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Beolab 50 - addressing the speaker/room interface.

I previously used a Pass Labs XVR-1 with Tad and JBL drive units in a custom design. I used it because it was audibly better than the DEQX I also tried.

I'll take the 9800 with it's old fashioned passive crossover thanks.

I'm using an XVR-1 with JBL 4435s, and the improvement over the internal passive crossovers is dramatic. YMMV, of course.
 
I'm using an XVR-1 with JBL 4435s, and the improvement over the internal passive crossovers is dramatic. YMMV, of course.

There certainly seems to be a consensus over on the Lansing forum that the big JBLs sound better when bi or tri amped. But each to his own.
 
I'm trying to work out why boundary reflections should affect distortion
Indirectly.
- Compared to free field, rooms provide room gain in the bass, the smaller the room the more room gain.
- Plus you get a reverberant field in a room, this will be more significant in a smaller room.
- In a small room you tend to sit nearer the speakers to begin with.

All this means the speaker SPL needed tends to be less in small rooms, for bass especially but across the range.

Smaller speakers with an earlier roll-off and less SPL capability can have low distortion in smaller rooms.
 
I'm trying to work out why boundary reflections should affect distortion,

Indirectly.
- Compared to free field, rooms provide room gain in the bass, the smaller the room the more room gain.
- Plus you get a reverberant field in a room, this will be more significant in a smaller room.
- In a small room you tend to sit nearer the speakers to begin with.

All this means the speaker SPL needed tends to be less in small rooms, for bass especially but across the range.

Smaller speakers with an earlier roll-off and less SPL capability can have low distortion in smaller rooms.

Indeed, but that's not what the measurement system will be looking at. It will be measuring distortion at the same same SPL at the same measurement distance from the speaker.

The question is, why should bass enhancement from reflected boundaries give an increase in distortion? Why should distortion components be amplified any more than the fundamental?

Looking at the plots above - assuming the anechoic(?) plot for the JBL is accurate, then the distortion is about 20 dB down at 20 Hz and about 30 dB down at 50 Hz

Although the level will (may) be higher in-room, why would the distortion be (relatively) higher?
 
Although the level will (may) be higher in-room, why would the distortion be (relatively) higher?
Ah right, I agree. Not sure why Keith asked for that - perhaps to look at Merlin's in-room FR?

Just to finish off my tangent (!) the distortion plot of the Kii Three won't be that bad in-room, as stated by the magazine: "Duly adjusted to room placement the bass reserve catches up" - I'm assuming this means some setting that outputs less bass. So the Kii distortion plot is a little unkind - but only because Kii were themselves unwise enough (IMO) to do anechoically flat-to-20Hz in the first place when this isn't needed once Kiis are placed in four walls. But from the sound of your posts, I'm preaching to the converted!
 
Kii really ought not to have sent a pre production prototype to be reviewed , one without the motion feedback or limiting implemented. They are I believe having the speakers independently measured at the Klippel? laboratory.
Keith
 
Ah!

Rookie mistake to send pre production protos for review indeed - especially if they didn't check them and measure them at the factory first

;)

Honestly I've been there done that with in room plots at the listening position and at 1m etc. I was doing to almost two decades ago. Audio, for me, is an illusion. If that illusion sounds authentic to your own ears then it's fine IMHO. It's just not something I worry about now Keith and I no longer have all of the equipment. I know how the room measures and know the bass roll off of the speaker I use is ideally suited to it.

In that respect I'm in the same camp as many well respected designers. You need the frequency response to be reasonably accurate but fiddling with electronics to get them "perfect" is, IME, a waste of energy.

I've also found that, in my systems, electronic active crossovers are superb when it comes to clarity and detail, but all of the implementations I've tried were lacking to a degree in "musicality" or as I prefer to call it authenticity or coherence.

To me music is a fantastically dynamic medium and it's dynamics (and the lack of dynamic compression) that really makes or breaks a system and adds that level of authenticity that is lacking in many systems that focus on other metrics.
 
Ah!

Rookie mistake to send pre production protos for review indeed - especially if they didn't check them and measure them at the factory first

;)

Honestly I've been there done that with in room plots at the listening position and at 1m etc. I was doing to almost two decades ago. Audio, for me, is an illusion. If that illusion sounds authentic to your own ears then it's fine IMHO. It's just not something I worry about now Keith and I no longer have all of the equipment. I know how the room measures and know the bass roll off of the speaker I use is ideally suited to it.

