[Hoiman]

Yesterday we got the KEF Blade in our house. I have an 4BSST and SP2. When we listened the KEF Blade in the store we where flabbergassed by the sound, it sounded amazing. The amplifier used was an integrated Esoteric F-03A.
BUT when it was connected at home to my Bryston set it was awfull, the whole speaker resonated when someone played the bass. What was happening? We tried everything, turned the KEF Blade speaker in other positions, but the resonation stayed.
The people from the store where flabbergassed because they didn't know what happend. Does someone here maybe know what the problem is? Is the Bryston 4BSST to strong or maybe to weak? The speaker was good in the high, mid and normal low (like a drum), but in the real low (a bass gitar) it went wrong. Someone?

Tomorrow I got the B&W 803 3D instead, to test.

[CanadianMaestro]

Synergy. Bad in this case.

It's good that you can audition speakers at home.

[James Tanner]

Yesterday we got the KEF Blade in our house. I have an 4BSST and SP2. When we listened the KEF Blade in the store we where flabbergassed by the sound, it sounded amazing. The amplifier used was an integrated Esoteric F-03A.
BUT when it was connected at home to my Bryston set it was awfull, the whole speaker resonated when someone played the bass. What was happening? We tried everything, turned the KEF Blade speaker in other positions, but the resonation stayed.
The people from the store where flabbergassed because they didn't know what happend. Does someone here maybe know what the problem is? Is the Bryston 4BSST to strong or maybe to weak? The speaker was good in the high, mid and normal low (like a drum), but in the real low (a bass gitar) it went wrong. Someone?

Tomorrow I got the B&W 803 3D instead, to test.

I can not see it being the amp?  What speakers were you using the 4B with before?

james

[Jonathan]

BUT when it was connected at home to my Bryston set it was awfull, the whole speaker resonated when someone played the bass. What was happening? We tried everything, turned the KEF Blade speaker in other positions, but the resonation stayed.

In my opinion, it sounds more like a room problem than an amp problem. I once sold a pair of Quicksilver 90 watt monoblocks after buying some new speakers, thinking it was the cause of problems in the bottom end. Unfortunately, the problem persisted with a high wattage/high current solid state amp, too.  I ended up keeping the second amp (I still miss those Quicksilvers) and buying a different pair of speakers. Problem solved.

[Hoiman]

What speakers were you using the 4B with before?

Phonar 5P cabinet with self made filter and tweeter by Ed Maas (he was a speakerbuilder in the Netherlands)

[Hoiman]

In my opinion, it sounds more like a room problem than an amp problem.

We also thought about that, the store has a wooden floor and we have a stone floor. But if this is the case why was the speaker resonating and not the stuff in my room? I must say it was a really weird phenomenon, the guys from the store never heard this before.

[Xinon]

Has nothing to do with the amp.
Can be easily checked by taking the amp to the store.

[Hoiman]

Can be easily checked by taking the amp to the store.

That is also an idea.
Tomorrow we 're going to check it with the B&W. They are much cheaper  then the KEF Blade so I hope they also sound right.

[Hoiman]

Maybe the problem was/is that one of the requirements is that the amplifier is between 50 - 400 watt by 4ohm and the 4BSST delivers 500 watt by 4 ohm?

[restrav]

Its room interaction. The amp should actually be a perfect match for the load of those speakers.

[CanadianMaestro]

Maybe the problem was/is that one of the requirements is that the amplifier is between 50 - 400 watt by 4ohm and the 4BSST delivers 500 watt by 4 ohm?

Nah....usually the other way around...not enough power = bad karma etc.

[Hoiman]

Wow the B&W 803 3D are here. What a sound, but the Bryston 4BSST can hardly drive the speakers, so I think I need a more powerfull amp. Maybe the new 4BCube? Does someone have some experience with B&W 803 3D?

[CanadianMaestro]

14B-squared, man. No more worrying about whether a future speaker upgrade will be under-powered.
 

[S Clark]

Absolutely it's a room node.  Especially as you describe the resonance to be related to bass(guitar or violin).  It took several bass traps, absorption panels, and diffusors to overcome a similar node in my listening area.  Jazz commonly has a bass player that takes a run down a low scale.  My room boomed at around 120 Hz- about three notes- and they jumped out at the listener. 

Are you using any room treatments, and if so, what?

[PierreB]

« but the Bryston 4BSST can hardly drive the speakers, so I think I need a more powerfull amp »

Wow, not enough power??? 
How big is your room.

[Hoiman]

Are you using any room treatments, and if so, what?

Extra thick sofa, extra thick curtains and a roller blind. A plant and a big garment on the floor.

With the B&W I don't have any problem with the real low bass, so it must be the speakers in combination with the Bryston amp, I think.

[Hoiman]

How big is your room.

Around 65 square meter.

[SoCalWJS]

Are the KEF's you listened to in the house the same ones you heard at the Dealer? Any chance something came loose in the speaker during transport?

Otherwise, probably a room node as others have stated.

[Hoiman]

Are the KEF's you listened to in the house the same ones you heard at the Dealer?

Yes the same, maybe something happend with the transport, that is one of the things my wife and I thought of too.

[Grit]

The current 803D's recommended amplifier is 50-500 watts @ 8 ohms @ 90db/W/m, which is within the 4B-SST2's range.

If not room acoustics, perhaps your power outlet/line isn't able to provide the power necessary? Or perhaps some wiring flaw/problem?