Why would you want to separate coil and cone weight, they are both part of the moving system? MMS is weight of cone + mass of the air in front of the cone.
The comment above about kick drum loosing its "kick" when lowpassed at 250hz is a good observation, it means the kick drum like all instruments have harmonic tones above the fundamental (around 50-60hz for kick drum) that stretch quite far up in frequency.
The comment above about kick drum loosing its "kick" when lowpassed at 250hz is a good observation, it means the kick drum like all instruments have harmonic tones above the fundamental (around 50-60hz for kick drum) that stretch quite far up in frequency.
You guys really need to use your RTA’s kicks have transient info at 1000hz that has nothing to do with a harmonic
What’s the difference between transient and “detail retrieval” (what is this lol)....to me it makes no sense...the standard for judging SQ is an impulse response...an impulse response IS a transient...
If mms changes does le change? That may put some perspective on things
What’s the difference between transient and “detail retrieval” (what is this lol)....to me it makes no sense...the standard for judging SQ is an impulse response...an impulse response IS a transient...
If mms changes does le change? That may put some perspective on things
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Makes sense to me.
Any idea (or link) on how to play with phase using REW?
I’ve not delved into much of that part of the software yet, only really using PEQ which always seems to help tremendously.
But I’m thinking until I correct/improve phase, I’m only halfway there.
Perhaps there is better/easier software than REW that I could use with mini DSP HD?
Camplo, i don't think you are following what the point of the discussion was...pardon me if i'm incorrect.
Because whether a kick has a 1000Hz transient is immaterial to it.
Yes, the overall full-range impulse response is the standard for judging SQ, and defines both detail performance such as harmonics, and transient response. (as well as mag and phase across the spectrum)
But, we have been discussing subs, and what things effect a sub's transient response.
A sub doesn't contribute anything at 1000Hz.
For me, I steadfastly do not want it to contribute much above xover, so it's of no concern that inductance limits higher frequency response.
Multi-way takes care of response above the sub.
Going back to BL matters. Here's a great paper by Bennet Prescott of B&C regarding their sub design philosophy. https://bennettprescott.com/downloads/TechTalk_Design_202002.pdf
(Kinda ironically fitting since this thread is about a B&C horn/cd
)If the idea of what a sub's impulse and frequency response looks like isn't presenting itself.....try this thought experiment....
Low pass a sub with a brickwall lpf at 100Hz. Listen/measure it alone.
Play a 60Hz sine wave through it.
Play a 60Hz square wave through it, with its very sharp rise time.
How will their sounds compare?
How will their impulse responses compare?
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The easiest way to improve phase is to substitute IIR crossovers in traditional DSPs with linear phase FIR xovers. So it takes a FIR processor.
The catch there is that the biggest gains from flattening phase come from the lower in frequency you can go. And standalone processors that have that capability get $$$. So many folks go the PC route for this.
Please forget this foolish question…
Another senior moment!
Phase and FIR adjustment capabilities are built into the minidsp HD!
I get crossed up between REW being more of just the measuring device (in my case)…and the DSP for making the adjustments …
If you follow mark's usual method of flattening the response of each driver out of band for an octave or two either way with IIR EQ then slap a complementary linear phase crossover on of whatever order, the phase will pretty much have fixed itself
The MiniDSP is very tap limited and if you want to use it for more than two channels that only gets worse. That is no real issue above a few hundred Hz but if you start to go below that it becomes quite a juggling act to get the response you want.
REW is very good for making adjustments with a MiniDSP as it's EQ options have the MiniDSP definitions built in. That allows you to virtually see what EQ can do and the prediction will be very close to reality.
The MiniDSP is very tap limited and if you want to use it for more than two channels that only gets worse. That is no real issue above a few hundred Hz but if you start to go below that it becomes quite a juggling act to get the response you want.
REW is very good for making adjustments with a MiniDSP as it's EQ options have the MiniDSP definitions built in. That allows you to virtually see what EQ can do and the prediction will be very close to reality.
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Yep, the miniDSP HD is a limited little bugger. Damn shame it runs at 96kHz instead of 48k.
But John, it may work ok for a complementary lin phase xover only at the 400Hz target you have in mind. I'd use the HD's para EQs on your subs and me464 first...and see how that goes with the lin phase xover.