In that respect I'm in the same camp as many well respected designers. You need the frequency response to be reasonably accurate but fiddling with electronics to get them "perfect" is, IME, a waste of energy.

I've also found that, in my systems, electronic active crossovers are superb when it comes to clarity and detail, but all of the implementations I've tried were lacking to a degree in "musicality" or as I prefer to call it authenticity or coherence.

To me music is a fantastically dynamic medium and it's dynamics (and the lack of dynamic compression) that really makes or breaks a system and adds that level of authenticity that is lacking in many systems that focus on other metrics.

Good post.
 
Yeah that motorized tweeter going up and down is a bit naff - what's the point of that, exactly? Just a visual effect to impress people?

Certainly reminds me why I dislike B&O - a bit like in the nineties, when they had this mini system that sounded crap, but had two glass doors that would open automatically when you came close with your hands, yay! You could certainly hear where the money was invested. :rolleyes:

Granted, this clearly seems to be more serious, and orders of magnitude more expensive, but it's just too gimmicky for my taste.
I've always had the impression B&O made funky pieces of furniture that played music rather than hi-fi kit that looked nice.
They opened a showroom in Glasgow in the mid nineties round the corner from my central Glasgow flat at the time. I had just bought a pair of Meridian DSP5000s costing £3,300. I went into the B&O shop just for a nosey and spotted a pair of speakers that looked like miniature daleks. The shop assistant saw my curiosity and offered to let me hear them. He was really enthusiastic about these things and proudly told me they were B&O's flagship speakers that cost £12,000. I listened for a few minutes and then told him my new Meridians at a quarter of the price widdled all over them. The B&Os were OK but very far from 12k's worth. The guy looked utterly crestfallen as I left the shop.
 
I've always had the impression B&O made funky pieces of furniture that played music rather than hi-fi kit that looked nice.
They opened a showroom in Glasgow in the mid nineties round the corner from my central Glasgow flat at the time. I had just bought a pair of Meridian DSP5000s costing £3,300. I went into the B&O shop just for a nosey and spotted a pair of speakers that looked like miniature daleks. The shop assistant saw my curiosity and offered to let me hear them. He was really enthusiastic about these things and proudly told me they were B&O's flagship speakers that cost £12,000. I listened for a few minutes and then told him my new Meridians at a quarter of the price widdled all over them. The B&Os were OK but very far from 12k's worth. The guy looked utterly crestfallen as I left the shop.

That was then, this is now.
Keith
 
I've always had the impression B&O made funky pieces of furniture that played music rather than hi-fi kit that looked nice.
They opened a showroom in Glasgow in the mid nineties round the corner from my central Glasgow flat at the time. I had just bought a pair of Meridian DSP5000s costing £3,300. I went into the B&O shop just for a nosey and spotted a pair of speakers that looked like miniature daleks. The shop assistant saw my curiosity and offered to let me hear them. He was really enthusiastic about these things and proudly told me they were B&O's flagship speakers that cost £12,000. I listened for a few minutes and then told him my new Meridians at a quarter of the price widdled all over them. The B&Os were OK but very far from 12k's worth. The guy looked utterly crestfallen as I left the shop.

I think most people would have a negative reaction at being told that their pride and joy was a worthless piece of rubbish.

I once made the mistake of telling a Naim fanboy how much better my Sony 9000ES amp was than my then Naim kit, and got invited to a fisticuffs discussion to 'sort it out'.

For what it's worth, I first heard the 'dalek' B&O speakers when I was a dyed in the wool, flat earth, PRaT owning Naimee, and thought them tuneless lifestyle speakers on a cursory listen when they first came out.

I changed my tune months later when visiting interstate and heard them in a much bigger and better room, over an extended demo, and the salesman was a fellow practicing classical musician who also happened to know his audio gear.

They really opened my eyes and my ears and became my new 'dream' speaker, supplanting my previous 'favourite' - the B&W 801.

Cheers
 
Jonboi,

I think most people would have a negative reaction at being told that their pride and joy was a worthless piece of rubbish.
JCBrum of the AVI forum told me my Tannoys were meant for a museum or, better yet, a bonfire, to which I replied --


Joe
 
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