Speaker problem

[nandax]

hey guys,..
i'd like to amplify sound from mp3 to the speaker, i've made the amplifier circuit.
and i use Skytronic 902.296 mid range speaker with frequency response (300 Hz- 12 KHz) and I add bandpassfilter to fulfill the frequency response, and it worked.
the problem occurs when I change my speaker to
FR12-8 full range speaker with frequency response(f(-10db) 70-18000 Hz
when i tried to change my filter, the sound from the speaker is really small, and not good. and i adjust the filter with cut off frequency in -10db, is sounds better but not perfectly in treble sound..
somebody can help me?
what is f(-10 db) means? is it not in -3 db?

[sreten]

Hi,

F-10 = the -10dB downpoints.

There is not need to add a further -10dB bandpass ciricuit.

Rated power 15 W
Maximum power 40 W
Nominal impedance Z 8 Ohm
Frequency response 70–18000 Hz
Mean sound pressure level 85 dB (1 W/1 m)
Maximum cone displacement 5 mm
Resonance frequency fs 110 Hz
Magnetic induction 0,8 T
Magnetic flux 150 µWb
Height of front pole-plate 3 mm
Voice coil diameter 20 mm
Height of winding 4,5 mm
Cutout diameter 114 mm
Net weight 0,284 kg
D.C. resistance Rdc 6,8 Ohm
Mechanical Q factor Qms 5,61
Electrical Q factor Qes 2,8
Total Q factor Qts 1,87
Equivalent volume Vas 8,7 l
Effective piston area Sd 87 cm²
Dynamically moved mass Mms 3,8 g
Force factor Bxl 1,7 T m
Inductance of the voice coil L 0,22 mH
Heat resistance −25 ... 70 °C

With a Qts of 1.9 outside a box you can use it open
baffle or with some bass filtering in a 7 to 10L box.
The treble end could be shelved down for better balance.

/sreten.

[nandax]

Originally posted by sreten



Hi,

F-10 = the -10dB downpoints.

There is not need to add a further -10dB bandpass ciricuit.

Rated power 15 W
Maximum power 40 W
Nominal impedance Z 8 Ohm
Frequency response 70–18000 Hz
Mean sound pressure level 85 dB (1 W/1 m)
Maximum cone displacement 5 mm
Resonance frequency fs 110 Hz
Magnetic induction 0,8 T
Magnetic flux 150 µWb
Height of front pole-plate 3 mm
Voice coil diameter 20 mm
Height of winding 4,5 mm
Cutout diameter 114 mm
Net weight 0,284 kg
D.C. resistance Rdc 6,8 Ohm
Mechanical Q factor Qms 5,61
Electrical Q factor Qes 2,8
Total Q factor Qts 1,87
Equivalent volume Vas 8,7 l
Effective piston area Sd 87 cm²
Dynamically moved mass Mms 3,8 g
Force factor Bxl 1,7 T m
Inductance of the voice coil L 0,22 mH
Heat resistance 25 ... 70 °C

With a Qts of 1.9 outside a box you can use it open
baffle or with some bass filtering in a 7 to 10L box.
The treble end could be shelved down for better balance.

/sreten.

thanks for the reply..
but i dont quite understand with this sentence ("With a Qts of 1.9 outside a box you can use it open
baffle or with some bass filtering in a 7 to 10L box.
The treble end could be shelved down for better balance.
")
do u mean i dont have to add filter to get the appropriate response frequency?

[Taco]

Originally posted by nandax


thanks for the reply..
but i dont quite understand with this sentence ("With a Qts of 1.9 outside a box you can use it open
baffle or with some bass filtering in a 7 to 10L box.
The treble end could be shelved down for better balance.
")
do u mean i dont have to add filter to get the appropriate response frequency?

The driver's T/S parameter indicate that it will function with minimal additional filtering on an open baffle. Though in that case the low frequency output is rather limited.

If you want to use this driver in a closed box, the alignment (interaction box and driver) is not optimal, therefore you need some sort of high-pass filter to get it right.

An alternative could be a box with additonal holes (controlled leaking), such that you do not have to add additional filtering components to correct the box alignment

In all cases it is adviced to add a parallel LCR (coil, capacitor and resistor in parallel) in series with the driver to tailor the high frequencies for the proper SPL level (better balance).

[nandax]

Originally posted by Taco


The driver's T/S parameter indicate that it will function with minimal additional filtering on an open baffle. Though in that case the low frequency output is rather limited.

If you want to use this driver in a closed box, the alignment (interaction box and driver) is not optimal, therefore you need some sort of high-pass filter to get it right.

An alternative could be a box with additonal holes (controlled leaking), such that you do not have to add additional filtering components to correct the box alignment

In all cases it is adviced to add a parallel LCR (coil, capacitor and resistor in parallel) in series with the driver to tailor the high frequencies for the proper SPL level (better balance).

thanks for the reply
so if i want to use this speaker in closed box, i need that high pass filter right?
do i need low pass filter also , in order to keep the high frequency within the frequency range?