How high a frequency can a mono sub woofer (placed under the other speakers in a 3-way) be crossed before the perception of stereo (soundstage, depth, imaging etc) from a pair gets audibly compromised?
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There is technical evidence to say that imaging still offers placement if the cutoff is 700Hz, not that it's normally necessary to use them that high.
Some like to focus on how low they are able to perceive direction, but this leaves out some of the factors involved.
Some like to focus on how low they are able to perceive direction, but this leaves out some of the factors involved.
This also depends on the filter used.
With car subs placed behind the listener, 200 Hz -12dB/oct start to make the bass come from behind.
If in a home set-up the sub is placed between the stereo speakers or two subs, one at each side, things get much more relaxed. 700 Hz seems a save region, even with not too steep filters. Anyway, sometiong like 120-200 Hz seems more reasonable. Because of THX most people thing 80 Hz is the frequency to go, but that is quite low.
With car subs placed behind the listener, 200 Hz -12dB/oct start to make the bass come from behind.
If in a home set-up the sub is placed between the stereo speakers or two subs, one at each side, things get much more relaxed. 700 Hz seems a save region, even with not too steep filters. Anyway, sometiong like 120-200 Hz seems more reasonable. Because of THX most people thing 80 Hz is the frequency to go, but that is quite low.
Depends on the recording and instruments.
I ideally run stereo subs. With numerous spreader effects, phase and complicated filters used in some electronic music.
The bass sounds correct and better stereo, since the synthesis relies on a stereo image. Even below 80 Hz
Assuming average speakers 15" or smaller.
The transducers likely remain omni up to 200 /250 Hz
Most the issue if a actual sub, assuming 4 layer coil with high inductance.
There can be less clarity or no clarity not much more above 80 to 120 Hz
So the typical generic sub crossover will remains the same old 60 to 120 Hz at the highest
I ideally run stereo subs. With numerous spreader effects, phase and complicated filters used in some electronic music.
The bass sounds correct and better stereo, since the synthesis relies on a stereo image. Even below 80 Hz
Assuming average speakers 15" or smaller.
The transducers likely remain omni up to 200 /250 Hz
Most the issue if a actual sub, assuming 4 layer coil with high inductance.
There can be less clarity or no clarity not much more above 80 to 120 Hz
So the typical generic sub crossover will remains the same old 60 to 120 Hz at the highest
If I understand the question correctly: about 80hz. My old cinema system crossed @60hz, and blindfold you couldn't tell where the sub was. The new system crosses @100Hz, and I can hear the sub in the corner.
As for stereo vs mono subs, I'm a fan of 2x mono simply for reduced distortion at high power levels.
e.g. If you drummer and bass-player are on the R/H side of the stage, on reproduction, the R/H sub in a stereo will be doing all the work while L/H sub will be using a lower signal. I'm sure somebody here can do more accurate math, but your R/H sub may be peaking a 1000w when your L/H sub is barely touching 100w.
As for stereo vs mono subs, I'm a fan of 2x mono simply for reduced distortion at high power levels.
e.g. If you drummer and bass-player are on the R/H side of the stage, on reproduction, the R/H sub in a stereo will be doing all the work while L/H sub will be using a lower signal. I'm sure somebody here can do more accurate math, but your R/H sub may be peaking a 1000w when your L/H sub is barely touching 100w.
Had a few cheesy blue tooth systems with sub using smaller bass drivers and crossed 150 Hz
With normal Jazz , Rock the location of the sub was noticeable.
Most the issue is a annoying weird separation of instruments like bass or drums.
if crossover to high.
Exactly for theater cinema sound effects, and hard hitters, no more than 60 Hz for mono subs.
And as mentioned with real subs the difference between 60 to 100 Hz not very audible no detail.
Switching over to music, high crossovers are annoying, and way less boost will be used than sound effects.
Music will sound bloomy and stupid with strange separation in bass instruments.
With normal Jazz , Rock the location of the sub was noticeable.
Most the issue is a annoying weird separation of instruments like bass or drums.
if crossover to high.
Exactly for theater cinema sound effects, and hard hitters, no more than 60 Hz for mono subs.
And as mentioned with real subs the difference between 60 to 100 Hz not very audible no detail.
Switching over to music, high crossovers are annoying, and way less boost will be used than sound effects.
