ran out of knowledge
I'm back... I have been very busy since the Corona measures have lifted a bit. This is off course a good thing.
I ran into some problems and I think all of them are mentioned in your replies.
I have tried several setups and all of them sounded not very good. Here is a list of thing I experimented with.
- low pass (several types and frequencies) on the Alpha's connected in parallel and high pass on the Beta 12LTA, 1,5 uf on tweeter(two Icepower stereo amps)
- low pass (several types and frequencies) on the Alpha's connected in parallel and NO filter on the Beta 12LTA, 1,5 uf on tweeter.(two Icepower stereo amps)
-low pass (several types and frequencies) on each of the Alpha's and added a third amplifier for the Beta 12LTA, 1,5 uf on tweeter.
I think that I realy understand too little about it because al those people who build a similair setup can't all be wrong.....?
Or maybe my expectations where too high...after a ten year waiting to build this...
I guess it the first there must be a setting to let this setup sing. Three amps are nice to look at so I would like to end up with just the two Icepower amps (for the future I want to build a 6ch amp).
So if someone could give an advise on the setup en (startpoint?) setting on the DSP I would over the moon...
Raymond
I'm back... I have been very busy since the Corona measures have lifted a bit. This is off course a good thing.
I ran into some problems and I think all of them are mentioned in your replies.
I have tried several setups and all of them sounded not very good. Here is a list of thing I experimented with.
- low pass (several types and frequencies) on the Alpha's connected in parallel and high pass on the Beta 12LTA, 1,5 uf on tweeter(two Icepower stereo amps)
- low pass (several types and frequencies) on the Alpha's connected in parallel and NO filter on the Beta 12LTA, 1,5 uf on tweeter.(two Icepower stereo amps)
-low pass (several types and frequencies) on each of the Alpha's and added a third amplifier for the Beta 12LTA, 1,5 uf on tweeter.
I think that I realy understand too little about it because al those people who build a similair setup can't all be wrong.....?
Or maybe my expectations where too high...after a ten year waiting to build this...
I guess it the first there must be a setting to let this setup sing. Three amps are nice to look at so I would like to end up with just the two Icepower amps (for the future I want to build a 6ch amp).
So if someone could give an advise on the setup en (startpoint?) setting on the DSP I would over the moon...
Raymond
If you don't have a lot of experience doing this by ear, you will need to measure. That also has it's difficulties, but should help you get where you need to go.
For now don't worry about the tweeter, you need to get the bass and mids running together. You did not mention what types of filters you used. Please also tell us the dimensions of your baffle and where the drivers are placed. I get an approximate size from your photo.
For now don't worry about the tweeter, you need to get the bass and mids running together. You did not mention what types of filters you used. Please also tell us the dimensions of your baffle and where the drivers are placed. I get an approximate size from your photo.
OK, I had a look and here is what I would suggest as a starting point.
This should at least get you started down the right road.
- Alpha 15s in parallel. Low pass 2nd order 140 Hz
- Alpha notch filter 1900 Hz Q2 -10dB
- Beta LTA. High pass 2nd order 250Hz. Try reverse polarity.
- Try a high shelf on the Beta 12 @600Hz -5dB to flatten it. Listen if that gives a better tonal balance.
This should at least get you started down the right road.
Thanks! Tomorrow morning I will try this. The notch filter is set in the last EQ settings in the software? The same for this shelf? Sorry for my questions... of course I will look this up but I want to get started!
Raymond
Raymond
Yes, you can set filters in your MiniDSP software. I don't own one, but the software should be fairly straight forward. There are many people here who use the software. Failing that, I can help.
Look for the PEQ (Parametric EQ) section. There you will have the filters you need. I don't know if those filters apply globally or per output. If per output that's better, as you want the notch PEQ on the woofers and any shelf only on the Beta 12.
Look for the PEQ (Parametric EQ) section. There you will have the filters you need. I don't know if those filters apply globally or per output. If per output that's better, as you want the notch PEQ on the woofers and any shelf only on the Beta 12.
I have put the settings you mentioned in place and wow! That is way different than I heard earlier on this speakers. So thanks again Pano.
Before I change anything I have a few questions about these settings.
There is a low pass at 140 and a high pass at 250, what happens with the frequencies between 140 and 250?
And there is a notch at 1900hz which I get when looking at the frequency response, but is this still needed when there is a low pass in place?
I like the sound with this setting but the voices seem muffled, before they where way too much so I think it has to do with the settings.
I also placed the speakers further apart and a bit further away from the window, this helps quite a bit.
R.
Before I change anything I have a few questions about these settings.
There is a low pass at 140 and a high pass at 250, what happens with the frequencies between 140 and 250?
And there is a notch at 1900hz which I get when looking at the frequency response, but is this still needed when there is a low pass in place?
I like the sound with this setting but the voices seem muffled, before they where way too much so I think it has to do with the settings.
I also placed the speakers further apart and a bit further away from the window, this helps quite a bit.
R.
OK, good - thanks for trying the settings, glad they went in the right direction.
Try listening to voices with only the Beta LTAs playing, still crossed at 250 Hz. Does that make any difference? Are the Alpha woofers making the muffled sound? The answer yes or no will lead you in the direction you need to go. Work on getting the Beta LTAs sounding good, then add in the Alphas for support. Tweeters will be the sugar on top.
