What am I missing here - Crossover Filters

[Robbie010]

Measured my speaker drivers individually this morning

Woofer looks fine - HP 40hz / LP 700hz + a little EQ.

Tweeter looks fine - HP 5000hz / LP 17khz

However, no matter what I do I can’t get the midrange to play ball. Initially measured with just a high-pass at 700hz and a lo-pass at 4,500hz and this is what I got

Tried applying a hi-shalf and lo-shelf, that didn’t help.

Its almost as if the crossover isnt applying the filter settings.

Any advice?

 

[Keith_W]

A bit of context would be good. We are not mind readers, you know.

 

[Dumdum]

View attachment 478283

Measured my speaker drivers individually this morning

Woofer looks fine - HP 40hz / LP 700hz + a little EQ.

Tweeter looks fine - HP 5000hz / LP 17khz

However, no matter what I do I can’t get the midrange to play ball. Initially measured with just a high-pass at 700hz and a lo-pass at 4,500hz and this is what I got

Tried applying a hi-shalf and lo-shelf, that didn’t help.

Its almost as if the crossover isnt applying the filter settings.

Any advice?

Take the low pass off the tweeter for a start! There is zero need for a low pass on the high freq driver

Xovers will only be textbook if the driver is perfectly flat in response and has zero roll off

Not sure why you feel a 5khz high pass and a 700hz low pass will work together though?

If drivers are the same distance/timing from the listening position (acoustically… a midrange with a cone on the same baffle as a tweeter with a dome won’t have the same timing) then you need to have matching acoustic crossovers of the correct shape to get a good phase relationship between the two drivers

 

[Robbie010]

Thanks.

At the minute, I don’t know what I don’t know. Thats why I posted in the newbie/beginner section.

Please be gentle!

Context is DIY 3 way setup:

Fane 12-250TC 12” full range woofer in 55L seal cab - 100db 1w/1m

Faital HF144 1/4” compression driver - 109db 1w/1m

18Sound XT1464 Horn - 110db 1w/1m

Visaton TL-16H Horn tweeter - 100db 1w/1m

Crossover / DSP - dB-Mark CXA48+

Amps - KJF MA- 01 8 way Hypex ncore.

Anything else I need to elude to?

 

[Dumdum]

Thanks.

At the minute, I don’t know what I don’t know. Thats why I posted in the newbie/beginner section.

Please be gentle!

Context is DIY 3 way setup:

Fane 12-250TC 12” full range woofer in 55L seal cab - 100db 1w/1m

Faital HF144 1/4” compression driver - 109db 1w/1m

18Sound XT1464 Horn - 110db 1w/1m

Visaton TL-16H Horn tweeter - 100db 1w/1m

Crossover / DSP - dB-Mark CXA48+

Amps - KJF MA- 01 8 way Hypex ncore.

Anything else I need to elude to?

It’s not three way with four drivers?

And in your first post you listed two?

You need to explain more about what you’re trying to do and achieve… it sounds like you’ve just thrown together four drivers and don’t really know why

 

[somebodyelse]

It’s not three way with four drivers?

No - the 18Sound XT1464 is just a horn, to be paired with the Faital HF144 1.4" (not 1/4"!) compression driver which has a suggested usage range of 700Hz to 18kHz. The Visaton TL-16H has a suggested range >5kHz.

What's less clear is why the mid sweep doesn't start until >3kHz

 

[Robbie010]

It’s not three way with four drivers?

And in your first post you listed two?

You need to explain more about what you’re trying to do and achieve… it sounds like you’ve just thrown together four drivers and don’t really know why

That is the details of 3 drivers and a horn/waveguide….

Faital HF144 compression driver mated with 18Sound XT1464 horn/waveguide.

As per the posted FR, there are 3 distinct responses, woofer, midrange and tweeter.

 

[Bwaslo]

Maybe measure only the midrange, scale the plot vertically until something shows?

 

[DWPress]

dB-Mark CXA48+

That's a pretty funky unit - briefly looking over the operating manual looks like a lot of options to potentially go wrong with, a deep dive would be required to figure out your channel mapping and input/output options along with frequency range and XO. Are these drivers already assembled in a speaker box or are you measuring in free air? Can you measure the drivers without any HP/LP filters (in REW) to determine their frequency response as a base for getting started?

 

[Robbie010]

That's a pretty funky unit - briefly looking over the operating manual looks like a lot of options to potentially go wrong with, a deep dive would be required to figure out your channel mapping and input/output options along with frequency range and XO. Are these drivers already assembled in a speaker box or are you measuring in free air? Can you measure the drivers without any HP/LP filters (in REW) to determine their frequency response as a base for getting started?

12” woofer is mounted in 55L sealed cab:

Midrange horn is mounted on a bracket:

Tweete is a free standing unit:

 

[Keith_W]

That's a pretty funky unit - briefly looking over the operating manual looks like a lot of options to potentially go wrong with, a deep dive would be required to figure out your channel mapping and input/output options along with frequency range and XO.

OP please pay attention to what I have bolded. I took a look at the manual of your DSP unit and it does not look easy to set up.

I'll put it this way: your woofer should have a low pass filter (LPF). Your tweeter should have a high pass filter (HPF). Your mid, however, needs a BANDPASS filter. This means, LPF AND HPF. Your measurement clearly shows that you have set your filters incorrectly:

- midrange driver has a HPF but no LPF. The HPF seems to be set too high, so the mid and bass drivers are unlikely to sum properly.
- tweeter has a LPF, but for some reason you started your measurement at 3.5kHz. So I can't see if it has a HPF or not.

The manual does not contain enough detail on how to set up XO filters. All I can see is this extremely pixelated menu:

And there is an X-OVER button on the front panel:

In short: after looking at the manual, I still can't tell you how to set your bandpass filter. You'll have to figure that one out.

