ported vs sealed which do you preffer?

[tracer1]

The first criteria in designing speaker box enclosure is to know the parameters of your speakers:
1. Resonance Frequency * free air
2. Speaker Coil DC Resistance
3. Amount of Volume Space it will Resonate

Out of these parameters with the aid of various formulas, you can determine the exact volume requirement of different Speaker Brands & Manufacturers. The best design is to limit the Hump between +or- 3db for good sound clarity (if requested, I can give you the formulas)
Going back to the issue: Ported ot Closed(Sealed)
I preferred ported for many reasons. In one ported enclosure, you can design 2 low resonance frequencies at one octave apart. Your enclosure is flexible to receive different effective resonance frequencies.
Using port tubes, you can adjust your resonance frequency as long as it is within +or-3db.
Conclusion: If the speaker is enclosed with correct volume, either ported or closed, effective resonance frequency can be achieved, thus good bass clarity is expected.

Wow! google na google ang dating hehehe!
OK din naman yung research mo bro pero sakin, iba parin ang experience kesa theory

[busy road]

Wow! google na google ang dating hehehe!
OK din naman yung research mo bro pero sakin, iba parin ang experience kesa theory

Bro, I used to design speaker before. If you have a frequency generator, you can determine exactly the frequency response of your box. Experience will tell you. If you know the theory, you will have less trial and error method experience. Good luck...

[afrasay]

well tama yun iba na pag you have mid to high power ok ang sealed. muddy bass for ported? you can easily control the woofer movement by adding acoustic materials, say fiberglass or foam, inside your enclosure. may mid bass woofer and adjustments naman so if trip ninyo yun super low bass without the need for big, power zapping amps try ninyo ported with mid bass combination. in the end its how you tweak your system and how you use the most important part of system, your ears.

[busy road]

well tama yun iba na pag you have mid to high power ok ang sealed. muddy bass for ported? you can easily control the woofer movement by adding acoustic materials, say fiberglass or foam, inside your enclosure. may mid bass woofer and adjustments naman so if trip ninyo yun super low bass without the need for big, power zapping amps try ninyo ported with mid bass combination. in the end its how you tweak your system and how you use the most important part of system, your ears.

Tama ka diyan, bro. Generally in my experience, super low bass is not advisable for moving vehicles (that is, matatabunan lang ng external noise with frequencies ranging from 60Hz and above). But, if for indoor use like home, 35Hz is most likely acceptable especially for soft music.

In addition, closed box enclosure is designed for only one frequency resonance. If it is designed at 45Hz, don't expect it to produce 35Hz effectively. On the otherhand, Ported box can be designed with multiple frequency resonances, like 35Hz and 70Hz (an octave apart) at the same time. Meaning, the ported enclosure can provide wider effective frequency response.
Most manufacturers, are investing more on ported box for the purpose of requirement flexibility. Generally, closed box is more cheaper and can be easily designed. Without knowing the required parameters, trial and error method can be applied by adjusting the box volume to achieve the target bass response.

[tracer1]

Bro, I used to design speaker before. If you have a frequency generator, you can determine exactly the frequency response of your box. Experience will tell you. If you know the theory, you will have less trial and error method experience. Good luck...

o kaya Oscilloscope, gumagawa din ba ng sukat ng box yang freq. generator? sample naman jennn

[busy road]

o kaya Oscilloscope, gumagawa din ba ng sukat ng box yang freq. generator? sample naman jennn

Oscilloscope or frequency generator are instruments used to determine the parameters of the speakers(woofer). If you know the parameters, so with the box volume. Yung box dimensions or sukat ng box, designer ang magde-decide at hindi ang frequency generator. To finally assess your design, you can use the frequency generator to determine the actual resonance frequency response of the box.

