JBL 3-Ways

[cjwebber]

I figured I would share what I have been working on for a few months!

Woofer: D140f
Midrange: 375 w/Smith Repro (THANKS LEE!!!)
Tweeter: 075

Custom built crossover at 500hz and 7000hz. I know 500 is lower than the recommended. I experimented with both 500 and 800 with my electronic crossover, and 500 just seemed right to me...I may receive some flack for that.

I am hoping to get a stand for the 375 once I save up some more money. I know Lee has some pretty ones...

I am also saving for a DAC.

These are being driven by a modest Jolida FX-10 and I can truly say I am blown away by the detail, accuracy, and smiles that these new speakers give me. My wife even said, "Wow, it sounds like we're at their concert!"

Can someone point me in the right direction on where each component should be placed in relation to the others? I don't quite understand phasing...596885968959690

[hjames]

Component placement?-
For the best imaging, you want to time-align all 3 drivers -
you should get the front of the voice-coils in the same vertical plane ...
Think of where the diaphram is in the bullet tweeter, in the 375 on the smithhorn, and in the woofer.

Of course, thats means the ducklips would stick out well past the front of the cabinet
to line the 375's diaphram up with the front of the voicecoil in the woofer ...
- you'd need to make sure everything is well supported.

Note that I do NOT do that with my 3 ways ...
but I do know it would sound better if I did ...

[NickH]

Depends if Lee made a exact copy of the 2397 or not. Worse case scenario your 375's are running un loaded down around 500hz. It will cause distortion at worse it can cause over excursion of the diaphragm and premature failure.

Personally I run my jbl 2" drivers at 800hz. I've tried 500 but went back to 800.

But that's very nice work you've done. Did you design the crossover yourself?

You should be quite happy with them, I sure would be.

Nick

Off topic, what beer is that on your desk? The bottle look like a red stripe bottle with a different label.

[cjwebber]

But that's very nice work you've done. Did you design the crossover yourself?

You should be quite happy with them, I sure would be.

Nick

Off topic, what beer is that on your desk? The bottle look like a red stripe bottle with a different label.

Thank you. I had a gentleman in California design and build them for me. A friend of a friend.

Diabolical IPA by North Peak

[NickH]

Thank you. I had a gentleman in California design and build them for me. A friend of a friend.

Diabolical IPA by North Peak

I've yet to find an IPA I like. But thanks for letting me know. I'll have to try and find some.

Nick

[cjwebber]

I've yet to find an IPA I like. But thanks for letting me know. I'll have to try and find some.

Nick


IPAs are my favorite :) The more hops the better for me!

[NickH]

IPAs are my favorite :) The more hops the better for me!

Im more of a lager man. The only really hoppy beer I like is imperial stout. But Ill try any beer. Im a beer junky. The darker the better for me. But I draw the line at barley wine. Bad memories, LOL.





What type of crossover circuit did you use? I used 2nd order linkwitz riley for mine. Im very happy with it. I tried to keep it as simple as possible.


Nick

[Lee in Montreal]

As was mentionned, 500Hz is perhaps a bit low. 2397s are usually crossed around 800Hz. Even the much bigger 2350 has a hard yime going down to 500Hz. But damn, am I impressed by how "period looking" your appartment is. Definitely feels like early 1960s. Furnitures and accessories are all there. Congrats on your good tastes... ;)

In regard of the time alignment, it will be difficult to do when introducing passive filters between amp and drivers. Caps and coils tend to shift the phases. It will basically be done by hear. Aligning diaphragms/cones won't work. But if donw properly, it will clean-up the sound.

[Chas]

But damn, am I impressed by how "period looking" your appartment is. Definitely feels like early 1960s. Furnitures and accessories are all there. Congrats on your good tastes... ;)


Looking at the pictures, I get the feeling that Kennedy is still the president......weird!:D

[cjwebber]

I've been chewin' on this 500 vs 800. I think I may have to go to 800.
should've consulted the forum instead just my own thoughts :blink:

I've sent an email to the guy who made the crossovers asking for a schematic and direction on how to switch it to 800hz. Should this be relatively easy? I am completely ignorant when it comes to that kind of stuff...

In regards to your compliments for our house...thank you :) I am definitely stuck on 50s/60s design and snatch up whatever I can on craigslist and thrift stores.

[macaroonie]

I've been chewin' on this 500 vs 800. I think I may have to go to 800.
should've consulted the forum instead just my own thoughts :blink:

I've sent an email to the guy who made the crossovers asking for a schematic and direction on how to switch it to 800hz. Should this be relatively easy? I am completely ignorant when it comes to that kind of stuff...

In regards to your compliments for our house...thank you :) I am definitely stuck on 50s/60s design and snatch up whatever I can on craigslist and thrift stores.


