If we keep the volume levels low, we could theoretically add some low-frequency equalization to compensate for output at 90 Hz.
To the uninitiated, it would seem that applying some equalization might fix the problem. This small pod has choked the woofer, and it’s now producing 10.3 dB less output at 90 Hz. Equally troublesome is the fact that bass output has been reduced dramatically. The system Q has jumped to an unruly 1.605.
Our enclosure modeling software shows a peak of 4.5 dB at 236 Hz. What happens to the frequency response of our mid-woofer? The yellow trace shows us that our woofer system now has a peak at 236 Hz and that the low-frequency output is dramatically reduced.
What if someone who doesn’t have experience using speaker modeling software decides they want to install this speaker in a pod in the kick panel of a car or, worse, on the vehicle’s dash? Let’s be generous and assume this pod has an internal air volume of about 2 liters or 0.07 cubic feet. Both calculations indicate that this mounting location will work superbly when combined with a subwoofer. In this application, the driver’s -3 dB point is acceptable at 89.15 Hz, and the system has a Q of 0.672. The predicted frequency response of our typical 6.5-inch midrange speaker when installed in a door or rear parcel shelf. This enclosure is large enough to simulate an infinite-baffle installation. The graph below shows the driver’s predicted frequency response in an enclosure with an air volume of about 3 cubic feet.
Yes, we have the benefit of increased physical power handling, but we trade bass output.įor this example, we’ll use a 6.5-inch midrange driver that’s been designed for infinite-baffle installations in the doors of a car or truck or on the rear parcel shelf of a sedan. This spring adds to the compliance of the speaker to form a high-pass filter. In a sealed enclosure, air acts as a spring. Modeling Speaker BehaviorĪnytime a speaker will be used at frequencies below 300 Hz, we need to ensure that there’s enough air volume behind the driver so as not to affect the overall system compliance. If the enclosure used with the speaker is too small, you’ll end up with unwanted distortion and limited low-frequency extension.
In this range, most drivers with a cone diameter of 4 inches or more can play down to around 125 Hz or lower. In this context, when we talk about bass, we are discussing audio frequencies below about 300 Hz. As stated before, different vehicles will have slightly different tuning but with these specs will sound the same.Dash pods, kick-panel enclosures and sealed enclosures in doors might look cool, but they aren’t always an ideal solution for a speaker that will attempt to produce bass. 35-40hz tuning means the enclosure will play down to 28hz and up to 60hz, typically.
This box chart will usually land you in the tuning area of 35-40hz for your vehicle tuning. These volumes are NET volume which are after vent and displacement of subs. These Specs are designed to get the same sound from a 10inch speaker as you would a 15! Output will differ depending on wattage and cone area but there is not a difference in frequency response.
Through decades of trial and error, we have what we call perfect box specs that will fit most of our subwoofers applications and have the resonate cabin frequency in combination with our box tuning for the perfect sound. This effects overall subwoofer sound, tuning, and amplifier output. This include port specs, box volume, and subwoofer multiplier to further guide you along your journey to the perfect bass response for your vehicle.īox tuning works in conjunction with the vehicle cabin’s resonate frequency. DS18 has combined all our experience together to bring you a set of box specs that would work for most vehicles.
Box specs are not static but can change with every vehicle, every speaker placement, and even weather conditions can affect your vehicles audio. Our engineers and techs have had over 25 years of experience tuning enclosures and cabins for the best bass response. To help our customers, we have designed a set of box specs that can help any novice or professional builders along with questions they may have about enclosure specs. We here at DS18 want you to get the absolute best sound and output from your new DS18 speakers. DS18 Subwoofer Box Recommendations 6.5” -21”