[tracer1]

Oscilloscope or frequency generator are instruments used to determine the parameters of the speakers(woofer). If you know the parameters, so with the box volume. Yung box dimensions or sukat ng box, designer ang magde-decide at hindi ang frequency generator. To finally assess your design, you can use the frequency generator to determine the actual resonance frequency response of the box.

so that means yung capacity lang ng sub spkr ang na-me measure ng freq. gen... or yung capacity nito to produce very low frequency, pero yung box depende parin sa gagawa, and that means nasa designer parin ng box ang magpapaganda at magpapalakas ng boom hindi sa tulad mong maker mismo ng sub spkr?

labo ata dre!?

diba dapat kung maker ka ng sub spkrs dapat alam mo rin ang definite size ng box para sa product mo?

paki sagot naman ng maayos para maliwanagan naming mga boom-boom enthusiasts? mahirap kasi yung puro theory o haka-haka lang

[jim]

yung tungkol sa enclosure (box) may recommended naman ang maker nung sub, usually kasama sa manual, na design at dimensions. mas maganda sundin na lang recommendations ng manufacturer.

[busy road]

yung tungkol sa enclosure (box) may recommended naman ang maker nung sub, usually kasama sa manual, na design at dimensions. mas maganda sundin na lang recommendations ng manufacturer.

Yung recommended dimensions are based directly on the parameters of the speakers. Some manufacturers are giving their speaker's parameters for any designer to start with. If not, you can still determine the parameters by using some testing instruments. It's good kung may manufacturer na nagbibigay ng mismong dimensions, this is to get away from further calculations and testing.

[busy road]

yung tungkol sa enclosure (box) may recommended naman ang maker nung sub, usually kasama sa manual, na design at dimensions. mas maganda sundin na lang recommendations ng manufacturer.

Bro, you're right. Though dimensions are not given, volume and tuning frequency are enough. I saw one ...http://www.rockfordfosgate.com/produ...9&locale=en_US

[busy road]

so that means yung capacity lang ng sub spkr ang na-me measure ng freq. gen... or yung capacity nito to produce very low frequency, pero yung box depende parin sa gagawa, and that means nasa designer parin ng box ang magpapaganda at magpapalakas ng boom hindi sa tulad mong maker mismo ng sub spkr?

labo ata dre!?

diba dapat kung maker ka ng sub spkrs dapat alam mo rin ang definite size ng box para sa product mo?

paki sagot naman ng maayos para maliwanagan naming mga boom-boom enthusiasts? mahirap kasi yung puro theory o haka-haka lang

Bro, mas maganda kasi kung actual ang testing. In any case try to figure out nalang.

To design your Bass Speaker Enclosure, the main target is to determine the box volume and at what optimum resonance frequency it can deliver. The resonance frequency (Hz) is the effective bass that the box can produce. Without the speaker parameters and some calculations it will be hard to achieve the correct box volume.

One of my Simple Projects: (Mid range and tweeter speakers are excluded)

Speaker Type: PRO-W88AD
Maximum and Nominal Power: 150/100 Watts
Impedance: 8 Ohms
Manufacturer: DAI-ICHI

First, you have to determine the parameters:
1) Fs = free-air resonance frequency
2) Qts = total magnification factor
3) Vas= equivalent air volume compliance

Free-Air Resonance Frequency:

Set up diagram(see attachment)

First, calibrate by inserting the 10 ohm resistor in place of the driver.
Adjust the voltage output of the audio frequency sine-wave generator until the ac voltmeter reads 0.01 volts.
Replace the 10 ohm resistor with the driver to be tested.
Keep the output voltage constant. 0.01 volts represents 10 ohms, 0.015 volts represents 15 ohms, etc.
Vary the frequency control of the audio frequency generator to find maximum resistance (Rmax). At that point, frequency is resonant frequency (Fs).
With this test I got:
Fs = 53 Hz (*Rmax = 25.7 ohms)

Total Magnification Factor:

Re = 7.4 ohms (measured speaker dc resistance)

Ro = Zmax / Re = 25.7/7.4 = 3.47 ohms

Rx = (ro)^1/2 X Re = (3.47)^1/2 X 7.4 = 13.8 ohms

Impedance to frequency curve(see attachments)

Adjust the sine-wave or frequency generator until the resistance is equal to Rx. This will occur twice as shown in the graph above. F1 is the lower frequency when the resistance equals Rx. F2 is the higher frequency when the resistance equals Rx.
Rx = 13.8 ohms
F1* Rx = 29Hz
F2* Rx = 92Hz

Qms = the mechanical control coming from the suspension system's damping abilities.

Qms = Fs X (ro)^1/2 / (F2-F1) = 53 X (3.47)^1/2 / (92-29) = 1.56778

Qes = the electrical gauge of the control on a driver coming from the counter - EMF generated in the voice coil.

