I am making good masters. That's an objective thing when Shogun Audio keeps coming back to you.
Not happy?
Could you describe exactly in very plain words, what this aspect of volume vs resonance is ?
thx
I am making good masters. That's an objective thing when Shogun Audio keeps coming back to you.
Not happy?
Congrat! Nice to have 'important' label as client ( underground label).
So your 'specialised' in one genre only? And you master for digital and streaming isn't it?
Yes i thought you was someone else, you are way younger than the person i thought. Lucky you are.
Camplo: different tools for different people, remember the mastering engineer i worked with the most had dynaudio Bm5.
But like Humbledeer ( well i suppose if i'm wrong correct me) he was specialised on one certain kind of music.
It's all about to have reference of how it must 'sound' on your system and if it translate well where it must be played/ will be played.
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Hi Jack,
I've been thinking of vented subs as two subs for quite a while...tapped horns too.
Well, really any sub or even hornloaded mid, where there are two different path lengths in play.
I have a ported hornloaded mid, where the direct path is about 2ft longer than the port path. It's always weird to see polarity correct, and a smaller negative impulse peak, precede the larger primary horn peak. Almost begs which peak to time to...
I've never understood how hornresp shows the same phase trace for vented sub's Output 1 (direct) and Output 2 (vent) ??? Do you get it?
But I see it does. Between that, and the very long wavelengths when both direct and vent are summing, I've kinda come to conclude the entire response can be considered minimum phase.
And I know the entire response can be EQed with minimum phase pretty precisely, which to me is the min phase acid test.
So I do think a vented sub is min phase....
And I see the BR trade-off as solely wanting more low end extension, with its practical alternative being however many sealed boxes and amps it takes to get to the same low corner. (at the same SPL) (ain't gonna stuff no second driver in a vent haha)
I think there has been a strong consensus that sealed subs sound better than vented, for nearly forever.
My belief is that is unfortunately primarily due to bad vented designs, and secondarily due to the increased group delay inherent with vented.
I also think folks seldom encounter an apples to apples comparison, with the same SPL and low end extension...and outdoors...which is the only possible way to truly compare, imo/ime.
I've put the same driver, bms 18n862 in both a sealed box, and vented box tuned for 31Hz f3.
Then i matched the sealed to the vented response via linkwitz transform(LT) using minidsp.
The sealed sub with the transform easily had the lower measured group delay at 31Hz. Which in my mind stands to reason, because a LT is essentially an out-of-band magnitude flattening, which also flattens phase.
However, once the LT got swamped by the sealed's natural roll-off and its response turned sharply south, group delay shot up even faster than the vented's.
(Hopefully neither of the boxes gets asked to go much lower than f-3.)
Should add it took maybe two sealed with LT, to match the SPL of one vented. And excursion below tuning was about an equal issue to solve for both.
For me, the picture i like to keep in mind, is that group delay is simply the rate of change in phase ....which is for all practical purposes the rate of change in frequency.
Group delay, spectrograms, etc ...are all just a bunch of different looks to find ways to argue about good ole phase and whether it's audible
Lol
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Decay - gradual decrease in the magnitude
Magnitude - spatial quality : SIZE
Phase - the point or stage in a period of uniform circular motion, harmonic motion, or the periodic changes of any magnitude varying according to a simple harmonic law to which the rotation, oscillation, or variation has advanced from its standard position or assumed instant of starting
Stop using all forms of high damping, you'll hear. Unless you remove the box I guess...
Couldn't agree more.
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Hi Jack,
I've been thinking of vented subs as two subs for quite a while...tapped horns too.
Well, really any sub or even hornloaded mid, where there are two different path lengths in play.
I have a ported hornloaded mid, where the direct path is about 2ft longer than the port path. It's always weird to see polarity correct, and a smaller negative impulse peak, precede the larger primary horn peak. Almost begs which peak to time to...
I've never understood how hornresp shows the same phase trace for vented sub's Output 1 (direct) and Output 2 (vent) ??? Do you get it?
But I see it does. Between that, and the very long wavelengths when both direct and vent are summing, I've kinda come to conclude the entire response can be considered minimum phase.
And I know the entire response can be EQed with minimum phase pretty precisely, which to me is the min phase acid test.
So I do think a vented sub is min phase....
And I see the BR trade-off as solely wanting more low end extension, with its practical alternative being however many sealed boxes and amps it takes to get to the same low corner. (at the same SPL) (ain't gonna stuff no second driver in a vent haha)
I think there has been a strong consensus that sealed subs sound better than vented, for nearly forever.
My belief is that is unfortunately primarily due to bad vented designs, and secondarily due to the increased group delay inherent with vented.
I also think folks seldom encounter an apples to apples comparison, with the same SPL and low end extension...and outdoors...which is the only possible way to truly compare, imo/ime.
I've put the same driver, bms 18n862 in both a sealed box, and vented box tuned for 31Hz f3.
Then i matched the sealed to the vented response via linkwitz transform(LT) using minidsp.
