It would seem that the much more efficient (compared to the Jordans) Alpairs are going to be difficult to match to the big Goldwoods. I'm going to give the Eminence Alpha, in H-frame, and the Alpair 12 a try. Any suggestions for starting passive crossover components? TIA - Pat
Excuse my ignorance, but what is the problem with lowering the sensitivity of the Alpair 12s with resistors? Isn't the negative contribution of a resistor much more subtle than the other differences between drivers? Would not the reduced dynamic headroom of the Jordan represent a larger compromise?
No problem at all. Just laziness and enjoying the sound as is. I was more curious about the Eminence driver than about playing with pads for the high end. Pads are common and I have them in many other designs, so my apologies for it sounding like I was against them when I just wandered off in another direction.
Set up the H-frames again after listening for months to pure open baffles. The H-frames sound better in my room. Fuller, richer with more fine detail. Complicated bass lines can be followed more easily. My son spent a couple hours with me last night (he fractured his foot at karate) listening to 80s music. Lots of synth, heavy bass lines and all sorts of fun nonsense in that great era of music (Yaz, Squeeze, Pet Shop Boys, Blondie, Split Enz, etc). We both enjoyed and he commented that the H-frames sounded 'really good.'
How would you describe returning to big bass-reflex cabs after months of OB/H-frames ?
Anyone ever think of turning the H-frame 90 degrees from the "front" of the speaker to make something a bit more WAF friendly? Say maybe a line of something smaller so the thing is isn't terribly deep either, like, say 4x DA175-8, probably alternating cone direction to keep the structure more stable during operation?
This way the front could be a clean finish with the full ranger situated at ear level in the top. You could even do snap on/magnetic grill covers for both sides of the H if necessary for your environment, or maybe just sock the whole affair like one of those Emerald OBs.
I like those 7" Daytons. Zaph seems to like them too. My POV, though, is that I play electric bass and a little electric guitar besides and those little drivers can handle the entire spectrum if used to amp them. Of course, you'd need at least a pair to make a competent coffee house amp, but 4x per speaker paired with, I don't know, the RS100-8 (still my personal favorite full ranger, though I can't say I've experienced more than a handful of what would be considered "quality" units), and using an active cross of some sort (I use the Dayton APA150, and it has let me set up all sorts of quick, no hassle OB fullrange + helper arrangements, even using low Q woofers) to help get good response out of the smaller drivers should be pretty nice.
Being OB like that, would turning the H 90 degrees cause any sort of phase issues? I've only encountered a phase issue once and that was with a box sub many years ago, and it had a knob that fixed that for me (still sounded like garbage though; sub is long gone and never been replaced by another box). Not that I'm planning on building anything like that right now. I'm currently limited to building office rigs right now, which means they would need to be OB and fit between desktop level and the ceiling, though it might be possible to build a floor to ceiling sub line behind the center of the desk (its diagonal in a corner with a fake ficus currently in residence) for a little 2.1 action (the APA150 gives me that flexibility). Just some thoughts I'd been having that I figured I'd throw out into the universe since they're not doing me any good right now.
Kensai
This way the front could be a clean finish with the full ranger situated at ear level in the top. You could even do snap on/magnetic grill covers for both sides of the H if necessary for your environment, or maybe just sock the whole affair like one of those Emerald OBs.
I like those 7" Daytons. Zaph seems to like them too. My POV, though, is that I play electric bass and a little electric guitar besides and those little drivers can handle the entire spectrum if used to amp them. Of course, you'd need at least a pair to make a competent coffee house amp, but 4x per speaker paired with, I don't know, the RS100-8 (still my personal favorite full ranger, though I can't say I've experienced more than a handful of what would be considered "quality" units), and using an active cross of some sort (I use the Dayton APA150, and it has let me set up all sorts of quick, no hassle OB fullrange + helper arrangements, even using low Q woofers) to help get good response out of the smaller drivers should be pretty nice.
Being OB like that, would turning the H 90 degrees cause any sort of phase issues? I've only encountered a phase issue once and that was with a box sub many years ago, and it had a knob that fixed that for me (still sounded like garbage though; sub is long gone and never been replaced by another box). Not that I'm planning on building anything like that right now. I'm currently limited to building office rigs right now, which means they would need to be OB and fit between desktop level and the ceiling, though it might be possible to build a floor to ceiling sub line behind the center of the desk (its diagonal in a corner with a fake ficus currently in residence) for a little 2.1 action (the APA150 gives me that flexibility). Just some thoughts I'd been having that I figured I'd throw out into the universe since they're not doing me any good right now.
Kensai
>>> How would you describe returning to big bass-reflex cabs after months of OB/H-frames ?
