410 line array modification

Bahjark

Bahjark

May 30, 2018
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#1
I'm wanting to modify a 410 cabinet so that one column of speakers does not produce high frequencies, in order to give it better dispersion. In effect, I guess, it would be like a low pass filter on two of the speakers. Anyone ever tried this, and if so, how? I am handy with a soldering iron and can read instructions, but don't know if it would involve capacitors or resistors or what type.
Thanks in advance
 
#9
Bahjark said:
I'm wanting to modify a 410 cabinet so that one column of speakers does not produce high frequencies, in order to give it better dispersion. In effect, I guess, it would be like a low pass filter on two of the speakers. Anyone ever tried this, and if so, how? I am handy with a soldering iron and can read instructions, but don't know if it would involve capacitors or resistors or what type.
Thanks in advance
Click to expand...

Google "talkbass .5 alignment" and you will get a bunch of hits.

I suspect the results with .5 alignment are a bit confounded and here's why. Whenever you use any sort of filter like an HPF or LPF it introduces phase shift. With a crossover, ideally you design a complementary HPF and LPF so the phase integrates throughout the crossover region.

When you use only an LPF, the phase errors introduced by the filter are going to steer the dispersion pattern across the top of the LPFs range. So you may find that you are trading one problem for another.

I did an experiment running .5 alignment with some EVM18Bs. The idea was to run one 18B from about 100hz down and run the other full range. The phase errors between the two drivers made the low end looser and less defined, and I preferred the sound with both drivers run full range.

The speaker processor I was using was a Klark Teknik DN9848E and I did all alignments by ear. It's possible I could have gotten better results if I had some sort of alignment suite like SMAART. The DN9848E has all-pass filters which may have allowed me to compensate for the phase errors, but that sort of subtle alignment is not something you can do by ear IMHO.

I have heard some HiFi and also high end pro speakers with .5 alignment that I thought sounded really good. An example is the Meyer UMP-1P. UPM

Have fun and Good luck!
 
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#10
It involves at the very least an appropriate value choke in series with the high-passed woofers. For a second order filter, an appropriate value shunt capacitor would be required.
 
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#12
Adressed to folks who are handy with tools such as LT Spice.
Actually its possible to emulate the benefits of .5 alignments with this tool.
This means that its possible to emulate the dispersion for a standard 410 cab at 45 degree off axis position and compare the outcome with the original sound file.
Especially for bass guitar the difference isn't as big as it sometimes looks on paper such as is for "more generic" dispersion plots.
I think its nice to have a .5 alignment but for my personal needs with bass guitar its not a "must have".

edit,
I have got a 212+HT cab (the 12"s are line arrayed) and I have got the 810 fridge.
The 810 fridge suffers a little bit on dispersion issues (a little bit at some content) when listening at off axis postition but (at least to me) that's nothing to talk home about.
 
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