KEF LS50 disappointment :(

[shkumar4963]

Thanks David. But how do I evaluate each segment of the chain separately.

 

[Frank Harvey]

Thanks David. But how do I evaluate each segment of the chain separately.

See if you can loan an alternative product, either from a friend or dealer, to see if the issue suddenly disappears when you change a single item. But as I say, I'd feed a full fat signal into the system to do this. I appreciate some people are quite happy with Spotify's quality, but if your system isn't doing what it is supposed to be doing (or at least what you expect it to), you need to start at the source and try and narrow down the cause. Signal quality comes before source though.

 

[shkumar4963]

Thanks again David. I understand your approach. But as you know most independent stereo shops have been closed in US. There are only 2 or 3 in my town and they are all very far away. So the only choice I have is to buy them online and then try to return them - not a workable solution in my situation.

is there another way to isolate the problem using testing with REW? Any orher suggestion?

 

[Frank Harvey]

Thanks again David. I understand your approach. But as you know most independent stereo shops have been closed in US. There are only 2 or 3 in my town and they are all very far away. So the only choice I have is to buy them online and then try to return them - not a workable solution in my situation.

And this seems to be a direction the UK is slowly taking, as more and more people move over to online sales for a bargain, rather than supporting their local dealers - then people suddenly realise they have no dealer within 100 miles, they wonder why.

is there another way to isolate the problem using testing with REW?

REW will only help identify a room issue rather than any shortcomings with the system itself - a system can still sound great despite room issues.

 

[shkumar4963]

Thanks David again.

Hopefully someone else will have a suggestion or two on how to test at least few components in my chain.

if not Amazpn offers some return privileges but I can not do it more than once. So give me your best suggestion for what to try first. I believe you had suggested preamp as the first culprit.

What unit would you suggest I buy and try first. I probably would like to stay within 500-800 dollars range. Please suggest a few model numbers that I can look in amazon and buy to try. e.

 

[shkumar4963]

Thanks Vladimir. Sounds good.

I will try that.

Could you suggest another cd that has many low end instruments playing at the same time. That may be even better in testing if low octav resolution is a problem in my system.

 

[Vladimir]

Try this test disc: The Sheffield Lab Drum & Track Disc (2000), use tracks by Ron Tutt and Jim Keltner. It's available both on Spotify and Tidal. It will tell you straight how punchy and fast the LF transients are.

 

[spiny norman]

Are we really reduced to quoting reviewers comments at each other now?

The pair of you are sounding like the plonkers I used to get in my shop, they knew every review, word perfect. Still did not have a clue...!

Come on, you can both do better than this.

Sorry for the delay: been busy these past few days what with presents to deliver and all that. And apologies for forgetting that there is only one correct opinion.

 

[davedotco]

Are we really reduced to quoting reviewers comments at each other now?

The pair of you are sounding like the plonkers I used to get in my shop, they knew every review, word perfect. Still did not have a clue...!

Come on, you can both do better than this.

Sorry for the delay: been busy these past few days what with presents to deliver and all that. And apologies for forgetting that there is only one correct opinion.

You are quite right, in such a situation there is only one opinion that matters.

Yours.

Who gives a flying f**k what someone else thinks?

 

[Vladimir]

IMO* everything is fine with your components, and all are above average quality. You just need to tweak a bit with the sub placement, frequency and amplitude. Which takes time and can be a bit frustrating.

* *biggrin* flying fork?

 

[Vladimir]

Step 1 - Get a CD that has a good recording without loudness compression. So most pop and rock are out. Steely Dan - Aja or Donald Fagen - Nightfly will work if nothing better available to you. This will eliminate if the recordings are the issue.

Step 2 - If you still hear muddy bass, time to try eliminating the subwoofer. Play again without a sub.

