PMC Twenty 21, listening fatigue?

Ive had systems that gave me fatigue in the past and it is very annoying!

Have you tried the speakers without the granite slabs? I once put some under my old Rogers and the result was awful. The sound hardened up and there was a glassy quality which became difficult to listen to. As soon as they went back on the carpet the sibilance and harshness disappeared. 

James

The effect could be the speakers, the electronics - or the room. And the room can certainly be a major factor. I don't know those particular speakers, but I don't recall allegations of them being fatiguing. It could be worth getting REW (Room EQ Wizard) free software and a suitable microphone and measuring the room response at your listening position, to see what it is doing, and if you have any significant peaks in the response, or extended decay times etc, which might be factors.

I know that in my current room my preferred position for speakers aesthetically makes for a fatiguing sound, though due to clearly audible room effects, so I use them in optimised positions, and move them whenever their position affects other room use. (even heavy speakers are surprisingly easy to 'walk' on their spikes on a carpeted floor, leaving negligible marks on  the way or in their resting positions.

I'd get hold of the bespoke PMC stands, which do a lot for the performance of the speakers. Hopefully your dealer can lend you some for a couple of weeks. And lose the slabs. What speaker cable are you using? Are the electronics on a decent stand?

I found the same albeit with the 'twenty5' series - I believe it uses the same tweeter as the earlier 'twenty' series and I do have mis givings. To my ears they  have a graininess to them - after a while it just grated and I had to switch off - quite off putting. I thought it was just me and my overly sensitive hearing..i do suffer occasionally from hyperacusis especially when stressed or overly tired

I've got 23's but have heard 21's and this is not what I would describe as a characteristic of the speaker. The only time it has been the case for me is when there has been something else wrong upstream... thus for me they're quite revealing of anything else that isn't right in the system. 

A friend of mine has 21s hanging off a Roksan Caspian MM2 and fronted by a computer driven DAC, the breed of which I can't remember now.  Personally I think they sound quite nice and full bodied for such a small speaker, but I do find that fatigue sets in quite quickly at high volume.  I mean they go loud without much of a problem, but loud is a relative term and the fact is said friend has a tendency to push them out of their comfort zone, at which point I find they become quite shouty and hard sounding.  I may well listen at roughly the same level often enough with Proac D18s, which have their own comfort zone, but if I swapped them for 21s I think I'd expect to have to dial it back a little to get the best from them.  

Hi I have these speakers .... and several things become apparent when using them....they are quite inefficient and like to be driven hard to really balance out..... mine really start rocking at about 83-85db ... this is pretty darn loud .... as a sustained 85db can start to cause hearing damage. I have used a Nait5i.... and they work fine ... but it did not have a huge amount base drive. These speakers love the nap250dr and above. I use a really good sub and this transforms low level listening.  I think you may be turning the wick up to make them sing .... at which point the amp starts to harden a bit..... try the speakers close to the rear wall...on the pmc stands... this may help. I think these are quite demanding little speakers.....

Richieroo posted:

Hi I have these speakers .... and several things become apparent when using them....they are quite inefficient and like to be driven hard to really balance out..... mine really start rocking at about 83-85db ... this is pretty darn loud .... as a sustained 85db can start to cause hearing damage. I have used a Nait5i.... and they work fine ... but it did not have a huge amount base drive. These speakers love the nap250dr and above. I use a really good sub and this transforms low level listening.  I think you may be turning the wick up to make them sing .... at which point the amp starts to harden a bit..... try the speakers close to the rear wall...on the pmc stands... this may help. I think these are quite demanding little speakers.....

This were the 'relative' thing can come in.  I assume you mean an average of 83-85db, but in what size room, and measured at what distance from the speaker?

Innocent Bystander posted:

And the room can certainly be a major factor.

+1 

When we listened to our Twenty5.23 in the dealer's demo room, my wife wasn't terribly fond of the speakers. The room was somewhat on the bright side, and my wife in particular felt the speakers were a bit harsh. Her assessment totally changed when we had the speakers for home demo.

Also +1 for the comment that the PMC are incredibly revealing. They don't tolerate poor quality recordings, for instance. Problems in the "chain" will be revealed by PMC. Tricky, but at the same time big rewards for good recordings. The only downside: occassioanal sleep deprivation when I listen to music for too many hourse in the evening. Just don't want to go to bed...

