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Zilch's AK Design Collaborative - Econowave Speaker

Zilch said:
That's looking very good, Skywave; I rarely have the guts to post with a 5 dB scale. ;)

See what's happening to phase in the crossover region.
Click to expand...


Well, I know it looks bad...tarted it up unintentionally.

Here's min phase response. Don't know what it implies yet.
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If anybody has gotten the DE250 to work with the 6x6 waveguide, let me know. I tried for the hell of it. DE250 (purple) with D220.

I think I could use some of Geddes' notch filters.
 

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Any need (or advantage) to tweak the crossover to work with the 123A-1/2213H? I believe the 4311B and L100 use 1500 Hz and 2500 Hz for the low x-over. 2 ft^3 sealed box...may build 3-4 ft^3 boxes eventually.
 
Skywave's working on it. My own suggestion for a Zobel from a couple of years ago appears earlier in this thread. That was not with the eWave filters, tho. Once he comes up with an answer, I'll verify it here.... :yes:
 
Got the baffles cut! Got the PE order submitted! PH612's are in stock! Now have about 79 cents left in Paypal!

:banana: :banana: :banana:

Man, this project is taking forever! But, other than the instructions in this thread, I'm kinda making everything up as I go.

This is fun!
 
Dredging up OLD discussion...

Zilch said:
The variations between the two types of adapters are less than those between the two drivers themselves.

With respect to the diminished response at the extremes, there's nothing to be done about that above 18 kHz, but I'd probably be considering whether I need to tweak the basic highpass filter at the low end based upon the response in combination with the woofer(s). That's in the crossover region, and might actually be advantageous with a woofer having a peaked response there.

Again, whether these larger variations are the result of using throat adapters or not is indeterminate, and there are no horns or waveguides that are at once both bolt-on and thread-on to resolve that.

...
Click to expand...

Hows about taking the bolt-on adapter off of a 2426 so it could be threaded on, then putting it back on so you could use the bolt-to-threaded adapter?:scratch2:

And yes, you guys finally got me to order a waveguide and crossover parts this morning... Should be here next week, I'm going to set 'em up with 2205's redone as 2234's, should be fun! I also have a pair of 10's from the (REALLY) Large Advent 3-way Maestro's, but no cabinets for those yet. Need to find out what size they worked in sealed... (EDIT: 33.5X16X10 outside...)
 
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4343 said:
Hows about taking the bolt-on adapter off of a 2426 so it could be threaded on, then putting it back on so you could use the bolt-to-threaded adapter? :scratch2:
Click to expand...
Did that recently with XT1086, which has the requisite 3-bolt mounting.

Answer: The Selenium drivers, thread-on vs. bolt-on, measure differently. I should still have that data if I didn't already post it. No matter how we slice it, the geometries are different, and matter.... :yes:
 
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jhoyt said:
Got the baffles cut! Got the PE order submitted! PH612's are in stock! Now have about 79 cents left in Paypal!

:banana: :banana: :banana:

Man, this project is taking forever! But, other than the instructions in this thread, I'm kinda making everything up as I go.

This is fun!
Click to expand...
Yup, Yup- received mine (and the 220TIs) today! (just ordered from PE on Tuesday) I also just received a pair of 908-8B purchased off the Bay, (for my Altec Malibu project) so I'm stoked. Going to get a quickie version of the EV crossover on a breadboard tonight and see how these Altec 414-16E deal with a 2ft^3 ported SP-200 enclosure (they're used to a lot more breathing room in a 9844) Then let the testing begin!!
:music:
WOT
 
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Mo Zo

Zobel is not effective on standard EWAVE crossover using B&C DE250/QSC HF and JBL 123A-1 woofer.
The spread to accommodate the Selenium D220 lower range bump leaves a deficit in that range and cutting further is
not helping.

So here are FR measurements of standard EWAVE X-O and JBL 123A-1/Selenium D220/JBL 6x12 Waveguide and best of Zobels I have tried:
17uF/32Ohm. I think what this woofer really needs is a notch filter at the indicated frequency; I really want a narrow Q notch there.