I have not done this yet but expect to eventually. I have a few ideas using pro sound woofers in bass reflex cabs sketched out around my desk. The idea is basically to build two, power them with an amp and use them as stands to sit some type of monitor speaker on top. I have been playing with a small bookshelf speaker design using a small pro sound woofer (dayton) and a piezo. I still really enjoy piezo tweeters without shame! Crossed over too low they are not good... crossed over high enough they sound great to me. I prefer the little monitor overall to the Fostex 127e i have in a slotted box. Eventually i will put up some pics and you can pick it apart... or build a pair and enjoy a cheap two way.
http://www.zillaaudio.com/fostex-127e-slotted-box.htm
Turning the H-frames is an interesting idea actually. As long as you have them more than a foot and a half from the side walls i don't see why they would not fill a room with sound. Combining the power of pro sound drivers with the delicacy of full range drivers has been keeping me interested for the past year or so. When MJK combined expensive Lowthers with inexpensive Goldwood/Eminence pro sound drivers i think he was onto something really great sonically in a home environment.
Once the bass is right in your room it's only a matter of taste in finding the right speaker. H-frames or other woofers allow a modular system to be built. Kind of fun for DIYers like us.
I have not done this yet but expect to eventually. I have a few ideas using pro sound woofers in bass reflex cabs sketched out around my desk. The idea is basically to build two, power them with an amp and use them as stands to sit some type of monitor speaker on top. I have been playing with a small bookshelf speaker design using a small pro sound woofer (dayton) and a piezo. I still really enjoy piezo tweeters without shame! Crossed over too low they are not good... crossed over high enough they sound great to me. I prefer the little monitor overall to the Fostex 127e i have in a slotted box. Eventually i will put up some pics and you can pick it apart... or build a pair and enjoy a cheap two way.
http://www.zillaaudio.com/fostex-127e-slotted-box.htm
Turning the H-frames is an interesting idea actually. As long as you have them more than a foot and a half from the side walls i don't see why they would not fill a room with sound. Combining the power of pro sound drivers with the delicacy of full range drivers has been keeping me interested for the past year or so. When MJK combined expensive Lowthers with inexpensive Goldwood/Eminence pro sound drivers i think he was onto something really great sonically in a home environment.
Once the bass is right in your room it's only a matter of taste in finding the right speaker. H-frames or other woofers allow a modular system to be built. Kind of fun for DIYers like us.
Dipoles have a cardioid radiation pattern with nulls to the sides. By rotating them 90 degrees you would be directing the nulls toward the listening position.
If it were cardioid the null would be to the rear. Dipoles tend to be "figure of eight" which has the positive lobe to the front, the negative lobe to the rear and the nulls to the sides (and top/bottom) - in fact in all directions on the plane of the baffle.
Hmmm.....
The bass section of my system is dipole. And for the layout of living space, the speakers are located along the wide side of the room. They are largely toe-in for compensating the non-ideal positions.
Walking around in the room, it's often and common to get to the side of the speaker, while more or less facing the one on the far side (because of the toe-in). In such far off center conditions, overall tonal balance is OK but not perfect, because the dispersion of (horn loaded) mid-high is wider then the bass (funny but true). So in the far off-center positions, bass is relatively weaker.
It's not only slightly bass-shy, the qualities of the bass sound are also different. The senses of intensity, impact, and focus are gone when not in front of the speakers.
Another funny but true fact is about the sub - my sub is also dipole and located at the center between main speakers, with its open back very near the rear wall. It's working only at the bottom octave, but it's not 'filling the room', the sound pressure is produced mostly in front of it.
BTW, the woofers of my main channels and sub are identical and their lower cutoff is the same (with slightly different 'tuning'). The higher end of the main channels are set higher to the midbass. With all these woofers, the bass (especially lower bass) is still not 'filling' the room. It's mostly 'restricted' in the front, spreading narrowly across the couch only, which I found a very good feature of this system.
I've never seen or listen to that Gradient speakers, so I don't know how it sounds actually.
I still like to see the woofers facing me.
In the region of discrete room modes (that is below 200-300 Hz, depending on room size) loudspeakers can not be considered as direct radiators. They simply feed the room modes. Because of the inherent directivity a dipole which is aligned along a room axis will feed the room modes along that axis more than the modes perpendicular to it. If you align the dipole diagonally, as is recommended for the Helsinki, it will drive the modes along the depth and the width of the room to equal parts. Since you do not hear the direct radiation of the driver, but the room modes, you will get bass even when sitting in the plane of the driver.
Hmmm....
My own experience was mentioned above, at 90 degree of the driver's axis, the bass would be very weak. So the highly directional bass is shooting at the direction/space where no one is there. I don't know what the benefit is by such arrangement.
Has anyone listened to or measured that Helsinky?
And I happened to find this: Dipole positioning and room modes
Is that you, Rudolf?
There's a measurement in the link. Under 30-some, it's about 10dB less at 90 degree.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.