KEF Q550 headache...help!

Colbe

Novice Member
Hi all, new to this forum.
After being away from hifi for many years I decided to set mine up again.
But in an expensive hole I think.
I have an old school Technics amp A800s MK2 along with a pair of celestion 9 speakers that are mint.
Decided on a set of floor standing and opted for KEF Q550.
DULL!!! But apart from that they do something odd that needs the public help.
When I offer some base it seems to flare to the point of making the cones rattle.
Yet my celestion are deep smooth and much better.
What am I doing wrong guys?
I've changed speakers over from A to B etc. Celestion work on both without issue.
Have I bought a pair of lemons??
 

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andybebbs

Active Member
I have kef q550 speakers which work great on my rega elicit-r but i must say they are not the most bass oriented speakers. i recently got a relt5i to go along side my kefs and now it all sounds great.
 

gibbsy

Moderator
If that is the position of your Q550s in the photograph then that not the best position for any speaker. Your are going to get a lot of boundary issues. Bring the speakers out into the open and see if the problems persist. They are not the deepest bass speakers and rely on two passive radiators to boost the response. It could be that something has come loose within the speaker itself.

I have KEF R300s and the bass response is fast and agile. One of KEF's strong points.
 

Ugg10

Distinguished Member
Just going to state the obvious (we have all been there), check the speakers and amp are wired up red to red and black to black (afaik the q550s are single wire only so no issues with jumpers etc). Also if your amp has a tone defeat button / source direct use that and the use the balance to listen to left and right separately to see if they sound similar, this will help identify issues with drivers. Finally if you have Spotify, use one of the test tone play lists to make sure you are getting an even 20-20khz sweep on both speakers.
 

Helix Hifi

Well-known Member
Just going to state the obvious (we have all been there), check the speakers and amp are wired up red to red and black to black (afaik the q550s are single wire only so no issues with jumpers etc). Also if your amp has a tone defeat button / source direct use that and the use the balance to listen to left and right separately to see if they sound similar, this will help identify issues with drivers. Finally if you have Spotify, use one of the test tone play lists to make sure you are getting an even 20-20khz sweep on both speakers.
Which test sweep do you recommend? Should I just type in 20-kHz? I’m curious to see how my speakers are behaving.
 

Helix Hifi

Well-known Member
Hi all, new to this forum.
After being away from hifi for many years I decided to set mine up again.
But in an expensive hole I think.
I have an old school Technics amp A800s MK2 along with a pair of celestion 9 speakers that are mint.
Decided on a set of floor standing and opted for KEF Q550.
DULL!!! But apart from that they do something odd that needs the public help.
When I offer some base it seems to flare to the point of making the cones rattle.
Yet my celestion are deep smooth and much better.
What am I doing wrong guys?
I've changed speakers over from A to B etc. Celestion work on both without issue.
Have I bought a pair of lemons??
As mentioned by gibbsy, the speakers aren’t doing you any favors by placing one speaker behind the sofa. But I can understand if there is little room. Still KEF speakers need about 50 hours to sound good. The drivers need some workout before they sound good. If you got tone controls on the amplifier, then try and turn the bass on max, same with the treble. But be careful that you don’t play too loud to begin with when you start playing some music. About half past 9 should do the trick. As mentioned don’t play too loud! This is because the speakers may malfunction because the amplifier has to work harder if you adjust the tone controls. Still it’s great for burning in your speakers. I used the same tactics on my speakers. Good luck. 👍
 

Colbe

Novice Member
If that is the position of your Q550s in the photograph then that not the best position for any speaker. Your are going to get a lot of boundary issues. Bring the speakers out into the open and see if the problems persist. They are not the deepest bass speakers and rely on two passive radiators to boost the response. It could be that something has come loose within the speaker itself.

I have KEF R300s and the bass response is fast and agile. One of KEF's strong points.
Hi gibbsy, that's not where they live, just out the box and only had short lengths of qed cable.
They are now 12ft apart and opposite side of the room from amp. As they are brand new I called KEF and spoke to a helpful chap called Ron. After looking up my amp info he suggested could be under powered.
Next challenge is to get it on my av amp and test. Fingers crossed they will produce more punch and low end.
What I can't get my head around is how my celestion 9s have such capability on the same amp.
I've got a sub I could add but if I knew that was needed I'd have bought bigger speakers😕.
Can only hope it's because the kefs are more greedy and will wake up on another amp.
If not I can't see me living with these.
Can't spend that much and have my old ( very old!) Little celestion show them the door!
Also wondered if the cables traveling side by side is an issue? Anyone comment on this?
(
IMG-20210310-WA0005.jpeg
The pic is plan B)
Thanks.
 

