Well after going through the thread again, I think I'll go with about a 4mH inductor (air-core) on the Fostex which should get me in the neighborhood of 600Hz, and then get a 3mH for the woofer to complete the 2nd order part on the woofer.
BTW, those suggestions were from one of Jerome's posts...
BTW, those suggestions were from one of Jerome's posts...
This morning I decided on a pair of Erse 3mH 18awg air core inductors for a slightly higher 700Hz crossover point and ordered them from Parts Express. These will be going on the Fostex FE103E's.
I figure that if these speakers sound this good with unknown value, cheap iron core inductors, having good quality air core inductors of a known and correct value will only make things better.
As for the inductors on the Vifa woofers, I'll probably go with the equivalent iron core Erse inductors at 3mH. Their DCR of 0.178Ω is better than the air core version at 0.93Ω.
Of course, if anyone has any suggestions as to which ones I should go with on the woofers, please feel free to speak up.
I figure that if these speakers sound this good with unknown value, cheap iron core inductors, having good quality air core inductors of a known and correct value will only make things better.
An externally hosted image should be here but it was not working when we last tested it.
As for the inductors on the Vifa woofers, I'll probably go with the equivalent iron core Erse inductors at 3mH. Their DCR of 0.178Ω is better than the air core version at 0.93Ω.
An externally hosted image should be here but it was not working when we last tested it.
Of course, if anyone has any suggestions as to which ones I should go with on the woofers, please feel free to speak up.
I don't know how much luck I'm going to have asking this as it seems that this thread is just about dead now for whatever reason, but...
I was researching Zobel networks for my Vifa P21WO driver. Since I will be crossing over at around 700Hz, I don't think I'll need one, right? The Vifa's impedance doesn't start rising until after 1kHz, 300Hz PAST the XO point.
Now one thing that I am concerned about is the resonance peak that it has around 50Hz (as to what WinISD suggests), thought the Fe of the driver is 28Hz.
At any rate, is there any way of taming this peak as it jumps up to 20+ ohms?
I was researching Zobel networks for my Vifa P21WO driver. Since I will be crossing over at around 700Hz, I don't think I'll need one, right? The Vifa's impedance doesn't start rising until after 1kHz, 300Hz PAST the XO point.
Now one thing that I am concerned about is the resonance peak that it has around 50Hz (as to what WinISD suggests), thought the Fe of the driver is 28Hz.
At any rate, is there any way of taming this peak as it jumps up to 20+ ohms?
Exactly, meaning that the amp is reacting to the rise in the Fostex's impedance from 1kHz on up where it gradually rises to 20 ohms, getting less power to the driver. Though if the Fostex had a flat impedance, then it might become too forward on the top end, correct?
Now the resonance peak I was talking about was with the Vifa driver. It peaks to about 24-25 ohms around 50Hz. I think you answered that question referring to the Fostex driver.
I want to know if I should address that resonance peak on the Vifa driver.
chops,
Interesting to compare what you r doing with the new Neat Acoustics Ultimatum XLS (on the page 7 of the August edition of Hi-Fi News&RR).
Look at the top "upward-firing" super tweeters.
Neat Acoustics ultimatum XL6 product information
Interesting to compare what you r doing with the new Neat Acoustics Ultimatum XLS (on the page 7 of the August edition of Hi-Fi News&RR).
Look at the top "upward-firing" super tweeters.
Neat Acoustics ultimatum XL6 product information
Attachments
I'm referring to the actual impedance peak down around the 50Hz mark. In fact, according to WinISD, there's two peaks, one at 17Hz and one at 53Hz, both of which peak at 24 ohms.
chops,
Interesting to compare what you r doing with the new Neat Acoustics Ultimatum XLS (on the page 7 of the August edition of Hi-Fi News&RR).
Look at the top "upward-firing" super tweeters.
Neat Acoustics ultimatum XL6 product information
Thanks for that link Inductor. That link can be used as some "inspirational food" to get my speakers finalized as far as the top tweeter(s) is concerned.
The isobaric design is something I've played around a bit with in the past as well. Hmm, maybe I could do something like that in my next design. Maybe use four Audio Note 8" drivers for the isobaric section and use another pair of Audio Note 8" drivers for the lower mid-bass/midrange and then over to a nice 4-5" fullrange driver, and another top firing tweeter.
Yes. There are 2 because it is a BR. You only worry about those peaks if you are intending to drive them with a current amp.
dave
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I don't think I'll worry about it too much as the amp and speakers have performing perfectly this whole time and sounding great doing so.
That's true Dave!
And I have just finished installing the new 3mH inductors for the Fostex drivers, which from what I gather should be getting me around the 700Hz XO point in conjunction with the 51uF cap. At this point, nothing is soldered, just twisted together (and a couple alligator clips) so I can swap out parts if need be a lot easier. Once everything is totally finalized, then I'll make proper XO boards, soldered and using terminal strips.
