When you look at group delay, try down to 20Hz too. Even if the measurement is inaccurate, the group delay caused by the XO will be visible as a diff from the raw response of the driver.
I think it should also work using a flat .frd for the woofer, and only the actual impedance to see the effects in group delay.
I think it should also work using a flat .frd for the woofer, and only the actual impedance to see the effects in group delay.
Something like that, you can even disable the tweeter, and look only at LF 20-200Hz maybe. However, it seems you did it backwards since it goes negative. Anyway, now you try to add a impedance compensation for the upper resonance peak on the woofer and look what happens with group delay (and frequency response). My guess would be abt 10mH, some hundreds of uF, and abt 8ohms resistance. You can tune it and look at the impedance plot, when the upper peak is gone, and there is only a smooth line, you are done.
You can also watch GD while you do this, if it was a good measurement, you could use it to try and tune the group delay curve as smooth as possible. This last bit is just my own theory, not sure how valid it is. I think sudden changes in group delay is bad too, not just the absolute number.
You can also watch GD while you do this, if it was a good measurement, you could use it to try and tune the group delay curve as smooth as possible. This last bit is just my own theory, not sure how valid it is. I think sudden changes in group delay is bad too, not just the absolute number.
Please, take this as my experience, not criticism.
I use the suppled files for purchase decision, then make my own measurements in the prototype box. I do my .frd @ 1M so I get the nasties from the baffle included. Old WT-II, precursor of the DAT.
I shutter at those square edges on the baffle. One of the big advantages of painted cabinets is easy for nice big radiuses. I prefer to get my tweeter closer and offset.
Flat responses are for 1mm measuring of the driver. You do not want a flat response @ 1M or your listening position. Big long discussion with many variables. Most speakers are way too bright. I think the Peter Walker curve is too steep, but do research it.
I am advocate of a LP in the tweeter. The goal is to reduce the harmonics from exciting it's breakup resonances, which in turn via IM causes harmonics down in the mid and treble. The more perfect your electronics are , the less important, but I find it helps even with good stuff. Yea, you can't hear 18K, but the effects may be @ 4.
What were your assumptions for offset? Guess half VC or did you have a way to measure?
Do you play these very loud? The crossover creeping down might start to strain the tweeter a little. 2K seems a happier point. Mine wound up creeping down too and I am not sure I am happy with it. But that is a big mid, so compromise, compromise, compromise. My new center used the DXT with a pair of SB's
I use the suppled files for purchase decision, then make my own measurements in the prototype box. I do my .frd @ 1M so I get the nasties from the baffle included. Old WT-II, precursor of the DAT.
I shutter at those square edges on the baffle. One of the big advantages of painted cabinets is easy for nice big radiuses. I prefer to get my tweeter closer and offset.
Flat responses are for 1mm measuring of the driver. You do not want a flat response @ 1M or your listening position. Big long discussion with many variables. Most speakers are way too bright. I think the Peter Walker curve is too steep, but do research it.
I am advocate of a LP in the tweeter. The goal is to reduce the harmonics from exciting it's breakup resonances, which in turn via IM causes harmonics down in the mid and treble. The more perfect your electronics are , the less important, but I find it helps even with good stuff. Yea, you can't hear 18K, but the effects may be @ 4.
What were your assumptions for offset? Guess half VC or did you have a way to measure?
Do you play these very loud? The crossover creeping down might start to strain the tweeter a little. 2K seems a happier point. Mine wound up creeping down too and I am not sure I am happy with it. But that is a big mid, so compromise, compromise, compromise. My new center used the DXT with a pair of SB's
Thx for the good advices 
The next step is to get correct FRD files.
I agree with round edges in order to reduce diffractrions, but thats the final touch.
LP in the tweeter is interesting, never thought about it.
I have very good experience with 2,2K HP on DXT:
https://www.hifisentralen.no/forume...d-seas-dxt-diskant.103210/page-2#post-3446352
I dont like flat response either. I like this «Trained Listeners» response which i use in my main system with dsp:
The next step is to get correct FRD files.
I agree with round edges in order to reduce diffractrions, but thats the final touch.
LP in the tweeter is interesting, never thought about it.
I have very good experience with 2,2K HP on DXT:
https://www.hifisentralen.no/forume...d-seas-dxt-diskant.103210/page-2#post-3446352
I dont like flat response either. I like this «Trained Listeners» response which i use in my main system with dsp:
You may be surprised how significant a 1/2 or 3/4 radius is. I sure was the first time. Same with asymmetric tweeter position. Spreading the diffractions will lower the apparent treble allowing less roll-off for the natural sound but retain detail. I was surprised that radius of the BACK corners made an audible difference. It was a live room.
I personally do not prefer the bass bump as shown above, But do notice a smooth slope though the 2000 to 5000 region.
"Super" must be a batchlor. I have to meet the WAF.
I personally do not prefer the bass bump as shown above, But do notice a smooth slope though the 2000 to 5000 region.
"Super" must be a batchlor.
I have to meet the WAF.Attachments
It's not clear to me what phase you used in XSim. You have to use at least a derived phase, else the simulation will be useless.
Also 1.78" for the path difference between a 8" woofer and a (small) waveguided tweeter seems too much, I measured a lower value for a flat face tweeter mated to a 7" woofer.
GD is only relevant in the bass and depends on the box tuning.
Ralf
The DXT tweeter has a too small waveguide to be mated efficiently to a 8" bass, you need a much larger waveguide. The DXT is perfect for a LR2 acoustic crossover with a 5-6" mid.
Also 1.78" for the path difference between a 8" woofer and a (small) waveguided tweeter seems too much, I measured a lower value for a flat face tweeter mated to a 7" woofer.
GD is only relevant in the bass and depends on the box tuning.
Ralf
The DXT tweeter has a too small waveguide to be mated efficiently to a 8" bass, you need a much larger waveguide. The DXT is perfect for a LR2 acoustic crossover with a 5-6" mid.
I have been looking at some of the 1 1/8 tweets, new Peerless ceramic as one, so it can get down to the 1700 or so range where so many 6's are happier. 2K is OK, 2200 even better. ( distortion wise) but getting even a 5 inch to behave that high is not easy. We still need a really good, high efficiency, easy to use, 400 to 4K midrange. Then an 8-4-1 bookshelf would be killer, or a 10-4-1 floor stander back to the good old "Monkey Coffin" full range days. I had almost convinced myself to try the B&G planer tweets before they stopped production.
There are a lot of 5" that can be crossed at 2.5KHz easily without problems. The DXT will be good for a 10-5-1 or even a 12-6-1.
Ralf