The sealed sub with the transform easily had the lower measured group delay at 31Hz. Which in my mind stands to reason, because a LT is essentially an out-of-band magnitude flattening, which also flattens phase.
However, once the LT got swamped by the sealed's natural roll-off and its response turned sharply south, group delay shot up even faster than the vented's.
(Hopefully neither of the boxes gets asked to go much lower than f-3.)
Should add it took maybe two sealed with LT, to match the SPL of one vented. And excursion below tuning was about an equal issue to solve for both.
For me, the picture i like to keep in mind, is that group delay is simply the rate of change in phase ....which is for all practical purposes the rate of change in frequency.
Group delay, spectrograms, etc ...are all just a bunch of different looks to find ways to argue about good ole phase and whether it's audible
Re' HR
It simply sums the port and cone outputs together taking into account the path length difference and presents the resulting magnitude and phase. That never bothered me. What did bother me the one time I did think about it was not seeing the port output as a 2nd peak in the IR.
I was scoring a technical point about vented not being min phase. When you consider the wavelength of that low frequency energy coming out the port of a sub, its so close to minimum as not to matter. Its not quite so minimum for a higher tuned box such as for a midwoofer where it might matter a little bit which way the port faces or for a woofer that is used well above 100 Hz and the pipe resonance is not far enough out of band to be fully suppressed. (Yes, another reason to use a brickwall XO)
All of these things that you mentioned as thinking of two subs, I think of ways to make use of the energy coming off the back of the cone to extend the LF response. Various artifacts can come along with that energy. In well done designs they are suppressed far enough not to matter in the intended application. But, correct me if I'm wrong, its usually easier and smaller albeit often expensive to use two sealed drivers instead. And for me an impatient old guy, its way quicker and much less risky to go sealed.
I should feel embarrassed because shortly after I made that post this morning I found myself converting a paper CBT design from sealed to vented - but it was because the array didn't have enough sealed drivers to get down to sub territory and the driver seemed amenable to vented.
I appreciate the lively discussion today - it provided a diversion which we all needed.
The second paragraph in the Explanation section of the "Bass reflex" Wikipedia entry linked below may help to clarify why this can happen at low frequencies (after taking opposing polarities into account).
Bass reflex - Wikipedia
So how closely were these matched? Only a LT will not give you the same response obviously. As can be seen from my example, only a little deviation can make quite a big difference in group delay already.
Is this what was measured? How did that relate to the simulation? It really sounds like it does not match up with the simulation. In that case, one of the two is wrong.. or something else was measured. In the last case, we should find out what that was. Hence me asking
You might want to ask your other half about this
Everything is compromise.. even the Veyron is, try going on holiday with it with 3 kids..
It's just about making the right compromise. I think this topic is more about what kind of compromise options there are and what kind of effect they will have (correct me if I'm wong). Along the way possibly find some new truths, shatter some old ones..
I'm happy someone can take a joke!
I think you are right about compromises. And finding the best ones are what makes this fun.
Hats off to TS for starting the thread in a way that he got peoples attention! At the risk of TS coming off as arrogant. This thread became interesting after all!
I think I see a minimum phase relationship between this and several other threads
Active Radiator Technology aka ART... will beat out port/vent performance, every time, and theres no denying it. Instead of adding a port to your next sub project, add ART. Conveniently available everywhere loudspeaker drivers are sold.
Optimum Frequency Response Curves in the Bass Range
A study of the audibility of different bass alignments by Ingvar Ohman.
First published in Musik och Ljudteknik, Sweden.
Optimum frequency response curves in the bass range.
A study of the audibility of different bass alignments by Ingvar Ohman.
First published in Musik och Ljudteknik, Sweden.
Optimum frequency response curves in the bass range.
Big News! The VituixCad now reads the phase files from Horn Resp (I wouldn't work before)
So when you design your vented design in HornResp thats full of dampening material, you go to the wizard window, looking at FR press f9 to save FR file, Import the response to Vituix, View and export IR to REW. Done.... I feel like a view has been lifted from my eyes. Of course the first thing I modelled was a fully stuffed constant CSA transmission line and compared it to its equal volume sealed....I almost shed a tear to see the decay visualizations....I am now unstoppable
So when you design your vented design in HornResp thats full of dampening material, you go to the wizard window, looking at FR press f9 to save FR file, Import the response to Vituix, View and export IR to REW. Done.... I feel like a view has been lifted from my eyes. Of course the first thing I modelled was a fully stuffed constant CSA transmission line and compared it to its equal volume sealed....I almost shed a tear to see the decay visualizations....I am now unstoppable
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What does he mean with objective and subjective?
Imo you should first start with subjective measurements (ears), then try to correlate that with objective measurements (equipment). If you find a strong correlation and causation, then you can use the objective measurements to design your speakers.
Btw Greg Timbers likes bass reflex better because you get 6dB more output. Duh, you use the back side of the speaker to.
And return thanks to you, and to all, ....for a very nice ongoing discussion
Much needed while in lockdown ....
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