Subwoofer very loud and boomy on Airplay from Amp

[panther]

I have a Yamaha WXA-50 Amp with a Martin Logan Dynamo 800x sub connected to the aux out connection which lets me EQ and run ARC on the sub from the Martin Logan Subwoofer App. When I play music from my PC through a JDS Labs Element II that goes into the AUX IN on the amp everything sounds great. When I switch to Airplay or stream music on spotify or Internet Radio the subwoofer is going out of control with its volume and the sound quality is boomy and terrible. No combination of volume settings on the Amp or my ios devices fixes this, the sub will still be very boomy when the music volume is low. I have to dial the sub volume down to minimum to make it not shake my house. I am at a loss for why this would happen ( I was told by Martin Logan that I just need to configure the sub settings once and they stay after that). Does anyone have an idea why I might get such massive differences in volume and quality between the 2 sources.

 

[andreasmaaan]

What a ****** problem

Could you clarify what "ARC" stands for, and also what you mean by "from an AMP"?

 

[panther]

ARC is Anthem Room Correction. Sorry I meant to write From an App (martin logan subwoofer control app. just lets me set volume as well as the low pass filters and a few other settings remotely.

 

[witwald]

Typically, I would expect that the AUX out connection does not vary in output level (its output simply follows the level of the AUX input, or provides a fixed output level from a digital input signal). Shouldn't you be using the subwoofer out connection on your Yamaha WXA-50 amp? That will likely be placed after the volume control in the amp, and also sums the left and right channels together. The low-pass filter on the subwoofer is then applied to this signal. As you increase or decrease the power level going into your speakers, the signal going to the subwoofer is increased or decreased accordingly, staying in sync. It is also possible to use the "Speaker Level: Left and Right via banana jacks" that are provided on the 800X subwoofer.

 

[waynel]

Typically, I would expect that the AUX out connection does not vary in output level (its output simply follows the level of the AUX input, or provides a fixed output level from a digital input signal). Shouldn't you be using the subwoofer out connection on your Yamaha WXA-50 amp? That will likely be placed after the volume control in the amp, and also sums the left and right channels together. The low-pass filter on the subwoofer is then applied to this signal. As you increase or decrease the power level going into your speakers, the signal going to the subwoofer is increased or decreased accordingly, staying in sync. It is also possible to use the "Speaker Level: Left and Right via banana jacks" that are provided on the 800X subwoofer.

This! The aux jack is fixed volume. Use the subwoofer jack, it has a LPF at 250Hz which shouldn’t interfere with the crossover in your sub. Oh, and rerun arc once you’ve done this.

 

[panther]

Ok a big thanks to you both that makes sense. When I use the sub out it sounds much better on streaming. I guess my concern going forward is that now I need to figure out a new amp as this Yamaha amp is for our tv setup. I’ll have to find out what other amps do for aux out if they don’t have a dedicated sub out and offer streaming options.

 

[waynel]

Ok a big thanks to you both that makes sense. When I use the sub out it sounds much better on streaming. I guess my concern going forward is that now I need to figure out a new amp as this Yamaha amp is for our tv setup. I’ll have to find out what other amps do for aux out if they don’t have a dedicated sub out and offer streaming options.

get something with proper bass management

 

[witwald]

Ok a big thanks to you both that makes sense. When I use the sub out it sounds much better on streaming. I guess my concern going forward is that now I need to figure out a new amp as this Yamaha amp is for our tv setup. I’ll have to find out what other amps do for aux out if they don’t have a dedicated sub out and offer streaming options.

Glad that using the subwoofer output works better (as expected). The AUX output on other amps will work the same as on your Yamaha WXA-50. As suggested in an earlier post, an amplifier with proper bass management would be the way to proceed for best results. That way you will get high-pass filtering on the main speakers, as well as low-pass filtering on the subwoofer. It would of course be quite feasible to use the inbuilt low-pass filter on a subwoofer like the Martin Logan Dynamo 800X. If your chosen amplifier doesn't have bass management, or a subwoofer out, then you can still use the speaker level inputs, but it could be difficult to get a smooth degree of blending between the subwoofer and the main speakers, as you will only have the subwoofer controls to work with. Also, without any bass management, the full low-frequency power content is going into the main speakers, so that the benefit of getting the subwoofer to take over some of the duties performed by the main speakers is not there.