Hi Everyone;
I've been reading here for some time, and am very happy to see the healthy amount of discussion of the Tangband 871 fullrange drivers. I've lived with 2 of these (in the form of the CSS ELF 1.0) for over a year now, and have been frankly quite amazed at the value, and in particular, the imaging when used as nearfield monitors. In my admittedly limited experience, there are few speakers as addictive as these for small scale, 'intimate' music.
Currently I am using one of these as a center channel speaker in my small home theater. At low volumes, it sounds great for dialogue. Once the action picks up a bit though, things get very congested, even crossed at 100hz. What I would like to do is build a new center using one or more of these drivers, as the quality, cost and simplicity of the design are 1st rate. The only thing I'd like to improve on is the output capability.
I am aware of the CSS Spires center, which is similar to what I describe here, but I have a number of concerns about this kit including putting the crossover at 1k and having 5 drivers in a line horizontally, which I understand may cause poor horizontal dispersion.
Any ideas or suggestions?
I've been reading here for some time, and am very happy to see the healthy amount of discussion of the Tangband 871 fullrange drivers. I've lived with 2 of these (in the form of the CSS ELF 1.0) for over a year now, and have been frankly quite amazed at the value, and in particular, the imaging when used as nearfield monitors. In my admittedly limited experience, there are few speakers as addictive as these for small scale, 'intimate' music.
Currently I am using one of these as a center channel speaker in my small home theater. At low volumes, it sounds great for dialogue. Once the action picks up a bit though, things get very congested, even crossed at 100hz. What I would like to do is build a new center using one or more of these drivers, as the quality, cost and simplicity of the design are 1st rate. The only thing I'd like to improve on is the output capability.
I am aware of the CSS Spires center, which is similar to what I describe here, but I have a number of concerns about this kit including putting the crossover at 1k and having 5 drivers in a line horizontally, which I understand may cause poor horizontal dispersion.
Any ideas or suggestions?
Even an MTM will have poor horizontal dispersion horizontally placed; more drivers will make things worse. Either switch to a driver that has more output capacity or find a way to keep the array vertical. One method is two small arrays to either side of the screen to maintain the center of screen imaging, while placing the two sources far enough away from each other to minimize horizontal plane phase glitching.
Hmm, that is an interesting suggestion Bill... how far apart would the 2 arrays have to be? I could actually accomodate this type of arrangement in my setup fairly easily, but I'm not sure I'd have the necessary power from my receiver, plus the cost would be much higher.
What about using 2-3 drivers only? I was under the impression that it takes 4 drivers for 'line array' behaviour to occur, though I can certainly be wrong as my knowledge of the subject is extremely limited.
What about using 2-3 drivers only? I was under the impression that it takes 4 drivers for 'line array' behaviour to occur, though I can certainly be wrong as my knowledge of the subject is extremely limited.
one option that requires good woodworking skills is to use 3 drivers (1 x 871 and maybe 2 of the W4s) and build them like Vandersteen does his center channel as shown below.
http://www.vandersteen.com/pages/VCC-5lit.html
http://www.vandersteen.com/pages/VCC-5lit.html
Once you're over a half wavelength apart phase glitching becomes non-problematic; three feet apart is a half wavelength at 180 Hz, and below that room modes become strong enough to overshadow phase difficulties anyway.
Line array behavior begins as soon as you're source is higher than a true point in space; what changes with height is the frequency that line characteristics extend (downward) to.
Amp power is no problem. With every doubling of cone area you pick up 3dB of increased radiation efficiency. Just make sure you keep the impedance right. I think 2 drivers per side wired series in each box, with the two boxes wired parallel. This would give you 6dB more sensitivity with a level impedance load.
Dave;
I know the 871 really wants a higher crossover... but surprisingly enough, when using the reciever's 100hz crossover, it really doesnt start to distort at all until the high 80db range. Only the peaks really present 'congestion' problems. Does sound a little 'thin' though, especially on deep male voices.
Navin;
That looks like an impressive center channel! Unfortunately my woodworking skills are rudimentary at best, I'd likely botch it horribly. Also I'm not sure whether the design is contingent on using the external fullrange driver and inward firing mid/basses or not. I'd like to avoid crossovers if possible, if not at least complex ones.
Bill;
thanks for the elaboration. So you think 2 per side would be suitable? In that case, perhaps I should just look at 2 of the superelf that CSS has, which uses the 871 as a mid/tweeter and another tb 3" driver as the bass. Or is the idea to use 2 of the same per side, wired as you described?
I know the 871 really wants a higher crossover... but surprisingly enough, when using the reciever's 100hz crossover, it really doesnt start to distort at all until the high 80db range. Only the peaks really present 'congestion' problems. Does sound a little 'thin' though, especially on deep male voices.
Navin;
That looks like an impressive center channel! Unfortunately my woodworking skills are rudimentary at best, I'd likely botch it horribly. Also I'm not sure whether the design is contingent on using the external fullrange driver and inward firing mid/basses or not. I'd like to avoid crossovers if possible, if not at least complex ones.
