Eton 8.1 cross-over confusion

Jimmy154 · 12th February 2004, 03:44 PM

I have purchased a pair of Eton 8-800/37 woofers and some MB Quart MCD 25 tweeters.

I plan on using a similar version of the Eton 8.1 x-over, here's the link http://www.eton-gmbh.de/dlstream.php...e1771eec176c51 My question is when Eton recommends the gauges for the inductors, do you think those are minimum gauges or they're the exact gauges you need to use for the x-over.

Also what's MKP stand for? And the resistors can all be metal oxide right? Or should I use metal film? The bi-polar cap needs to be bi-polar? I'm asking because I have a bunch of non-polar caps.

Jimmy154 · 15th February 2004, 02:05 AM

No one knows whether the inductors wire diameters Eton recommends, are minimum gauges or they're the exact gauges you need to use for the x-over?

The link again is http://www.eton-gmbh.de/dlstream.php...e1771eec176c51

sreten · 15th February 2004, 12:18 PM

L1 can be any gauge, due to R1, if its DCR is significant subtract it from R1.

L2 and L3 I'd treat as recommended gauges.

IMO : L3 being a size smaller gauge will have little effect, larger gauge pointless.

IMO : L2 will have a higher DCR than L3 and a size larger gauge makes some sense.

So IMO using a size smaller gauges for L1 and L3 will be OK.
L2 I'd regard as minimum recommended gauge.

MKP is a manufacturer of capacitors, implies a quality level.

In its position the bi-polar capacitor will have little effect on sound
quality, which is why bi-polar is specified. Non-polar will be better.

sreten.

Jimmy154 · 15th February 2004, 04:45 PM

Thanks sreten,

I forgot to mention that I only have 1 mm or 2 mm gauge diameter wire for inductors. So all the wire I have is larger than one of the recommended diameters. I'd like to use the larger gauge wire for L1,2,3 if it helps make the speaker sound better.

Also I didn't mention that I have no bi-polar caps, but I have a bunch of non-polar caps. That's why I was asking.

As for the MKP capacitor, I'm not sure my caps are as good and I don't know how I can find out. But they are Bennic caps and less expensive.

Jimmy154 · 22nd February 2004, 08:56 PM

Also I was told to change the value of the tweeter capacitor from 4.7 uF to 9.0 uF. Wouldn't this change the x-over point drametically and wouldn't I also have to change the tweeter inductor value (L3)?

I suspect that the 9.0 uF recommendation might be a single cap with a 6 db/octive roll-off, no? It's a different tweeter than the Eton 25 SD, I will use a MB Quart MCD 25, also 8 ohm.

sreten · 22nd February 2004, 10:03 PM

Quote:

Originally posted by Jimmy154
Also I was told to change the value of the tweeter capacitor from 4.7 uF to 9.0 uF. Wouldn't this change the x-over point drametically and wouldn't I also have to change the tweeter inductor value (L3)?

I suspect that the 9.0 uF recommendation might be a single cap with a 6 db/octive roll-off, no? It's a different tweeter than the Eton 25 SD, I will use a MB Quart MCD 25, also 8 ohm.

1) No. It will change the Q of the 2nd order filter and the c/o
frequency (less than you appear to think it will) with L3 the
same.
Presumably the different Q is intentional.

2) I can't see how R2 and R3 are the same for a different
tweeter, unless they fortuitously have similar parameters.

sreten.

Jimmy154 · 23rd February 2004, 01:23 AM

Quote:

Originally posted by sreten

2) I can't see how R2 and R3 are the same for a different
tweeter, unless they fortuitously have similar parameters.

I was thinking about that problem also. I used this L-pad calculator http://www.lalena.com/audio/calculator/lpad/. I thought according to this calculator that the only parameter that needs to be the same is the nominal impedance or "Z" in the calculator. Both the tweeters have the same nominal impedance, 8. And the attentuation seems to be between 4.4 and 4.7 db for the Eton 25 SD tweeter. Which seems like a lot cause the woofer is 89 db and the tweeter is 90 db. What am I missing? Are you suppose to use the DCR at the x-over freq. to design the attentuation circuit?

Jimmy154 · 25th February 2004, 03:14 PM

One last thing (I hope).

