Many people use active full range EQ. Do a search in the digital forum for Behringer DEQ2496.
The TACT units (www.tactaudio.com) are higher end room EQ systems and work very well.
Cheers
Steve
The TACT units (www.tactaudio.com) are higher end room EQ systems and work very well.
Cheers
Steve
Important to note
If you're looking at EQing a fullranger, you want to make sure the active EQ is not operating at frequencies that are, say, more than 10 dB below the natural center of a +/- 3dB response curve (nominal sensitivity spec). Going much further than that will make the LF excursion of the driver dominate the drivers behavior, and really mess things up. Using an EQ to kill the 'lowther shout' however, might make a mediocre fullranger into a helluva good speaker. The breathy, foward aspects of many fullrange hifi drivers make them unlistenable to me, eqing them might make it more tolerable.
I'm working on a speaker that runs the mid full range and cap couples the tweeter, a la Reference DeCapo 3As, but has a better balanced sound than those or lowthers..... not 'shouty'....
If you're looking at EQing a fullranger, you want to make sure the active EQ is not operating at frequencies that are, say, more than 10 dB below the natural center of a +/- 3dB response curve (nominal sensitivity spec). Going much further than that will make the LF excursion of the driver dominate the drivers behavior, and really mess things up. Using an EQ to kill the 'lowther shout' however, might make a mediocre fullranger into a helluva good speaker. The breathy, foward aspects of many fullrange hifi drivers make them unlistenable to me, eqing them might make it more tolerable.
I'm working on a speaker that runs the mid full range and cap couples the tweeter, a la Reference DeCapo 3As, but has a better balanced sound than those or lowthers..... not 'shouty'....
There are problems with using eq to get more bass extension. In a vented box you would only get more extension by adding eq below tuning, and that gets ugly! Group delay goes through the roof as does the cone excursion and distortion - it is pushing the driver too far.
Eq is ok in sealed subs which have a large excursion and the group delay is already very low. Active eq is necessary in many speakers, but when you have a vented box you can't really eq it below tuning!
You could do it in a sealed 2 way, but there is really no point IMO - you loose extension by going sealed, then try to get it back with eq - no real gain, and probably higher distortion.
Eq is ok in sealed subs which have a large excursion and the group delay is already very low. Active eq is necessary in many speakers, but when you have a vented box you can't really eq it below tuning!
You could do it in a sealed 2 way, but there is really no point IMO - you loose extension by going sealed, then try to get it back with eq - no real gain, and probably higher distortion.
paulspencer,
I thought the main point of using active EQ in a sealed box over a ported box was that the bass could be amplified/equalised over the whole low end frequency response (within reason) instead of just at the ports resonant frequency +/- a few hertz, thus giving a less boomy (one note) bass?
I thought the main point of using active EQ in a sealed box over a ported box was that the bass could be amplified/equalised over the whole low end frequency response (within reason) instead of just at the ports resonant frequency +/- a few hertz, thus giving a less boomy (one note) bass?
IME experience, equalisation can make a make a big improvement to an otherwise awful loudspeaker, but it doesn't seem to improve a good speaker very much. 
I have a 12 inch woofer in a 100 litre sealed box and I am going to try some of this equalisation stuff on it pretty soon. Should be interesting... Will post the results.
I have a 12 inch woofer in a 100 litre sealed box and I am going to try some of this equalisation stuff on it pretty soon. Should be interesting... Will post the results.
G'day niallsmart,
The frequency response of a vented box is quite flat down to the F3 point after which it will have a 4th order rolloff (24db/octave). A sealed box has a much higher F3 say 40 Hz with a 2nd order (12db/octave) rolloff. If you just want extra extension, you can use a Linkwitz transform which will make the response flat to a point which you determine. The advantage of eq is that it also allows you to take room gain into consideration and deal with room acoustics problems.
Boominess is not directly related to the flatness of frequency response. It may be related to room gain which can cause large peaks and troughs in response. Most likely is that it is caused by excessive group delay and a poor transient response. A sealed box is generally better in both regards, although this may change after you add eq.
A sealed box with eq is likely to achieve a better in room response than an unequalised vented sub. But the vented sub will be more efficient and will have higher SPL and extension and you can also use eq with it (but you need to be more gentle).
cheers,
Paul
The frequency response of a vented box is quite flat down to the F3 point after which it will have a 4th order rolloff (24db/octave). A sealed box has a much higher F3 say 40 Hz with a 2nd order (12db/octave) rolloff. If you just want extra extension, you can use a Linkwitz transform which will make the response flat to a point which you determine. The advantage of eq is that it also allows you to take room gain into consideration and deal with room acoustics problems.
