monitor speaker stands built by Jstas' dad - very nice!

WOW! Nice custom made speaker stands! Congrad to you and Jstas's Dad for the great work!

You really don't need anything, they sit pretty well as it is.

I sat KLH Model 6's on them and they are much larger and heavier speakers, just to test out. They didn't move at all, even with them playing and vibrating.

But if you are really worried, some of the Rubbermaid foam rubber shelf liner would work out just fine. If you are interesed, a lip could be put on the backs too to keep them from sliding off.

Very nice work. I'd like to get some taller stands more like those eventually. I've got some original stands with my 7's, but they're the shorter ones. From my listening position, with the speakers on the stands, they're still about 9" below ear level.

cnh wrote: »

They look great...is the reason they tilt due to the size of the Monitor 7s and the attempt to point the tweeters at ear level?

cnh

The reason they tilt is basically a cheap form of time alignment.

On more expensive loudspeakers, you'll notice that a lot of the time, the tweeters are mounted on top of the speaker, and set farther back than the mids and woofers. This is because high frequency waves travel faster than low frequency waves, which can cause a delay in the times at which the separate frequencies hit your ears.

Tilting them back pulls the tweeters back a little farther, and makes it so that the various frequencies are all getting to your ears at the same time. Using tilted stands is much cheaper than actually building a time aligned speaker. The Polk RTA12's are basically part of the Monitor series but were truly time aligned, and were also more expensive. They also didn't come with stands to the best of my knowledge.

It does make a difference, I've listened to my 7A's both with and without the stands, and it's noticeable.

It does also help to get the tweeters up to ear level.

gdb-The original stands had small round pieces of a foam rubber like material on each corner of the stands for that purpose. I doubt they're even necessary though.

nice work, indeed.

comfortablycurt wrote: »

The reason they tilt is basically a cheap form of time alignment. On more expensive loudspeakers, you'll notice that a lot of the time, the tweeters are mounted on top of the speaker, and set farther back than the mids and woofers. This is because high frequency waves travel faster than low frequency waves, which can cause a delay in the times at which the separate frequencies hit your ears.

Tilting them back pulls the tweeters back a little farther, and makes it so that the various frequencies are all getting to your ears at the same time. Using tilted stands is much cheaper than actually building a time aligned speaker. The Polk RTA12's are basically part of the Monitor series but were truly time aligned, and were also more expensive. They also didn't come with stands to the best of my knowledge.

Curt- sound travels approximately 1100 feet per second be it 20 Hz, 20 kHz, or anything in between. The one and only reason for the tilt back of the Monitor stands is to align the tweeter axis with the listener’s ears.

In addition to the set back of the drivers, in order to exhibit true time alignment, the crossovers used in the speakers must be first order filters which the Monitor series of speakers definitely are not. True time alignment can only be found in Vandersteen, Thiel, VMPS, etc. speakers.

As I posted a while ago, I was an original Monitor 10 owner (1980-1990) and recently scored two pairs of Monitor 10s manufactured in 1978. All four speakers are in perfect condition with Peerless tweeters and the original warranty cards still attached to the back of the speakers.

I’ve been formulating in my head a future post to explain what I think is far and away the weak point of the 10s; that being the stands. Like my new old 10s, the (short) stands are in perfect condition but leave much to be desired. Just the slightest touch can rock the speakers fore and aft while they are almost impossible to move side to side.

Unfortunately, as Professor Newton liked to say “for every action there is an equal and opposite reaction”. I say unfortunately because all of the drivers in the 10s are moving fore and aft in response to the music. The fore and aft motion of the drivers is being converted to a fore and aft motion of the speaker thus not allowing maximum transparency or detail. Worse is the muddying of the base response, which is usually blamed on the side-by-side setting of the two active mid-woofers (which may be true too).

I attribute the fore and aft rocking of the speaker to:

1- The base of the stand to the floor should be three or four point contacts, not a large flat surface to the floor
2- The rubber pads between on the top plate of the stand and the bottom of the speaker are in shear rather than compression due to the tilt of the top plate resulting in the speaker trying to slide off
3- Well, the tilt of the stand itself

So what to do? I’m going to fabricate four new stands for the speakers. The stands will raise the tweeter axis to ear level and eliminate the other deficiencies I describe above. I still need to decide whether to use wood or metal for the stands. I will report back when the stands are completed. This will take a while as I'm building a home theater in the basement.

