Kef Q150 Bookshelf Speaker (review by Erin)

[Miker 1102]

Resonances of about 1khz I also experienced with the SP1587 driver in Q100. Resonance is a consequence of suspension. If a dumping mass is added, it resolves a lot. In the pictures, I marked where some flexible material should be applied.I also took off the HF and changed the dumping, both the amount and the type and then measured the impedance to see what the differences are.
The biggest concern is in the meager crossover.
The picture is not mine but a member from another forum.
Picture source:https://www.diyaudio.com/community/...ks-like-inside-a-real-kef-q100-driver.368717/

I like these but

I'm familiar with that song. That is definitely a speaker resonance, not inherent to the source. None of my speakers have such a strong resonance playing that part.

Not sure if it's a flaw with that particular Q150 or if it's the resonances around the 1khz mark being triggered. Oftentimes with cheaper speakers that have multiple significant(enough to show up in measurements) resonances, even if they're not too bad on a sweep, if you get the exact right frequency it's very noticeable.

That happened to Amir on the Elac UB52.

I have this issue. I can hear this in a couple of songs. You literally feel like how is this possible. It sucks becaue they blend well in my room with the subs and have a beautiful image.

 

[Miker 1102]

Yap... first thing first is check for any loose screws... e.g. binding post, mounting bracket, etc. Felt like an idiot a couple of times before with stuff like this.

From anecdotal memory though (sold them long ago), I did experience a grating resonance like this in a pair of Q100 that only showed up with certain content/listening levels.

Thank you for saying this. I am playing Led Zeppelin's Rain song and it is awful.

 

[Miker 1102]

I wonder if rotating the q150s on to their sides and putting weights on top would help with the resonance issues. I love mine but the cabinets feel cheaper than the Klipsch rp500m’s that I used to have as well

This helped wirh the issue. It toned it down somewhat. I lose some height as I have them on stands.

 

[TobyMoby]

Would try to glue something heavy on the outer/inner side like bitumen and so on.

KR

 

[TobyMoby]

Bought a pair, will activate with APO, an AVR, with two 12" woofers, xo 300 Hz.

KR

 

[Hagan66]

Thanks for another speaker review, @hardisj

Kef Q150 Bookshelf Speaker Review

Kef Q150 Review

www.erinsaudiocorner.com

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Discuss!

Love these speakers. Had them in a small bedroom for 6 months. Have them in white...QED XT25 speaker cable, Bluesound Node 2i going into a Chord Mojo DAC and out to an Arcam Solo Mini CD player/Amp. Great soundstage and fabulous detail for the price. Bass output fine for my tastes ...

 

[TobyMoby]

Inspired by the Genius Geddes I put some PPI 30 Foam on/into the Koax. Key word: short time reflections. Then the EQ.

No english native speaker, sorry.


KR

 

[AvPioneer]

Can someone tell me what's going on with the Q150?

Track: Frozen 2 - Into the Unknown

The "oh ohhh ohhh" voice cracks and sounds terrible. Not sure if the full tragedy comes through in the video.

I bought the Metas a couple weeks ago but when the Q150s went on sale I bought them hoping to save $1300+ and have been a/b'ing them with different music. Q150 was winning me over until "ohhh ohhhhh"

Can confirm my set of Q150’s don’t do this. I think it was a QC problem from the factory.

 

[Hagan66]

Can confirm my set of Q150’s don’t do this. I think it was a QC problem from the factory.

Pricewise, a great speaker for a bargain price imo

 

[ROOSKIE]

This speaker is doing the sale thing everywhere now for $300 or less when 'opened box'

https://www.bestbuy.com/site/kef-q-series-5-25-2-way-bookshelf-speakers-pair-satin-black/5913623.p?skuId=5913623

KEF Q150 (Walnut)

Bookshelf speakers

www.crutchfield.com

 

[JRT]

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Interesting that a coaxial driver seemingly centered on a baffle 7.08 inch (18 cm) wide x 11.92 inch (30.3 cm) tall would produce such different response on horizontal and vertical polars intersecting on the frontal axis. I would have expected some differences in interference from edge diffraction from different radial distances to the baffle edge, but would have expected the effects of those differences to appear lower in frequency, not reaching up near the vicinity of 3_kHz to 5_kHz. Seems strange.

 

[aarons915]

Bought a pair, will activate with APO, an AVR, with two 12" woofers, xo 300 Hz.

KR

How did this work out? Looking at the distortion plots I would think 150Hz would be the highest you need to go to play as loud as you need and keep the point-source presentation of the Q150 intact.

 

[Tangband]

Thanks for another speaker review, @hardisj

Kef Q150 Bookshelf Speaker Review

Kef Q150 Review

www.erinsaudiocorner.com

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Discuss!

I have been playing a little with GLM on my monitors, mirroring the freq. response of this popular speaker. The frequency response that q150 have, is making many recordings less shut in, but with neutral recordings and classical music this becomes tiring after some minutes. Music with a single female playing guitar can benefit from a little boost at 1 kHz and a rising treble.

 

[bolo431]

You get 3 EQs:

v1: optimise for PIR -> too many PEQs around the crossover that may not work
v2a: optimise for PIR but smooth target -> better but still too many small and peaky PEQs
v2b: remove the last PEQs and keep only the first 3 from v2a -> recommended EQ.

edit V2a

Preference score 4.8 and 6.9 with a sub
with an EQ 6.1 and 8.2 with both

I added some smoothing to the eq designed in V1. This yield a lower score but more realistic as it is less sharp around the crossover and both LW and PIR looks good.