Colbe

Novice Member
Just going to state the obvious (we have all been there), check the speakers and amp are wired up red to red and black to black (afaik the q550s are single wire only so no issues with jumpers etc). Also if your amp has a tone defeat button / source direct use that and the use the balance to listen to left and right separately to see if they sound similar, this will help identify issues with drivers. Finally if you have Spotify, use one of the test tone play lists to make sure you are getting an even 20-20khz sweep on both speakers.
Thanks, yes all wired correctly. First thing I checked. Tried on both channels of amp as well.
 

Colbe

Novice Member
As mentioned by gibbsy, the speakers aren’t doing you any favors by placing one speaker behind the sofa. But I can understand if there is little room. Still KEF speakers need about 50 hours to sound good. The drivers need some workout before they sound good. If you got tone controls on the amplifier, then try and turn the bass on max, same with the treble. But be careful that you don’t play too loud to begin with when you start playing some music. About half past 9 should do the trick. As mentioned don’t play too loud! This is because the speakers may malfunction because the amplifier has to work harder if you adjust the tone controls. Still it’s great for burning in your speakers. I used the same tactics on my speakers. Good luck. 👍
Going to give all that some thought. That location pic is actually showing the speakers facing into the dining room not the lounge.
If I offer base they go nuts and scared I damage them..they get into a flap easily.
All info greatly appreciated.🙂
 

Helix Hifi

Well-known Member
Going to give all that some thought. That location pic is actually showing the speakers facing into the dining room not the lounge.
If I offer base they go nuts and scared I damage them..they get into a flap easily.
All info greatly appreciated.🙂
I see. Then perhaps the placement may work after all. Regarding the drivers on the speakers. Do they rattle too much? If so are they new? It could be you need to tighten the bolts around the drivers. Still if they are brand new I would send them back ASAP. The bass drivers on my left speaker rattles the closet door if I play really loud. :oops: :laugh: So you’re not alone. I see in the post above they are brand new. KEF speakers need some quality power to control the bass. Around 100 watts in 8 ohm. The reason the old speakers may work better is maybe because the specifications are different. 8 ohm-90 dB sensitivity speakers are easier to drive then 4 ohm-87 dB sensitivity speakers. Check the manual for the KEF speakers. It should say both ohm, sensitivity. Regarding the amplifier it can be very important that amplifier covers the frequency all the way from 20 hz-20khz. Plus check the TDH specs. The lower the number the better.
 
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Ugg10

Distinguished Member
Which test sweep do you recommend? Should I just type in 20-kHz? I’m curious to see how my speakers are behaving.
This is the playlist I use. There is a track on there that does a 20hz-20khz left and right sweep, track 33.

 

Colbe

Novice Member
Which test sweep do you recommend? Should I just type in 20-kHz? I’m curious to see how my speakers are behaving.

I see. Then perhaps the placement may work after all. Regarding the drivers on the speakers. Do they rattle too much? If so are they new? It could be you need to tighten the bolts around the drivers. Still if they are brand new I would send them back ASAP. The bass drivers on my left speaker rattles the closet door if I play really loud. :oops: :laugh: So you’re not alone. I see in the post above they are brand new. KEF speakers need some quality power to control the bass. Around 100 watts in 8 ohm. The reason the old speakers may work better is maybe because the specifications are different. 8 ohm-90 dB sensitivity speakers are easier to drive then 4 ohm-87 dB sensitivity speakers. Check the manual for the KEF speakers. It should say both ohm, sensitivity. Regarding the amplifier it can be very important that amplifier covers the frequency all the way from 20 hz-20khz. Plus check the TDH specs. The lower the number the better.
Screenshot_20210311_073135_com.android.chrome.jpgthis is the spec but a little over my head. Your thoughts?
 

andybebbs

Active Member
i`m thinking you have a fault somewhere as had no problems with my q550 speakers driven with a rega elicit r which is 105 watts at 8ohms.
 

gibbsy

Moderator
Is the problem just with one speaker or with both. Both would suggest that the amp is not driving them well. Even though you have 55 watts into 8 ohms the problem is going arise when the speakers ohm loading drop to their minimum of 3.6 ohm. If the amp cannot sustain enough power to maintain 3.6 ohm then you can have distortion, especially with deep bass notes. It has a damping factor of 70 which isn't that great.