Boominess is not directly related to the flatness of frequency response. It may be related to room gain which can cause large peaks and troughs in response. Most likely is that it is caused by excessive group delay and a poor transient response. A sealed box is generally better in both regards, although this may change after you add eq.
A sealed box with eq is likely to achieve a better in room response than an unequalised vented sub. But the vented sub will be more efficient and will have higher SPL and extension and you can also use eq with it (but you need to be more gentle).
cheers,
Paul
Circlotron said:IME experience, equalisation can make a make a big improvement to an otherwise awful loudspeaker, but it doesn't seem to improve a good speaker very much.
Yes, I noticed this when firing up my first pair of DIY speakers and/or my first DIY car audio system. The bass tone control only increased the drivers excursion, but I could barely hear a difference unless I turned the control down quickly and memorised the amount of bass output. The treble control, well that just made the tweeter sound more forward and more sparkly.
Though, to improve on what you've said, 'Equalisation can make an awful loudspeaker sound good, but can also make a good speaker perfect.
Active EQ
I've ran an line level EQ for years. I have an old MXR stereo 15 band EQ. I run it threw a Ward Montgumery reciever (the EQ is currently in the preamp poweramp loop). The reciever pushes about 70 watts threw a pair of 6 ohm Scott s-15 speakers. The speakers are like 30 years old. I'm in a college dorm room right now, and pretty much shake everything. I love sealed enclosures. I'm going to go home and get a pair of retrofitted EPI enclosures (original drivers cost to much for me to get serviced / replaced). My amp should be able to push about 100 watts into 4 ohms and I can't wait to hear it.
- Nick
I've ran an line level EQ for years. I have an old MXR stereo 15 band EQ. I run it threw a Ward Montgumery reciever (the EQ is currently in the preamp poweramp loop). The reciever pushes about 70 watts threw a pair of 6 ohm Scott s-15 speakers. The speakers are like 30 years old. I'm in a college dorm room right now, and pretty much shake everything. I love sealed enclosures. I'm going to go home and get a pair of retrofitted EPI enclosures (original drivers cost to much for me to get serviced / replaced). My amp should be able to push about 100 watts into 4 ohms and I can't wait to hear it.
- Nick
How about a line array? Seems like with the tremendous sensitivity of line arrays, and the large driver radiating area, it should be possible to make a line array do nearly anything. All one would need to do is EQ down the other frequencies and only slightly EQ up the bass and then suddenly, with a line like the Needles from CSS, you could have deep, authoritative bass down to 60 Hz. I heard some 901s once, and their bass was very punchy, tight, and potent. Of course they're still just 901s, but I am sure the same could be achieved with a line array.
60 herts isn't low enough. A lot of the music I listen to is authoritative down to about 40 herts, which makes it tough for the speakers. When you play mixes of different recordings, one can be tight and the next can be way over eq'ed cause they ran a really steep eq when the mastered it. I wouldn't use ported speakers, if I ever did I'd design a really steep bass eq to cut the bass after the port's frequency (i've blown up to many speakers).
I definately agree with the "60 Hz isn't enough" idea, but at the same time, it may not be the best, depending on the drivers, to try to push them down that low.
Yesterday I was toying with the idea of an array using 8 fullrange drivers (like the 4inch Tangband aluminium) with a subwoofer - the AV12. It would be stylish with all aluminium drivers and the height would make it easier to include a very long vent which you would need with the AV12 to avoid vent turbulence. Eq would be needed to tame a peak at 10khz (as I recall) and to possibly bring the high end above 10khz up a little. This setup should be able to get a reasonably flat response from 20 - 20k and could be very dynamic.
Yesterday I was toying with the idea of an array using 8 fullrange drivers (like the 4inch Tangband aluminium) with a subwoofer - the AV12. It would be stylish with all aluminium drivers and the height would make it easier to include a very long vent which you would need with the AV12 to avoid vent turbulence. Eq would be needed to tame a peak at 10khz (as I recall) and to possibly bring the high end above 10khz up a little. This setup should be able to get a reasonably flat response from 20 - 20k and could be very dynamic.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.