Hi fluid, i've recommended folks use out-of-band flattening for an octave of two so it would be valid for traditional IIR xovers like LR24's. Frankly, i find that much flattening usually way to difficult to do, even when not filter count constrained.
I always end up saying screw it when trying out shallower linear phase or IIR xovers, just because of the extra flattening difficulty.
And with my typical 96dB/oct lin phase xovers, it's a cinch...I mean it only takes 1/3 octave or so out-of-band flattening.
Couple that flattening ease with reduced lobing from reduced xover region, and it seems like a no-brainer to me......
But John, it may work ok for a complementary lin phase xover only at the 400Hz target you have in mind. I'd use the HD's para EQs on your subs and me464 first...and see how that goes with the lin phase xover.
Hi fluid, i've recommended folks use out-of-band flattening for an octave of two so it would be valid for traditional IIR xovers like LR24's. Frankly, i find that much flattening usually way to difficult to do, even when not filter count constrained.
I always end up saying screw it when trying out shallower linear phase or IIR xovers, just because of the extra flattening difficulty.
And with my typical 96dB/oct lin phase xovers, it's a cinch...I mean it only takes 1/3 octave or so out-of-band flattening.
Couple that flattening ease with reduced lobing from reduced xover region, and it seems like a no-brainer to me......
I agree with most of what you say, the forced 96K sampling is a real head scratcher. The chip itself would be much more useful if sigma studio could be used with it directly rather than the MiniDSP software.
The steeper the slope the less the out of band flattening matters, but I still think it would be worthwhile to do as much as you can as that will make the acoustic response match the electrical response of an ideal crossover more closely and make the crossover as complementary as it can be and limit any chance for off axis weirdness.
I have effectively unlimited bands of EQ on my system so it has been a long time since I have had to think about how many filters I can use. I have also spent a long time wrangling my arrays into line so I now find it much easier to look at a response and know what EQ to use to flatten it out without much effort.
As an example the below graph shows the difference between a pure inversion of the impulse response and the manual EQ I came up with in a few minutes. About five filters, one more at 550 could have split the difference but I left the dip rather than generate a peak.
If the drivers are really hard to flatten then they aren't suitable for a lower order crossover. As you like steep and linear it is probably somewhat irrelevant to you
The steeper the slope the less the out of band flattening matters, but I still think it would be worthwhile to do as much as you can as that will make the acoustic response match the electrical response of an ideal crossover more closely and make the crossover as complementary as it can be and limit any chance for off axis weirdness.
I have effectively unlimited bands of EQ on my system so it has been a long time since I have had to think about how many filters I can use. I have also spent a long time wrangling my arrays into line so I now find it much easier to look at a response and know what EQ to use to flatten it out without much effort.
As an example the below graph shows the difference between a pure inversion of the impulse response and the manual EQ I came up with in a few minutes. About five filters, one more at 550 could have split the difference but I left the dip rather than generate a peak.
If the drivers are really hard to flatten then they aren't suitable for a lower order crossover. As you like steep and linear it is probably somewhat irrelevant to you
I think I was just surprised that someone was surprised to find that a kick has signal as high as 250hz...regardless of what driver...you are focusing on subwoofers, I see now. I do remember this type of discussion in my thread in the past regarding the shape of the impulse with a driver that is say trying to play flat to 30hz as I have intended for my subs...
In another life I dream of building an identical set of mains to place symmetrically behind me to either drown myself in direct energy or to cancel out as much energy in the room as possible.
if you want to improve the subs transient....outside of the things we discussed like mms and le....I personally would think that the easy road is efficiency (imagine playing down to 30hz at 110db under 1mm) and not too think about too much else since we all try to use top shelf drivers anyway. From there maybe an active cardiod system for the subs but from the little I do understand about cardiod, its best used in a span of midrange? Still I wonder, what would happen with extra subs placed at the mains or somewhere in the room as active acoustic treatment...bass is such a room thing and the room tends to be sloppy in comparison to the woofer.
In another life I dream of building an identical set of mains to place symmetrically behind me to either drown myself in direct energy or to cancel out as much energy in the room as possible.
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To achieve 110dB of output at 30Hz requires a volume displacement of about 750cm3 with closed box speakers.
