Stereo subwoofers

[olds1959special]

So you are using high level connections with your speakers/subs?

Yes. I use a splitter from the RCA outputs of my DAC (which I use to control the volume) and send the right to the left / LFE input on the right sub and the left to the left / LFE input on the left sub. The gain is one notch up on both and the LPF is set pretty low to match my speakers, maybe at around 45 Hz.

 

[Chrispy]

Yes. I use a splitter from the RCA outputs of my DAC (which I use to control the volume) and send the right to the left / LFE input on the right sub and the left to the left / LFE input on the left sub. The gain is one notch up on both and the LPF is set pretty low to match my speakers, maybe at around 45 Hz.

That would be low level connectors then. High level is same as speaker level (i..e. with speaker wire). An lpf of 45 hz seems very low, but you don't have proper bass management, so more a matter of taste I suppose.

 

[Steven Holt]

Is it okay to place identical subs next to each speaker, one fed the L and one fed the R for stereo bass?

Sure, it's OK to do that, but I don't think you're going to get the results you want esp. for one or two albums. Cost-wise it's kinda crazy. One good sub should do you just fine. I'm not convinced of this thiing, 'stereo bass'.

 

[goryu]

IMO, the main reason for using 'stereo' subs is for controlling the room's eigentones, that is, its standing waves. Placing the subs at mid points on opposite walls does a lot to ameliorate them. Read Paragraph 3 Section 4:

https://audioroundtable.com/misc/Welti_Multisub.pdf

Unless I missed something, I don't believe that study investigated stereo subs but rather all subs feed the same mono signal...unless you are calling stereo subs just 2 subs, both in mono...

 

[levimax]

One thing I don't see talked about is how much audible change, if any, is done by the "summing to mono" process it's self. Assumimg 80 Hz cross over and everything sent to the sub(s) is summed to mono and that there is some uncorrelated information on the 2 channels below 80 Hz then the way the 2 channels sum electrically, including cancellation and constructive interfearance is going to be different than the way the 2 signals "sum" in the air when played through speakers. In addition this abruptly "summed at 80 Hz signal" is going to have to "blend" with the now 2 different stereo signals through the crossover zone. I definately notice subtle differences between stereo and mono bass but not sure how much is AE, or stereo, or if it is just "summing artifacts?"

 

[Elkerton]

Unless I missed something, I don't believe that study investigated stereo subs but rather all subs feed the same mono signal...unless you are calling stereo subs just 2 subs, both in mono...

Of course you're right. In fact, it works only for mono bass signals, but I'm of the camp that believes what localizes bass is its overtones.

 

[GalZohar]

To localize my PB-3000 subwoofers crossed at 80Hz I must have ears very close to the subs (much less than 1 meter). At the MLP there is no way. Even speaker bass somewhat above 80Hz is almost impossible to localize.

As far as I understand, you need the direct sound to be noticeably stronger and earlier than the reflections in order to localize it, and for low frequencies in realistically sized rooms that just won't happen as the reflections make up most of the sound you hear.

If you don't have proper bass management I would start with that before messing with mono/stereo subs. Also without proper multi subwoofer calibration, you can sometimes get strange cancellations between the subwoofers on some frequencies if they play mono. A proper calibration should provide a major improvement, and then you could also try to experiment with mono vs stereo subs in a more fair comparison test (with the mono subs being properly calibrated and integrated with each other as well as the main speakers).

 

[levimax]

To localize my PB-3000 subwoofers crossed at 80Hz I must have ears very close to the subs (much less than 1 meter). At the MLP there is no way. Even speaker bass somewhat above 80Hz is almost impossible to localize.

As far as I understand, you need the direct sound to be noticeably stronger and earlier than the reflections in order to localize it, and for low frequencies in realistically sized rooms that just won't happen as the reflections make up most of the sound you hear.

If you don't have proper bass management I would start with that before messing with mono/stereo subs. Also without proper multi subwoofer calibration, you can sometimes get strange cancellations between the subwoofers on some frequencies if they play mono. A proper calibration should provide a major improvement, and then you could also try to experiment with mono vs stereo subs in a more fair comparison test (with the mono subs being properly calibrated and integrated with each other as well as the main speakers).

There is some evidence that "Stereo Bass" is about more than localization https://assets.swoogo.com/uploads/4646601-673c03ab61c93.pdf

 

[sfogg]

Low Frequence Envelopment
Speaker placement, externalization, and envelopment in home listening rooms
Multichannel sound systems and their interaction with the room
Loudspeaker and listener positions for optimal low-frequency spatial reproduction in listening rooms.
Envelopment and Small Room Acoustics