Music will sound bloomy and stupid with strange separation in bass instruments.
With distortion, buzzes and rattles a sub is very easy to locate by ear, with any crossover. If the sub and surrounding environment are free of distracting noises, and the sub(s) are symmetrically located in front of the listening position, 300Hz LR24 will make them next to impossible to locate.
One time you may notice this is when managing baffle step, because using a speaker that has a baffle step means you'll get complex reflections from the nearby walls around the lower midrange that are difficult to suppress.. and within these efforts it may become clear when listening to material that has such a harmonic spread, that we localise primarily on >700Hz.
Thanks for all the responses, gents.
I had this notion of combining a good passive 2-way 1" dome + 6.5" woofer with a 10" or dual 6.5" sub in one box, a 43-45" tower.
I want to avoid a passive XO between the sub and (now) mid because of the large value caps & Inductors needed to go low, say 200Hz or lower, but also wanted to avoid the wiring mess & added cost of something like miniDSP 2x4HD or Flex.
The Wiim Ultra & Amps have good mono sub outputs -- fixed LR4 both high/low pass but 40~250Hz, level, and 0-180 deg phase controls. If this could be used for the bass to mid XO, all I would need to add is one stereo or mono amp. Easy peasy.
But --- it looks like the XO frequency needs to stay below ~150 Hz to retain enough stereo separation. If I was building this system full active (as per most of my builds in the past decade), I'd choose 200~250 Hz XO point to offload the bass excursion from the mid driver as much as possible to reduce IM distortion and increase max SPL & dynamics.
I guess the question is how much of these advantages is gained with 150hz LR4 vs 200 or 250Hz? Or even lower 100~125hz LR4? -- if this proves necessary to maintain good stereo.
The drivers I have in mind are...
The 2-way passive:
Satori MW16P + Satori TW29P or TW26ADC (like SBA's ARA kit design)
Sub/bass:
2x Seas 6.5" Al cone custom woofers, 29Hz Fs, 6mm Xmax or 1x Dayton RSS265HF-8
All of these drivers are in hand. I have experience with all of them except for the Satori MW16P.
I know the Dayton makes a great sealed 1.3 cf sub with a modest DSP/PEQ. It would probably be mounted on the side to keep the front baffle width under 9" with big side edge roundovers.
Not quite as certain about the 2x Seas combo. One in a sealed <1cf box with some PEQ does pretty well, tho not that low or loud. Thus 2.
I had this notion of combining a good passive 2-way 1" dome + 6.5" woofer with a 10" or dual 6.5" sub in one box, a 43-45" tower.
I want to avoid a passive XO between the sub and (now) mid because of the large value caps & Inductors needed to go low, say 200Hz or lower, but also wanted to avoid the wiring mess & added cost of something like miniDSP 2x4HD or Flex.
The Wiim Ultra & Amps have good mono sub outputs -- fixed LR4 both high/low pass but 40~250Hz, level, and 0-180 deg phase controls. If this could be used for the bass to mid XO, all I would need to add is one stereo or mono amp. Easy peasy.
But --- it looks like the XO frequency needs to stay below ~150 Hz to retain enough stereo separation. If I was building this system full active (as per most of my builds in the past decade), I'd choose 200~250 Hz XO point to offload the bass excursion from the mid driver as much as possible to reduce IM distortion and increase max SPL & dynamics.
I guess the question is how much of these advantages is gained with 150hz LR4 vs 200 or 250Hz? Or even lower 100~125hz LR4? -- if this proves necessary to maintain good stereo.
The drivers I have in mind are...
The 2-way passive:
Satori MW16P + Satori TW29P or TW26ADC (like SBA's ARA kit design)
Sub/bass:
2x Seas 6.5" Al cone custom woofers, 29Hz Fs, 6mm Xmax or 1x Dayton RSS265HF-8
All of these drivers are in hand. I have experience with all of them except for the Satori MW16P.
I know the Dayton makes a great sealed 1.3 cf sub with a modest DSP/PEQ. It would probably be mounted on the side to keep the front baffle width under 9" with big side edge roundovers.
Not quite as certain about the 2x Seas combo. One in a sealed <1cf box with some PEQ does pretty well, tho not that low or loud. Thus 2.
