Question Kef Q900: what amp to pair with?

[PieterG]

It took me a couple of weeks or researching to realize i need help from people who know a lot more than i do... and that's you.

The situation -- I own a pair of Kef Q900 floor standers, which have been used as front channels in a (poorly configured) surround setup. I want to move these into another room and play stereo music through them, mostly from the streamer i intend to buy: the Cambridge CXN100.

The question -- What amplifier should i use to drive the Q900?
Online research gives me conflicting information: they are not difficult to control, yet their bass is tricky because the impedance can drop very low. Many sources suggest using a high power amp to overcome that, but others say it's unnecessary for anything except nightclub volume or extremely large rooms.

I do understand that maximum watts say very little about an amp's efficiency. What i don't understand is that pairing suggestions range from a modest Marantz PM6007 to a high power Rotel or Yamaha at 2500+ euros. I noticed that Arcam A15 is popular here, praised for its neutral character and ability to drive all but the fussiest speakers. I'd like to believe that.

The dilemma -- I picked the Cambridge streamer for its wide stage and detail, and i care enough to set it up in a room for critical listening. I like my music with breathing room between the instruments, plenty of detail. My goal is to have room filling sound that resembles my Fiio portable player with quality in ear monitors. However, i don't feel like spending twice the amount on analog amplification alone. If it takes that, i'm probably better off with a different amp and speakers.

Please, if you have good advice, i'm all ears. (Apologies for the poorly chosen pun.)
If you happen to have experience with Kef floor standers, that would be extremely helpful.

Thanks!

 

[Din5]

I had KEF Q5's , the sound was transformed when I fed them with a Rega Elicit-R amplifier (105W/Ch into 8ohms). Much better control of the bass etc with high levels of detail. Having a large available amount of power in an amplifier allows the amp to supply immediate large amount of current to the speakers when required, so its not just about how loud the amp will go !

 

[Fandango Andy]

It took me a couple of weeks or researching to realize i need help from people who know a lot more than i do... and that's you.

The situation -- I own a pair of Kef Q900 floor standers, which have been used as front channels in a (poorly configured) surround setup. I want to move these into another room and play stereo music through them, mostly from the streamer i intend to buy: the Cambridge CXN100.

The question -- What amplifier should i use to drive the Q900?
Online research gives me conflicting information: they are not difficult to control, yet their bass is tricky because the impedance can drop very low. Many sources suggest using a high power amp to overcome that, but others say it's unnecessary for anything except nightclub volume or extremely large rooms.

I do understand that maximum watts say very little about an amp's efficiency. What i don't understand is that pairing suggestions range from a modest Marantz PM6007 to a high power Rotel or Yamaha at 2500+ euros. I noticed that Arcam A15 is popular here, praised for its neutral character and ability to drive all but the fussiest speakers. I'd like to believe that.

The dilemma -- I picked the Cambridge streamer for its wide stage and detail, and i care enough to set it up in a room for critical listening. I like my music with breathing room between the instruments, plenty of detail. My goal is to have room filling sound that resembles my Fiio portable player with quality in ear monitors. However, i don't feel like spending twice the amount on analog amplification alone. If it takes that, i'm probably better off with a different amp and speakers.

Please, if you have good advice, i'm all ears. (Apologies for the poorly chosen pun.)
If you happen to have experience with Kef floor standers, that would be extremely helpful.

Thanks!

They are easy to drive, manufactures recommendation is anything above 15W. Realistically, you probably want 30W+ so as not to work the amp too hard.

If you are in the UK I would take a serious look at an Audiolab 6000A. the mark II came out earlier in the year. you can get the old version for £299 in silver or £399 in black. it isn't that long ago they were getting five star reviews at £700. Great sounding amp with 50W per channel, more than enough for your needs.

 

[PieterG]

Thank you @Din5 and @Fandango Andy for your replies. Much appreciated.
These are a perfect illustration of the conflicting information i have been finding...

They are easy to drive, manufactures recommendation is anything above 15W. Realistically, you probably want 30W+ so as not to work the amp too hard.

vs.

I had KEF Q5's , the sound was transformed when I fed them with a Rega Elicit-R amplifier (105W/Ch into 8ohms). Much better control of the bass etc with high levels of detail.

For reference: online sources indicate my Onkyo AVR is comparable to about 90W into 8 ohms. That should be adequate power, but it's unclear from the specs if it can control current properly when the Q900 drop to around 3 ohms.

Yesterday i put my speakers in a decent position and played them with the AVR in direct mode through the front stereo channels only. With ample breathing room the bass isn't very powerful and the sound overall seems to lack body and and feels compressed/nasal (sorry - i'm not familiar with the terminology here).