Also, as I ran out of large enough nylon wire ties, I'm using gobs of duct seal to hold all the components in place, which possibly helps isolate them from vibrations. The iron core inductors tucked over in the corners by themselves have been sitting there in the duct seal for a few weeks now without issue.
As usual, a few pics...
Before...
After...
And of course, one of my many faithful babies hanging out with me!
And I have just finished installing the new 3mH inductors for the Fostex drivers, which from what I gather should be getting me around the 700Hz XO point in conjunction with the 51uF cap. At this point, nothing is soldered, just twisted together (and a couple alligator clips) so I can swap out parts if need be a lot easier. Once everything is totally finalized, then I'll make proper XO boards, soldered and using terminal strips.
Also, as I ran out of large enough nylon wire ties, I'm using gobs of duct seal to hold all the components in place, which possibly helps isolate them from vibrations. The iron core inductors tucked over in the corners by themselves have been sitting there in the duct seal for a few weeks now without issue.
As usual, a few pics...
Before...
After...
And of course, one of my many faithful babies hanging out with me!
Well it's been a little over a week and I am rather happy with the sound I'm getting from these speakers.
The new 3mH inductors have improved the speakers in a couple areas. For one, they have shifted the XO point slightly up to where I believe it helps fill out the midrange and give vocals a bit more body and connectivity. This is what I was aiming for and it seems to have worked.
The other thing that these inductors did was improve the impact and depth of the bass. The bass is stronger, snappier, deeper and more dynamic than before. They had great control before, but now they really have a tight grip on things and seem to have no problems at all on reaching down to the lowest octaves. And this part is hard to explain, because the natural thing to say would be that there's "more bass" for the given power. I think saying that the bass is "more vibrant" is a better description of what I'm hearing.
I'm still playing around with the ambiance tweeters. I have removed the 3.3 ohm resistors and have nothing but the two 3uF caps inline with them for the overall 1.5uF rating (roughly 13kHz XO point). I'm also still playing with their positioning.
I do have to say, orchestral pieces such as Beethoven's Concertos No 3 & 4 with Emanuel Ax sound excellent. Lots of dynamics, lots of very quiet, subtle details and very realistic piano reproduction. Listening to this CD through these speakers darn near put me in an emotional state it sounds so good!
On a slightly different note, I am now looking at changing up from my 23 watt tube amp to a true dual mono, 150 watt Class D amp kit that I'll put together myself. I'm mainly doing this so I can turn on my system for short periods of time without worrying about shortening the life of the tubes, not to mention that on my days off, I usually have the system up and running for about 16 hours or more. Plus, this is still my brother's amp and I'd like to give it back to him now that I know it is highly dependable and 110% fully operational once again. He has also agreed to pretty much pay for my new amp kit in return for not only repairing his amp, but also including two NOS 5U4G's and two matched quads of NOS Russian output tubes.
The new 3mH inductors have improved the speakers in a couple areas. For one, they have shifted the XO point slightly up to where I believe it helps fill out the midrange and give vocals a bit more body and connectivity. This is what I was aiming for and it seems to have worked.
The other thing that these inductors did was improve the impact and depth of the bass. The bass is stronger, snappier, deeper and more dynamic than before. They had great control before, but now they really have a tight grip on things and seem to have no problems at all on reaching down to the lowest octaves. And this part is hard to explain, because the natural thing to say would be that there's "more bass" for the given power. I think saying that the bass is "more vibrant" is a better description of what I'm hearing.
I'm still playing around with the ambiance tweeters. I have removed the 3.3 ohm resistors and have nothing but the two 3uF caps inline with them for the overall 1.5uF rating (roughly 13kHz XO point). I'm also still playing with their positioning.
I do have to say, orchestral pieces such as Beethoven's Concertos No 3 & 4 with Emanuel Ax sound excellent. Lots of dynamics, lots of very quiet, subtle details and very realistic piano reproduction. Listening to this CD through these speakers darn near put me in an emotional state it sounds so good!
On a slightly different note, I am now looking at changing up from my 23 watt tube amp to a true dual mono, 150 watt Class D amp kit that I'll put together myself. I'm mainly doing this so I can turn on my system for short periods of time without worrying about shortening the life of the tubes, not to mention that on my days off, I usually have the system up and running for about 16 hours or more. Plus, this is still my brother's amp and I'd like to give it back to him now that I know it is highly dependable and 110% fully operational once again. He has also agreed to pretty much pay for my new amp kit in return for not only repairing his amp, but also including two NOS 5U4G's and two matched quads of NOS Russian output tubes.
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