KEF R3 Meta - Review & Measurements by Erin

[MAB]

I dug up my measurements on a 15" paper cone woofer. I have two of them. I measured them both fresh out of the shipping carton with a DATS V3. I have been playing them for the past 6 months. I just demounted them and remeasured:

I measure 1-2% change over the first 6 months, 3% for Q(ms). The break-in as I measure it over 6 months is about the same as driver to driver matching, as near as I could observe.

Here is the impedance trace for Driver 1 in a 60 liter sealed enclosure prior to use and after 6 months:

When making these measurements I did do things like normalize for lead resistance. I let them settle to ambient room temperature. I didn't normalize for the actual temperature though, and temperature has a large effect.

So I did the next reasonable thing, I put the woofer in the refrigerator for 10 mins.

After just 10 mins soaking in the fridge I remeasured, then took a few more measurements over then next few hours as the speaker warmed up.

As @HarmonicTHD suggested, temperature is a large effect, much larger than break-in. I need to wait much longer than 3 hours to let the driver equilibrate after just 10 mins exposed to cold! I am not surprised, this is similar to previous measurements I posted.
@jackocleebrown , I hope this is intelligible. I am trying to reconcile actual driver measurements of break-in with the data you presented. I am obviously operating on a small sample size with limited variety. Am I missing something?

Thanks!

 

[HarmonicTHD]

I dug up my measurements on a 15" paper cone woofer. I have two of them. I measured them both fresh out of the shipping carton with a DATS V3. I have been playing them for the past 6 months. I just demounted them and remeasured:
View attachment 333901
I measure 1-2% change over the first 6 months, 3% for Q(ms). The break-in as I measure it over 6 months is about the same as driver to driver matching, as near as I could observe.

Here is the impedance trace for Driver 1 in a 60 liter sealed enclosure prior to use and after 6 months:
View attachment 333897
When making these measurements I did do things like normalize for lead resistance. I let them settle to ambient room temperature. I didn't normalize for the actual temperature though, and temperature has a large effect.

So I did the next reasonable thing, I put the woofer in the refrigerator for 10 mins.
View attachment 333898
After 10 mins soaking in the fridge I remeasured, then took a few more measurements over then next few hours as the speaker warmed up.
View attachment 333899
As @HarmonicTHD suggested, temperature is a large effect, much larger than break-in. I need to wait much longer than 3 hours to let the driver equilibrate after just 10 mins exposed to cold! I am not surprised, this is similar to previous measurements I posted.
@jackocleebrown , I hope this is intelligible. I am trying to reconcile actual driver measurements of break-in with the data you presented. I am obviously operating on a small sample size with limited variety. Am I missing something?

Thanks!

Nice work. Thanks. This I would expect from KEF.

 

[terfenol-D]

Per the directions that came with the R3 and measured distance to the wall I have the hollow tube foam plug in my speakers. Planning on using DIRAC to help control lower frequencies/room modes. What are people's thoughts about using DIRAC with or without the plugs? Better to let DIRAC do everything, better to follow R3 directions and use the tube foam plug, or else completely plug the speaker, etc.? Thanks.

 

[Steve Dallas]

D

Per the directions that came with the R3 and measured distance to the wall I have the hollow tube foam plug in my speakers. Planning on using DIRAC to help control lower frequencies/room modes. What are people's thoughts about using DIRAC with or without the plugs? Better to let DIRAC do everything, better to follow R3 directions and use the tube foam plug, or else completely plug the speaker, etc.? Thanks.

Dirac without plugs. The plugs reduce level and extension. You want the extension the ports give you. Dirac will take care of taming the peaks and correct the phase.

Mine (non-Meta) go down to about 34Hz without plugs and with Dirac correction to 1KHz.

 

[terfenol-D]

D


Dirac without plugs. The plugs reduce level and extension. You want the extension the ports give you. Dirac will take care of taming the peaks and correct the phase.

Mine (non-Meta) go down to about 34Hz without plugs and with Dirac correction to 1KHz.

View attachment 335039

Thank you!

 

[HarmonicTHD]

Per the directions that came with the R3 and measured distance to the wall I have the hollow tube foam plug in my speakers. Planning on using DIRAC to help control lower frequencies/room modes. What are people's thoughts about using DIRAC with or without the plugs? Better to let DIRAC do everything, better to follow R3 directions and use the tube foam plug, or else completely plug the speaker, etc.? Thanks.

Depends if you use a sub. Plug with sub and unplug without. You can always cross check with REW.

 

[MAB]

Hi,

Since the subject of break-in and run-in is off topic for these wonderful speakers, I started another thread on speaker break-in measurements.

Speaker Break-In and Environmental Measurements

The subject of speaker break-in comes up often. It's also called run-in. It's different than aging, or wear-out. I see people posting YouTube videos of woofers being deformed into the shape of a potato-chip, while the 'tuber yells at me to make sure and break in my drivers before ever...

www.audiosciencereview.com

@jackocleebrown perhaps if you have a chance we can discuss the topic there.
Thanks,
MAB

 

[maty]

More measurements

KEF R3 Meta Video review & test. English subtitles. Видео обзор и тест полочной акустической системы

 

[Rednaxela]

For anyone wondering:

 

[VintageFlanker]

R5 Meta just measured...

 

[exm]

Is there an easy overlay to compare R3 and R5?

 

[stren]

Nice - that looks way better than my memory of the old R5

 

[VintageFlanker]

Is there an easy overlay to compare R3 and R5?

I'm sure @sweetchaos is already working on it...

 

[Vacceo]

It´s quite interesting to think that in older speakers series, KEF used to make the usual types of speakers on "small" and "large" versions. For example, the old IQ´s come in small and large bookshelfs (1 and 3), small, large and larger tower (5, 7 and 9) and small and large center (2 and 6). From those days, the tendency still remains, however, the small bookshelf has been dropped.

Perhaps it has to do with the presence of the LS50´s, as they´d be the "small" version of a bookshelf.

 

[sweetchaos]

Here you go:

 

[sweetchaos]

Erin's written review is now live:

KEF R5 Meta Tower Speaker Review

KEF R5 Meta Tower Speaker Review

www.erinsaudiocorner.com

 

[HarmonicTHD]

Erin's written review is now live:

KEF R5 Meta Tower Speaker Review

KEF R5 Meta Tower Speaker Review

www.erinsaudiocorner.com

Nice.

Maybe even open a new thread about the R5 Metas. Unless I have overlooked it and it exists already.

 

[Opal]

What could be the reason for the R3 meta and R5 meta having such a difference in the mid to high frequency? I thought both uses the same uni-q driver?

 

[Dovydas]

Could somebody compare R5 Meta measurements to Focal Aria 936? Would it be an upgrade or difference is to small to even consider replacing Arias?

 

[HarmonicTHD]

What could be the reason for the R3 meta and R5 meta having such a difference in the mid to high frequency? I thought both uses the same uni-q driver?

Different x Over Frequency maybe?