Zilch's AK Design Collaborative - Econowave Speaker

[DonQuixote99]

Hi y'all. I'm pondering e-waving a set of RCA Dimensia 500s. This suggests itself because one of the OE tweeters is bad, and they aren't making any more.... But the woofers and the cabs are very good looking:

Anyway, they are basically 3-way acoustic suspensions, with very seeming-good woofers--cast aluminum baskets, polished fronts, carbon fiber cones, etc. Question is, can they go high enough? Can't tell much by testing, they need new surrounds. Model number is W2563A, just in case they're in a database somewhere....

Here's what I can get from inspecting the stock crossover:

I'm not sure, but seems to me these values indicate a cross from woofer to midrange somewhere under 1000 Hz. True?

 

[kagey]

Has anyone used the Dayton Audio DATS, (Dayton Audio Test System)?

I bought one and it seems to work very well. Setup and calibration is pretty easy. Can't really testify to T/S accuracy but when measuring coils and caps the results agree to better than 1% with a Stanford Research 715.

I made the mistake of connecting it to the output of an amplifier and immediately blew up 2 smd chips inside the DATS. They were cheap but a big pain to replace. Instructions warn against connecting to an amp or any ground and tell you what happens if you do......warranty is voided.

 

[Kegger]

Do you think it was the ground that hosed it or to high an output from the amp?

 

[Kegger]

Hi y'all. I'm pondering e-waving a set of RCA Dimensia 500s. This suggests itself because one of the OE tweeters is bad, and they aren't making any more.... But the woofers and the cabs are very good looking:


Anyway, they are basically 3-way acoustic suspensions, with very seeming-good woofers--cast aluminum baskets, polished fronts, carbon fiber cones, etc. Question is, can they go high enough? Can't tell much by testing, they need new surrounds. Model number is W2563A, just in case they're in a database somewhere....

Here's what I can get from inspecting the stock crossover:

I'm not sure, but seems to me these values indicate a cross from woofer to midrange somewhere under 1000 Hz. True?

I would say you got nothing to loose to try it out with them there. :thmbsp:

Also if it were me I'd consider flipping the cab upside down, an mounting
the waveguide between where the woofer and floor are now, that would
get the woofer/waveguide placement closer to ear height/higher I'd think.

Also looks like then putting the grill back on would cover all the drivers but
let the waveguide be open at the top, might look pretty clean like that.
(wouldn't need to remove any of the old drivers and or fill any holes either)

 

[Sir.Byrd]

Hi y'all. I'm pondering e-waving a set of RCA Dimensia 500s. This suggests itself because one of the OE tweeters is bad, and they aren't making any more.... But the woofers and the cabs are very good looking:

Anyway, they are basically 3-way acoustic suspensions, with very seeming-good woofers--cast aluminum baskets, polished fronts, carbon fiber cones, etc. Question is, can they go high enough? Can't tell much by testing, they need new surrounds. Model number is W2563A, just in case they're in a database somewhere....

Here's what I can get from inspecting the stock crossover:

I'm not sure, but seems to me these values indicate a cross from woofer to midrange somewhere under 1000 Hz. True?

You sure that the positive feeds from that side of the L1?

 

[DCinDC]

good catch Sir!

 

[DonQuixote99]

You sure that the positive feeds from that side of the L1?

Right you are. Fixed the drawing above.

Does make more sense that way....

 

[dumptruck]

Looks like it'd be somewhere around 300Hz on the woofer.

 

[DonQuixote99]

I would say you got nothing to loose to try it out with them there. :thmbsp:

Also if it were me I'd consider flipping the cab upside down, an mounting
the waveguide between where the woofer and floor are now, that would
get the woofer/waveguide placement closer to ear height/higher I'd think.

Also looks like then putting the grill back on would cover all the drivers but
let the waveguide be open at the top, might look pretty clean like that.
(wouldn't need to remove any of the old drivers and or fill any holes either)

Well, I can do some experiments. I'll hook up one of those woofers in one of my HPM-100s some kind of way. That will cross them at 3000. Be interesting to see what they sound like.

I was figuring upside-down, but I don't think I'd want to put the grill on that way. I think those woofers are too good looking to cover up. Prob. can make plugs for the MR and tweeter holes with material cut out for the waveguide.

 

[DonQuixote99]

Looks like it'd be somewhere around 300Hz on the woofer.

As low as that? Drat.

 

[4343]

As low as that? Drat.

Still need to try it without the crossover or with an ewave crossover to see what it can do. Sometimes a woofer _could_ be used as a 2-way, but what it ended up in was a 3-way.

 

[DonQuixote99]

Well, did an experiment, and I'm encouraged enough to try another one.

What I did was mount the 550T woofer in an HPM 100, on a cardboard baffle adapter, like this:

Given that the driver, when I tried it out, pretty much sounded like it was playing on a tabletop, this is an idea I won't try again. But it played 1000 and 2000 Hz test tones at equal-sounding volume, and clearly. So I'll try playing it without a crossover in it's own cabinet, as the next experiment.

Of course the surround is crumbling on this woofer, so that will mess it up some....

