[Old rocker]

I was wondering is there would be an issues blending LR with Butterworth filters in a 3 way front active system? I have measured my front stage in REW with both LR and BW and what I found is the midbass to midrange is smoother with LR but I get a better blend using BW between the mids and tweeters.
Any issues mixing the filters?

 

[RedSwede]

I'd be interested with this as well. I have a similar "issue". I just used LR24 to start with. Then I was experimenting, and noticed I could get a better RTA (from better phase matching) with BW24 an a little x-over separation.

Lo and behold, I then listened to some music and there was a notable increase in smoothness AND clarity. So it's left as is and I'm not touching it - but I would be interested to hear some more experienced input.

 

[daloudin]

Using different filters for different crossover points is not a problem - per your example: LR for the Low Crossover + BW for the High.

What's "usually" not done is mixing them at the same crossover point - say Low Pass with LR and High Pass with BW at 80 Hz.

See the current thread (the title has nothing to do with the conversation): Using helix auto set (auto eq) function

 

[Old rocker]

I agree RedSwede, I was playing around last night and took the below measurements with the exact same signal crossed at 24dz at 300hz between midbass and mids and at 2500hz between the mids and tweeters. The green is BW and the Purple is LR.
To your point in my situation at 300hz I could play around with the BW and gap the crossover to flatten the peak (existed with both LR and BW) or use the LR crossover between these drivers. For the mid/tweeter the BW is much closer to the target curves and can be EQed.
Disregard the excessive bass as I am a basshead and the 35hz and lower curve shows a classic example of my sub in too small of a box. I am looking at sub options now.

 

[Old rocker]

Thanks Daloudin, you have always provided lots of great feadback on my other posts.

 

[Old rocker]

One thing I missed. The REW graph i sent was my right channel only so it was easier to see the difference .All measurements were taken with AF UM1 mic and averaged from 6 different position headrest measurements.

 

[Eric Stevens]

You can mix the filter types even at the same crossover. The filter type and slope is just going to alter phase and amplitude of the individual driver which will change the way to the two drivers combine together. Could be better and could be worse. Its no different than changing the mounting position or delays of an individual or both drivers. Th

Outside of its effect through the crossover range you cannot hear phase in and of itself, what you hear when changing phase / delay / driver position is the combined response of the drivers together.

I prefer to leave that variable out of the tuning process and stay with with LR4 typically because there is narrower range of frequencies where I have to get drivers to play nice together.

 

[Old rocker]

Thanks Eric, I knpow may people prefer LR and I am on the fence myself. I did prefer the BW between thye mids and tweeters as it "appeared" to improve the front stage. My mids are located in the factory corner dash location and my tweeters are in the sail panel at the top of the door panel.

 

[cathul]

Well, the difference between BW and LR is the following:
LR crossover point is at -6 dB
BW Crossover point is at -3dB.
If you tuned the BW filters to a target curve that is intersecting at -6dB and have better summing you have better phase response with the BW filters.
The phase with the LR crossovers could be fixed though. With such a deviation I would be cautious to say one sounds better than the other as this might be due to the higher volume. And most often louder is interpreted as better (in this case this might be true due to better phase).

 

[Old rocker]

Thanks cathul, i did notice a slight boost with BW in the midrange and midbass on the REW Right channel I shared above. If I understand thing right the boost should bot be a problem as long as I am not clipping the amp.

 

[dumdum]

You can use both together and the number in the dsp doesn’t matter as long as the phase is good and they sum well 👍🏼

 

[oabeieo]

to be continued…….

 

[bertholomey]

to be continued…….

Boy was I disappointed this morning when I opened this thread to read the lengthy response you had posted, but I didn’t have a chance to read yesterday. Are you tweaking it and then will repost?


Sent from my iPhone using Tapatalk Pro

 

[oabeieo]

Boy was I disappointed this morning when I opened this thread to read the lengthy response you had posted, but I didn’t have a chance to read yesterday. Are you tweaking it and then will repost?