At 1mm excursion that is an Sd of 7500cm2 or the equivalent of 6.25 18" drivers. So I don't think that is practical or easy for most.
And that is at 1m so it would be progressively more demanding for greater distance..
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Why limit it to 1mm excursion? Almost any 18" driver can easily handle 5 times as much. So one could argue that a single 18" sub is sufficient from an output point of view.
That said, I don't think output is (almost) ever the problem. It's spreading out the bass nodes. To do that well in most rooms you need at least 2 or 3 subs in my experience. More is usually better.
That said, I don't think output is (almost) ever the problem. It's spreading out the bass nodes. To do that well in most rooms you need at least 2 or 3 subs in my experience. More is usually better.
Well, if you mean efficiency of the driver, i really doubt it.
If you mean efficiency of the driver and cabinet together, I agree.
Here's an example of sub efficiency that's certainly at less that 1mm excursion.
Orbit Shifters & Labhorns
I measured 4 boxes to make a passband-integrally-weighted* 118dB, at 2.83v, 1m. Ain't bad huh
, It's an old T Danley design called Labhorn.
Not exactly small either...like fluid's example.
*Truest, no BS way i know, to measure sensitivity/efficiency.
You can't say that to a person with 4 - 18's designed for nearfield lol....
because we hate distortion.
We are talking transient performance not output.
Yes cab+woofer.... At least I got this one right lol
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2 more sub units has always been the finale for my system though I have already exceeded my expectations on bass, I'm just having fun like you guys. It is my opinion that bass can never be text book good in a room without spending big big bucks on building a literal top notch studio room even though we own top notch subs. So theres no reason to expect too much beyond our current practices which apparently are good enough since people have home mastering studios.
I'd like to investigate active room treatment....I sorta feel like active cardiod is the entry to that...I forsee some type of technology related to noise cancellation placed near and/or around the listener
in the terms of IR I've been discussing the Strauss 2way and the idea of having "things" be better as a two way only vs NOT using subwoofers is the philosophy that mr. Strauss promotes saying it does more damage than good...I can see it....but just now I am reminded that multi subs are a thing to increase bass sq so I wonder where that discussion goes...sounds like a wordy way of saying that less bass excites the room less thus less mess....thats not the same as saying a 2 way is better than 2 way with a sub...if you guys can't tell I am bent on exposing the Strauss but anyway...If I just ran my Axi with no crossover (yes you can do this lol) and fixed the FR and whatever else, I'm sure I to could make a claim that adding a mid woofer only messes things up....then again,, running a two way flat to 30hz with a two, apparently is a thing...at some volume I should be able too do this with my subs turned off, using just the 15"
I'd like to investigate active room treatment....I sorta feel like active cardiod is the entry to that...I forsee some type of technology related to noise cancellation placed near and/or around the listener
in the terms of IR I've been discussing the Strauss 2way and the idea of having "things" be better as a two way only vs NOT using subwoofers is the philosophy that mr. Strauss promotes saying it does more damage than good...I can see it....but just now I am reminded that multi subs are a thing to increase bass sq so I wonder where that discussion goes...sounds like a wordy way of saying that less bass excites the room less thus less mess....thats not the same as saying a 2 way is better than 2 way with a sub...if you guys can't tell I am bent on exposing the Strauss but anyway...If I just ran my Axi with no crossover (yes you can do this lol) and fixed the FR and whatever else, I'm sure I to could make a claim that adding a mid woofer only messes things up....then again,, running a two way flat to 30hz with a two, apparently is a thing...at some volume I should be able too do this with my subs turned off, using just the 15"
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What multiple bass sources can do that a single one cannot is to reduce spatial variability of the response over an area.
If the speaker is designed for a single position in a carefully controlled acoustic environment the argument could be put forward that the extra crossover and sources are not needed. That is not how most people would use it themselves and using that justification to build a similar design would likely lead to disappointment.
Most opinions that are not based on objective data are dangerous to take at face value without understanding the usage and preferences of the person giving the opinion.
If the speaker is designed for a single position in a carefully controlled acoustic environment the argument could be put forward that the extra crossover and sources are not needed. That is not how most people would use it themselves and using that justification to build a similar design would likely lead to disappointment.
Most opinions that are not based on objective data are dangerous to take at face value without understanding the usage and preferences of the person giving the opinion.