[netaron]

So, I have been trying very hard to integrate my subs with my mains. Utilizing the sub output from the preamp seems to leave a little to be desired as far as matching bass on both drivers.

So just for the heck of it, I connected the subs in parallel to my N55+ speaker outs, and there it was. It seems the bass output processed through the amp is slightly "different" compared to the pre sub outputs. Integration was a snap after this.

Is this normal?


Haron

[kyrill]

hi

your subs are
1)  "only" speakers" or
2( are they active ( build in amp) ?

[AKSA]

Hi Haron,

The output of bass from the 'sub-out' RCA on the preamp is 1.075 times higher than that from the 'pre-output' socket, and since this is only 0.63dB you would likely not notice it.

However, if the gain of your plate amp on the sub is below about 30 db, then signal from the preamp would not keep pace with the amp and it would still sound muffled.

The AKSA has high gain (31.6dB) and this means the sub-woofer amp must keep up;  any less than this and it won't integrate.

Cheers,

Hugh

[andyr]

So, I have been trying very hard to integrate my subs with my mains. Utilizing the sub output from the preamp seems to leave a little to be desired as far as matching bass on both drivers.

So just for the heck of it, I connected the subs in parallel to my N55+ speaker outs, and there it was. It seems the bass output processed through the amp is slightly "different" compared to the pre sub outputs. Integration was a snap after this.

Is this normal?

Haron

Hi Haron,

AIUI, there are 2 ways of driving subs with "main" speakers:
a) you have 2 outputs from your pre-amp ... one to the "main" amp and the other to the sub amp.  This is a "low-level" input to your sub amp.
OR
b) you drive your sub amp from the main amp's speaker terminals.  This is a "high-level" input to the sub amp (they are being driven by the signal going to the main speakers) and you are basically not using the input gain-stage of the sub amp.

Several sub manufacturers recommend "high-level" connections ... IMO, as Hugh has suggested, possibly because the gain-stage of their sub amp is not up to scratch?   

In my active system, I am driving my bass drivers using the GK-1 "Sub Out" and the other drivers using the normal "Tube Out", and I can asure you there is no "integration issue" with my GK-1! 

Regards,

Andy

[andyr]

However, if the gain of your plate amp on the sub is below about 30 db, then signal from the preamp would not keep pace with the amp and it would still sound muffled.

The AKSA has high gain (31.6dB) and this means the sub-woofer amp must keep up;  any less than this and it won't integrate.

Cheers,

Hugh

Hi Hugh,

I'm afraid I can't understand your comment above?  Typically, sub plate amps have a volume control (as well as roll-off frequency control) so this must surely adjust the gain of the plate amp - ie. the volume of the sub relative to the volume of the main speakers? 

regards,

Andy

[DSK]

Like AndyR, I have achieved excellent integration using GK-1 SS out to sub and tube out to main amp. However, it is a tedious and difficult task to truly optimise the integration by ear alone. I highly recommend using measurement equipment to save a lot of time, mental fatigue and self doubt. It gets you to the finishing post far more quickly, then use your ears as the final judge.

I have often wondered whether using the speaker (high) level method would have an undesired effect on the main amp's feedback loop ... Hugh?

[AKSA]

Hi Andy,

Simple!  If the plate amp has a gain of 30, and the AKSA a gain of 38, then even if the plate amp vol control is turned to max the gain would still be 13.5dB BELOW the gain of the AKSA.  This would be very, very clearly audible, or perhaps more appropriately, inaudible.

This is another way of saying that the output of the AKSA might be 10Vrms, while the output from the plate amp would only be 7.9Vrms, a long way behind.

This happens because the system volume control is positioned before both amps.

Hi Darren,

No effect on feedback at all......

Cheers,

Hugh

[andyr]

Hi Andy,

Simple!  If the plate amp has a gain of 30, and the AKSA a gain of 38, then even if the plate amp vol control is turned to max the gain would still be 13.5dB BELOW the gain of the AKSA.  This would be very, very clearly audible, or perhaps more appropriately, inaudible.

Cheers,

Hugh

Not simple ... elementary!    Must've been having a "senior moment"! 

Thanks, Hugh! 

Regards,

Andy