KEF speakers are a hard drive and will not suit many amps. The Rega Brio mentioned above with the 550s is a very good small amp and has only 50 watts into 8 ohms yet is capable of sustaining the drops required of the 550s.

When you say you offer up bass to the speakers I take it you have bass control on the amp. What happens if you leave the bass at mid point. Is it fine then. Like andybebbs above I'm giving my KEFs plenty of power with a Rega Elicit-R.
 

Colbe

Novice Member
Is the problem just with one speaker or with both. Both would suggest that the amp is not driving them well. Even though you have 55 watts into 8 ohms the problem is going arise when the speakers ohm loading drop to their minimum of 3.6 ohm. If the amp cannot sustain enough power to maintain 3.6 ohm then you can have distortion, especially with deep bass notes. It has a damping factor of 70 which isn't that great.

KEF speakers are a hard drive and will not suit many amps. The Rega Brio mentioned above with the 550s is a very good small amp and has only 50 watts into 8 ohms yet is capable of sustaining the drops required of the 550s.

When you say you offer up bass to the speakers I take it you have bass control on the amp. What happens if you leave the bass at mid point. Is it fine then. Like andybebbs above I'm giving my KEFs plenty of power with a Rega Elicit-R.
Hi yes base control on amp. If left midway no distortion. But poor sound, empty. If I add what I woould say reasonable amount it seems to flare into a flapping frenzy on both base speakers.
So it is looking like amp issue.
Im in conversation with andybebbs regards an amp.
Can I send him my details? Don't want to break rules.
 

gibbsy

Moderator
Hi yes base control on amp. If left midway no distortion. But poor sound, empty. If I add what I woould say reasonable amount it seems to flare into a flapping frenzy on both base speakers.
So it is looking like amp issue.
Im in conversation with andybebbs regards an amp.
Can I send him my details? Don't want to break rules.
No problems with you chatting by PM at all. Although I don't have Q550s, I have R300s I also own an Elicit-R if you need any information on that particular amp.
 

Helix Hifi

Well-known Member
View attachment 1474368this is the spec but a little over my head. Your thoughts?
It seems like the amplifier is not ideal. If you don’t mind buying amplifiers from Hegel, then the KEF speakers we’ll sing. But sadly Hegel are very expensive. Rotel is also very good. But Rotel can be bit sharp in the upper midrange. Now you could try the Marantz PM6006. Even if I mentioned around 100 watts (PM6006 only has 45 watts), the Marantz amplifier is very powerful. Good luck.
 

Colbe

Novice Member
It seems like the amplifier is not ideal. If you don’t mind buying amplifiers from Hegel, then the KEF speakers we’ll sing. But sadly Hegel are very expensive. Rotel is also very good. But Rotel can be bit sharp in the upper midrange. Now you could try the Marantz PM6006. Even if I mentioned around 100 watts (PM6006 only has 45 watts), the Marantz amplifier is very powerful. Good luck.
Thanks for all your input. Might try Yamaha s 701? Seems one available on here.
Thanks again
 

Helix Hifi

Well-known Member
@Colbe, the NR803D is bit more expensive then the AS701, if I’m not mistaken. It has 100 watts in 8 ohm. Plus it also has160 watts in two channels in 4 ohm. And it can reach as high as 290 watts in dynamic peaks!
 
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Helix Hifi

Well-known Member
@Colbe, but I don’t think you can go wrong with either one of the mentioned Yamaha amplifiers. But the NR803D has digital room correction software, if I’m not mistaken. The AS701 has subwoofer connection, loudness control. The latter may come in handy.
 

Colbe

Novice Member
@Colbe, but I don’t think you can go wrong with either one of the mentioned Yamaha amplifiers. But the NR803D has digital room correction software, if I’m not mistaken. The AS701 has subwoofer connection, loudness control. The latter may come in handy.
Working on the important figures which include divorce costs..might be the as801🤣
 

password1

Distinguished Member
Perhaps you prefer the sound of the celestion speakers.

Newer or more expensive does not mean better.
 

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