I am startig to build a semi-activr lodspeakers and deciding which amplifier module to use for them. bass/mid - active, mid/treble - passive. The sensitivity of bass section is 96dB however after low bass and baffle step correction it is around 87 dB. Sensitivity of mid/high section is around 90dB after baffle step correction. For mid/high section I will use 110W/8Ohm AB class amplifier module (Hypa 17). The question is the bass section. I can use the same amplifier or Hypex UCD400HG. I have made a test box powered by 400W PA amplifier and measured the output voltage of the amplifier at very loud music. I have measured +/-40V peaks.
1. Is it better to use 2 identical amplifiers for both sections
2. Or it is better to use hypex UCD400 for bass and have little reserve in the power (speaker has 700W)
3. Is it good think to mix 2 types of amplifier in one system?
4. Is it OK to use class D amplifier for bass section (20-220Hz)?
Thank yo in advance!
Frank
1. Is it better to use 2 identical amplifiers for both sections
2. Or it is better to use hypex UCD400 for bass and have little reserve in the power (speaker has 700W)
3. Is it good think to mix 2 types of amplifier in one system?
4. Is it OK to use class D amplifier for bass section (20-220Hz)?
Thank yo in advance!
Frank
Your question/s are confusing, because I think you may be confused about the setup and your needs. For example;
Passive BSC attenuates the frequencies above the BSC point.
A passive box? Unless you have a very big room, I doubt you will see that voltage in an active set-up at "normal" listening levels.
Here is some explanation:
1. The BSC is active and also the freq.response compensation is active. In the enclosed file you can see the freq.response of the woofer in 85l box tuned to 30hz. The freq response is corrected by attenuating according to the green line (from 0dB to -6dB). The final response is according to the red line (not on 96dB level - it is on 90dB level). If I make BSC it needs approx 3-6dB more power on the bass section. The need of power will decrease sterting from 50Hz and higher.... I need higher power only in lower frequencies, however it defines how big amplifier I need.
2. I made a Bass box and used crossover and graph.eq. in foobar to do the corrections in point nr.1. At the moment I have tested it with 1 bass box and 2 satelites. I have measured the output level of the signal of the bass section. Maybe I can take off 3dB from the measurements because I have used 1 bass box but I think my explanation in point 1 is more less correct.
3. The main question was about amplifiers and it remains:
a. Is it better to use 2 identical amplifiers for both sections
b. Or it is better to use hypex UCD400 for bass and have little reserve in the power (speaker has 700W)
c. Is it good think to mix 2 types of amplifier in one system?
d. Is it OK to use class D amplifier for bass section (20-220Hz)
Thank you in advance!
Frank
1. The BSC is active and also the freq.response compensation is active. In the enclosed file you can see the freq.response of the woofer in 85l box tuned to 30hz. The freq response is corrected by attenuating according to the green line (from 0dB to -6dB). The final response is according to the red line (not on 96dB level - it is on 90dB level). If I make BSC it needs approx 3-6dB more power on the bass section. The need of power will decrease sterting from 50Hz and higher.... I need higher power only in lower frequencies, however it defines how big amplifier I need.
2. I made a Bass box and used crossover and graph.eq. in foobar to do the corrections in point nr.1. At the moment I have tested it with 1 bass box and 2 satelites. I have measured the output level of the signal of the bass section. Maybe I can take off 3dB from the measurements because I have used 1 bass box but I think my explanation in point 1 is more less correct.
3. The main question was about amplifiers and it remains:
a. Is it better to use 2 identical amplifiers for both sections
b. Or it is better to use hypex UCD400 for bass and have little reserve in the power (speaker has 700W)
c. Is it good think to mix 2 types of amplifier in one system?
d. Is it OK to use class D amplifier for bass section (20-220Hz)
Thank you in advance!
Frank
Rule of thumb would be for example; 100Watt sub/bass so 50Watt mid and 20Watt treble or say 250Watt sub/bass so 120Watt mid and 40Watt treble. That is how our ears work. Class D amplifiers will happily handle 20HZ sub to 22kHZ hf. As our hearing cuts off around 17kHZ there is no point in wasting energy producing harmonics that we cannot hear.
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