As I'm doing much research on a new project that echos this project closely, I decided to bring this thread back to the foreground as I have a couple questions still.
These speakers have been sitting unused for well over three years (actually closer to four), and I just decided to pull them out and fire them up again in my main system. For first couple of hours playing were rather horrific to say the least. Disjointed, lacking in bass, midrange and treble, just all over the place. Very non-pleasing experience.
I left them playing as I went and did a few other things around the house. I came back to them a couple hours later only to find them sounding rather spectacular! I guess the drivers and XO components had to loosen up and be reacquainted after such a long siesta. After a few more hours, they were back up to 110% performance.
I never did buy or build that amp kit I was talking about in my last post here. About a year later, we moved, and from there I started slowly upgrading components in my system. To make a long story short, I now have a somewhat inexpensive but extremely good sounding Marantz HT receiver with minimal HT junk in it, a fully updated Schiit Bifrost DAC and dedicated, stripped down and tweaked laptop running JRiver, Mojo Audio power cables on everything, Wire World USB, HDMI, IC's and speaker cables on everything, and the crem de la crem... A fully customized, fully loaded Odyssey Audio Khartago Kismet amplifier that literally has the balls and finesse to power just about any speaker load out there, all the way down to 1 ohm without breaking a sweat.
Oh, and twelve speaker cable isolators (the real ones off of telegraph poles) that do absolutely nothing for the sound, but look neat and make for easy cleaning/vacuuming around them.
I can certainly say one thing without a doubt, these speakers have never sounded better. They are an absolute joy to listen to. They blow the NHT 2.9's right out of the water in every way, top to bottom. I also swapped out the NHT's with my brother for his Polk RTi12's which do a few things better than the NHT's, mainly detail and articulation in the bass and a better, wider sound stage. Again though, the Vifa/Fostex combo simply blows them out of the water in every way. The Vifa's offer up even deeper bass, more impact, and a lot more texture and detail, even at 2am whisper levels. In fact, the last time I ever heard this kind of bass detail and texture was with large open baffles with FOUR 15" woofers. And as far as imaging, sound stage width, depth and height, these little Fostex drivers perform every bit as good as excellent bookshelf speakers. I have never heard any tower speakers produce actual bookshelf imaging and sound staging. These sure do though!
Anywho... I have a couple questions about these old project speakers and their very simple series crossovers.
1) These speakers sound excellent with just about everything you throw at them, though sometimes they still tend to sound a bit thin in the lower midrange, especially with male and female speech. It's not as noticeable with music. In fact, hardly at all, though there are some recordings that it is apparent in. With speech however, it is quite noticeable just about all the time.
Is this possibly due to the Fostex still being a slight too efficient in comparison to the Vifa driver? (91 dB for the Vifa, 89 dB for the Fostex) They are crossed over around 500-700 Hz IIRC and the Fostex has a 10 ohm/10 watt resistor on it.
2) This one stumps me, and I've noticed this ever since the beginning with these speakers. Every once in a while with some music and again with speech, sometimes it sounds like the Fostex drivers are going in and out of phase with the Vifa drivers. Even when I run the Audyssey setup on the receiver, it senses these speakers as being normal, yet the other three speakers being out of phase. I tried switching the speakers cables at the binding posts on the main speakers and Audyssey still saw the other three speakers as out of phase. I switched the polarity back to normal on the main speakers, but switched the polarity on the Fostex drivers only. Audyssey showed everything being out of phase. I switched them back and flipped the polarity on the Vifa's only. Audyssey still showed everything out of phase, so I switched them back to normal.
So my question is, why am I getting this out of phase anomaly? Is it because of where the crossover frequency is (somewhere around 500-700 Hz)? Is it the nature of series crossovers? Is it due to baffle step and crossover mis-match? Or, is it again due to the Fostex driver being slightly too efficient over the Vifa in their operating range?
These speakers have been sitting unused for well over three years (actually closer to four), and I just decided to pull them out and fire them up again in my main system. For first couple of hours playing were rather horrific to say the least. Disjointed, lacking in bass, midrange and treble, just all over the place. Very non-pleasing experience.
