i have grounded my cerwin vega re-30. they were being used as my rear channels. so i reversed the room layout. put the tv and everything on the oppsite wall and hung my nht2.5i upside down using the same celling ancors. re-30 are still rear channels. half inch i bolts screwed into the threaded t-nuts used for the outriggers. i used a washer and a nut to lock the i-bolt in place. used black webbing and a swivel to string it all together. t-nuts should only see about 14 lbs of weight each. i did this about a week ago and i have seen no problems. the grills even went on upsidedown to keep name upright. the tweater is just over ear level while sitting.
now using a swivel the speakers can move freely in any direction. i tried using chains but it looked awful, i could not get them square to the room and it put the speaker in direct contact with structure of the house (which i think is undesireable).
so they can move in any direction they want, and with side fireing sub this could get intersting.
i put a lazer on top of one of the speakers facing the oppsite wall. any movement showes up. it took about 10 minuts for them to stop moving after i set the lazer in place.
i just got started with the lazer and it seems that the speakers sit just as still as i do. if i sit still the lazer does also. if i walk quickly around the house they will move a little bit. if i simply blow on the side of the speaker the lazer moves off the chart. none of this movement is seen without the help of the lazer.
that being said, the music does not seem to cause them to move at any volume. i am on my second disk (foxy brown/broken slience), before that was eagles, greatest hits vol 2. trust me i crank it up when i get the chance. i don't have any test cd's but i think i will try "fat boy slim" next.
the lazer i'm using is craftsmen lazer/level. i will continue to listen to loud music of all kinds and report back the first time i see that music has made the speakers move. |
The experiment has been run, and here are the results.
The Boston Acoustics speaker weighing ten pounds was suspended by a single rope, so that it was about ¼ inch above a table top..just about ear level for a seated person. The center of the speaker was 63 inches from the pivot point in the ceiling, and the period of pendulum swing was measured as 2.5 seconds, which is 0.4 Hz. Loud organ music was played
as loud as the speaker could handle.
Because of the way the speaker was hung it never completely stopped swinging at 0.4 Hz. The motion was about 1/8 inch peak to peak. (The motion was easy to evaluate because the speaker was ¼ inch from the table top). This was with no music playing. If I were going to hang speakers permanently I guess I would use three ropes/chains.
When the music started the small motion of the speaker was very carefully observed for any change relative to what was happening before. There was absolutely no effect as a result of playing the music. The test was repeated about five times.
This is the first time I have hung a speaker in many years, and although when I did I never was conscious of them moving, I must admit that I never looked for movement at the level of this experiment.
By the way, the little box sounded much better than I expected, and I think that I have solved the problem of where to put the rear speakers in my HT set up. Up till now the B&W 550s have just been kicking around behind the couch. |
Eldartford...I am looking forward to your report. |
Bottom line regarding why they sound better where they're at is that the speakers are probably in a much better acoustical spot overall! If your speakers are coupling with the room (bass) better, and imaging better(in relation to room boundaries from where you are sitting/listening), it's because the location is better than it was, in relation!
Speaker/seating location, location, location!...nothings changed... |
Line...I have a little Boston Acoustics A40 that I will try. I have weighed it (10 pounds) and trussed it up with a rope so I can hang it. I haven't got around to doing the experiment yet...will report results. |
Eldartford...I hear you. There is one thing that i can think of that may have made these 901's move...could it be that these speakers have a port and a burst of air coming out of the port could get them to move? |
Line...Unfortunately no audiophile on this site would confess to having Bose 901s, so we can't check this out. :-) Maybe I'll give it a try (quickly so the wife doesn't see) with a Maggie.
Your point is well taken that those Bose 901s have a lot of driver relative to the enclosure. But the only way for a tiny push to get a heavy pendulum swinging is if the force is timed and repeatedly applied at exactly the pendulum swinging frequency: in our case this would be 1 Hz or lower. However, audio signals would push and pull more or less equally at 20 Hz or higher, with no mechanism to get synced up with the pendulum swing. Maybe you could do it with a specially designed test signal if you had a DC-coupled amp. |
There is a post or two on this thread that suggested that a speaker could not be moved by music, at least not in a way that could be seen by an observer and i just though i would post what i have seen; that's all. If any read anything more then that in my post, then it is your head, not mine. I have never seen speakers move since then. The 901's have a lot of drivers for there cabinet size, perhaps this why they able to moved so much from this burst of sound, maybe the canon shots in Tchaikovsky 1812 Overture would do the same thing: i don't know. I don't think music could be found that would have the right timeing in pumping action to match your speakers mass that would get then swinging more and more like a child on a swing. I must say, that there is some music that moves me. |
As I said, some people will continue to believe that music will set suspended speakers swinging, until they actually try it. Of course (unless you use three chains) they can swing if you get them started some other way, like a room fan. |
goog point, Gregadd. so it is possable the speaker does not move at all.
