Now I'm all confused. I was under the impression that I was right around the 500Hz mark, but now you're saying I'm down at 210Hz. Is that because of the two resistors on the Fostex (the resulting 21 ohms)?
I want to be up around a 500Hz XO point, but I also need the Fostex padded down some so the speaker (as a system) isn't so forward sounding.
To change padding with minimal affect on the XO point you need an L-Pad. ANd in a series XO, probably not a good idea to be adding that much series R all by itself.
dave
Why is that? Does an L-Pad always show the amp an 8 ohm load?
Also, why is it not a good idea to have that much series resistance?
Just so you know Dave, I'm not doubting or questioning your suggestions. It's just that I can not find much information on series XO's along with the "do's" and "don'ts". Most everything that pops up on searches are for parallel XO's.
And is it just me or does it seem that series XO design is all just trial and error? There doesn't seem to be any definite rules so to speak.
This is one of the sites I've already read through. Again, it really doesn't tell you much about a series XO and how to design one, choosing the correct inductors and capacitors to get a desired XO point.
It like several others just tells you the most basic "basics" of a series XO and nothing more. Not to mention a few of the links that would probably really be useful are no longer in service.
If someone did a wonderful write-up like AllenB did with a typical parallel XO for series XO's, that would be great, but there just isn't anything like that out there yet that I can find. No calculations to use or anything.
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How?!
Nowhere in those links does it mention anything about calculating the correct XO components for the drivers used or for the desired XO point.
For a butterworth the forumulas are the same as for parallel XO.
Try Bagby's Passive XO Designer. (i've only used v2 (all the newer ones get too fancy)
dave
Try Bagby's Passive XO Designer. (i've only used v2 (all the newer ones get too fancy)
dave
The way you make that first statement, you make it sound like a Butterworth network is a series network. However, when using a XO calculator, it shows a cap on the tweeter and inductor on the woofer in parallel. And when I put in crossover point and impedance, it comes up with nothing close to the 51uF cap I'm using, until I get down to around 390Hz, unless that's my XO point.
I've had Bagby's software installed for the past few days and can't figure the darn thing out. All I can manage to do is put in the driver names and crossover points, that's about it. I don't know where or how to put in driver parameters and get anything to work.
Butterworth is a filter with a Q = 0.707. It can be made with a series or a parallel XO (or any number of active solutions)
I found the newer ones far more complex than i needed (and use of VB made it non-functional)
dave
Just as a fun update, I've been living with my speakers for a couple weeks now, re-tuned to 28Hz, an inductor on the woofer along with the 51uF cap. I removed the 3 ohm resistor on the Fostex and have just the 10 ohm resistor on it along with its inductor, and also added a little poly-fill behind each woofer to help reduce reflections.
The bass has evened out and reaches down really deep now, probably right around 20Hz or possibly a little lower. The upper bass is tighter, more controlled and highly detailed and articulate. Nimble if you will...
The Fostex driver is about as near perfect a match as I think I'm going to get as far as levels are concerned to the Vifa woofer. No one frequency range stands out or sounds out of place. It all just kind of jells together the way it should. The AR grills that I adapted over to these speakers have seemed to help in "jelling" everything together, let along making the towers look better.
These speakers have a expansive sound stage with good depth and height. Some of the sounds, especially vocals tend to hover about 2' above the speakers right smack in the middle of them, roughly 6' above the floor. It almost makes you feel like you can reach out and touch the singer.
One of my brothers is really picky when it comes to some of my speaker creations, usually having something negative to say about them, and he's heard these little FE103E's before and never cared for them. In fact, he straight out didn't like them at all. However, as I have been on the road this entire weekend, he stayed at our place to take care of our cats and such. While here, he had three solid days to listen to my system and he really likes what he hears. The only complaint he has about them is that he said they could use just a little more "air" on the extreme top end, but that also has a lot to do with the program material.