I've send them on holiday since they were complaining about being over worked. 😛 Just kidding. What you will quickly learn is that your electrical crossover point and the resulting acoustic crossover point are not the same. The would be only if the driver's outputs were perfectly flat - and they are not. By spreading the crossover points electrically, I have tried to get the actual acoustical crossover point at around 200 Hz. This works because the driver response are not flat throughout the crossover region.
That notch is to combat the huge ~2K peak they Alpha as on its factory response. Yes, it will be way down already because of the 140 Hz low pass, but the peak is shown at 10dB (big) and 2K is a sensitive area. It's a trick you should keep up your sleeve, you may or may not need it.
Good info, thanks. Did you try with and without the shelf filter on the 12 inch? Did you try reverse polarity? Vocal sounds can be made clear or muddy by energy in the 3 kHz and 6 kHz ranges. That's where we hear the consonants that allow us to understand the words. If there is not enough energy there, or too much in the lower vocal range, then voices can sound muffled. Why there is an imbalance will be hard for me to determine at a distance.
Try listening to voices with only the Beta LTAs playing, still crossed at 250 Hz. Does that make any difference? Are the Alpha woofers making the muffled sound? The answer yes or no will lead you in the direction you need to go. Work on getting the Beta LTAs sounding good, then add in the Alphas for support. Tweeters will be the sugar on top.
The problem lies with the Beta driver. I tried polarity on the Beta this didn't solve the problem. I removed the high shelf and this helped a little.
You mentioned the amount of energy around the 3-6 kHz, so I took a good look at the frequency response and at 4 kHz there is a large -15dB dip.... So I am experimenting in the EQ in this area.
I noticed that I can go bad very quickly in this region, but the voices do get brighter...
You mentioned the amount of energy around the 3-6 kHz, so I took a good look at the frequency response and at 4 kHz there is a large -15dB dip.... So I am experimenting in the EQ in this area.
I noticed that I can go bad very quickly in this region, but the voices do get brighter...
Yes the 3-6K octave is going to be touchy and difficult. Without measurements it will be difficult for me to know what going on 7500 km away. 🙂 And I don't know the Beta LTA well enough to offer known fixes.
Without measurements you'll just have to listen and tweak, listen and tweak. You'll get there, but it will take time.
Without measurements you'll just have to listen and tweak, listen and tweak. You'll get there, but it will take time.
Since you have the MiniDSP there is one thing you might try. Put a large value cap on your tweeters for protection, then use them active for a test. Try a steep crossover between the Beta and the tweeter. Try 4th order or higher. Move that crossover point up and down, just don't go below tweeter Fs. This will give you an idea of where to get out of the Beta and into the tweeter.
I know you will be doing this as a passive crossover, but cutting off the Beta LTA with a steep filter and going over to the tweeter will help you hear where the problem areas are.
I know you will be doing this as a passive crossover, but cutting off the Beta LTA with a steep filter and going over to the tweeter will help you hear where the problem areas are.
As far as taming the Emi Beta 12 LTA mid range rise... depends on how high frequency wise you intend to take it. You can use a simple 1st order low pass inductor based on a 3 db down passive calculation around 750 Hz or so, or work a broad trap starting around 700 Hz up to 7,500 Hz if you are taking the Beta out as far as it can go before main natural roll off. The 1st order will give you an acoustic -6 db on axis around 3,500 Hz give or take. You also need to remember this driver will have a natural rear roll off starting around 1,100 Hz or so if I recall. Below that even with either of the two options above, you are looking at a gross efficiency of better that 100 db/w once you flatten things out on the forward axis. Anyway, hope the above clues help move your design in a positive direction.
Well, this project I waited so long for gives me headaches. One of my Icepower amps has a problem with its auxiliary power supply so I have to fix that.
But before this problem I couldn't get a decent sound from the Beta and tweeter or in combination with the Alpha's.
So I went back to the threads and articles about the Beta and Alpha's. I tried all the settings they eventually ended up with. Most of them use simple filters and no EQ!?
It must be me I reckon, but I do not even remotely get the sound and experience they write about.
In my search to get it right using EQ, I get lost in the endless possibilities and advices..... This is due to my lack of knowledge in using these tools is guess.
This isn't the "quick" project is was hoping for, my idea was that since many people went before me I could concentrate on the building side of this project. Well lesson learned there....haha.
I will take this project up from the start, using all your advice and take my time..
R.
But before this problem I couldn't get a decent sound from the Beta and tweeter or in combination with the Alpha's.
So I went back to the threads and articles about the Beta and Alpha's. I tried all the settings they eventually ended up with. Most of them use simple filters and no EQ!?
It must be me I reckon, but I do not even remotely get the sound and experience they write about.
In my search to get it right using EQ, I get lost in the endless possibilities and advices..... This is due to my lack of knowledge in using these tools is guess.
This isn't the "quick" project is was hoping for, my idea was that since many people went before me I could concentrate on the building side of this project. Well lesson learned there....haha.
I will take this project up from the start, using all your advice and take my time..
R.
Hard to say. Probably start with 2.2-3uF or similar. But you'll need to flatten the Beta with a shelf, as John mentioned above.