I left them playing as I went and did a few other things around the house. I came back to them a couple hours later only to find them sounding rather spectacular! I guess the drivers and XO components had to loosen up and be reacquainted after such a long siesta. After a few more hours, they were back up to 110% performance.
I never did buy or build that amp kit I was talking about in my last post here. About a year later, we moved, and from there I started slowly upgrading components in my system. To make a long story short, I now have a somewhat inexpensive but extremely good sounding Marantz HT receiver with minimal HT junk in it, a fully updated Schiit Bifrost DAC and dedicated, stripped down and tweaked laptop running JRiver, Mojo Audio power cables on everything, Wire World USB, HDMI, IC's and speaker cables on everything, and the crem de la crem... A fully customized, fully loaded Odyssey Audio Khartago Kismet amplifier that literally has the balls and finesse to power just about any speaker load out there, all the way down to 1 ohm without breaking a sweat.
Oh, and twelve speaker cable isolators (the real ones off of telegraph poles) that do absolutely nothing for the sound, but look neat and make for easy cleaning/vacuuming around them.
I can certainly say one thing without a doubt, these speakers have never sounded better. They are an absolute joy to listen to. They blow the NHT 2.9's right out of the water in every way, top to bottom. I also swapped out the NHT's with my brother for his Polk RTi12's which do a few things better than the NHT's, mainly detail and articulation in the bass and a better, wider sound stage. Again though, the Vifa/Fostex combo simply blows them out of the water in every way. The Vifa's offer up even deeper bass, more impact, and a lot more texture and detail, even at 2am whisper levels. In fact, the last time I ever heard this kind of bass detail and texture was with large open baffles with FOUR 15" woofers. And as far as imaging, sound stage width, depth and height, these little Fostex drivers perform every bit as good as excellent bookshelf speakers. I have never heard any tower speakers produce actual bookshelf imaging and sound staging. These sure do though!
Anywho... I have a couple questions about these old project speakers and their very simple series crossovers.
1) These speakers sound excellent with just about everything you throw at them, though sometimes they still tend to sound a bit thin in the lower midrange, especially with male and female speech. It's not as noticeable with music. In fact, hardly at all, though there are some recordings that it is apparent in. With speech however, it is quite noticeable just about all the time.
Is this possibly due to the Fostex still being a slight too efficient in comparison to the Vifa driver? (91 dB for the Vifa, 89 dB for the Fostex) They are crossed over around 500-700 Hz IIRC and the Fostex has a 10 ohm/10 watt resistor on it.
2) This one stumps me, and I've noticed this ever since the beginning with these speakers. Every once in a while with some music and again with speech, sometimes it sounds like the Fostex drivers are going in and out of phase with the Vifa drivers. Even when I run the Audyssey setup on the receiver, it senses these speakers as being normal, yet the other three speakers being out of phase. I tried switching the speakers cables at the binding posts on the main speakers and Audyssey still saw the other three speakers as out of phase. I switched the polarity back to normal on the main speakers, but switched the polarity on the Fostex drivers only. Audyssey showed everything being out of phase. I switched them back and flipped the polarity on the Vifa's only. Audyssey still showed everything out of phase, so I switched them back to normal.
So my question is, why am I getting this out of phase anomaly? Is it because of where the crossover frequency is (somewhere around 500-700 Hz)? Is it the nature of series crossovers? Is it due to baffle step and crossover mis-match? Or, is it again due to the Fostex driver being slightly too efficient over the Vifa in their operating range?
Well I guess the above post is a moot point now. I decided to swap out the Fostex drivers with Alpair 10.2 drivers.
I kept the series x-over parts as is minus the removal of the 10 ohm, 10 watt resistor on the + leg of the Fostex. The 51uF cap is still across the woofer along with the "unknown" iron-core on the + leg of the woofer, and the 3mH Erse air-core is across the Alpair.
These Alpairs haven't been used in over 3 years, and they only had about 200 hours on them on small OB's, so they probably have to be broken in again.
The new project that I'm going to be working on is going to be using these same drivers, only in new, better enclosures and finely tuned series x-overs. Also, the new project will actually be using new 10.3 drivers, not the older 10.2 drivers that I'm using currently. However, I can use these to get me into the ballpark at least.
Anyway, here's a few pics taken just a couple hours ago... Please excuse the dust.
