Hezz said:
Multiple soundcard in a PC for this usage is a big no no unfortunately. Latency issues between the cards mean compensating is difficult unless the delays are absolutely constant and the exact delay is know and then compensate for. Big headaches are possible with this solution.
Much better is something such as the RME HDSP9652 which, whilst a completely digital card, can be used with outboard converters allowing for many channels all on one card. The route all channels take through processing must be equal and hence so are the relative delays from processing. This can either be done by applying the same processing to each channel or by knowing the exact latency of each plugin and compensating for it with a line delay.
Again it sounds complicated but is very simple once you know what the latencies are, and this is easily identified by the plugin itself and Console which actively reports latencies.
ackcheng said:
Hi
I'm guessing that your using neville/thiele crossovers? And the tweeter is probably crossed a little too low, the Raven isn't as robust as the RAAL and I don't like the sound the RAAL makes when crossed 1.5Khz.
To my ears the Linkwitz filters sound MUCH better at least for the LGT's.
Try LR 4th orders and cross the tweeter at 2.5Khz or maybe even 3Khz. Give both a try.
Also what exact AT drivers are you using? Is it a 5" and an 8" and if so what are the ranges these drivers are working in?
The 5" is definitely capable of working lower than 350hz, so shift it down to 200hz, I'm betting you'll notice a difference in the midrange cohesive. What sort of loading is your AT bass driver in?
The Tact sub looks fairly capable but I would never use it up 150hz especially since its not part of the main driver stack. If you give more info on your setup, perhaps a couple of photo's too, I'll be able to better advise.
Shin,
Thanks for your advice. I am using AT 5'(15CM) C-quence as mid and 23CM as my woofer. both of them are 8 ohms version
Raven 2.0 - 2000Hz up
15cm C-quenze - 350Hz - 2000Hz
23 cm C-quenze - 150Hz - 350Hz
Tact W210 - 150 Hz and below
I am using Linkwitz filter cross at 96dB slope.
may be I should try this
Raven 2.0 - 3000Hz up
15cm C-quenze - 350Hz - 3000Hz
23 cm C-quenze - 100Hz - 350Hz
Tact W210 - 100 Hz and below
If I shift the mid down to 200Hz, my woofer will only be working from 100hz to 200 Hz?
I am using class D Hypex amps to drive the speakers
Thanks for your advise! Will try to take some photos tonight!
Thanks for your advice. I am using AT 5'(15CM) C-quence as mid and 23CM as my woofer. both of them are 8 ohms version
Raven 2.0 - 2000Hz up
15cm C-quenze - 350Hz - 2000Hz
23 cm C-quenze - 150Hz - 350Hz
Tact W210 - 150 Hz and below
I am using Linkwitz filter cross at 96dB slope.
may be I should try this
Raven 2.0 - 3000Hz up
15cm C-quenze - 350Hz - 3000Hz
23 cm C-quenze - 100Hz - 350Hz
Tact W210 - 100 Hz and below
If I shift the mid down to 200Hz, my woofer will only be working from 100hz to 200 Hz?
I am using class D Hypex amps to drive the speakers
Thanks for your advise! Will try to take some photos tonight!
ackcheng said:
Hi again Arthur,
It sounds like your system is basically the LGT but in slimmed down TMW form. At least from a driver perspective anyway.
The thin midrange problem I was having and which you seem to be relating to was due to some over excessive stop band correction which Uli fixed and showed me how to avoid. Before making any changes are you sure you haven't fell into this trap also?
During this project I made a few discoveries about the RAAL ribbon which will very likely apply to any ribbon. I'm not sure about dome tweeters but their dead and lifeless nature means it probably doesn't matter how they're used, they'll still sound unnatural.
Dome tweeter jokes aside, if I crossed the RAAL low at 1.5Khz it simply sounds wrong in comparison to what I have now. You lose the presence and body of the upper midrange/lower treble and this is true despite very similar measured performance. Perhaps it is odd high order harmonic distortion from the ribbon being crossed low? Perhaps it is a mass/radiating area issue? I'm not 100% sure about either but I can say it doesn't sound as good. Try the Raven at 3Khz, since your crossing to the 5" the narrowing directivity of the mid driver will improve overall power response and better mate the directivity patterns of the two drivers at the crossover points. I assume you mid and tweeter spacing is close here.I would try to abandon the steep filters for use with AT drivers, it harms the sound more than it helps. They're wideband and smooth at both ends so why create a problematic solution to an issue that doesn't exist. Its best to evaluate on the basis of each case and go for the lesser of evils approach. For example I found steep filters worked well with the ATC midrange but this was actually beneficial because I was running it right upto its upper and lower limits where resonanaces and distortion, respectively, became an issue overiding negatives surrounding steep filtering.