Sent from my iPhone using Tapatalk Pro

i made a Thread instead. ;-)

Crossover Phase Shift Explained

I have been asked by a bunch of you to post some illustrations. Here are some things I hope can help. 1st off. The idea of using an APF to get rid of phase shift from a crossover is complete nonsense. The phase shift of the all pass goes in the wrong direction. An out of band all pass can help...

www.diymobileaudio.com

 

[Old rocker]

That's an amazing share oabeieo, thanks for that.
It has opened my eyes to testing my system more. In most cases I was following Andy's suggestion of 24db LR but I have also read many people who compete prefer 12db slopes. I have been a hobbyist for over 40 years and in the old days it was always passive 12ds and 24db on subs. I have a JL twk88 and will have to investigate how to add APF on my unit if possible.
Below in my system measurement all EQ flat with 24db LR at 70hz, 300hz and 3,000hz with all measurements are an average of 6 position drivers headrest.
Your post got me thinking my right midrange in red. Could it could be out of phase as it peaks just before the 300 and dips just before the 3k crossover points. The mids are located in my factory dash location near the windshield so that could also be reflections..

 

[oabeieo]

That's an amazing share oabeieo, thanks for that.
It has opened my eyes to testing my system more. In most cases I was following Andy's suggestion of 24db LR but I have also read many people who compete prefer 12db slopes. I have been a hobbyist for over 40 years and in the old days it was always passive 12ds and 24db on subs. I have a JL twk88 and will have to investigate how to add APF on my unit if possible.
Below in my system measurement all EQ flat with 24db LR at 70hz, 300hz and 3,000hz with all measurements are an average of 6 position drivers headrest.
Your post got me thinking my right midrange in red. Could it could be out of phase as it peaks just before the 300 and dips just before the 3k crossover points. The mids are located in my factory dash location near the windshield so that could also be reflections..

View attachment 334941

thank you

the JL VXI amps have APF the twk does not. So you simply just can’t add the cascade. If your amps have filters you can add it using the amps filters , just try and match as much as possible… you have to find the topology of the amps crossover…. Even a partial shift is better then none…. Example , if your amps are a 12db not 24 , you’ll still shift half of the phase and be closer. It’s still worth it….. and the frequency doesn’t have to be exact for that cascade. As Long as it’s close it will work…. If it’s a 12db maybe try using amps filter at 60 rather then 80 as it will start to roll off sooner…. It doesn’t have to be exact. Just want to spin the phase as much as possible in the right direction. So you’ll just turn on amp filters on mid and tweet , not midbass. Midbass leave off and do it in dsp the way you want…. Or do everything in amps filters and not use dsp for the hp at all…. A few ways to do it .

yeah once in the car things can behave completely different….

I will say there are a few extremely reputable people that do nominate the LR4 as always use. And it’s good advice given the complexity of crossovers. But I also believe some may have a foot in the race as far as not wanting the returns on there speakers because someone decided to use too shallow of a slope and too low of a crossover. I’m in the industry and it’s surprising how many people are fine with listening to fully saturated and clipped outputs. It’s not even music anymore (but hey it’s loud).

so in that regard, hey a crossover that works well. Easy to implement, and has high attenuation. Win win if you ask me….

I just see so many people on this forum that I truly believe are a little smarter then that. Most of us on here are not the masses. We are the diy crowd and it’s fitting to try and help as many people realize better sound quality. Even if it comes contrary to what’s recommended by someone who has a business selling car audio items.

A little caution is always good. Filters can make sound quality leaps and bounds better if done just right.

ill try and add more to that post and get into some real world measurements

 

[Old rocker]

I have invested in good quality equipment but that is only the half of it... if its not set up and tuned correctly then the quality means nothing.
I have really stepped up my learning ion the last year and this form has taught me so much.
I do greatly appreciate the shares and advice.