[23bw]

Hi everyone,

I recently upgraded my main speakers to Vienna Beethoven Concert Grands (max 300W) and noticed the volume contol on my SSP doesn't feel all that linear any more.  A low volumes, my new speakers sound good but they don't seem to come alive and really sing until I turn it up to around -10db on my Bryston SP1.7.  At around -8 to -11 db, the effects are like an on/off switch.   Never noticed such a problem on the smaller Vienna Mozart Grands (max 200W).  Nothing else has changed in my system except replacing the mains.   

Each of the mains are running off a channel from a 9B-SST.  Is this a symptom that I need more power?  When I bought the 9BSST, I thought it was the end of all AMP upgrades.  I'm wondering now if a 4B-SST is in my future or is this something else.

[srb]

Although the Beethoven Concert Grand has greater power handling, more drivers and can ultimately move more air and play louder than the Mozart Grand, it has 1dB greater sensitivity.  If there are not a lot of hours on them, perhaps the driver suspensions and voice coil spiders are still a bit stiff (and perhaps the new woofers are stiffer than the Mozart Grand's midbass drivers were when new) and the volume hits a point where the resistance is not a factor.
 
The 9BSST may run out of steam driving the new speakers to higher levels than you could previously, but I wouldn't expect a lack of power to have anything to do with the volume transition you're experiencing, so hopefully it is just a matter of some additional mechanical break-in hours.
 
Steve
 
 

[23bw]

Thanks for chiming in Steve.   The Beethovens certainly move more air and that's why I got them.   They are not new but I don't know how many hours are on them and whether they are considered broken in yet.   Given that they are a few years old, I suspect they are past the break-in stage.   I'm really tempted to get 4B-SST but would like to try one before buying it.   

[srb]

Given that they are a few years old, I suspect they are past the break-in stage.   

Yes, you referred to them as "my new speakers" so I assumed they were brand new but they are new to you!  In that case, I would also agree with you that at several years old they must surely be mechanically broken in.
 
Hmmmmm .....
 
It would be interesting to have the opportunity to swap in a 4BSST for comparison.  Good Luck.
 
Steve

[23bw]

Yes, you referred to them as "my new speakers"

Yeah, I should have worded it "new to me" speakers. 

[SHV]

Hi everyone,

I recently upgraded my main speakers to Vienna Beethoven Concert Grands (max 300W) and noticed the volume contol on my SSP doesn't feel all that linear any more.  A low volumes, my new speakers sound good but they don't seem to come alive and really sing until I turn it up to around -10db on my Bryston SP1.7.  At around -8 to -11 db, the effects are like an on/off switch.   Never noticed such a problem on the smaller Vienna Mozart Grands (max 200W).  Nothing else has changed in my system except replacing the mains.   

Each of the mains are running off a channel from a 9B-SST.  Is this a symptom that I need more power?  When I bought the 9BSST, I thought it was the end of all AMP upgrades.  I'm wondering now if a 4B-SST is in my future or is this something else.

For perhaps an easy way to find out if more power is the answer to your problem, the 9B-SST amp modules can be bridged.  This will essentially double the power output.  How to bridge the modules is in a PDF at the Bryston web site.

http://bryston.com/pages/technical.html

(under discontinued technical docs. near bottom of page)

Steve

[23bw]

For perhaps an easy way to find out if more power is the answer to your problem, the 9B-SST amp modules can be bridged.  This will essentially double the power output.  How to bridge the modules is in a PDF at the Bryston web site.

http://bryston.com/pages/technical.html

(under discontinued technical docs. near bottom of page)

Steve

Wow!!  Being that each channel was a separate module in the 9BSST, I never expected to be able to bridge them.   Yeah, this will be an excellent zero-cost experient that will answer my question.   I'm going to give this a try this weekend!  Thank you!!!   

[Mag]

IMO what your experiencing is the huge strain on the power draw a multi-channel system has on an amp when you are running all channels. In my case it was a Yamaha av/receiver.

When bass was heavy you could see a large voltage drop on my power bar.

What you need is a good power conditioner like the Torus or similar, that keeps the voltage/power draw constant. Your speakers will then be working to their capability and not lagging.

Unless the clipping lights are showing red when you crank up the volume. You have enough power with the 9B SST.

[95Dyna]

Wow!!  Being that each channel was a separate module in the 9BSST, I never expected to be able to bridge them.   Yeah, this will be an excellent zero-cost experient that will answer my question.   I'm going to give this a try this weekend!  Thank you!!!   

The Beethoven Concert Grands are 4 ohms nominal and the minimum impedence is not listed.  Be aware when you bridge the modules to gain more power output that you will halve the impedence the amps sees from the speakers so if there are any troublesome dips below 4 ohms you may run into current deficiencies.  I learned this first hand when bridging a pair of amps into mono.  The amps would sometimes pop fuses during demanding passages.

[SoundGame]

For perhaps an easy way to find out if more power is the answer to your problem, the 9B-SST amp modules can be bridged.  This will essentially double the power output.  How to bridge the modules is in a PDF at the Bryston web site.

http://bryston.com/pages/technical.html

(under discontinued technical docs. near bottom of page)

Steve

I don't believe that bridgeable Bryston amps are designed to be operated bridged into less than 8 ohms.  So the 9B bridged into a nominal 4 ohms speaker would be a no-no, as I understand it...

[Phil A]

The minimum impedence has been measured at around 3 ohms.  Also the sensitively is apparently less than the advertised 91db - http://www.stereophile.com/content/vienna-acoustics-beethoven-concert-grand-loudspeaker-measurements

I would not think it would be a good idea to bridge channels to drive them.

[SHV]

The 8 Ohm restriction is stated for bridged 3B-SST and 4B-SST; no warning for bridged 6B and 9B.  It will be interesting to read what James has to say on this subject.

Steve

[*Scotty*]

To clarify an earlier post concerning the 2006 Stereophile review. The review of your speakers included measurements of frequency response and impedance curves, your speakers have an impedance minimum of 2.83 ohms at 90 Hz with a phase angle of zero. If the amp in bridged mode can drive a 3ohm impedance with no phase angle to contend with you should be in good shape.
Many times the impedance minimum of a loudspeaker is associated with a severe phase angle which makes the speaker load at the frequency where the dip in impedance occurs much more difficult drive. This does not seem to be the case with this particular loudspeaker.
 If your speakers are new or if they have been sitting around unused for quite awhile their behavior may change dramatically as they break-in and the spiders loosen up.
 The speakers are also estimated to be 87.3dB(B)/2.83V/m by Stereophile, This is considerably lower than the 91dB specified by Vienna Acoustics.
Scotty

[SoundGame]

The speakers are also estimated to be 87.3dB(B)/2.83V/m by Stereophile, This is considerably lower than the 91dB specified by Vienna Acoustics.
Scotty

Without doing any research on the VA specification, there is typically a 3db difference between an anechoic measurement of sensitivity vs. an in-room measurement.  Add another 3db if the sensitivity is a measurement of two speakers in-room.  So the difference in the Stereophile vs. VA sensitivity rating could be due to the difference in the parameters of such a measurement.  That said, an 87.3 dB (erring on the side of caution) sensitivity rating is around the norm/average for passive speakers.  Nothing to really be worried about there.