For me what you're proposing makes no sense. Pick a man for a job and let him get on with it. Pretty much any 6.5" woofer can do 80Hz. If you want to reduce excursion maybe a simple cap will reduce excursion. This frequency is the woofer's domain - what is was designed for. A pair of 6.5" woofers will provide more detail than a subwoofer can. Subwoofers are designed to cover frequencies below the woofer's frequency range. Why you insist on the sub getting all up inside the woofer's business - I don't get it.
I might have used the wrong language to describe what I wanted to do in the first post. I talked about a sub because that's the Wiim feature I want to try and use for this crossover.
With a nice 1" + 6.5 midrange, cut at 120 Hz, you can get more SPL from the speaker than you will ever want. The sub is the limitation in most cases. Using 2x 6.5" as subwoofer makes no sense at all. Use at least a 10" at each side if you want to hear a little louder.
The "80 Hz" you see bandied about often is actually based on how far down the subwoofer's response will be at 200 Hz if it has an acoustic LP response with an Fb of 80 Hz and a 12dB/octave slope. If you use a steeper cutoff, you can go with a higher filter frequency, e.g. 100 Hz. Of course this also depends on the output level of the subwoofer compared to the rest of the speakers.
In my car, my main speakers are treated with a 160 Hz HP filter, but their actual response extends down to 100 Hz due to cabin gain, and that's where the effective acoustic LP filter of my car's subwoofer is. I could have pushed it lower, but there's no way that the 6.5" speakers I have in the doors will be able to cleanly reproduce lower frequencies with 150W of power applied to them, hence the 100 Hz compromise.
In my car, my main speakers are treated with a 160 Hz HP filter, but their actual response extends down to 100 Hz due to cabin gain, and that's where the effective acoustic LP filter of my car's subwoofer is. I could have pushed it lower, but there's no way that the 6.5" speakers I have in the doors will be able to cleanly reproduce lower frequencies with 150W of power applied to them, hence the 100 Hz compromise.
I dispute that. Just depends who is listening, what you're playing, the room.
Just set aside the language I was using -- sub -- and please just consider whether mono'ed woofers crossed at 150Hz or lower in a stereo pair of 3-ways would work.
Possibly not.
That's ok. I'm not committed to the idea, I just wanted others' take on it.
I will likely build the enclosure, install the chosen drivers, and give the idea a try, seeing I already have a Wiim Ultra to work with. If it doesn't work well, I will see about making an all-passive 3 way, probably with the Dayton RSS 265HF at 200~300 Hz or go active with the miniDSP 2x4HD.
This was actually the reason I bought the RSS390HF and not the HO version like my friends, namely because it only has a 2 layer coil, and I do think that I have a more detailed and firm bass than they have. We both use closed optimal boxes, DSP and very powerful amplifiers, but the difference in back-emf and the 50% larger box for the HF, seems to make it sound better.
When I asked Dayton, they also confirmed that the High Output HO version, was mainly aimed at car-subs with box-size restrictions. But if you have the space, go for the High Fidelity HF version.
Maybe the difference is not that big, but you do get more wiggle room in your setup, to tune things together.
I always try to aim a using drivers that have a good wide frequency response, so that I have more freedom to play with.
To the OP - if you intend to take advantage of the distributed bass - like Geddes - you do need to have mains, that play low enough for them to "blend" with the subwoofers. I've only heard one system work, with a high cross-over point, and that was the Lyngdorf:
https://lyngdorf.steinwaylyngdorf.com/taiwanese-award-for-mh-2-bw-2/
They simply used satellites on the wall, and then measured the distance to where you pleased to place the woofers - preferably on each side - use 2, and then dialed that into the DSP.
You have to consider whether you want a woofer or a subwoofer - or both - We can't just fiddle with the term without considering everything else 😉
I suppose it could be relevant to know what music you listen to and whether that music has stereo information (and phase differences in particular) below a certain frequency.
Wikipedia cites columbia college:
Wikipedia cites columbia college:
https://en.m.wikipedia.org/wiki/Sound_localization
When asked if he feels that directivity below 700hz can be ignored in a typical room environment, Earl Geddes wrote..
I control directivity below this frequency regardless, since the difficulty in getting a smooth DI rises in this region.
I control directivity below this frequency regardless, since the difficulty in getting a smooth DI rises in this region.