I do like the amount of detail from the speakers, and the better speaker placement gives nice left/right separation. I hope this indicates at least that they have potential. Things improve for me when the volume goes up, but i need a good room filling sound at a level where normal conversation is possible.

Perhaps this update helps to get more targeted advice?

 

[BiggaJ]

I do have for sale on eBay a lovely Gato Audio DIA 250s-NPM amp. It will drive most speakers, I had it hooked up to a pair of Audio Physic Classic 15s.

 

[Fandango Andy]

Thank you @Din5 and @Fandango Andy for your replies. Much appreciated.
These are a perfect illustration of the conflicting information i have been finding...


vs.


For reference: online sources indicate my Onkyo AVR is comparable to about 90W into 8 ohms. That should be adequate power, but it's unclear from the specs if it can control current properly when the Q900 drop to around 3 ohms.

Yesterday i put my speakers in a decent position and played them with the AVR in direct mode through the front stereo channels only. With ample breathing room the bass isn't very powerful and the sound overall seems to lack body and and feels compressed/nasal (sorry - i'm not familiar with the terminology here).

I do like the amount of detail from the speakers, and the better speaker placement gives nice left/right separation. I hope this indicates at least that they have potential. Things improve for me when the volume goes up, but i need a good room filling sound at a level where normal conversation is possible.

Perhaps this update helps to get more targeted advice?

Din5 may have just found the alchemy of speakers and amp that are a perfect match. Either that or his original amp was terrible! Do you have a good local hifi shop that may be able to lend you a demo model?

 

[Integralista]

It took me a couple of weeks or researching to realize i need help from people who know a lot more than i do... and that's you.

The situation -- I own a pair of Kef Q900 floor standers, which have been used as front channels in a (poorly configured) surround setup. I want to move these into another room and play stereo music through them, mostly from the streamer i intend to buy: the Cambridge CXN100.

The question -- What amplifier should i use to drive the Q900?
Online research gives me conflicting information: they are not difficult to control, yet their bass is tricky because the impedance can drop very low. Many sources suggest using a high power amp to overcome that, but others say it's unnecessary for anything except nightclub volume or extremely large rooms.

I do understand that maximum watts say very little about an amp's efficiency. What i don't understand is that pairing suggestions range from a modest Marantz PM6007 to a high power Rotel or Yamaha at 2500+ euros. I noticed that Arcam A15 is popular here, praised for its neutral character and ability to drive all but the fussiest speakers. I'd like to believe that.

The dilemma -- I picked the Cambridge streamer for its wide stage and detail, and i care enough to set it up in a room for critical listening. I like my music with breathing room between the instruments, plenty of detail. My goal is to have room filling sound that resembles my Fiio portable player with quality in ear monitors. However, i don't feel like spending twice the amount on analog amplification alone. If it takes that, i'm probably better off with a different amp and speakers.

Please, if you have good advice, i'm all ears. (Apologies for the poorly chosen pun.)
If you happen to have experience with Kef floor standers, that would be extremely helpful.

Thanks!

Hi Pieter, first of all Kef Q900 is very good speaker, big piece of "meat" for good price. They are designed for mid to big size room and no problem with loud listening. And they work from 32Hz above. So they have a lot of bass. But...They are 2,5 way with 3x8inch bass driver. One is active or connected to crossover in speaker and rest are passive membranes. This speaker is also quite large. Yes, this speaker will work with some small amp like Audiolab 6000 or Marantz 6007 but not good enough. This speaker has substantial bass output but need a lot of current and control. Tip like Rega Elicit or Elex or similar Naim Audio (even used ones) is very good one. A friend of mine was using Kef R7 with some 20years old Bryston R60. What a good sound it was! Kefs are picky and demanding speakers. I recommend to think twice and try some amp at home before you decide.

 

[PieterG]

I have no idea what's going on, but none of my replies to other replies are going through. I get an error saying my content is spam-like or contains inappropriate elements... 🙄

 

[PieterG]

@BiggaJ I had to look up that Gato. It's a gorgeous design!
It certainly looks capable enough on paper, but on the wrong side of the budget i have in mind.

 

[PieterG]

@Integralista what you say makes a lot of sense - thank you.

Kef Q900 is very good speaker, big piece of "meat" for good price. They are designed for mid to big size room and no problem with loud listening. And they work from 32Hz above. So they have a lot of bass. But...They are 2,5 way with 3x8inch bass driver. One is active or connected to crossover in speaker and rest are passive membranes. This speaker is also quite large. Yes, this speaker will work with some small amp like Audiolab 6000 or Marantz 6007 but not good enough. This speaker has substantial bass output but need a lot of current and control.