Hi yes I do have a small room but I also demo them in quite a large room.....same thing really...they are super revealing....but not that efficient .... to get the bass to bogie you need a fair bit of volume....at which point the amp can get stressed...

Richieroo posted:

Hi yes I do have a small room but I also demo them in quite a large room.....same thing really...they are super revealing....but not that efficient .... to get the bass to bogie you need a fair bit of volume....at which point the amp can get stressed...

Sorry, hang on a minute, I just looked at your profile.  You've got nac 272, 555PS, nap500dr, super luminar speaker cable and the 21s in a 8ft by 9ft office.  I am quite sure that a NAP500, DR or otherwise,  is more than capable of driving PMC Twenty 21s, but snapping back to reality for a moment, does this not seem a bit out of balance somewhere?

I only chose 21's for the room size ..... my observations are that the speaker is fantastic ... but it is inefficient and more demanding than you would think. I tried it with Nait5i and it was good ... but I could imagine in a bigger room you could be pushing the amp without really being aware of it. Naim amps are pretty load tolerant...but there is a limit ... and when you start hitting it the sound will be more fatiguing without it be immediately apparent. I am not suggesting it needs a 500 ..... to be good... How load do you have them ..... if as I suspect your up around 85db you will be pushing it especially in a bigger room.

You may try using original stands that can be also filled by shot or some other stuff to your liking. I remember it is suggested not to toe them in. But a little toe in may curb that fatiguing effect, who knows.

Hal has a good point try the speakers firing dead ahead....read KK HI fi news review ...PM measures quite a high treble peak....that is moderated by dead ahead positioning. One last thing the cable from source to amp could also help a bit ..... ask your dealer about trying a different cable.... like chord... Also place the speaker fairly close to rear wall....let us know how you get on....

I've designed some Exakt filters for the Twenty.21 and it has been an interesting experience.

With attenuation, baffle step filters and the crossover, the tweeter has ended up around -15dB on the mid-bass - which is pretty extreme.  The mid-bass has some harshness around the lower mid-range too, which is fixed by a very gentle introduction to the crossover roll-off slope - the nominal crossover point I've settled on is 1700Hz, but it starts to roll-off the mid-bass very gently from about 1050Hz.  Its got some interesting peaks well above the crossover point (3.5k and 5.2k from memory) that are quite heavily rolled-off at that point, but even so they need to be tackled.  Took me about 5 or 6 sessions of 2 or 3 hours each time to get the filters right for this speaker.  Quite a challenge.  They definitely need a few more watts than the Twenty.26 to get to a similar volume level - I think the mid-bass is not very efficient.

They sound significantly better now.  I only bought them as rears to match the Twenty.26 but now I think they'd be good as main speakers.  I've had them on 2/3 sand filled Atacama SE24s and on non-filled Linn Katan stands - prefer them on the Katan stands.  In my room I find they work well around 7 to 8 inches from the rear wall, but that's probably not too helpful as rooms are so different.

In the Twenty.26 filters that Linn created, there's a -6dB (ish) step from bass to mid and another -1.5dB (ish) from mid to treble so the drivers seem to integrate more easily compared to the little 21.  I've still taken another 1.9dB out of the treble in my interpretation of the Exakt filters - its possible to listen to these for hours.

Excuse my ignorance of Linn Exakt and please correct me if I have got this wrong.

I assume that the process of designing filters is in-room using a microphone at the listening position? If so, then what you are reporting is the behaviour of the speakers and the room, as affected by the placement of the speakers and listening position and everything in the room, or some averaging thereof. That then would mean that the filters and assessment of what they are doing is not a good indication of the situation in any significantly different setup?

Alternatively the measurements under some standardised conditions, whether anechoic, or nominal room and positioning - in which case in fact the same applies if the listening setup is significantly different.

Either way this does not seem to help the OP, unless what is significant is the observation that the 15dB cut of the tweeter (full range of it?) relative to mid-bass is unusual, suggesting that relative to the midbass the treble is brighter than commonly found with speakers, possibly contributing to fatigue?