I only have the capacitors to make a 14.9 uF non-polar cap for the x-over. Should I just buy a 15 uF polar cap or this doesn't make a big difference?

sreten · 25th February 2004, 07:29 PM

Quote:

Originally posted by Jimmy154
One last thing (I hope).

I only have the capacitors to make a 14.9 uF non-polar cap for the x-over. Should I just buy a 15 uF polar cap or this doesn't make a big difference?

Using non-polar will be better, as I originally said.

You only use bi-polar to save cash in non-critical positions,
or a bypassed bi-polar when you can't afford a non-polar.

sreten.

Jimmy154 · 25th February 2004, 09:13 PM

Yes, but they're non-polar and I can only make 14.9 uF instead of 15 uF. Should I buy a non-polar of polar cap that's 15 uF. Does the .1 uF make that much difference? They're 5% caps I believe.

12th February 2004, 03:44 PM	#1
Jimmy154 diyAudio Member Join Date: Jun 2002 Location: Los Angeles	Eton 8.1 cross-over confusion I have purchased a pair of Eton 8-800/37 woofers and some MB Quart MCD 25 tweeters. I plan on using a similar version of the Eton 8.1 x-over, here's the link http://www.eton-gmbh.de/dlstream.php...e1771eec176c51 My question is when Eton recommends the gauges for the inductors, do you think those are minimum gauges or they're the exact gauges you need to use for the x-over. Also what's MKP stand for? And the resistors can all be metal oxide right? Or should I use metal film? The bi-polar cap needs to be bi-polar? I'm asking because I have a bunch of non-polar caps.

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15th February 2004, 02:05 AM	#2
Jimmy154 diyAudio Member Join Date: Jun 2002 Location: Los Angeles	No one knows whether the inductors wire diameters Eton recommends, are minimum gauges or they're the exact gauges you need to use for the x-over? The link again is http://www.eton-gmbh.de/dlstream.php...e1771eec176c51

15th February 2004, 12:18 PM	#3
sreten diyAudio Member Join Date: Nov 2003 Location: Brighton UK	L1 can be any gauge, due to R1, if its DCR is significant subtract it from R1. L2 and L3 I'd treat as recommended gauges. IMO : L3 being a size smaller gauge will have little effect, larger gauge pointless. IMO : L2 will have a higher DCR than L3 and a size larger gauge makes some sense. So IMO using a size smaller gauges for L1 and L3 will be OK. L2 I'd regard as minimum recommended gauge. MKP is a manufacturer of capacitors, implies a quality level. In its position the bi-polar capacitor will have little effect on sound quality, which is why bi-polar is specified. Non-polar will be better. sreten.

15th February 2004, 04:45 PM	#4
Jimmy154 diyAudio Member Join Date: Jun 2002 Location: Los Angeles	Thanks sreten, I forgot to mention that I only have 1 mm or 2 mm gauge diameter wire for inductors. So all the wire I have is larger than one of the recommended diameters. I'd like to use the larger gauge wire for L1,2,3 if it helps make the speaker sound better. Also I didn't mention that I have no bi-polar caps, but I have a bunch of non-polar caps. That's why I was asking. As for the MKP capacitor, I'm not sure my caps are as good and I don't know how I can find out. But they are Bennic caps and less expensive.

22nd February 2004, 08:56 PM	#5
Jimmy154 diyAudio Member Join Date: Jun 2002 Location: Los Angeles	Also I was told to change the value of the tweeter capacitor from 4.7 uF to 9.0 uF. Wouldn't this change the x-over point drametically and wouldn't I also have to change the tweeter inductor value (L3)? I suspect that the 9.0 uF recommendation might be a single cap with a 6 db/octive roll-off, no? It's a different tweeter than the Eton 25 SD, I will use a MB Quart MCD 25, also 8 ohm.

25th February 2004, 03:14 PM	#8
Jimmy154 diyAudio Member Join Date: Jun 2002 Location: Los Angeles	One last thing (I hope). I only have the capacitors to make a 14.9 uF non-polar cap for the x-over. Should I just buy a 15 uF polar cap or this doesn't make a big difference?

25th February 2004, 09:13 PM	#10
Jimmy154 diyAudio Member Join Date: Jun 2002 Location: Los Angeles	Yes, but they're non-polar and I can only make 14.9 uF instead of 15 uF. Should I buy a non-polar of polar cap that's 15 uF. Does the .1 uF make that much difference? They're 5% caps I believe.

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