Qes = Qms / (ro-1) = 1.56778 / (3.47-1) = 0.63473

Qts = the total Q of the driver.

Qts = (Qms X Qes) / (Qms + Qes) = (1.56778 X 0.63473) / (1.56778 + 0.63473)
Qts = 0.452

To determine the Vas, it needs test box with volume=0.5154 Ft^3 for 8" speaker or use 1 ft^3 for 12" speaker. Using the above test procedure, determine the FCT or resonance frequency of the speaker while on the test box. In my case, I got 93 Hz.

Vas = 1.15[(FCT/Fs)^2 – 1] X Vbs = 1.15[(93/53)^2 – 1] X 0.5154
Vas = 1.223 ft^3

The speaker Parameters Are:
Fs = 53 Hz.
Qt = 0.452
Vas = 1.223 ft^3

Base on these parameters you can compute the following:

Box Volume:

Vb = 15(Qt)^2.87 X Vas = 15(0.452)^2.87 X 1.23

Vb = 1.889 Ft^3 (This is the volume required to design the enclosure)
Add approximately 10% of the computed volume to compensate the mass volume of the speaker, fiberglass, and any material enclosed.

Box Resonance Frequency:

Fb = (Vas/Vb)^0.32 X Fs = (1.23/1.889)^0.32 X 53

Fb = 46.2 Hz (This is the optimum effective frequency of the box)


So the next move is to determine the size of the port tube and the speaker already fixed. In my case, I used 3” Diameter PVC tube. You can reduce the diameter but be sure it will not create a whistling sound. The length of the tube can be determined from the port table (I wish e-copy is available) or trying different length with the aid of frequency generator. The target resonance frequency is 46.2 hertz at maximum impedance. Try adjusting the length of the port tube until you achieve 46.2 hertz at maximum impedance.

Hope this will help in understanding speaker enclosure. Though, more on theory parin ang dating. Sensiya na bro.
Kung gusto mo talagang mag-design, I suggest the book of David Whims - Speaker Design, which is available in any book store.

[buraot]

nice busy road...

[tracer1]

Bro, mas maganda kasi kung actual ang testing. In any case try to figure out nalang.

To design your Bass Speaker Enclosure, the main target is to determine the box volume and at what optimum resonance frequency it can deliver. The resonance frequency (Hz) is the effective bass that the box can produce. Without the speaker parameters and some calculations it will be hard to achieve the correct box volume.

One of my Simple Projects: (Mid range and tweeter speakers are excluded)

Speaker Type: PRO-W88AD
Maximum and Nominal Power: 150/100 Watts
Impedance: 8 Ohms
Manufacturer: DAI-ICHI

First, you have to determine the parameters:
1) Fs = free-air resonance frequency
2) Qts = total magnification factor
3) Vas= equivalent air volume compliance

Free-Air Resonance Frequency:

Set up diagram(see attachment)

First, calibrate by inserting the 10 ohm resistor in place of the driver.
Adjust the voltage output of the audio frequency sine-wave generator until the ac voltmeter reads 0.01 volts.
Replace the 10 ohm resistor with the driver to be tested.
Keep the output voltage constant. 0.01 volts represents 10 ohms, 0.015 volts represents 15 ohms, etc.
Vary the frequency control of the audio frequency generator to find maximum resistance (Rmax). At that point, frequency is resonant frequency (Fs).
With this test I got:
Fs = 53 Hz (*Rmax = 25.7 ohms)

Total Magnification Factor:

Re = 7.4 ohms (measured speaker dc resistance)

Ro = Zmax / Re = 25.7/7.4 = 3.47 ohms

Rx = (ro)^1/2 X Re = (3.47)^1/2 X 7.4 = 13.8 ohms

Impedance to frequency curve(see attachments)

Adjust the sine-wave or frequency generator until the resistance is equal to Rx. This will occur twice as shown in the graph above. F1 is the lower frequency when the resistance equals Rx. F2 is the higher frequency when the resistance equals Rx.
Rx = 13.8 ohms
F1* Rx = 29Hz
F2* Rx = 92Hz

Qms = the mechanical control coming from the suspension system's damping abilities.