As an aside, how do the speakers sound with the filtration applied? I once tried Dirac Live, which uses measurements atveraged from a number of locations just around the listening position, at a time when my room layout was wrong and causing significant peaks and troughs at the listening position - and the result just killed the music, and it was better with all the original imperfections, obvious though they were. (Solution was to do a thorough measurement of room with REW, and complete rethink of positioning,. I haven't tried Dirac since, but it might do better with less to try to correct.)

Richieroo posted:

Hal has a good point try the speakers firing dead ahead....read KK HI fi news review ...PM measures quite a high treble peak....that is moderated by dead ahead positioning. One last thing the cable from source to amp could also help a bit ..... ask your dealer about trying a different cable.... like chord... Also place the speaker fairly close to rear wall....let us know how you get on....

Yes, playing with toeing in can be a watpy of tweaking the sound, and might make a sufficient difference to address the fatigue factor, so as an easy thing to do it is most definitely worth playing.

Simon-in-Suffolk posted:

I found the same albeit with the 'twenty5' series - I believe it uses the same tweeter as the earlier 'twenty' series and I do have mis givings. To my ears they  have a graininess to them - after a while it just grated and I had to switch off - quite off putting. I thought it was just me and my overly sensitive hearing..i do suffer occasionally from hyperacusis especially when stressed or overly tired

They don't sound similar. I know what you are saying as I've experienced a bit too but not on the Twenty series. Either those minor differences with the tweeter grille or the different crossover but the top end on the Twenty and Twenty5 are very different animals. The older Twenty series, albiet a bit more closed in, is definately a tad smoother (contrary to what some reviewers have claimed). They certainly don't sound like the same tweeter after the changes they made.

No one's mentioned grilles. When all of my PMCs were new they were pretty heavy going for a few months and the only way to listen was with the grilles on. I even find the newer Twenty5 series need the grilles on to sound their best even after they have run in.

Hi am I right in taking that the twenty 5 series is brighter than the old twenty series....... if so omg ..... my little 20.21's are just about right ... meaning they are still exciting at the top end ... grills on.

Hi when I auditioned the twenty5 series, I didn't find them at all bright, in fact the tonal balance seemed rather neutral in my room with their  characteristic bass extension..it was the this slight but uber irritating graininess in the treble that to me let the side down

[@mention:35920103255542881] I have noted your observation on differences with the earlier twenty series where this perhaps is less noticeable or not apparent...

I auditioned a pair of PMC floor standers a while back, not ideal as it was only at a dealers,  but I agree it was not so much a tonal imbalance,  more like the treble has a different sound.  Simon notes graininess,  same thing maybe.  I put it down to the metal dome as I've had exactly the same reaction to them before.    At the same session I listed to a ribbon tweeter,  not sure the make,   now that was something I could live with.

Mike-B posted:

I auditioned a pair of PMC floor standers a while back, not ideal as it was only at a dealers,  but I agree it was not so much a tonal imbalance,  more like the treble has a different sound.  Simon notes graininess,  same thing maybe.  I put it down to the metal dome as I've had exactly the same reaction to them before.    At the same session I listed to a ribbon tweeter,  not sure the make,   now that was something I could live with.

Metal dome? They use a fabric dome tweeter. The protective mesh is indeed metal.

Richieroo posted:

Hi am I right in taking that the twenty 5 series is brighter than the old twenty series....... if so omg ..... my little 20.21's are just about right ... meaning they are still exciting at the top end ... grills on.

I have not yet heard new 25.21 or 25.22 but if new series is  hotter at top end this will give me something to consider. My 20.21's are already quite revealing. I have been thinking about getting 25.21 or 22 to go with CD5si-XS2-HcDR.

feeling_zen posted:

Metal dome? They use a fabric dome tweeter. The protective mesh is indeed metal.

Whoops ..  ..  I just checked the spec's & yes I was mistaken.     I 'noticed' the treble & as the tweeter looks remarkably similar to the metal dome Elac drivers I had back in the 80's ,    I just assumed - my bad ...........  it does not change my opinion that the treble was not quite to my taste.   I'm now toying with 282 & active ATC's,  they sound as I like it,  but maybe a house move first