Additionally, I found the best results with no Zobel and reversed connections to the HF as shown.
I see distortion rising at that peak, however.


Orange:
Sum/pos connection/no Zobel
Red:
Sum/rev connection/no Zobel
Blue:
Sum/rev connection/17uF/32 Ohm
attachment.php





Orange:
JBL 123A-1 raw
Green:
JBL 123A-1 on standard EWAVE X-O no HF
Red:
Sum/standard EWAVE X-O/no Zobel
Blue:
Sum/standard EWAVE X-O/17uF/32Ohm Zobel
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attachment.php

skywave-rider said:
I think what this woofer really needs is a notch filter at the indicated frequency; I really want a narrow Q notch there.
Click to expand...
Look where it's rolling off there: up at 2 kHz. It's playing too high, and the basic lowpass needs reworking to bring it down to 1.6 kHz or below. Add 3 uF across C2, making it 15 uF, and see what it does. That'll also knock down the peak.

Then, we'll see what needs to be done to bring the highpass down there, as well.... :yes:
 

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DE250 or D220 ?

Skywave ,

The 3 references to compression driver models are all over the map /

which one's actually being modelled ?

>< cheers :)

( never mind ;) , I see the edits now )


ps ; keep up the good work :thmbsp:
 
skywave-rider said:
Zilch.
Gaping maw...
Amazing how it just fits....
Click to expand...
Yes. I have also found that the eWave highpass for QSC/DE250 needs to be moved lower. The crossover is occurring up ~1.8 kHz; we gotta get that down to 1.6 kHz or below to widen the forward lobe. Also, 123A notwithstanding, the range of larger woofers that'll play competently up to 2 kHz is limited.

Brandon's at 1.3 kHz, but our C/C distance is a bit shorter, so we may be able to stay with eWave standard 1.6 kHz.... :yes:
 
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From the AVS forum:

jrbrodie77 said:
Hi Guys,

My names is John Brodie, I am a Loudspeaker Engineer for QSC Audio and I designed the horns that you guys are using. Just thought I would say 'Cool Stuff' and make a few comments. First off, the primary role of our service parts store is for supporting QSC products, although we are aware that a few people are buying the parts for DIY. Provided that the numbers are small, buying a few parts shouldn't be a problem. Please be aware that we don't stock huge quantities of each part. QSC prides itself on being a good citizen within the audio world and "doing things right", but the amount of support we can give this kind of project is obviously limited (but I couldn't help chime in).

A few notes regarding the HPR horns and DIY in general:

- All of our components are designed for use in very specific products. We have the luxury of designing and selecting all of the components as a system. For instance, in the HPR series, we have precise control over the EQ, crossover and limiting on each driver's band. This systems approach yields great results, but the individual components might be harder to use for DIY than parts that are designed expressly for DIY use. It's a good idea to buy the SC-2150 crossover and matching drivers and horns. NONE of our crossovers are even close to 'off-the-shelf', they are all designed using lab measurements, good software and many hours of listening. Don't expect to drop in a stock catalog crossover and get good results.

- We buy drivers from several manufacturers, including Celestion. A few of these drivers are standard catalog parts, but most of them are designed by our in-house transducer experts. 100% of the drivers that we use are measured at the end of the production line and checked against rigorous standards.

- Buy some measurement equipment. Given the choice between 1000$ in parts and no measurement capability, or 200$ in parts and 800$ to spend on a microphone and analyzer (and books). The analyzer, combined with proper knowledge and skill will win every time (and be more fun). CLIO, Praxis etc. will all get you there with a little practice.

Best regards,

John Brodie
QSC Audio Products
Click to expand...

http://www.avsforum.com/avs-vb/showthread.php?p=17354864#post17354864
 
Very cool QSC even bothered to chime in on a DIY
But basically he's saying there's a limit to how many horns they will sell to non-QSC speaker owners. Or did I read him wrong?
WOT
 
I believe he's saying they are pleased and proud to support DIY, but don't want anybody buying parts in quantity to build "product" for resale.
 
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