How to Route Bass Frequency Left/Right In A Triamp Set Up As One Channel

[Trdat]

The exact crossover number you choose does not matter.
in this example we went with 80.01, 80.02, 80.03 etc, but it could have been 80.1,80.2, 80.3. The numbers don’t even need to be sequential 80.01,80.1, 80.45, 80.21. As long as the number is not identical. If it’s an identical number AL will use the same calculation for all channels with identical crossover numbers.
since all speakers and locations in the room are not identical that’s not desirable.

usually a crossover has the same frequency for the high and low pass filters so their sum gives you a more or less flat frequency response and avoid comb filtering. You can have an overlap if you wish by ticking the appropriate box, see picture

Well due to choosing the same crossover point this time around it did sound better compared to many of my other filters that I have with different crossover points for HP and LP. Do you recommended always using the same crossover point? I know it is possible to get a good match without pre-ringing but I have been told its difficult to accomplish.

I also did tick the the box you mentioned and can't change the crossover point for the sub, usually it does with my other set ups. You could even try with the file you sent me, it doesn't allow me to add a number for the subwoofer highpass. Its not a big deal but curious why, it should be simple.

Thanks for the explanation on the .1, .2, .3 I kind of get it but its good enough for now.

 

[Omid]

I don't think you necessarily need to set the same crossover point for all your speakers. Your rear speakers probably don't extend down as low as your mains. It might be a coincidence that this setting turned out to sound better.
The option I showed you in the picture in my previous post allows you to overlap your tweeter and midbass. Try setting the high pass at 900Hz for your tweeter , and the low pass on your midbass at 5000Hz and you'll see that the overlap works. The sub lowpass is different though.
I don't think AL gives you the option to customize the crossover with the sub to allow an overlap (when you route the signal from a small speaker to the sub). It does let you choose where you cutoff the LFE signal, but that only applies to the LFE signal (the .1 in a 5.1 signal).

 

[Trdat]

I don't think you necessarily need to set the same crossover point for all your speakers. Your rear speakers probably don't extend down as low as your mains. It might be a coincidence that this setting turned out to sound better.
The option I showed you in the picture in my previous post allows you to overlap your tweeter and midbass. Try setting the high pass at 900Hz for your tweeter , and the low pass on your midbass at 5000Hz and you'll see that the overlap works. The sub lowpass is different though.
I don't think AL gives you the option to customize the crossover with the sub to allow an overlap (when you route the signal from a small speaker to the sub). It does let you choose where you cutoff the LFE signal, but that only applies to the LFE signal (the .1 in a 5.1 signal).

The whole idea is to overlap them on the sub so the 15inch mains can be also used as a low frequency output. I am not worried about an overlap between tweeter and midbass or for the rear speakers.

I have previously had a dissimilar overlap with the sub and midbass but that was with a standard tri-amp without the set up you had provided. One that had the sub as low frequency or bass rather than just sub as a separate channel.

Bernt do you have any input regarding this? You would know have an idea how my previous tri-amp set up was and perhaps why this time around even with the overlapping on it does not allow it...?

 

[Omid]

Yes, sorry I understand what you’re trying to get.
I just meant the ‘driver overlap’ option does function... but sadly only for speaker crossovers. To my knowledge, there isn’t a built-in way of achieving an overlap with a subwoofer. Perhaps Bernt can clarify this for us.

I have thought of one way that would help achieve what you’re looking for, but it would be convoluted and only work for people that have a multi channel DAC with the ability to mix channels, like a Motu. For simplicity I'll use a 2.1 setup, although it'd be the same for 5.1.

I'll just detail it here, for future reference (not sure it's actually a good idea). The principle is that while your main speaker will play the whole range 10-20000Hz, it will do so in 2 bands 10 to 120Hz (for example), and 120Hz to 20,000Hz ( your woofer would have a digital crossover with itself at 120Hz). Your subs would play 10-120Hz :

In the DAC's routing table you would set Channel 0&1 for the L & R woofer, Channel 2&3 for L&R woofer again (ie a duplicate of main), Channel 4&5 as Sub R&L.
Then in AL (see pictures) you would setup a 2.1 system, creating a subwoofer that has 4 drivers. When you run a measurement output Channel 0 & 1 would be for the woofer, output channel 2,3,4,5 would be for the 4 sub drivers.

I haven't tried this, but I think it should work. The downside is that it would create a crossover within the same woofer. I suppose AL can iron out the phase difference and volume changes, but it is not an elegant solution.

 

[Omid]

I tried it. It worked, but in my system it resulted in a poor frequency response and 24 dB attenuation (tried both 80 and 120Hz crossover). With a normal setup (2 mains crossing over at 80Hz to 2 subs, no overlap) I got a pretty flat response and 8-10 dB attenuation only.

 

[Trdat]

I tried it. It worked, but in my system it resulted in a poor frequency response and 24 dB attenuation (tried both 80 and 120Hz crossover). With a normal setup (2 mains crossing over at 80Hz to 2 subs, no overlap) I got a pretty flat response and 8-10 dB attenuation only.

Omid,

Appreciate your response, it's always great learning something new in particular a unique way to manipulate the settings to suit your goals. I will have to take a look and let it sink it, a little above what I can manage but I have got this far so a few reads should do it.

Once I understand it, I will get back to you and we can discuss why this method is different than when I just overlap the mid and bass in a normal 2.1 Tri-amp set up as I do not need to make it this complicated its as simple as choosing your crossover points.

Thanks again.

 

[Ofer]

This is all very interesting. The major reason I plan to dive into Audiolense is to create a system like @Trdat stereo 3way active xover with with the mains overlapping the sub. The different setups described by Omid are a bit over my head. Could the Sub be set as a "third" full range speaker and thus can be overlapped by the right and left mains? That way Audiolense will time align it and correct the overall response? maybe @juicehifi could pitch in.

 

[Trdat]

This is all very interesting. The major reason I plan to dive into Audiolense is to create a system like @Trdat stereo 3way active xover with with the mains overlapping the sub. The different setups described by Omid are a bit over my head. Could the Sub be set as a "third" full range speaker and thus can be overlapped by the right and left mains? That way Audiolense will time align it and correct the overall response? maybe @juicehifi could pitch in.

I'll let the experts chime in but I had set it up the standard way which is essentially setting the sub as a bass frequency and I am sure Audiolense time aligns it and fixes anamolies its just I was told to watch out for preringing which could be an issue with overlapping XO's.