You can see why the Ampeg mixed cabs work, the phase plots virtually overlay. Surprise, they did their homework! A homebrew kappalite cab is the bolded plot line.
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Mixing Cabinets and Phase Response.
- Thread starter IvanMike
- Start date
I don't think its possible to learn a ton by reading this old thread. To the contrary this oldish thread addresses issues of (real) phase consideration mismatched with propagation delay which actually is not a phase issue. Considerations of group delay are totally missing within the discussion likewise as (essential) damping considerations respectively filter characteristica of diffeent designed cabs.
IMO this thread is well suitable to establish myths rather than establish science knowledge.
The mods may do TB forum a good favour by deleting the whole thread for all.
@fast_frank_d why not start a new thread that can be dicussed all free from inherited waste?
Some of the TB members don't like to read zombie threads anyway.
As there are so many hits on this vintage thread. May be its possible to correct some stupid myth and misunderstandings a little bit.
From a (more) science consideration point of view.
Total signal caused by two coherent signals 1Vpeak each signal
Total signal caused by two coherent but 90 degree phase shifted signals 1Vpeak each signal
Note, the orginal sine waveform has now turned into cosine waveform. The transient noise caused by the "steep" signal start up remains just the same as is for the start up of the sine waveform.
Total signal if one of the two shifted signals was realtively phase shifted by 10 degree versus the other
Total signal if one of the two signals was relatively phase shifted by 45 degree
The total level each signal differes nearly unnoticeable at best, the transient noise frequency spectrum caused by the instantaneous start up each signal remains the same for each total signal. An instantaneous sine wave does cause just same transient noise spectrum as is for an instantaneous cosine wave or something in "the middle characteristc" of both signals.
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Do the signals combine the same way for a sound pressure wave?
You may have noticed, be he did stat a new thread: Phase offset audibility, particularly with mixed cabs
You may have noticed, be he did stat a new thread: Phase offset audibility, particularly with mixed cabs
My analysis: I stacked an Eden D210XLT on a D115XLT.
Suct.
Similar combinations may sound good either by accident or by design.
Suct.
Similar combinations may sound good either by accident or by design.
To your point, I ran an awesome sounding Avatar cab in parallel with an awesome sounding 410hlf, and it sucked also. Then I gathered up the T/S info for both cabs and got these phase plots. 15-90 degrees out in the bass range. It all made sense. Hoping with enough info, I can find the "reasonably close, and good enough" phase difference threshold.
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Just a clarification for ThisBass, the spl loss is definitely of interest and important, but the muddiness factor is what I was hoping to shed some light on.
Maybe if product availability and budget resources are unlimited, maybe. But if you want, for example, 2 different frequency response curves to sum properly with the same phase response curve, you're looking at mixing speakers, cabinets, and/or crossovers. But I am excluding crossovers from this discussion for the sake of simplicity and consistency with the original post. Just want to understand the audible threshold of any mismatch in phase.