EQ for KEF Q150 computed from ErinsAudioCorner data
Preference Score 4.8 with EQ 6.2
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.14
Dated: 2022-03-01-14:04:03


Preamp: -0.5 dB


Filter  1: ON PK Fc 13062 Hz Gain -4.34 dB Q 0.50
Filter  2: ON PK Fc   164 Hz Gain -1.36 dB Q 1.50
Filter  3: ON PK Fc   951 Hz Gain -1.63 dB Q 2.28
Filter  4: ON PK Fc  2528 Hz Gain +0.63 dB Q 3.99
Filter  5: ON PK Fc  1022 Hz Gain +1.29 dB Q 4.00
Filter  6: ON PK Fc  1177 Hz Gain -1.43 dB Q 3.98
Filter  7: ON PK Fc   792 Hz Gain -0.73 dB Q 3.97
Filter  8: ON PK Fc  1067 Hz Gain +1.01 dB Q 3.95
Filter  9: ON PK Fc  1568 Hz Gain +0.70 dB Q 3.98

View attachment 189910

V2b

If you look at the EQ, you see that all the last one have low gain and high Q. You can remove all of them and get most of the benefit from the EQ. Here are the results with 3 PEQs and that's my recommended one:

Preference score 4.8 and 6.9 with a sub
with an EQ 5.7 and 7.8 with both

EQ for KEF Q150 computed from ErinsAudioCorner data
Preference Score 4.8 with EQ 5.7
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.14
Dated: 2022-03-01-14:06:26

Preamp: -0.2 dB

Filter  1: ON PK Fc 13243 Hz Gain -4.37 dB Q 0.49
Filter  2: ON PK Fc   165 Hz Gain -1.30 dB Q 1.40
Filter  3: ON PK Fc   951 Hz Gain -1.63 dB Q 2.29

View attachment 189912


V1

Preference score 4.8 and 6.9 with a sub
with an EQ 6.9 and 8.2 with both

I optimised for flat LW and smooth PIR. The automated algorithm is optimising around 1kHz and it should not. The huge variations around the crossover are likely to drive a non minimal phase behaviour that IIR eq cannot correct. So the scores post EQ are likely to be optimistic.

EQ for KEF Q150 computed from ErinsAudioCorner data
Preference Score 4.8 with EQ 6.1
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.14
Dated: 2022-02-27-18:03:10

Preamp: -0.7 dB

Filter  1: ON PK Fc 12987 Hz Gain -3.99 dB Q 0.60
Filter  2: ON PK Fc   159 Hz Gain -1.36 dB Q 1.67
Filter  3: ON PK Fc   951 Hz Gain -1.73 dB Q 3.67
Filter  4: ON PK Fc  1012 Hz Gain +1.44 dB Q 3.99
Filter  5: ON PK Fc  1188 Hz Gain -1.80 dB Q 3.99
Filter  6: ON PK Fc  1339 Hz Gain +1.35 dB Q 3.37
Filter  7: ON PK Fc   805 Hz Gain -1.09 dB Q 3.99
Filter  8: ON PK Fc  1279 Hz Gain -0.93 dB Q 3.99
Filter  9: ON PK Fc  1054 Hz Gain +1.40 dB Q 3.98

View attachment 189528

Hello, thank you for the EQ presets, may I ask if any of these are still applicable with the ports plugged?

 

[tjcinnamon]

Wonder if the q150’s would be good on surround sound duty?

 

[Miker 1102]

I use them as rears. I think they sound good in combination with the other kef q series I have. Tbh, the best place for them in my set up is the fronts. They are really are unbelievably holographic in my room fm certain there isn't a better pair of 300 speakers any where.

 

[rnj]

I kept trying to prefer the elac dbr62 over these, but every time i kept coming back to the q150s. These ended up moving me more (I mean emotively) than the elacs. I would actually love for someone to explain to me why in audiophile terms (i'm no expert). I feel as though these are warmer and more 'alive' sounding than the elacs. The elacs maybe sounded more refined but just didnt move me so much. What does that say about my taste profile?

This is in a small/medium size room with a class D amp (niles si 2100 which deliver 100w at 4 ohms).

 

[Steve Dallas]

I kept trying to prefer the elac dbr62 over these, but every time i kept coming back to the q150s. These ended up moving me more (I mean emotively) than the elacs. I would actually love for someone to explain to me why in audiophile terms (i'm no expert). I feel as though these are warmer and more 'alive' sounding than the elacs. The elacs maybe sounded more refined but just didnt move me so much. What does that say about my taste profile?

This is in a small/medium size room with a class D amp (niles si 2100 which deliver 100w at 4 ohms).

The word "warm" means any of a number of things to me:

1. Distortion in certain frequencies
2. Elevated bass and/or midbass
3. Diminished treble

These speakers may have any or all of those qualities, and you may find that pleasing.

It is also possible the dispersion pattern of these speakers works better in your room. Different speakers do different things in different rooms, and it is natural to have a preference.

 

[tw 2022]

I kept trying to prefer the elac dbr62 over these, but every time i kept coming back to the q150s. These ended up moving me more (I mean emotively) than the elacs. I would actually love for someone to explain to me why in audiophile terms (i'm no expert). I feel as though these are warmer and more 'alive' sounding than the elacs. The elacs maybe sounded more refined but just didnt move me so much. What does that say about my taste profile?

This is in a small/medium size room with a class D amp (niles si 2100 which deliver 100w at 4 ohms).

i don't know about audiophile terms, but the dbr62's aren't a *given* as an upgrade over the q150s, it's just a different presentation...