By the way a good friend is (still) an original Monitor 10 owner from 1989. His 10s came with tall stands that raised the tweeter axis to ear lever without the tilt.

Russ

Well, according to everything I've ever heard, the stands were essentially intended as a cheap form of time alignment. Cheap being the key word here. It's not a truly time aligned speaker...they aren't claiming it to be.

Also, according to everything that I have ever read in regards to the speed of sound, high frequencies travel faster than low frequencies.

I don't ever really have these issues with the stands that you're talking about, mine don't really rock back and forth to much. Not enough for it to be a concern of mine anyway. They're very solid. I have considered putting some spikes on the bottoms though just to decouple them from the floor a little bit.

Russ_L wrote: »

AND, the speed of sound is independent of frequency. It mostly only varies with altitude.

Russ

Well, given that information, what is the point of even building a time aligned speaker? If high and low frequencies move at exactly the same speed, what are the benefits of having time alignment? Why is it called time alignment if it isn't aligning the time at which the different frequencies arrive?

I'm not saying your wrong, but your thoughts here are going against basically everything I've ever read on the subject.


I also have to strongly disagree with your statement of the stands being the weak point of the Monitor Series. I have a pair of 7A's, that didn't come with the stands. When I was initially using them, I had them on stands that were about 8 inches off the ground, and flat on the top.

I managed to track down a pair of original stands after having the 7's for a couple months, and noticed big improvements in the sound once I got them on the tilted stands. They sit about 2 inches lower than they did before, at roughly 6 inches. They sound much better though with the degree of tilt on them. It made the distinction between the different frequencies much sharper...the midrange cleared up quite a bit, the highs got a bit sharper and cleaner. Low end was possibly reduced a bit in overall quantity, but became much tighter and more focused overall.

Looking good.

Russ L, you need to go back and learn about Newton's laws again.

Your assertion that a speaker cone movement has an opposite reaction on the tilted stands is flawed.

Your hand is capable of much more force than any combination of speaker cones in the Monitor speakers. Your hand being able to move the speaker is not "a bad thing".

Newton's Law states that for every action there is an OPPOSITE and EQUAL reaction. They also state that an object at rest tends to stay at rest until an action of EQUAL or GREATER force acts upon it.

Yes, the speaker is creating an action. Yes, there is a reaction. But, due to the overall mass of the speaker AND the air pressure behind the cone, the force reacting to the movement of the cone is several times greater than the action of the cone.

Therefore, Newton's Laws state that given the physical work done by the cone in addition to the mass of the cone and many, many other factors, there is not enough force contained in the action of that speaker to move that enclosure. The enclosure is therefore an opposite force of EQUAL or GREATER magnitude than the force acting upon it.

In other words, Newton says ain't no way in hell your hand theory is gonna prove that those speakers are moving the enclosure.


BTW, thanks for dumping all over Al's thread and, honestly, my dad's work.

DB those look awesome. And by those I mean both the M7 and the stands. The M7 is on my list of speakers to own.

Scott

Old thread, but lots of good info here.
Incidentally, what is the degree of tilt of the original Monitor 7 and 10 stands, as seen in the attached brochure.
Anyone have an original set and can post some pics??
Thanks.

I found this.
Appears to be one of the original designs.
I did a speaker stand test with 3 different heights and angles.
One was a set of Polkstands with the stamped metal top. Also used Plateau stands with the fronts about 7” from the floor. Last pair were no name brand 6” from floor in front and 12 degrees of tilt.
I used Ohm C2 speakers. They sounded like three totally different speakers!!!!!!!! Just sayin that stands make a huge difference.

In relation to the speaker cones movement rocking the speaker back and forth, no one has mentioned the fact that the passive radiator counteracts the movement of the “mid woofers”, 180 degrees out of phase.
Mid woofers move in, PR moves out by internal air pressure exceeding atmospheric..
Mid woofers move out, PR moves in by atmospheric pressure exceeding cabinet pressure.
This would cancel out most, if not all of any movement.
Not that I think that there would be any movement except at low frequencies.

I’ve seen sub woofers move, especially ones with woofer and PR mounted at opposite ends.
Also large subs if in a light cabinet.

Oh, and I like your dad’s stands. He does good work.

Mr Relish

One reason Walsh speakers sound good. Vertical cone movement means no horizontal rocking.
Less doppler smear.

High end speakers weigh a lot for stability and to lessen cabinet coloration.