more refined network.

Danny has numerous other issues, but I think he's more than capable of parting together a simple crossover like this.

Dave.
The cost of the components doesn't correlate to measurable output quality though. If it did, Danny would be sending @amirm his mod speakers to be measured (for free) on a $100K rig that GR could only dream of having.
 

maty

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I think it is more interesting to know the frequency response at the listening point, especially if it is in the far field, before to make a new more complex crossover.

At 30º-40º-50º it seems that this bump is not so important. The small -2 dB dip at 600 Hz is more interesting. In near field maybe a new soft filter is more logic. About 1.3 dB of gain.

KEF Q100 frequency at 30 40 50 degrees measured by Zvu.png


In the filters I have verified that better quality horizontal components (signal path) greatly change the sound in my loudspeakers. Tweeter filter is more critical. If we increase complexity so will the cost, specially with boutique components. And viscoelastic material.

The upgrade cost has to be in line with the cost of the loudspeakers, I mean.
 
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dreite

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The cost of the components doesn't correlate to measurable output quality though. If it did, Danny would be sending @amirm his mod speakers to be measured (for free) on a $100K rig that GR could only dream of having.
I'm talking about the change in crossover design.....not necessarily the cost of his "audiophile-quality" components. Two different things.

Dave.
 

jtwrace

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I'm talking about the change in crossover design.....not necessarily the cost of his "audiophile-quality" components. Two different things.

Dave.
The issue there is the "design" isn't correlated beyond very basic measurements that only show a very small part of what is happening. Polar Plots tell a much larger story so anything less is quite elementary in speaker design.
 

dreite

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The issue there is the "design" isn't correlated beyond very basic measurements that only show a very small part of what is happening. Polar Plots tell a much larger story so anything less is quite elementary in speaker design.
Danny did post some basic polar response measurements of his "design." You could question the accuracy/veracity of those results, I guess.

Regardless, it seems you want to get into an argument regarding Danny's speaker design prowess.....with me on Danny's side. I'm sorry, but I'm not your guy. :)

Carry on.

Dave.
 

jtwrace

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Danny did post some basic polar response measurements of his "design." You could question the accuracy/veracity of those results, I guess.

Regardless, it seems you want to get into an argument regarding Danny's speaker design prowess.....with me on Danny's side. I'm sorry, but I'm not your guy. :)

Carry on.

Dave.
No interest in that...just stating facts. :)
 

maty

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I have long since opted for Jantzen Superior Z-cap on the advice of Tony Gee. http://www.humblehomemadehifi.com/Cap.html

In the SE version, no longer for sale, Buchardt S400 SE are also used.
https://forum.polkaudio.com/discussion/189765/buchardt-s400-versus-buchardt-s400-special-edition
In a previous thread on the S400 I stated that I had a damn good idea what the cause of the peaky/shouty issue was, the Bennic/Dayton caps. The upgraded crossovers in the SE proved I was correct. It also proves that crossover components do indeed matter...
 

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aarons915

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Indeed every review I watched started with that and ended with "great imaging." In a live music venue, nothing comes out a single point source....
I missed this comment before, I don't think speakers are meant to produce instruments identically to the respective polar patterns they create, that would be impossible for any speaker. But regardless of the polar pattern, instruments' reflections should be the same in all directions, this is what a coaxial speaker does that typical line source speakers can't. Vocals are the biggest difference to me and of course they are a true point-source, at least talking about a live singer without amplification.

I never noticed the difference until I carefully A/B a Coaxial and a standard 2-way in mono but after doing that it's clear that the coaxial sounds more "clear". I did compare my LS50 to a Revel M105 and noted that the Revel were the closest to a point-source presentation that I've heard aside from a coaxial but they're still not quite there.
 

Bombadil

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I doubt many casual visitors know what the panthers mean, they probably just skim down to the conclusion and read that, if they only get as far as the first image and base all their decisions on that then they are still getting more than they paid for.
If you could help me with the meaning of the Pink Panther Postman I'd appreciate it. It seems to be applied to devices that work OK but with caveats.
 

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