 

[dualazmak]

I'll put it this way: your woofer should have a low pass filter (LPF). Your tweeter should have a high pass filter (HPF). Your mid, however, needs a BANDPASS filter. This means, LPF AND HPF. Your measurement clearly shows that you have set your filters incorrectly:

Yes, I fully agree with this comment given by @Keith_W.

OP @Robbie010, as for your proper XO-EQ configuration, my PC-software-DSP-based (I use DSP-EKIO) XO-EQ configuration would be of your reference and interest; please visit my posts #931 and #1,009 on my project thread. Of course, you need to carefully select and set all of the proper LP, HP, EQ filters fit for your own SP drivers.

I know and understand that your metal horn super-tweeter VISATON TL16H is highly efficient but very narrow directivity, just like my FOSTEX T925A. I assume, therefore, my efforts on wide-3D reflective dispersion of such metal-horn super-tweeter sound would be of your reference and interest.

Spoiler

- A new series of audio experiments on reflective wide-3D dispersion of super-tweeter sound using random-surface hard-heavy material:
____Part-1_ Background, experimental settings, initial preliminary listening tests: #912
____Part-2_ Comparison of catalogue specifications of metal horn super-tweeter (ST) FOSTEX T925A and YAMAHA Beryllium dome tweeter (TW) JA-0513; start of intensive listening sessions with wide-3D reflective dispersion of ST sound: #921
____Part-3_ Listening evaluation of sound stage (sound image) using excellent-recording-quality lute duet tracks: #926
____Part-3.1_ Listening evaluation of sound stage (sound image) using excellent-recording-quality jazz trio album: #927
____Part-4_Provisional conclusion to use Case-2 reverse reflective dispersion setting in default daily music listening: #929

 

[DWPress]

12” woofer is mounted in 55L sealed cab:

After Looking at the rest of this post it's all just wrong, assembling drivers randomly in space is not going to achieve audio nirvana and the DSP box you choose to implement it all with is a nightmare. I'm really sorry to say it's best to start with a new concept for most of the components and a serious exploration of the dB-Mark's capabilities. I'm pretty sure it'll do what you want it to do, and you've already paid, for it but wow, just WOW, on the GUI.

 

[Robbie010]

Thank you all for your input.

This is obviously the start of my project, not the end. I’m looking to learn along the way and needed to start somewhere……

By the late afternoon yesterday I did manage to dial in some kind of crossover settings that measured close to ok. The dB-Mark software is fairly intuitive, if you have some technical knowledge regards crossovers, which I obvioisly don’t!

There are essentially 2 sets of settings, when you select an Input you get this:

When you select an output, you get this:

Each individual input and output has a mute button, gain control from +12db to -80db and the option to link inputs together and outputs together.

In addition, on the output side you have selectable input buttons, A, B, C & D, to link specific inputs to specific outputs.

Inputs Setting Options are:

Noise Gate
Delay
Polarity
DEQ
6x PEQ
AGC
Compressor
Master Gain

Output Setting Options are:

Delay
Polarity
X-Over (Linkwitz, Bessel or Butterworth)
6x PEQ
Compressor
Limiter
Master Gain

The settings I ended with yesterday were:

Output 1 & 2 -Woofer: +9db

Bessel HPF 40hz 12db
Linkwitz LPF 1000hz 36db

Output 3 & 4 - Comp & Horn: -5.5db

Linkwitz HPF 800hz 24db
Linkwitz LPF 6,000hz 24db

Output 5 & 6 - Tweeter: +1db

Linkwitz HPF 4,000hz 24db
Linkwitz LPF 18,000hz 12db

I then took a couple of measurements, the speakers were in their usual positions, mic central, around 2.5m away, 90° with correct calibration file:

I’m not sure why there is a big dip in the Left speaker response but not the Right speaker?

 

[Sokel]

I’m not sure why there is a big dip in the Left speaker response but not the Right speaker?

Wrong phase or no mid.

 

[Robbie010]

I was just looking at the Phase graph:

Left:

Right:

 

[Sokel]

I was just looking at the Phase graph:

Left:

View attachment 478518

Right:

View attachment 478519

Check your connections, something has been connected with reversed polarity.

 

[Robbie010]

God damn it! I spent hours trying to work that out.

 

[DanielT]

Looks like some exciting speaker drivers you have. Good luck with the crossover and the placement of the drivers for optimal sound. I'll just jump into this thread and give you a tip, if you're interested. The thread below, since it's based on Fane 12-250TC, which you also use:

P

'Fane Sovereign 12-250TC project measurements'

Jun 28, 2022

One of my friends has built a pair of floorstanding loudspeakers using 12" Fane 12-250TC fullrange drivers. I am posting this on his behalf and with his permission.

Cabinet is sealed with the below parameters:

Made of 19mm baltic birch plywood using internal bracing (unfortunately I do not currently have the pictures of the inside of the cabinet)

The final result looks like this:

The objective measurements will follow below, also with the mdat file attached

Subjectively the sound is typcial to fullrange drivers:
- very 'live sound', you feel like you could...

• ppataki
• Replies: 83
• Forum: DIY Audio Forum

• 

 

[Keith_W]

Output 1 & 2 -Woofer: +9db

Bessel HPF 40hz 12db
Linkwitz LPF 1000hz 36db

Output 3 & 4 - Comp & Horn: -5.5db

Linkwitz HPF 800hz 24db
Linkwitz LPF 6,000hz 24db

Output 5 & 6 - Tweeter: +1db

Linkwitz HPF 4,000hz 24db
Linkwitz LPF 18,000hz 12db

Why is there a HPF for your woofer and a LPF for your tweeter?