Hi everyone,
I'm working on a sub plan to add to my current hi-fi setup (Marantz PM 6005 and Dali Spektor 2). The sub will be used 80% for music and 20% movies.
I already have the plate amp, a Mivoc AM80 mkII and I'm now in the process of choosing the speaker based on the results I get on WinISD. This will be a budget sub and the main contenders for now are Dayton DCS165 and Mivoc AWM104 (this one comes paired with the AM80 in a kit).
I would like to get your opinion on the results I get with the Dayton DCS165: With a vented box tuned at 37hz I get most of my requirements (which means relatively small box of 0.5 ft3, F3 at 35hz). The main problem is the cone excursion, which is way above the limit for low frequencies from 10hz-35hz.
In the graphs attached, in green the dayton in a 0.5 ft3 vented box tuned at 37hz, and in blue the Mivoc in a 0.88ft3 box tuned at 37hz (as per kit).
I guess this could be corrected with a high pass filter in order to protect the speaker from low frequencies but I would like to avoid it in order not to add extra stops in the circuit (also I'm not familiar at all with electronics - crossovers)
My questions are:
- Is this normal for a sub design in WinIsd?
- Is there something wrong with the design? I tried to play around with the parameters and looks like there is no way to keep the low frequency below XMax, and the excursion of the Mivoc seems to be under control overall.
- I suppose most of the music and movies are centred at higher Hz and I wouldn't expect a 20Hz frequency at 0db, am I correct?
- Would you recommend at all to go ahead with the Dayton and no high pass filter despite the cone excursion in the project?
Thanks,
Nico
I'm working on a sub plan to add to my current hi-fi setup (Marantz PM 6005 and Dali Spektor 2). The sub will be used 80% for music and 20% movies.
I already have the plate amp, a Mivoc AM80 mkII and I'm now in the process of choosing the speaker based on the results I get on WinISD. This will be a budget sub and the main contenders for now are Dayton DCS165 and Mivoc AWM104 (this one comes paired with the AM80 in a kit).
I would like to get your opinion on the results I get with the Dayton DCS165: With a vented box tuned at 37hz I get most of my requirements (which means relatively small box of 0.5 ft3, F3 at 35hz). The main problem is the cone excursion, which is way above the limit for low frequencies from 10hz-35hz.
In the graphs attached, in green the dayton in a 0.5 ft3 vented box tuned at 37hz, and in blue the Mivoc in a 0.88ft3 box tuned at 37hz (as per kit).
I guess this could be corrected with a high pass filter in order to protect the speaker from low frequencies but I would like to avoid it in order not to add extra stops in the circuit (also I'm not familiar at all with electronics - crossovers)
My questions are:
- Is this normal for a sub design in WinIsd?
- Is there something wrong with the design? I tried to play around with the parameters and looks like there is no way to keep the low frequency below XMax, and the excursion of the Mivoc seems to be under control overall.
- I suppose most of the music and movies are centred at higher Hz and I wouldn't expect a 20Hz frequency at 0db, am I correct?
- Would you recommend at all to go ahead with the Dayton and no high pass filter despite the cone excursion in the project?
Thanks,
Nico
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It's normal for all vented boxes, the excursion always goes up steeply below box tuning frequency.
Therefore, it's not inherently saying there's anything wrong with your particular version of a vented box.
You're right that most music has declining level below where the kick drum sits (sweeping generalisation, there will certainly be exceptions!), so full power at 20Hz is less common. LF sound effects in movies can be quite powerful, so you may tax the driver more with that content than with music.
Lastly, if you check the specs for the AM80, it says it already has a subsonic filter (another term for high-pass filter BTW) at 30Hz, 18dB/Octave - you can model the effects of this in the filters tab of WinISD (use Butterworth alignment absent any more detail coming to light on that when you re-read the manual ;-) ) which will take care of most, if not all of the problem.
Therefore, it's not inherently saying there's anything wrong with your particular version of a vented box.
You're right that most music has declining level below where the kick drum sits (sweeping generalisation, there will certainly be exceptions!), so full power at 20Hz is less common. LF sound effects in movies can be quite powerful, so you may tax the driver more with that content than with music.
Lastly, if you check the specs for the AM80, it says it already has a subsonic filter (another term for high-pass filter BTW) at 30Hz, 18dB/Octave - you can model the effects of this in the filters tab of WinISD (use Butterworth alignment absent any more detail coming to light on that when you re-read the manual ;-) ) which will take care of most, if not all of the problem.
Thanks David for the great tip, I completely missed the subsonic filter!
Adding a 3rd order filter (18db/octave) at 30Hz the cone excursion is much more manageable, and doesn't get over the Xmax until 50-55W.
Overall looks like the sub will have a F3 of 35Hz, with a box of 0.52ft3 and slot port tuned at 37hz. For a classic subwoofer should tick all the boxes?
Thanks!
Nico
Adding a 3rd order filter (18db/octave) at 30Hz the cone excursion is much more manageable, and doesn't get over the Xmax until 50-55W.
Overall looks like the sub will have a F3 of 35Hz, with a box of 0.52ft3 and slot port tuned at 37hz. For a classic subwoofer should tick all the boxes?
Thanks!
Nico
Attachments
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