FWIW I landed up at 600 ish using large format mid. 800 seems to leave too much in the bass driver ( 2235 in my case ) causing some ' darkness ' in that area. I'm active so its easy to dial it in but over time I gradually drifted the turnover downwards. Below that it does mess up somewhat.

YMMV as always

[hardtime]

I am sure that it will be great once you EQ for the room. There are a lot of hard surfaces in the picture.
Many new consumer amps come with a mic and will automatically EQ for the room.

[Mr. Widget]

I've sent an email to the guy who made the crossovers asking for a schematic and direction on how to switch it to 800hz. Should this be relatively easy? I am completely ignorant when it comes to that kind of stuff...
Changing the crossover frequency will require a fair amount of rework...

I find holes in frequency response preferable to bumps... and harshness the most annoying. I liked the 2397 and Westlake horns best at 1200Hz in a four way, but you can probably be pretty happy with your components at a lower crossover frequency.

Yeah, where is the Kennedy portrait? :D


Widget

[ivica]

Changing the crossover frequency will require a fair amount of rework...

I find holes in frequency response preferable to bumps... and harshness the most annoying. I liked the 2397 and Westlake horns best at 1200Hz in a four way, but you can probably be pretty happy with your components at a lower crossover frequency.

Yeah, where is the Kennedy portrait? :D


Widget

http://www.audioheritage.org/vbulletin/showthread.php?5951-Wood-Horn-3-way&p=58582&viewfull=1#post58582


http://www.audioheritage.org/vbulletin/showthread.php?3849-JBL-2397-Curves&p=263329&viewfull=1#post263329

one figure or hundred words....thanks to Mr.Widget

regards
ivica

[badman]

Component placement?-
For the best imaging, you want to time-align all 3 drivers -
you should get the front of the voice-coils in the same vertical plane ...
Think of where the diaphram is in the bullet tweeter, in the 375 on the smithhorn, and in the woofer.




In regard of the time alignment, it will be difficult to do when introducing passive filters between amp and drivers. Caps and coils tend to shift the phases. It will basically be done by hear. Aligning diaphragms/cones won't work. But if donw properly, it will clean-up the sound.

I agree with Lee here- lining up the voice coils is not inherently a time-aligned speaker. The acoustic center of a horn tends to be a little bit down the length of the horn, from what I've seen, and as mentioned, the crossover really throws it for a loop. Small changes make a big difference here- just tweak it back and forth until it sounds right- use the stand up and sit down test to judge any lobing from the XO, unless you have a mic, which is an even better way to do it.

[Dan]

I've been chewin' on this 500 vs 800. I think I may have to go to 800.
should've consulted the forum instead just my own thoughts :blink:

I've sent an email to the guy who made the crossovers asking for a schematic and direction on how to switch it to 800hz. Should this be relatively easy? I am completely ignorant when it comes to that kind of stuff...

In regards to your compliments for our house...thank you :) I am definitely stuck on 50s/60s design and snatch up whatever I can on craigslist and thrift stores.

Going active 3-way using MiniDsp is good way to go. It can do time alignment, parametic EQ, selectable x-over slopes, gain. Connects to your laptop via USB.

Tripath amps from Hifimediy are cheap and sound great.

Dan

[4313B]

I agree with Lee here- lining up the voice coils is not inherently a time-aligned speaker. The acoustic center of a horn tends to be a little bit down the length of the horn, from what I've seen, and as mentioned, the crossover really throws it for a loop. Small changes make a big difference here- just tweak it back and forth until it sounds right- use the stand up and sit down test to judge any lobing from the XO, unless you have a mic, which is an even better way to do it.
Well, we understand her gist. JBL did "time-align" their L220 and L250 systems, as well as the XPL Series, among others, granted all direct radiator systems. Horns do add a degree of complexity, delt with as you describe.
Going active 3-way using MiniDsp is good way to go. It can do time alignment, parametic EQ, selectable x-over slopes, gain. Connects to your laptop via USB.

Tripath amps from Hifimediy are cheap and sound great.

DanHave you played around with their mic offering along with REW?

[Dan]

[Have you played around with their mic offering along with REW?[/QUOTE]

I haven't tried thier Mic.

Dan

[Lee in Montreal]

Any digital crossover has an alignment function. It a few minutes it delays drivers and you get everything in phase.

[ivica]

Going active 3-way using MiniDsp is good way to go. It can do time alignment, parametic EQ, selectable x-over slopes, gain. Connects to your laptop via USB.

........Dan

It has to be aware that ordinary digital either analog networks have different time delay concerning the frequency, so if really time alignment want to be get much more complicated tools have to be applied. As I have remembered miniDSP used bi-quad IIR filter which are not "constant group delay" compensated types, but with more work (measurements and drivers movements) quite good results can be get,

Regards
ivica