With some AI help i educated myself a little on electrical current, damping factor, and bass control. Apparently the solution to the Q900 resistance dip is high current, which not all amps are able to generate. For example, a NAD C389/399 generates about 26A while an Audiolab 6000A only reaches 9A. Interestingly, a Marantz 60n gets up to 18A , while it's only rated 60W into 8 ohm.

The math gives me some suggestions that should work on paper. I can factor in the listening distance and volume, but it looks like the high current is critical for bass control, especially at higher volume. Ideally i'd like to hook up my speakers to a couple of those, but i don't know if we have many shops in Belgium that offer this.

 

[nopiano]

@Integralista what you say makes a lot of sense - thank you.


With some AI help i educated myself a little on electrical current, damping factor, and bass control. Apparently the solution to the Q900 resistance dip is high current, which not all amps are able to generate. For example, a NAD C389/399 generates about 26A while an Audiolab 6000A only reaches 9A. Interestingly, a Marantz 60n gets up to 18A , while it's only rated 60W into 8 ohm.

The math gives me some suggestions that should work on paper. I can factor in the listening distance and volume, but it looks like the high current is critical for bass control, especially at higher volume. Ideally i'd like to hook up my speakers to a couple of those, but i don't know if we have many shops in Belgium that offer this.

No need to disappear down a ‘rabbit hole’ of tech specs, though it’s very interesting.

A couple of replies above are both true:- your speakers don’t need a v powerful amp; they might sound great with a powerful one! I think you need a local dealer who will let you try something at home, with an option to return.

Your AVR is ok, but your description mirrors my experience of such amps, unless they’re a top of the range version. At least you have a point of reference now!

 

[Rui]

i think that some newer amplifiers let me a bit down and knowing that the speakers you refer are real good ,i´m not able to refer a new or recent amplifier because of my doubts as a performance to get the best out of your speakers, AV receivers aren´t at all my possible choice but a full on stereo amplifier the less power ones have the tendencie to heat up a lot and more power they do heat a lot but i think someone refered to Rotel amplifier, were without a doubt very good, but price wise ,i don´t know your budget but try to see what Rotel stereo amplifier brings to the table, so to speak . the two mono amplifiers with a control amplifier or pré are a better choice but as i said the price is too much , but you know better than i what is your budget to a new amplifier,
Also i´m a KEF speakers user but mine are mid 80´s the KEF ONE 80.000 hertz hyper tweeter some here might know them and sound good as it were before the joined adventure with Celestion to China, Celestion seems to have vanished

 

[PieterG]

Hi @Rui thanks for your reaction, and nice to see there are more folks out there who like KEF speakers. It's true that Rotel amps are mentioned as a match for these speakers, either as a fully integrated solution or pre/power combination. The 1572 or 1582 would be on my list if it wasn't 2000-3000 euros.
I was hoping to solve this with an integrated amp around 1000-1200, but could be convinced to go a bit higher after a good listening session.

 

[PieterG]

No need to disappear down a ‘rabbit hole’ of tech specs, though it’s very interesting.

A couple of replies above are both true:- your speakers don’t need a v powerful amp; they might sound great with a powerful one! I think you need a local dealer who will let you try something at home, with an option to return.

Your AVR is ok, but your description mirrors my experience of such amps, unless they’re a top of the range version. At least you have a point of reference now!

Rabbit holes are my job! (I'm a technical writer in the IT sector.)

I take comfort in the fact that you have had a similar experience. I'm going to reach out to a local shop that has a good reputation for supporting customers AND sells at competitive prices. If they'll work with me i can hopefully gain a lot of practical experience.

I feel like i've never unlocked the true potential of my speakers in 15 years. Or maybe it's unrealistic of me to expect that room filling sound can be as good as what i get out of my portable player with dual AKM DAC and balanced in ear monitors.

 

[nopiano]

Rabbit holes are my job! (I'm a technical writer in the IT sector.)

I take comfort in the fact that you have had a similar experience. I'm going to reach out to a local shop that has a good reputation for supporting customers AND sells at competitive prices. If they'll work with me i can hopefully gain a lot of practical experience.

I feel like i've never unlocked the true potential of my speakers in 15 years. Or maybe it's unrealistic of me to expect that room filling sound can be as good as what i get out of my portable player with dual AKM DAC and balanced in ear monitors.

Speakers in any room are a very different experience to iems, but for me it’s far more enjoyable. For some, the immediacy of headphones can’t be beaten; I prefer to feel some impact on my body, which speakers can deliver.

Keeps us posted on your trials, and good luck!