Zilch's AK Design Collaborative - Econowave Speaker

[ROSSO]

Well, I THINK this is right:

Re: http://audiokarma.org/forums/showpost.php?p=2018478&postcount=615 the CC schematic: R5 and R3 are shown as "1.5M" Capital "M" = megaohm here?

 

[Zilch]

Re: the CC schematic: R5 and R3 are shown as "1.5M" Capital "M" = megaohm here?

Yes. Anything between 1.0 and 2.2 Meg is fine, actually.

 

[Bauhausler]

Okay, I measured something with the microphone.

NOW are you happy?

Finally found the connectors and made a 30' mic cable. This is the pink noise response of:
AR3 cab/woofer
Kef B110 mid
D220Ti/PH612
Econowave crossover.

I'm pretty sure the 160 hz suckout and 80 hz peak are room effects.

 

[jackgiff]

NOW are you happy?

Finally found the connectors and made a 30' mic cable. This is the pink noise response of:
AR3 cab/woofer
Kef B110 mid
D220Ti/PH612
Econowave crossover.

I'm pretty sure the 160 hz suckout and 80 hz peak are room effects.

Hey Ross, looks like you are well on the way to doing that DE250 project.

Just need to re-prioritize a few things. :thmbsp:

 

[Zilch]

NOW are you happy?

Very much so. Kick the resolution down a notch to 30 dB full scale.

It looks like major rolloff at the VHF but is only 2.5 dB, in fact. It's rare I use that high a res, and I believe Jack and Skywave will suggest the same, though Todd may disagree.

Your whole gang there needs to get with measuring, in my view. There's plenty of design skills to unleash in the neighborhood.

Notch at 3K15 may indicate a polarity inversion. Flip it and see what happens.... :yes:

 

[Bauhausler]

Very much so. Kick the resolution down a notch to 30 dB full scale. It looks like major rolloff at the VHF but is only 2.5 dB, in fact. It's rare I use that high a res, and I believe Jack and Skywave will suggest the same.... :yes:

Kidding, of course. I finally found an hour to fool with this as an appointment was delayed. I'm looking forward to the learning curve on this. No pun intended.

I don't know about that rolloff. Could it be the cable? I used the longest thing I had, which was some Carol with 2 26ga conductors and shield. Shield to ground, red to hot and black to cold. 30 ft seems long for a cable but I see longer ones sold.

For grins I swapped in the JBL 2414H on the 6 X 6 waveguide. The HF dropped off a cliff starting at 8K. I was amazed. The compensation for this combo will be nothing like the D220TI/PH612.

 

[Zilch]

I don't know about that rolloff. Could it be the cable?

Mine's ~20 ft; I never tried any longer.

I presume you're measuring with just one speaker running at 1 - 2M on tweeter axis? It's possible to do it with both L & R at once, but there's a trick to that.... :yes:

 

[Bauhausler]

Very much so. Kick the resolution down a notch to 30 dB full scale.

It looks like major rolloff at the VHF but is only 2.5 dB, in fact. It's rare I use that high a res, and I believe Jack and Skywave will suggest the same, though Todd may disagree.

Your whole gang there needs to get with measuring, in my view. There's plenty of design skills to unleash in the neighborhood.

Notch at 3K15 may indicate a polarity inversion. Flip it and see what happens.... :yes:

Everything looks better with lower resolution!

I threw in a notch filter consisting of 25uf/25 Ohms/ 0.85mh to take down a peak tha twas appearing around 1250 hz.

Looks pretty good. The crossover to the AR woofer is around 100 hz.

 

[Zilch]

Looks pretty good.

I believe you've already told us it sounds good, too.

This is FUN stuff! :thmbsp:

 

[Bauhausler]

Mine's ~20 ft; I never tried any longer.

I presume you're measuring with just one speaker running at 1 - 2M on tweeter axis? It's possible to do it with both L & R at once, but there's a trick to that.... :yes:

It's a big room and I'm measuring the left speaker only, in listening position.

I should choose a position nearer the Behringer so I can see the display as I move the mic around. Changing the mic position easily shows the crossover nulls.
It's also useful to shift teh driver positions and see the nulls from time alignment change. This stuff is trickier than I would have thought.

I hooked up an Altec Bolero cabinet with 406Y driver and passive to the ewave crossover with the D220Ti/PH612 on top. It went to 40 hz really flat and the top end integrated beautifully. This is a super sounding combination. The deeper Altec driver is easier to time align with the top end. I might end up listening to this for a while. It helps that the woofer comes very close to the edge of the cabinet when stood on end, giving a realistic listening height when on a 12" stand.

***
*edit - much later
***

LIstening to The Arcade Fire's album Neon Bible on mono with a little boost in the bottom octaves after several Guinesses. This is a great setup and probably still will be after we sober up. I wish I knew what made this woofer sound so good when there's no objective reason why it should.