most speakers are kind of tough to hang and make look nice without using a drill. the outriggers on my nht2.5i should make a good platform for hanging upsidedown. i might be able to find an I-bolt that will screw directly into the threded holes the outriggers use. the grills will install upsidedown to keep the name upright, without changing preformance. i can then put my sub directly underneath one of them, killing 2 birds with one footprint. |
try to push a boulder. It doesn't move because the boulder push backed absorbing the energy. |
Yes...Like a child on a swing. |
the fact i have not seen the sp move do not mean it is not moving, it is moving back and forth in oppsite direction of the woofer. the mass of the air being moved in relation to the mass of all non moving parts of the speaker will determine how much along with a bunch of other factors, musical input would play a big part. with the right imput you could have them swinging back and forth with ease.
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the fact that my dogs can't physicaly pee on my speakers is enough for me, not that they would. young children cannot comprehend the importance of our highly valued speakers.
now i have seen a speaker box thrown back and forth like a rag doll. high grade sudwoofer in a cheep technics 3 way box hooked to carver tfm15 that was in mono config, and the box was on the ground. so i am sure it is possable. i just havent seen it in a stock speaker. |
Newbee...Yes that's what Newton said, but he also explained how to calculate how much that reaction would be. We agree that other effects swamp speaker movement, if any. |
Didn't Newton say that "for every action there is a reaction"? The issue isn't whether or not something moves, however imperceptively, its whether or not the movement makes a difference, sonically speaking. IMHO any differences caused by tiny movements would be swamped by other issues such a reverb in the room from the loud sounds which would be the result of the woofer cones excursions needed to cause the substative movement in the first place, etc. All the pro's and con's on these issues makes for some interesting speculation and a lot of testimonials, but beyond the issues of proper isolation from other surfaces, I really think they have little merit in the real world! Now hows that for a pile of crap! |
Well...i have to tell you; you had me doubting my memory, so i call my friend that was with me at the time when we seen the 901's and he remembers the same thing. It surprised us both and we looked at each other. He recalls the music; it was used in the movie Close Incounters of the Third Kind, where there is silence and then a powerful VAAROMMM. This made them move about 1/2" or so. They were hanging high, maybe 2ft. from the ceiling and 2ft. from the side wall and back wall. I attest, they moved. |
Line...You need two chains to avoid the speaker pointing in different directions. If you use three chains, it can't swing either. |
line, yes each speaker hangs to this day with 2 seperate chains. |
gmarcotte@...Do you know if each speaker had two chains going to the ceiling or more. This would make the difference. |
my step-dad had a set of 901's hanging by chains. i never saw them move but i did hear them one time clear as day and i was outside about 200 yards from the house. phase linear power amp as i recall. |
About 30 years ago i remember Boze 901 hanging by chain in a Hi Fi shop and soft classical music was playing. Suddenly there a very loud passage (VAAROMMM), this got them swinging a bit. |
i used 2 i bolts in the ceiling, a brass swivel and a bunch of black nylon webbing, (like seat belts are made of), to make a harness. |
i have a pair of cv re-30 hung upsidedown, to keep tweeter at ear level, for 10 years. 200 watts to each, even with the 12's maxed out on hip hop ive never seen them move. i have been thinking about putting my nht 2.5i in their place upsidedown after checking with nht about innerds. hanging them will give u more floor space, sound better, and keeps small hands, and pets away from your speakers. only problem ive had is a baffel came loose, needs some gorrila glue. if i figure out how i will send a picture. |
"Hanging them,you still will get vibration from the ceiling going down the wire to the speaker." They actually make vibration dampners for hanging speakers. Check this link to see'em. |
Albertporter...True, but...with the exception of Klipshorns and some Allison (sp?) speakers that were designed with room boundries in mind I find that the bass augmentation due to walls and floor sounds false to me. I prefer less bass, unless I can get it directly from the speaker.
I suppose it depends very much on the speaker used. Two that I have heard that were great suspended were Maggies (with a cathedral ceiling) and (believe it or not) Bose 901 (original model). |
Many speaker designs benefit from boundary reinforcement (bass gain) from proximity to foor plus rear wall. Put the numbers into CARA and view the huge difference placement make. http://www.cara.de/ENU/index.htmlBookshelf speakers in particular are seldom the last word in bass response, hanging them could cut further into perceived bass response. Ultimately, if you like them hung, go for it. If not, there are dozens of floor stands you can try. |
How far are they from the floor? I tried this a long time ago but looking back think I hung them too high (ear level when standing). |
Hanging sceptics will never be convinced until they try it. For those who have a logical bent, the following points may be of interest.
1. The mass of the speaker cone, and the air it moves, is tiny compared with the mass of the loudspeaker enclosure. For this reason movement of the enclosure will be unmeasurable. Vibration of the typical enclosure wall due to internal sound pressure will far exceed motion of the entire enclosure.
