Make a zip or rename the files to txt.
Generally, if the phase does not match, you either have to increase the order of a filter or you have to try another crossover frequency. 3rd order at 2 kHz is a bit low for the XT25.
Yes, an extra order on the tweeter might help. Is your acoustic phase data measured from a useful and relative distance from each driver?
I don't know if you are aware of the time lock feature in Holm.
1. Basically, you fix the mic position on the design axis. The axis along the midpoint between two drivers is a good choice because the vertical lobe will be symmetrical about this axis. Once you set the mic on this axis, don't move it through the whole process.
2. Measure the tweeter (or woofer) as a causal impulse.
3. Then use the "last detected impulse" in Holm and measure the woofer.
By time-locking on one of the driver's impulses, you will get the phase of the drivers relative to each other. Then just export the FRDs with phase and import into PCD. Adjust crossover frequency and filters to get phase overlap through the crossover.
1. Basically, you fix the mic position on the design axis. The axis along the midpoint between two drivers is a good choice because the vertical lobe will be symmetrical about this axis. Once you set the mic on this axis, don't move it through the whole process.
2. Measure the tweeter (or woofer) as a causal impulse.
3. Then use the "last detected impulse" in Holm and measure the woofer.
By time-locking on one of the driver's impulses, you will get the phase of the drivers relative to each other. Then just export the FRDs with phase and import into PCD. Adjust crossover frequency and filters to get phase overlap through the crossover.
You don't think to mention what bass unit you are using here, which tells me that you are new to this. 😀
IF it is an 8 inch paper unit and 1" tweeter, you face peculiar difficulties with a simple filter since an 8 inch bass rolls off fast, and a fabric dome tweeter doesn't.
Most successful speakers of this style on simple crossover used a mylar tweeter. There are good reasons for this, mostly to do with phase on a flat baffle. I give an example below of how it SHOULD be done. 😎
IF it is an 8 inch paper unit and 1" tweeter, you face peculiar difficulties with a simple filter since an 8 inch bass rolls off fast, and a fabric dome tweeter doesn't.
Most successful speakers of this style on simple crossover used a mylar tweeter. There are good reasons for this, mostly to do with phase on a flat baffle. I give an example below of how it SHOULD be done. 😎
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First point since you didn't post it is do you have the x, y and z offsets for the woofer correctly inputted?
Second point is that XT25 isn't too happy crossing that low. See Zaph|Audio - ZD5 for some good do's and don't's with this tweeter.
Second point is that XT25 isn't too happy crossing that low. See Zaph|Audio - ZD5 for some good do's and don't's with this tweeter.
Thank you everyone.
System7, you are correct, I am fairly new at this.
This is a 6.5'' woofer that I got at a swap meet. The cone is kevlar.
I thought that the tweeter would be good at 2,000 Hz. because of its low fs.
Should I be considering another tweeter?
System7, you are correct, I am fairly new at this.
This is a 6.5'' woofer that I got at a swap meet. The cone is kevlar.
I thought that the tweeter would be good at 2,000 Hz. because of its low fs.
Should I be considering another tweeter?
Something to think about if the woofer can't go high enough.
Here would be my 1st choice, easy to work with, good price.
The Madisound Speaker Store
Here would be my 1st choice, easy to work with, good price.
The Madisound Speaker Store
On second thought, might be better off looking for new woofers -
Did you happen to see this? Posted (re-posted) last night:
www.audiocircle.com/index.php?topic=42558.0
http://gr-research.com/m165xwoofer.aspx
Did you happen to see this? Posted (re-posted) last night:
www.audiocircle.com/index.php?topic=42558.0
http://gr-research.com/m165xwoofer.aspx
I think the woofer is good.
An externally hosted image should be here but it was not working when we last tested it.
Ok, your PCD offsets look correct.
Next question is have you tried reversing the tweeter polarity?
Also, do you have the frequency response graph for that woofer, especially something that includes the off-axis responses?
Next question is have you tried reversing the tweeter polarity?
Also, do you have the frequency response graph for that woofer, especially something that includes the off-axis responses?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Back to OP and the 2K point; take a look here, MS uses this tweeter in a kit xo-ed over at 2,500. I would go any lower than that. (mechanical buzz sound).
One good thing about the XT25, its a "standard size" you can always replace it with something that goes lower - e.g. ScanSpeak.
The Madisound Speaker Store
Crossover Schematic and Graphs
One good thing about the XT25, its a "standard size" you can always replace it with something that goes lower - e.g. ScanSpeak.
The Madisound Speaker Store
Crossover Schematic and Graphs
AllenB is correct, your only solution for phase is to modify the order of your networks.
Looks like you are about 60-70 degrees apart. Increasing either woofer or tweeter one order would be about enough to bend tweeter phase up or woofer phase down the right amount. Otherwise decrease order by one and flip the tweeter polarity.
David S.
Looks like you are about 60-70 degrees apart. Increasing either woofer or tweeter one order would be about enough to bend tweeter phase up or woofer phase down the right amount. Otherwise decrease order by one and flip the tweeter polarity.
David S.
The XT 25 is a very tough tweeter to work with.... It has no ferrofluid in the gap, and mostly because of that (also due to its badly damped resonance chamber) its low end response can be terrible, both frequency, and phase-wise. Unless you use an impedance correction network, right before the tweeter. One possible solution is on the picture, but you still should use 2nd or 3rd order network at minimum 2 kHz. The 16uF cap on the drawing is a bit idealistic, it should rather be around 8-10 uf (max). You can also try carefully remove the resonance chamber, and fill it densely with wool.
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I find most tweeters need a LCR when crossed near 2kHz. I normally use 18dB/oct, sometimes resorting to 24dB/oct if necessary.
Below is my network for the XT25SC90 (2,250Hz || 18dB/oct). More information can be found at SWIFT-II.
Regards
Mike
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If you have already purchased the XT25's, you can probably keep them but raise the xo a little to around 2500Hz and use an impedance flattening LRC circuit. But you are going to also have to watch out for the woofer's peaking response above 4000Hz. You may need to raise that xo order as well.
If you haven't bought them, then you might want to consider a tweeter that is more comfortable crossing around 2000Hz.
If you haven't bought them, then you might want to consider a tweeter that is more comfortable crossing around 2000Hz.
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