 

[jrock7]

Zilch, or anyone, have you ever tried crossing the D220ti at 3.5khz instead of 3khz, would there be any much difference in sound, could it work like that? (3.5khz xover)

 

[Bauhausler]

Zilch, or anyone, have you ever tried crossing the D220ti at 3.5khz instead of 3khz, would there be any much difference in sound, could it work like that? (3.5khz xover)

The actual acoustic crossover point with the D220TI/PH612 combination and Ewave crossover is 1600 hz or 2K - I forget exactly. The electrical crossover point of the high pass is higher than 2K because the driver/waveguide combination has rising response in the crossover region. If you change the electrical crossover point you have to take into account the actual output of both drivers in the crossover region and chose the slopes for flattest response. It's possible, of course, to change this but it's not a trivial exercise.
You can use a higher acoustic crossover point but it would shift more of the midband to the LF driver. Typically, the waveguide has better dispersion in that region than a woofer does. The effect is that the midrange could become more beamy if more of it comes from teh woofer.

Does that address your question?

 

[jrock7]

Ok Bauhausler, so even with a zobel on the woofer , would it work better that way. And coming from the woofer I dont think it would be beamy either, (from the HF horn it sounds really loud and beamy, thats what I want to tone down a little more)

 

[Russellc]

NOW are you happy?

Finally found the connectors and made a 30' mic cable. This is the pink noise response of:
AR3 cab/woofer
Kef B110 mid
D220Ti/PH612
Econowave crossover.

I'm pretty sure the 160 hz suckout and 80 hz peak are room effects.

Nice! If I remember right you have the DEQ 2496 right?
Russellc

 

[Russellc]

Very much so. Kick the resolution down a notch to 30 dB full scale.

It looks like major rolloff at the VHF but is only 2.5 dB, in fact. It's rare I use that high a res, and I believe Jack and Skywave will suggest the same, though Todd may disagree.

Your whole gang there needs to get with measuring, in my view. There's plenty of design skills to unleash in the neighborhood.

Notch at 3K15 may indicate a polarity inversion. Flip it and see what happens.... :yes:

Zilch, when you guys speak of "resolution" here is this some setting on the DEQ 2496 that is being refered to?

Russellc

 

[Zilch]

Ok Bauhausler, so even with a zobel on the woofer , would it work better that way. And coming from the woofer I dont think it would be beamy either, (from the HF horn it sounds really loud and beamy, thats what I want to tone down a little more)

Put an L-pad in there and determine how much additional HF attenuation you need to balance.

What driver/waveguide combination are you talking about, and which crossover are you using? It's unlikely any "beaminess" is coming from the HF.

Zilch, when you guys speak of "resolution" here is this some setting on the DEQ 2496 that is being refered to?

Yes. Compare the two curves, and you'll see Ross has changed the vertical scale from 2.5 dB per divsion to 5 dB, i.e., lower resolution.... :yes:

 

[Russellc]

It's a big room and I'm measuring the left speaker only, in listening position.

I should choose a position nearer the Behringer so I can see the display as I move the mic around. Changing the mic position easily shows the crossover nulls.
It's also useful to shift teh driver positions and see the nulls from time alignment change. This stuff is trickier than I would have thought.

I hooked up an Altec Bolero cabinet with 406Y driver and passive to the ewave crossover with the D220Ti/PH612 on top. It went to 40 hz really flat and the top end integrated beautifully. This is a super sounding combination. The deeper Altec driver is easier to time align with the top end. I might end up listening to this for a while. It helps that the woofer comes very close to the edge of the cabinet when stood on end, giving a realistic listening height when on a 12" stand.

***
*edit - much later
***

LIstening to The Arcade Fire's album Neon Bible on mono with a little boost in the bottom octaves after several Guinesses. This is a great setup and probably still will be after we sober up. I wish I knew what made this woofer sound so good when there's no objective reason why it should.

Very cool Bauhausler! :thmbsp: I am so envious, and have got to obtain one of these devices! I'm going to have to decide which of the many projects I've had on tap I can get rid of to finance one of these!

Russellc

 

[Russellc]

Put an L-pad in there and determine how much additional HF attenuation you need to balance.

What driver/waveguide combination are you talking about, and which crossover are you using? It's unlikely any "beaminess" is coming from the HF.

Yes. Compare the two curves, and you'll see Ross has changed the vertical scale from 2.5 dB per divsion to 5 dB, i.e., lower resolution.... :yes:

This IS very cool. I need one of these, or at least the mic. I would need that anyway, I do have True RTA installed and could maybe get by, but I think there's more people out there who have tackled the learning curve of the DEQ 2496 device, and that would be good support to have.

Russellc

 

[Bauhausler]

This IS very cool. I need one of these, or at least the mic. I would need that anyway, I do have True RTA installed and could maybe get by, but I think there's more people out there who have tackled the learning curve of the DEQ 2496 device, and that would be good support to have.

Russellc

The mic requires +15VDC for its internal amplifier. The DEQ2496 provides this. I don't know what kind of mic pre other people are using who use the mic ($50) without the DEQ2496.

 

[Russellc]

I figure by the time I get phantom power and a mic, pre amp etc, I just of well as got the DEQ 2496. I'm planning.:scratch2:

russellc