2. If the ropes or chains that suspend the speaker are three feet or more long, the pendulum swinging frequency of the rig will be 1 Hz or lower. No audio signal can excite swinging at this frequency.
3. The loudspeaker cone that emits midrange sound is vibrating a great deal at lower frequency, and when LPs are played, pushed in and out at subsonic frequency due to record warp. This does affect sonic quality, tolerable, but much more than any loudspeaker enclosure vibration.
4. When music is played the instruments move around a good deal, and even audiophiles don't usually put their heads in a clamp when they listen. Even if the speakers should move around a bit it wouldn't matter.
In my opinion, enclosure vibration is not a real issue however you mount it, (so long as it isn't so loose that it rattles) but hanging the speakers in free space away from floor and walls is good. Tall skinny speaker stands do the same thing. |
In live sound they hang speakers all the time. It tends to be one of the best ways to mount speakers. |
I hung some old pioneer speakers I bought mail order. but later it was proved they were innocent. It was the amp! |
RF, I hung a cd player some years ago from my ceiling, at the time I thought the sound was better than any other placement. I remember reading some years ago that using monofilament fishing line was the best material for hanging, very interesting! |
No Text Here, just more whining!!! |
Don't forget that there are two things you can do with speakers and floors: couple and decouple. It all depends on the underlying floor material, room acoustics, speaker characteristics etc. |
Love the feedback. Glad to know this has been tried successfully.
thanks all,
rf |
The main benifit of spikes is to create a stable and solid base for the speaker. No floors and no speaker bases are perfectly flat. By using 3 spikes, this creates a "tripod" type mount that can't rock in any direction.
My guess on hanging the bookshelfs is that the benifit of getting them up to listening height is more benificial than a solid mount. I doubt this would happen with larger speaker/woofer cones. I would like to hear your comparison of hanging vs. a good stand with spikes. |
newbee spkes where designed to penetrate carpet. For bear floors use tip toes. this increases dramtically the pressure (PSI)seen by the floor making it much more difficult to vibrate the speaker. |
Xenithon & Eldartford, I find your certainty on this issue refreshing, I've always suspected as much but have paid hommage to the speaker manufacturers who supplied their speakers with spikes (over 20 years ago!) and gave that reason (smearing from speakers boxes moving due to the pistonic action of the woofers) for their use. They never even mentioned the benefits that many now attribute to spikes and isolation devices.
I have a question for you. Assuming the correctness of your statement, if you were putting speakers on an uncarpeted concrete floor (covered by vinyl or thin hardwood) why would you ever need a coupling devise, such as spikes? And, if you were putting the speakers on a suspended hardwood floor why would you use spikes if they served to transmit vibrations from the speakers to the floor which would then resonate and add to the sonic mix.
I guess I just don't know what the benefit of spikes must be, except when used thru carpets to creat coupling with the floor beneath. What I have noticed is that there are a lot of advocates for spikes and a lot of reasons why they work in all sorts of applications other than coupling thru carpet. I've never expirimented - I've always had suspended hardwood floors and chose to decouple the speakers. Whats the straight scoop here? |
I think stability is the best approach.
Hanging them,you still will get vibration from the ceiling going down the wire to the speaker.
Try some cinder blocks.Different sizes avaliable.
I built some cinder block stands for a pair if dynaco A-1's I picked up for 5 bucks/pair.
The blocks are 6"x6"x18" high and solid,not hollow.Weigh a ton!
I painted them black,liguid nailed them to some 12"x12" ceramic foor tiles (for the base) I then put 4 round,wooden balls (walMart) under the tiles and put some blu-tak on the top of the blocks and speakers on top and have some very heavy and solid DIY stands.Total cost ~ $10/pair. |
Absolutely the best way to locate speakers (from the acoustic point of view). Not popular with wives. Ignore all the talk about the speakers moving. They don't. |
That assumption has been proven wrong. Not sure where exactly but I remember people doing experiments. They found that, even with large speakers with dual 10" drivers, the amount of air they moved induced minimal movement, not enough at all to cause any type of smearing. |
i had thought to try this a while back. it was explained to me that the drivers are supposed to move air and that this way they are also moving the speaker.was that incorrect? |
The only down side that I can think of is that the movement of the drivers might cause the speakers to move imperceptively and cause some sonic smear which could effect the speakers imaging. Thats one of the principal reasons for putting speakers on spikes on the floor. Eliminate the potential for movement. If imaging isn't a big deal why not. |
I remember doing that in the late 70's. My wife would shoot me if I tried it now. I have to get either a divorce or a music room! |
Being an audiophile you have to be crazy? This is actually the preferred way to do it.
greg |
Haven't done it but have heard of it. Meant to be the ideal means to isolate the speakers from the floor, which is especially important with resonant floors such as suspended wood etc. The main difficulty is actually having them in a safe way (wouldn't want $10k speakers falling on the floor now would we?). This is most important in cases where your speakers are heavy - 50+ lbs per speaker. |