I kept the series x-over parts as is minus the removal of the 10 ohm, 10 watt resistor on the + leg of the Fostex. The 51uF cap is still across the woofer along with the "unknown" iron-core on the + leg of the woofer, and the 3mH Erse air-core is across the Alpair.
These Alpairs haven't been used in over 3 years, and they only had about 200 hours on them on small OB's, so they probably have to be broken in again.
The new project that I'm going to be working on is going to be using these same drivers, only in new, better enclosures and finely tuned series x-overs. Also, the new project will actually be using new 10.3 drivers, not the older 10.2 drivers that I'm using currently. However, I can use these to get me into the ballpark at least.
Anyway, here's a few pics taken just a couple hours ago... Please excuse the dust.
So...
I've had these playing for the past 24 hours and the sound isn't all that great. I have to admit, at first, there was nearly no treble at all. It almost sounded like just a woofer and a midrange driver. It took about a good 10 hours or so for the treble to come into play.
I have the Alpairs wired out of phase which may be attributing to the gap in the midrange. Also, since the Alpair only has the 3mH inductor across it, it's running 1st order, but the Vifa has the 51uF cap and questionable iron-core on it, which I believe makes it a 2nd order. So that too could possibly causing a gap in the midrange.
The Fostex FE103e that I replaced had an Re of 7.5 ohms, the 10.2 is 7.2 ohms, 89 dB for the 103e vs 87 dB for the 10.2. Even though they are very different drivers, they are somewhat similar electrically. I figured since I'm running a basic series x-over, it would compensate enough to make the system at least sound as good as it did with the Fostex. It certainly doesn't though.
Output-wise, they actually do seem to be a good match, but sound-wise, not so much.
Just for testing purposes, should I strip back even further and make the x-over even more basic by removing the iron-core from the woofer and wire the 10.2 in phase?
Any other suggestions?
I've had these playing for the past 24 hours and the sound isn't all that great. I have to admit, at first, there was nearly no treble at all. It almost sounded like just a woofer and a midrange driver. It took about a good 10 hours or so for the treble to come into play.
I have the Alpairs wired out of phase which may be attributing to the gap in the midrange. Also, since the Alpair only has the 3mH inductor across it, it's running 1st order, but the Vifa has the 51uF cap and questionable iron-core on it, which I believe makes it a 2nd order. So that too could possibly causing a gap in the midrange.
The Fostex FE103e that I replaced had an Re of 7.5 ohms, the 10.2 is 7.2 ohms, 89 dB for the 103e vs 87 dB for the 10.2. Even though they are very different drivers, they are somewhat similar electrically. I figured since I'm running a basic series x-over, it would compensate enough to make the system at least sound as good as it did with the Fostex. It certainly doesn't though.
Output-wise, they actually do seem to be a good match, but sound-wise, not so much.
Just for testing purposes, should I strip back even further and make the x-over even more basic by removing the iron-core from the woofer and wire the 10.2 in phase?
Any other suggestions?
A lot happens in multi way and your thread gets pushed down below visibility. Bumping was good. The A10's should not sound like they lack treble. Play them full range by themselves and see if they still don't suit you. If the XO was designed for FE103E, you can't just stick the A10's in - very different driver. This sounds like a FAST system and ask moderators to move to fullrange forum where you will get more TLC.
If you have a mic, some measurements will quickly clear up any guesses you are working from. Even your laptop built in mic and REW will tell you if the XO is working properly or if there is a hole.
If you have a mic, some measurements will quickly clear up any guesses you are working from. Even your laptop built in mic and REW will tell you if the XO is working properly or if there is a hole.
I guess three "bumps" weren't enough...
Anyway, thanks to another forum section and some tweaking of my own on the x-over, I have it sounding the way it should, possibly better than it has the right to. Also, I had already adjusted the x-overs accordingly when I swapped out the Fostex drivers for the Alpair drivers. I'm not that bad off.
Anyway, thanks to another forum section and some tweaking of my own on the x-over, I have it sounding the way it should, possibly better than it has the right to. Also, I had already adjusted the x-overs accordingly when I swapped out the Fostex drivers for the Alpair drivers. I'm not that bad off.
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