In this instance I chose 24dB LR slopes and it really does suit the AT's offering a good blend of stop band rejection, lessening driver to driver crossover stopband interaction along with promoting a more cohesive sound from drivers more effectively blending creating less of a sense of shifting directivity lobes and tonality. By this I mean with steep filtering the drivers can become more subjectively isolated and I find I can tell a shift of sound direction and tonality when different frequencies, covered by different drivers, are playing. A bit more crossover overlap from shallower filtering can create a more cohesive speaker and we are lucky that we can make the drivers behave optimally to virtually eliminate the phase problems from doing so.
You've also got a lot going on down low: A sub crossed in at 150hz to an 8" driver that then works to 350hz. I haven't heard your system so can't say whether it works and maybe you have preference for this setup but looking at it on paper its less than optimal IMO. Personally I'd shift the mid down to 200hz which allows it to cover yet more of the frequency range, it works excellently in my setup where I tried it at 500hz, 300hz, 200hz and 150hz. 200hz had the best blend of mid/upper bass weight and seamless integration out to the midrange.
For the 8" I'd use this with just a low pass and no high pass then bring the sub in at non directional frequencies to blend with the overall sound and fill out the low end. Reason being the sub will be some distance from the main driver array and at 150hz sound is directional. Crossing in at say 50 or 60hz is much better.
These are just my thoughts on how I'd do it and not everyone agree's on how things should be implemented but since your not 100% happy with the sound and we also have similar drive units then I think some of the ideas might be worth looking at.
I did wonder about the size of that mid ... its also worth to mention that AT drivers are a bit bigger than others at the same nominal size, because ATs are measured by their actual cone size which others rarely are not, some are even measure with the chassis... so if you want a 5" you may actually need to consider a 4" AT ... if things hasnt changed
OK this may or may not prove interesting but it certainly brings home just how useless most of our rooms are and given this horrible performance, I frankly think its suspect to put across opinions on amplifiers, sources and loudspeakers anywhere outside of your own listening room. To think that cables make a difference here is frankly laughable, you've got far far bigger problems to worry about!
All measurements taken at the listening position some 2.7m away from the LGT's.
Please note none of these graphs are indicative of the loudspeaker natiive performance. I took them to show the just how much the room influences the loudspeaker and the sound you finally hear. Hopefully it brings home just how large a problem it is. Also bare in mind that this is with room correction[/b] expect things to look about 20-30% worse than this without.
First is a 1/24th smoothed FR and a 1 octave smoothed FR overlay with phase response. Its about +/-5dB, the saving grace is that most of these dips and peaks are narrow and the ear isn't so quick to pick up on such things, its still very far from ideal though No gating used
Next is step response.
Absolutely no way would a 3.5 way design using IIR filters look this good at the listening position. This at least shows a good transient behaviour is possible even at the listening position and in a poor room which is quite remarkable really. Nothing much to complain about here.
CSD showing decay behaviour during 1 second. Something to note is that noise floor of my measurements is around 55dB below the peak level of the loudspeakers hence you can see 'noise' in the area above 1Khz including the high pitch fan noise from the projector at 2.4Khz. Looking below 1Khz we can see awful decay behaviour. Digital room correction has somewhat calmed these problems but only physical treatments will serve to create cleaner behaviour. This type of plot is especially useful for seeing where treatment are most effective when applying them to your room.
By far the weakest link in the audio chain is not the loudspeaker but the room.
For comparison I will post the native performance of the loudspeaker to show just how much influence the room has on final sound quality.
All measurements taken at the listening position some 2.7m away from the LGT's.
Please note none of these graphs are indicative of the loudspeaker natiive performance. I took them to show the just how much the room influences the loudspeaker and the sound you finally hear. Hopefully it brings home just how large a problem it is. Also bare in mind that this is with room correction[/b] expect things to look about 20-30% worse than this without.
First is a 1/24th smoothed FR and a 1 octave smoothed FR overlay with phase response. Its about +/-5dB, the saving grace is that most of these dips and peaks are narrow and the ear isn't so quick to pick up on such things, its still very far from ideal though No gating used
An externally hosted image should be here but it was not working when we last tested it.
Next is step response.
Absolutely no way would a 3.5 way design using IIR filters look this good at the listening position. This at least shows a good transient behaviour is possible even at the listening position and in a poor room which is quite remarkable really. Nothing much to complain about here.
An externally hosted image should be here but it was not working when we last tested it.
CSD showing decay behaviour during 1 second. Something to note is that noise floor of my measurements is around 55dB below the peak level of the loudspeakers hence you can see 'noise' in the area above 1Khz including the high pitch fan noise from the projector at 2.4Khz. Looking below 1Khz we can see awful decay behaviour. Digital room correction has somewhat calmed these problems but only physical treatments will serve to create cleaner behaviour. This type of plot is especially useful for seeing where treatment are most effective when applying them to your room.
An externally hosted image should be here but it was not working when we last tested it.
By far the weakest link in the audio chain is not the loudspeaker but the room.
For comparison I will post the native performance of the loudspeaker to show just how much influence the room has on final sound quality.
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