I do agree that at times (not very often though), they could possibly use a tad bit of help on the most extreme top end. I have a pair of barely used Dayton Audio DC28F-8 tweeters laying around. I wonder if I could possibly add these to these towers, maybe mounted on the rear of the enclosures and crossed over high, maybe around 10kHz?
Any thoughts and/or suggestions?
The bass has evened out and reaches down really deep now, probably right around 20Hz or possibly a little lower. The upper bass is tighter, more controlled and highly detailed and articulate. Nimble if you will...
The Fostex driver is about as near perfect a match as I think I'm going to get as far as levels are concerned to the Vifa woofer. No one frequency range stands out or sounds out of place. It all just kind of jells together the way it should. The AR grills that I adapted over to these speakers have seemed to help in "jelling" everything together, let along making the towers look better.
These speakers have a expansive sound stage with good depth and height. Some of the sounds, especially vocals tend to hover about 2' above the speakers right smack in the middle of them, roughly 6' above the floor. It almost makes you feel like you can reach out and touch the singer.
One of my brothers is really picky when it comes to some of my speaker creations, usually having something negative to say about them, and he's heard these little FE103E's before and never cared for them. In fact, he straight out didn't like them at all. However, as I have been on the road this entire weekend, he stayed at our place to take care of our cats and such. While here, he had three solid days to listen to my system and he really likes what he hears. The only complaint he has about them is that he said they could use just a little more "air" on the extreme top end, but that also has a lot to do with the program material.
I do agree that at times (not very often though), they could possibly use a tad bit of help on the most extreme top end. I have a pair of barely used Dayton Audio DC28F-8 tweeters laying around. I wonder if I could possibly add these to these towers, maybe mounted on the rear of the enclosures and crossed over high, maybe around 10kHz?
Any thoughts and/or suggestions?
Build 3 ways ?
You have to remodeled the crossover in parallel, I can help you. You seem to have components in stock.
The crossover frequency should be lower 4/5kHz.
You can use a ND20 or ND16 ?
Dayton Audio ND16FA-6 5/8" Neodymium Dome Tweeter
Dayton Audio ND20FA-6 3/4" Neodymium Dome Tweeter
Dayton ND20FB-4 Rear-Mount 3/4" Neodymium Dome Tweeter
Add a super tweeter with a cap doesn't give the result as it could be.
You have to remodeled the crossover in parallel, I can help you. You seem to have components in stock.
The crossover frequency should be lower 4/5kHz.
You can use a ND20 or ND16 ?
Dayton Audio ND16FA-6 5/8" Neodymium Dome Tweeter
Dayton Audio ND20FA-6 3/4" Neodymium Dome Tweeter
Dayton ND20FB-4 Rear-Mount 3/4" Neodymium Dome Tweeter
Add a super tweeter with a cap doesn't give the result as it could be.
Two different schools of thought here.
Jerome, why the suggestions of other tweeters? Is it because they extend beyond 25+kHz?
Also, I'd like to keep the speakers as they are as a series 2-way design. It's a simple, clean design that sounds really good. I don't want to go switch over to a full 3-way.
Dave, so run just a small cap on the (+) side of the tweeter, correct? If so, which frequency would you say? How much do you think I'll have to pad it down?
I see you point(s), however I already have the DC28F-8 tweeters and if they're mounted in the back, better directivity wouldn't be an issue.
You won't have to. It's on the back and it's XO'd nice and high. The Dayton will be just fine for the job.
I was just thinking of something though... These speakers are only about 6" from the wall and I can't pull the speakers out any further than they are. Will this be an issue?
I was also wondering, what about aiming the tweeters straight up towards the ceiling, or at least aimed halfway up the rear wall at an angle? Say at a 45* angle?
don't pad it, just shrink the cap till it sounds right. If the tweeter is 8 ohms start with 1.5-1.8uF
dave
dave
At 1.5 - 1.8uF, that would put me somewhere in the neighborhood of 11kHz - 13kHz.
The short distance to the rear wall (roughly 6") won't throw things off? Also, should the tweeter be wired in or out of phase, or does it really matter up that high in frequency?
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