Bill;
thanks for the elaboration. So you think 2 per side would be suitable? In that case, perhaps I should just look at 2 of the superelf that CSS has, which uses the 871 as a mid/tweeter and another tb 3" driver as the bass. Or is the idea to use 2 of the same per side, wired as you described?
What you do isn't as important as having both sides identical. I'd shy away from anything that uses a 3 for a woofer; if you're going to try to get worthwhile response below 100 Hz you really need a 5 to get it. If you want to go 2 way I'd use an 871 paired with a W5-876 on each side, closed box, xover at 500 Hz. This would, however, give you two 8 ohm boxes, so your receiver would have to handle 4 ohm loads to parallel two boxes. If you think that your current F3 is OK and just need more sensitivity using a pair of 871 per side makes things very simple.
morbo said:
I wasn't thinking of the Vandersteen design, in fact I was just thinking out loud. I've been experimenting with two W4s and two W3s but it's still a work in progress. Bill's suggestion of using the W5 woofer may be closer to the mark, however, I think having an F3 below 60Hz would only be necessary if you're doing multi-channel music without a sub.
In case anyone is interested, I was intrigued by the idea of having a speaker on either side of the TV, run mono, as a center channel. I did a little experiment since I have 2 of the little ELF 1.0s. Normally I use 1 on top of the TV as my center, instead I set them up on either side of the TV. I lowered the level of the center and tried some movies. In the sweet spot, this sounds really good, certainly more dynamic and less restrained than the single 871 on top. Also, voices come from the center of the screen instead of just above it. It does look kind of funny though, the center speakers are almost closer to the mains than to each other in my setup (I am about 7 feet from the TV/speakers).
The problem was, as soon as I moved off axis, the center image started collapsing into the closer center speaker very sharply. This may just be because my seating is so close to the speakers, that the sweet spot is very small. But since the whole point of having the center channel is better off axis 'anchoring', I abandoned the idea, since my 'phantom' center sounds better than these 2 anyway
Still, it was a fun exercise and I learned something from it, nothing like testing these things yourself.
The problem was, as soon as I moved off axis, the center image started collapsing into the closer center speaker very sharply. This may just be because my seating is so close to the speakers, that the sweet spot is very small. But since the whole point of having the center channel is better off axis 'anchoring', I abandoned the idea, since my 'phantom' center sounds better than these 2 anyway
Still, it was a fun exercise and I learned something from it, nothing like testing these things yourself.
Thats a good idea, unfortunately in my setup there's no way to accomodate it. My TV stand is made up of 2 wide, short TV stands side by side. So there is no cavity dead center below the TV that I could use.
In fact I may just sacrifice the top end for the low end, and build a similar single driver center channel using the CSS 4.5" XBL driver. This would have better power handling and low end response, but lose out on the high end. Not much dialogue up there anyway so it might be ok.
OR, I may nix the idea altogether. You see, I was planning on moving the ELF 1.0s up to a nearfield, 'personal reference' computer setup I'm building once I upgraded by center. Since I've started using the phantom center for personal listening (to great effect I might add), maybe I'd be better off spending my money on something better for the nearfield system, which will get hours of daily use, than on this center, which only gets turned on once a week at most. Besides, it only benefits my off-axis listeners, and frankly my non-audiophile friends are not going to notice the improvement anyway, they already think I'm crazy for spending money on this stuff Decisions decisions.
In fact I may just sacrifice the top end for the low end, and build a similar single driver center channel using the CSS 4.5" XBL driver. This would have better power handling and low end response, but lose out on the high end. Not much dialogue up there anyway
so it might be ok. OR, I may nix the idea altogether. You see, I was planning on moving the ELF 1.0s up to a nearfield, 'personal reference' computer setup I'm building once I upgraded by center. Since I've started using the phantom center for personal listening (to great effect I might add), maybe I'd be better off spending my money on something better for the nearfield system, which will get hours of daily use, than on this center, which only gets turned on once a week at most. Besides, it only benefits my off-axis listeners, and frankly my non-audiophile friends are not going to notice the improvement anyway, they already think I'm crazy for spending money on this stuff
Decisions decisions.
Good idea. That's what I use along with my S5 Electronics tube amp. Sounds great for a little near-field system.
http://www.timn8er.com/s5_electronics_k.htm
I'm beginning to believe that a phantom center is the way to go in HT unless you have a big screen that can have sound coming directly from it. I'm still thinking that in the future, when I switch to a front projector, an upper and lower center may work.
A horizontal bessel array works great for a center channel because it disperses like a point source and gives you some efficiency increase over a single driver. I believe the wiring for a 5 driver bessel is +1, -2, +2, +1, -1 . The minus drivers are just out of phase and the 2s get twice the power of the 1s through a combination of series/parallel wiring.
Yeah I saw a few folks on here recommend bessell arrays and I got pretty excited about the idea, seemed perfect. However when I started reading about them, I found that you have to be fairly far away from the speakers for the array to 'gel'. Since I am about 6-7' from my center channel, it seemed that it would not be useful in my situation. Otherwise, I'd jump on a 5 x 871 array in a heartbeat.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.