 

[apurcell22]

Hello all
I am looking to finally getting ready to start on a pair of econowaves. I have a pair of seos 12's and a pair of denovo DNA-360 compression drivers. I am thinking of building as a 2.5 way design using the Dayton classic 12's to increase sensitivity. Is this a good idea? Can anyone help with the crossover? Thanks in advance
Al

 

[skywave-rider]

Hello all
I am looking to finally getting ready to start on a pair of econowaves. I have a pair of seos 12's and a pair of denovo DNA-360 compression drivers. I am thinking of building as a 2.5 way design using the Dayton classic 12's to increase sensitivity. Is this a good idea? Can anyone help with the crossover? Thanks in advance
Al

I read a good argument from Wayne Parham against 2.5 way designs. I'll try to find where and link to it.. It was bound up in the multisub concept IIRC.

 

[dumptruck]

2.5-way doesn't give you any more sensitivity, it just extends bass response (unless there's some kind of 2.5-way flavor I'm not aware of?). 2-way with dual woofers gives you +3(ish)dB, but spoils the polar response.

 

[Kegger]

Actually 2.5way "can" give you more sensitivity to a degree.

What happens is generally the extra woofer just has an extra coil on it with a 6db slope
compared to the other woofer at "cutoff" frequencies so it does add to the other above
the cutoff some as it rolls off, then of'course boosts the frequencies below the X cutoff
to raise the efficiency off those extreme lows..

Try it in an xover designer program and you'll see even the frequencies above the xover
point raise the sensitivity there as the woofer rollsoff from the 6db slope created with it.
(myself I like .5 ways on high sensitivity woofers, as they tend to rolloff early, can help)

You can also get increased sensitivity by not incorporating baffle step correction instead
using the second woofer to do it so no "loss" in sensitivity in that regard.

 

[skywave-rider]

Update

I received all 3 crossovers from DigitalChris, and measured capacitance for C-3 and C-1 which are in spec:
Crossover A:
C3: .473uF
C1: 3.31uF
Crossover B:
C-3: .473uF
C1: 3.28uF
Crossover C:
C-3: .468uF
C-1: 3.31uF

This is for EWave Standard kits.
I will be doing the FR sweeps today or tomorrow. Chris also sent me his mic and I'll check that out too with the same cal file he is using.

Chris built a super nice home theater, so let's help get the HF running right.
Here's his build thread:
http://www.avsforum.com/t/1290765/shh-no-talking-home-theater

 

[skywave-rider]

Since DigitalChris sent me his mic and cal file in addition to all 3 XO boards, I wanted to compare measurement mics to get a baseline. Chris, I would say that at the least, your mic is off cal, and I think the measurements with my mic show the crossovers are working well and as designed in the HF. I don’t have your drivers however, that’s another variable. But all things being equal, nice job on the XO build, and I think you are good to go.

I switched to 1/12 octave smoothing to try to get closer to Digital Chris’ measurements. All measurements done with DigitalChris' EWave Standard Kit XO boards. Driver is D220Ti and WG is standard JBL EWaveguide.

Image #1:
Mic comparison showing DigitalChris’ mic and CAL file, GREEN, my Cross Spectrum Labs mic, ORANGE, and Chris’ mic using the Cross Spectrum cal file, BLUE. I tried Chris’ mic with a Dayton cal file and another generic ECM file I had, but the CSL file brought his mic closest to my readings. Chris, I can send you that file if you want to try it with your mic. It’s pretty close except for the very top.

Image #2/3/4:
Used my CSL mic/1 meter/LPad set to middle:
XO A also w/ LPad set to max:

XO B:

XO C:

I’ll be sending the stuff back tomorrow unless you want me to try something else. And sorry for the delay on this, I didn’t realize I needed an LPad and had to dig one out of my storage locker.

 

[DigitalChris]

Thanks for doing those measurements Skywave. I am a bit confused though, your graphs seems to do very well, the upper end is an incline when mine decle, but my x-over boards and mic are acceptable. Why do my drivers act so different? I'm really starting to think it's the AVR.. Am I missing something here?

Either way, I don't think there's anything else you can do, you proved out my boards and MIC, you can send those back at your convenience

I will take that CAL file if you don't mind as well, thanks!

 

[skywave-rider]

DigitalChris,
I think the new Cal file will make up at least some of the difference in your measurements. If you have an opportunity to borrow a basic amp, just to compare, that might be good. I have a tiny Tripath TA2020 based chip amp I could jam into the box. Might be good to compare. Let me know.

On my graphs with the D220Ti driver, the last incline is the breakup, and the smoothing tends to make it look more like a ramp up as opposed to a sharper peak.

Thanks for doing those measurements Skywave. I am a bit confused though, your graphs seems to do very well, the upper end is an incline when mine decle, but my x-over boards and mic are acceptable. Why do my drivers act so different? I'm really starting to think it's the AVR.. Am I missing something here?

Either way, I don't think there's anything else you can do, you proved out my boards and MIC, you can send those back at your convenience

I will take that CAL file if you don't mind as well, thanks!