Qms = Fs X (ro)^1/2 / (F2-F1) = 53 X (3.47)^1/2 / (92-29) = 1.56778

Qes = the electrical gauge of the control on a driver coming from the counter - EMF generated in the voice coil.

Qes = Qms / (ro-1) = 1.56778 / (3.47-1) = 0.63473

Qts = the total Q of the driver.

Qts = (Qms X Qes) / (Qms + Qes) = (1.56778 X 0.63473) / (1.56778 + 0.63473)
Qts = 0.452

To determine the Vas, it needs test box with volume=0.5154 Ft^3 for 8" speaker or use 1 ft^3 for 12" speaker. Using the above test procedure, determine the FCT or resonance frequency of the speaker while on the test box. In my case, I got 93 Hz.

Vas = 1.15[(FCT/Fs)^2 – 1] X Vbs = 1.15[(93/53)^2 – 1] X 0.5154
Vas = 1.223 ft^3

The speaker Parameters Are:
Fs = 53 Hz.
Qt = 0.452
Vas = 1.223 ft^3

Base on these parameters you can compute the following:

Box Volume:

Vb = 15(Qt)^2.87 X Vas = 15(0.452)^2.87 X 1.23

Vb = 1.889 Ft^3 (This is the volume required to design the enclosure)
Add approximately 10% of the computed volume to compensate the mass volume of the speaker, fiberglass, and any material enclosed.

Box Resonance Frequency:

Fb = (Vas/Vb)^0.32 X Fs = (1.23/1.889)^0.32 X 53

Fb = 46.2 Hz (This is the optimum effective frequency of the box)


So the next move is to determine the size of the port tube and the speaker already fixed. In my case, I used 3” Diameter PVC tube. You can reduce the diameter but be sure it will not create a whistling sound. The length of the tube can be determined from the port table (I wish e-copy is available) or trying different length with the aid of frequency generator. The target resonance frequency is 46.2 hertz at maximum impedance. Try adjusting the length of the port tube until you achieve 46.2 hertz at maximum impedance.

Hope this will help in understanding speaker enclosure. Though, more on theory parin ang dating. Sensiya na bro.
Kung gusto mo talagang mag-design, I suggest the book of David Whims - Speaker Design, which is available in any book store.

OK noted,
kaso hindi rin lahat yan masusunod depende parin sa pag lalagyan,
example: pano kung VOX Beetle, mini cooper (austin) at iba pang small cars pag lalagyan ng subs? lalo na kung gusto ng customer yung boom-boom talaga na bastos sa tunog pero an liit ng space ng oto nya?

kung susundin ang exact ratios indicated para sa capacity ng isang sub sacrifice naman ang space na paglalagyan kasi no choice na mag iba rin ang design ng box o pano kung hindi box? fiberglas molding?

may nasusunod din kayang sukat dun tulad sa mga series ng PIMP my ride na kadalasan molding ng fiberglas sa mga trunks and sidings? pero ok parin ang sound.


Anyway bro thanks sa detailed explanations mo nanariwa tuloy ece days ko

[radifier]

bro where can i buy frequency generator?im bandpass fan and plan to improve my experience in making subwoofer enclosure

[busy road]

bro where can i buy frequency generator?im bandpass fan and plan to improve my experience in making subwoofer enclosure

I think that is available there. I got mine (company supplied) with model: ISO-TECH IGC2230, made in Taiwan. With counter na ito ranging from 1 Hz to 1 Mhz. I don't remember the price, but I guess it is within Php 10T.

[tracer1]

I think that is available there. I got mine (company supplied) with model: ISO-TECH IGC2230, made in Taiwan. With counter na ito ranging from 1 Hz to 1 Mhz. I don't remember the price, but I guess it is within Php 10T.

bro mura nyan a! compared sa oscilloscope 22k bili ko yr 2000 pa yun.

*busyroad
ganito ba itsura ng gamit mo?

[busy road]

bro mura nyan a! compared sa oscilloscope 22k bili ko yr 2000 pa yun.

*busyroad
ganito ba itsura ng gamit mo?

Mas manipis siya kaysa diyan at digital counter siya. One time I'll send you the picture.

[tracer1]

Mas manipis siya kaysa diyan at digital counter siya. One time I'll send you the picture.

tnx bro laking tulong din yang mga gadgets nayan.