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Stereo Bass using subwoofers

Krunok

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I think the idea of "subs integrated with mains" is unfortunate. At low frequencies, it is extremely likely that the best place for a bass source is not the best place for imaging/soundstage and general balance across the rest of the audible spectrum. Thanks to physics, our reduced ability to localize bass sources allows us to place a sub where it belongs in any particular room.

I agree, from the perspective of optimal SW placement it indeed is very unlikely.
 

Ron Texas

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Is anyone in this discussion using a crossover to separate out the bass and delay arrival of sound from the mains?
 

Krunok

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Is anyone in this discussion using a crossover to separate out the bass and delay arrival of sound from the mains?

I did that when I was testing BruteFIR plugin for Volumio that I helped develop. It was only for a few days after which I returned the subs.

Why are you asking?
 

Juhazi

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Is anyone in this discussion using a crossover to separate out the bass and delay arrival of sound from the mains?

Me!

Minidsp 2x4HD, a single 2x15" sub gets summed mono signal, LR2@90Hz, mains delayed, highpassed and eq'd to get symmetric responses in nearfield. Sounds amazingly good!

I do the same for 4- and 3-way stereo speakers' bass drivers too, crossed LR2 at 160-250Hz depending on speaker and room. Two pair in use, one as on-hold project
 

Ron Texas

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Me!

Minidsp 2x4HD, a single 2x15" sub gets summed mono signal, LR2@90Hz, mains delayed, highpassed and eq'd to get symmetric responses in nearfield. Sounds amazingly good!

I do the same for 4- and 3-way stereo speakers' bass drivers too, crossed LR2 at 160-250Hz depending on speaker and room. Two pair in use, one as on-hold project

Since the 2x4 has 4 outputs I guess it can send a summed signal to two subs. It has amazing functionality although it isn't the best measuring kid on the block. Probably good enough.
 

Severian

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Is anyone in this discussion using a crossover to separate out the bass and delay arrival of sound from the mains?

Yes. I run everything through my DSP and have a slight delay on the mains to account for the fact that they are closer than the subs. Getting this just right made a big difference at my listening position.
 
OP
dkinric

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Yes. I run everything through my DSP and have a slight delay on the mains to account for the fact that they are closer than the subs. Getting this just right made a big difference at my listening position.
Was this something the DSP software identified and corrected, or did you apply the delay by ear?
 

Severian

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Was this something the DSP software identified and corrected, or did you apply the delay by ear?

I use a Dayton Audio DSP-408 and have to input everything manually. It lets you set delay in terms of distance or time, so I used a laser measuring tool to figure out the difference between my mains and subs.
 

FrantzM

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I use a Dayton Audio DSP-408 and have to input everything manually. It lets you set delay in terms of distance or time, so I used a laser measuring tool to figure out the difference between my mains and subs.
Thanks, I did not consider a third option - Lasers.
Processing time can be a factor... Apparent increase in distance is one result.
 

onion

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I listen to music in my home theatre room. The stereo speakers are designed for cinema and are not full range. I had varying combinations of subs including matched (same brand same model) subs in the front corners; addition of rear corner different sub; matched subs in opposing corners; single subs etc.

Far and away the best sounding arrangement was matched front corner subs effectively 'coupled' (and room-corrected) with the speakers to make them full-range. The stereo amp has lt and rt analog outputs for both subs and speakers. With this arrangement, I could actually hear lower frequency resonances/ vibrations emanating from acoustic piano that can be heard live much more easily than in recordings. It's the first sound system I've had where it sounds like there's an actual real live piano playing in the room.
 

Ron Texas

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I use a Dayton Audio DSP-408 and have to input everything manually. It lets you set delay in terms of distance or time, so I used a laser measuring tool to figure out the difference between my mains and subs.

This unit takes an analog input and processes at 48 khz. I wonder if it is any better than just running everything through a MiniDSP 2x4 HD. Another thought is to use a Behringer DCX2496 which takes an AES/EBU digital input and processes at 96K. NB: there are audiophile tweaks for the DCX2496 along with claims that the analog output section isn't so great.

Note that distance isn't the only factor. There is latency in the sub's DSP of around 2ms and usually a 1ms latency to accelerate the driver.
 

Severian

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This unit takes an analog input and processes at 48 khz. I wonder if it is any better than just running everything through a MiniDSP 2x4 HD. Another thought is to use a Behringer DCX2496 which takes an AES/EBU digital input and processes at 96K. NB: there are audiophile tweaks for the DCX2496 along with claims that the analog output section isn't so great.

Note that distance isn't the only factor. There is latency in the sub's DSP of around 2ms and usually a 1ms latency to accelerate the driver.

I suspect it is roughly equivalent to the MiniDSP 2x4 HD in audio quality. I went with the Dayton based on price and the additional analog I/O options. I run two sources into it and wanted the flexibility to run a three or four way stereo system down the line. But when I have the ground loops addressed, my system is very quiet so as far as I'm concerned it's audibly transparent.

That said, I want to upgrade to something with balanced I/O. I'm looking at the t.racks units sold by Thomann. They seem to have quality components and many offer 96Khz sampling.
 

Ata

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Jazz bass guitar goes down to 32Hz, pipe organ down to 20Hz. With electronic music bass can go as deep as musician want. ;)

View attachment 47063

I like this diagram, is it a screenshot of some software (IRN)? I have been struggling understanding audiophile jargon, especially on YT, this brings some clarity. :)
 

Tom Danley

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Keep in mind that charts like that deal with the instrument's fundamental frequencies.

That is a valid view for the "sustain part" BUT if one has changes in level too, then the bandwidths are usually wider in both directions.
For example play a distortion free sine wave at frequency X, examine it's spectrum and it's just one frequency X.

Take that same signal and make it's amplitude ramp up and down and follow a gausian curve (the most gentile shape) from 0 to full to zero amplitude. If you do that within 5 or 6 cycles, you have a "burp" signal that now has about a 1/3 octave wide bandwidth and the shorter the envelope, the wider the bandwidth is require to reproduce that signal.
The up shot, for example if you play bass guitar and can play through something that really goes down low and loud enough to hear, you find your plucking or picking (especially with a bass like an EB-3 or PB) produces very low components that normal bass rigs can't produce.
Best,
Tom
 

Duke

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The up shot, for example if you play bass guitar and can play through something that really goes down low and loud enough to hear, you find your plucking or picking (especially with a bass like an EB-3 or PB) produces very low components that normal bass rigs can't produce.

That has been my impression as well.

In your estimation, what might be the ballpark "low enough" threshold to deliver the transient thumpage in plucking and picking, assuming the rig is "loud enough"?
 

Rip City Dave

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I know back in the days of vinyl, bass was mono. Did this change significantly after digital?

FWIW, I place my subs to even out room modes and play them in mono. I think that stereo bass would be less effective in controlling modes if there are large differences in bass content between channels.
 

DonH56

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No, and most if not all of the directional information is above a typical subwoofer's crossover anyway so directionality comes primarily from the main speakers anyway.
 

sigbergaudio

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I think this threshold is perhaps higher with most listeners than is generally assumed. As mentioned above, resonance or other distortion that has higher frequencies are likely the culprit. We successfully cross our loudspeaker + sub system at 100hz without localization issues.
 
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