Step 3 - If the sub was the issue, plug it back in and try to use it at a lower frequency, 80Hz and lower, 60Hz might fit. You need to go low enough to not be able to localize the sub in your room (not be able to tell the bass is coming from it). Also play with subwoofer positioning.

Step 4 - If you still hear muddy bass, play with speaker repositioning. Make sure your speakers are stabile on the stands, not wobbly.

 

[spiny norman]

Who gives a flying f**k what someone else thinks?

One assumes the readers of the respective magazines, or they wouldn't bother buying them, but thanks for the eloquence of your argument.

 

[shkumar4963]

You just need to tweak a bit with the sub placement, frequency and amplitude. Which takes time and can be a bit frustrating.

Thanks. Wll let you know what i find. By the way, how does one use phase angle in sub? Does it need to be aligned with Main's phase angle? How?

I will align amplitudes and select a cross over frequency based on REW measurements on LS50s and sub separately. Can REW provide phase information as well that will help setting the phase angle on the sub?

 

[shkumar4963]

Thanks again. My testing so far which is very limited indeed, shows that the bass is tight in LS50. Of course the LS50's don't have much low bass below 80 Hz (as tested by REW, 1 ft in front of the speakers).

Does that mean that my electronic chain is OK even if the bass becomes muddy after I add the sub to the system?

I will add the sub now and test again to see if that makes any difference in low bass resolution. Will let you know what I find.

Thanks Vladimir for your help.

 

[Vladimir]

You just need to tweak a bit with the sub placement, frequency and amplitude. Which takes time and can be a bit frustrating.

Thanks. Wll let you know what i find. By the way, how does one use phase angle in sub? Does it need to be aligned with Main's phase angle? How?

I will align amplitudes and select a cross over frequency based on REW measurements on LS50s and sub separately. Can REW provide phase information as well that will help setting the phase angle on the sub?

I honestly don't know how it's done. I'm sure there is a simple tutorial online, give it a google. If a member here can share instructions that would be swell.

 

[chebby]

Try this test disc: The Sheffield Lab Drum & Track Disc (2000), use tracks by Ron Tutt and Jim Keltner. It's available both on Spotify and Tidal. It will tell you straight how punchy and fast the LF transients are.

Available on Apple Music and iTunes too.

 

[chebby]

A brief comparison of my Audio-Note AX-Two loudspeakers (with the LS50s) from the fifth paragraph on both of these pages ...

http://www.dagogo.com/kef-ls-50-bookshelf-speaker-review/2

http://www.dagogo.com/audio-note-uk-ax-two-loudspeaker-review/3

... I need the 90dB sensitivity of the AX-Twos and I prefer their old-fashioned presention to the more 'technical' sound of the KEFs so I am entirely happy to live with my choice. (I also prefer the 'dated' cabinet proportions and build of the Audio-Notes.)

For reference purposes the AX-Twos cost £750 per pair when I bought them a couple of months ago.

 

[davedotco]

Who gives a flying f**k what someone else thinks?

One assumes the readers of the respective magazines, or they wouldn't bother buying them, but thanks for the eloquence of your argument.

I am not suggesting that people should not read reviews, just the fact that they are disected and revered as if gospel, when they are, in terms of sound quality at least, just another opinion.

This leads to buyers refusing to trust what they hear for themselves in favour of what they have read, often resulting in poor choices.

 

[Frank Harvey]

I am not suggesting that people should not read reviews, just the fact that they are disected and revered as if gospel, when they are, in terms of sound quality at least, just another opinion.

This leads to buyers refusing to trust what they hear for themselves in favour of what they have read, often resulting in poor choices.

Agreed. It doesn't matter how good a speaker is, or how good one person says it is - if it doesn't do what you want it to do, there will always be better out there, and could well lead to a costly correction.

 

[shkumar4963]

So we got the SB-12 NSD sub and tested it using REW in my room.

I also tested the LS50 without the Sub. The two graphs are given below. (@vladimir or David - Can you give me permission to post FR Images?)

