THE Crossover Thread

[George S.]

So I'm learning. Had the subs and woofers crossed at 80 Hz. Had a dip in response I really didn't want to EQ out, as they say boosting dips with EQ creates distortion and reduces head room.
Swept each sub and woofer separately from 0-200 Hz. Found the reason for the dip. Duh!
Changing crossover point to 50 Hz, and measuring rest of the drivers. Then redo crossovers points. Then redo sweeps to select best crossover type. Basically starting over for 20th time.
The JBLs really don't need a sub for music as the graph shows, but the subs reinforce the low end for home theater(and Infected Mushroom, thanks Lee!).

 

[George S.]

Here are the rest of the measurements. I'm going to remeasure the subs and woofers at a greater frequency range to verify 50 Hz is correct. Pretty sure it is.

 

[George S.]

Looks like 50 Hz is correct. Also going to try 130 Hz, or inverting polarity of one or more drivers. And then again it might be a delay issue. We'll see. Later.

 

[laatsch55]

And then try The Crystal Method--'" Vegas" track 4...

 

[George S.]

Will do Lee. I'm pretty burnt out on REW and juggling data. Going to take a break from this for a day or so.

 

[Mohawk]

Did amp gain matching to the drivers today within the MiniDsp plugin to approximate a "Harman house curve" I downloaded into REW. Going to give this particular house curve a shot.
Boosted the 700 WOPL output by 10 dB for the subs.
Left the 400 WOPL output unchanged for the woofers.
Reduced the 400 WOPL output by 7 dB for the midrange.
Reduced the PL300S2 output by 5 dB for the tweeters.
Been testing different gain profiles all day. I'm surprised by how much small a gain structure change affects the sound.
Next up is generating the EQ filters and plugging them in to closely match the house curve, then time alignment of the drivers.

Hey George,

Can you share the link for where you found the Harman house curve ?

 

[George S.]

This is supposed to be the Harman loudspeaker curve. But I'm finding it's too bass heavy to my liking. So, after more reading about curves and results, I'm going to recalculate and try a flat response as some suggest.
Deer Creek Audio has a better way to set delays. Works extremely well. Calibrate a tweeter to zero delay and measure all other active drivers against it. REW calculates the drivers individual delay automatically. Then plug the delay #s into your DSP and everything measured in the system is timed, even separate cabinets, against that one calibrated tweeter. Worked for my subs also.
https://deercreekaudio.com/tech-blog/f/using-delay-settings-to-integrate-your-audio-system

 

[George S.]

Flat SPL response from 10-20 KHz and steep LR 48 dB/Oct filters on all crossovers appear to be the best setup for my system, contrary to what I've read elsewhere .
Digital and FM Stereo sounds very, very good, the best ever Getting the driver timing spot on is critical.
Some of the albums I've played this morning sound not so good. So it's time to start swapping stylus's and such.
As for amp gain, I found it subjective. Even after adjusting for a flat response, still too much bass for my taste.
Found the best gain balance by ear. The 700 and 400 driving the subs and woofers at the MiniDsp reference level of 0, and the 400 and 300 driving the mids and tweeters at a -1 setting. What the -1 setting represents I think is 1 dB input to the amps, and there is a audible change in brilliance there by dropping one digit lower.
Time to listen to music instead of sweeps, and work on getting the best out of the turntable.
Lots more to learn about REW, but enough of that for now.
CSN&Y.....So Far....
Best I've ever heard it.

 

[Mohawk]

This is supposed to be the Harman loudspeaker curve. But I'm finding it's too bass heavy to my liking. So, after more reading about curves and results, I'm going to recalculate and try a flat response as some suggest.
Deer Creek Audio has a better way to set delays. Works extremely well. Calibrate a tweeter to zero delay and measure all other active drivers against it. REW calculates the drivers individual delay automatically. Then plug the delay #s into your DSP and everything measured in the system is timed, even separate cabinets, against that one calibrated tweeter. Worked for my subs also.
https://deercreekaudio.com/tech-blog/f/using-delay-settings-to-integrate-your-audio-system

Thanks for that link !

REW can definitely make your head spin....

 

[George S.]

Yup, yur welcome.
Cranked the system LOUD last night as I was alone for a short while. Played some Kyuss.
I'm very impressed and happy how it turned out.
The sound is so clear and balanced at all volumes.
Now I'm on the fence about upgrading the 4X10HD. We'll see.

 

[Hexis22]

That's an awesome rack of vintage gear George.

Now that you have everything set and you're happy with the sound...

- Try pulling the speakers out into the room away from the walls
- At each first reflection point (side walls/ceiling) between the speakers and the listening position, place sound diffusers/absorbers panels
- Re-calibrate DSP

You know, all in the spirit of making it better... and driving the wife absolutely bat shit crazy! (I'm speaking from first hand experience here).

I've tried this process many times, when the wife and kids were out of town for the weekend, with stunning results.

 

[George S.]

Eric, those are very good ideas about pulling the speakers out and and treating the room. But it's just not gonna happen. Where they sit is a compromise I've made to keep peace.
And I totally agree about the room treatment. Running sweeps, the reflections and frequency peaks and nulls are very apparent and profound.
And, we have a futon partially blocking the right channel. Something I live with.
All in all I'm happy with the compromises made. She doesn't complain about the hobby and spins records now and then.
George from Oz, the retired soundman who's been absent from the forum once remarked about making the system sound excellent at low volumes.
I'm there system wise.
Now to find some speaker jacks for the amps that are deep enough to fully accept the dual bananas I'm using on the speaker wire.
I have a idea I'm going to test on a extra chassis.

 

[laatsch55]

Sounds ominous....

 

[Bob Boyer]

Ya'll have a white Christmas this year, Lee? I heard one of the Dakotas got hammered last night. 18" or so of snow. Would make for a fun Christmas day.

 

[laatsch55]

We got 2" Bob. Just right.

 

[Gepetto]

We got 2" Bob. Just right.

That is just right Lee...

 

[laatsch55]

Yep, cool for the kids with no attendant problems...

 

[George S.]

Sounds ominous....

Naw, going to look for banana sockets that accept the full length of a plug instead of binding posts that will only accept 1/2 the length. They need that 4-40 stud as I don't want to drill the DCP boards.
If they're doubles with that red or black spacer between them, well, that would be ideal.
I'll look tomorrow.
Now listening to well worn and scratched Skynyrd albums using different stylus's and tracking weights. Three skips on the present side. I'll add a quarter gram and replay. Make that four skips.

 

[Louie3]

Here ya go: https://www.amazon.com/s?k=banana+p...a+plug+sock,aps,94&ref=nb_sb_ss_ts-doa-p_2_16

 

[Gepetto]

Naw, going to look for banana sockets that accept the full length of a plug instead of binding posts that will only accept 1/2 the length. They need that 4-40 stud as I don't want to drill the DCP boards.
If they're doubles with that red or black spacer between them, well, that would be ideal.
I'll look tomorrow.
Now listening to well worn and scratched Skynyrd albums using different stylus's and tracking weights. Three skips on the present side. I'll add a quarter gram and replay. Make that four skips.

It is not a good thing when your banana only goes halfway in...