Even though the Sub clearly shows a low frequency extension till 20 Hz, which was much better than LS50 with low frequency boost, I could not HEAR any difference between the two with multiple songs. No difference in clarity or sound levels.

The reason could be:

1. None of the songs had the low frequencies that are provided by the sub beyond what is available with LS50

2. My hearing is not good enough to resolve the difference between flat response provided by the sub compared to lumpy response provided by LS50

Can anyone think of any other reason? In either case, the low frequencies were somewhat muddy. By muddy I mean in most cases I could not feel the bass guitar strings moving individually. They were all blend in. Am I making any sense?

So unless someone can suggest anything else that I can do to improve the sound using SVS SB12NSD sub, I will return the sub and will use LS50s on their own.

 

[Vladimir]

What is your low pass filter set to?

 

[Ajani]

A brief comparison of my Audio-Note AX-Two loudspeakers (with the LS50s) from the fifth paragraph on both of these pages ...

http://www.dagogo.com/kef-ls-50-bookshelf-speaker-review/2

http://www.dagogo.com/audio-note-uk-ax-two-loudspeaker-review/3

... I need the 90dB sensitivity of the AX-Twos and I prefer their old-fashioned presention to the more 'technical' sound of the KEFs so I am entirely happy to live with my choice. (I also prefer the 'dated' cabinet proportions and build of the Audio-Notes.)

For reference purposes the AX-Twos cost £750 per pair when I bought them a couple of months ago.

Problem is that RGA (Richard Austen) is the biggest Audio Note Fanboy ever. He's been preaching about Audio Note for the last 15 years or so. For a large period of time he pretty much hated anything solid state and all Low/Average efficiency speakers. So it's no surprise he'd prefer the Audio Note. I'm only surprised that he didn't hate the KEF.

 

[Vladimir]

A brief comparison of my Audio-Note AX-Two loudspeakers (with the LS50s) from the fifth paragraph on both of these pages ...

http://www.dagogo.com/kef-ls-50-bookshelf-speaker-review/2

http://www.dagogo.com/audio-note-uk-ax-two-loudspeaker-review/3

... I need the 90dB sensitivity of the AX-Twos and I prefer their old-fashioned presention to the more 'technical' sound of the KEFs so I am entirely happy to live with my choice. (I also prefer the 'dated' cabinet proportions and build of the Audio-Notes.)

For reference purposes the AX-Twos cost £750 per pair when I bought them a couple of months ago.

Problem is that RGA (Richard Austen) is the biggest Audio Note Fanboy ever. He's been preaching about Audio Note for the last 15 years or so. For a large period of time he pretty much hated anything solid state and all Low/Average efficiency speakers. So it's no surprise he'd prefer the Audio Note. I'm only surprised that he didn't hate the KEF.

If the bass light LS50 had deep and punching bass compared to the AX2s, the ANs are seriously bass light. This is no surprise since you can't have high efficiency, small box and deep bass. You can have only two (Hoffman's Iron Law).

IME when I would plug bass ports and lose a lot of LF, I got the strong impression the speakers were faster, tighter and more detailed. Bass masks a lot of midrange information. So a bass light speaker may excel with music that compliments its defficiency. The designer decided to sacrifice low bass for efficiency, size and the resulting effect of more clarity. There are buyers who exactly want that for their choice of music (certanly not for Armin Van Buren) or room.

It really depends on the room how to position to get the most out of the LF coming out of the drivers (and probably some from the resonant box). Keeping the AX2 close to walls may help with accenting the bass that is there, but if there is no real punch the wall wont create one.

 

[shkumar4963]

Next step will be to see if REW + Foobar2000 can remove bump in FR curve of LS50 around 60 Hz. If it can, I will try to see if I can HEAR the difference.

 

[shkumar4963]

I tried going down to 60 hz but could not hear the difference. I can post REW FR graphs for between 90 and 30 Hz.