Monitor 12s in smaller room

fullvolume

I've owned a pair of Monitor 12 Series 2 speakers since new. I moved to a new house about four year ago and am just getting around to setting them up again.
However, they used to be in my main living room/dining area, an open space about 24x16ft, now my largest room is 14x12ft.
In the idea of saving floor space, I'm thinking of placing these up high, atop two end tables, a quick test run so far seems to work real well, it lessens the amount of bass transmitted to the floor and the rest of the house but they still seem to have that punch they always did.
Is there any rule of thumb as to how high, or how big of a room a certain size speaker should be used?

I've also got a pair of SDA SRS 2.3TL's, a pair of SDA 1A's, a pair of Monitor 10 Series II, a pair of Monitor 7's, and a pair of Monitor 5jr's. The 5jr's were always set up next to my 12's for late night listening, they sounded better at lower volume levels and they didn't impart as much bass to the structure of the house.

Nightfall

Tweeters at seated ear height. Monitor 12's on top of end tables are way too high.

pitdogg2

Nightfall wrote: »

Tweeters at seated ear height. Monitor 12's on top of end tables are way too high.

yep that would be a mess

fullvolume

That explains a lot. The most common seating position is at the bar between the dining area and living room, this puts the speakers about 14' away, and they're spaced about 12' apart.

For some reason I really like the way the bass feels and sounds when their elevated.

lawdogg

I think a little elevation can clean up the bass in a small room. Some experimentation may be in order in your new room to get em where you like em.

Mystery

If you really have to raise them, tilt them so the face angle is perpendicular to where you sit.
It's easier with small speakers but 12's are huge.
12's sounded good but small space makes them muddy.

fullvolume

I'd be a bit afraid to tilt them forward, they're a bit top heavy and when they were sitting on the plush carpet, they were a bit tippy. The lower stands tilt the speakers back about 5 degrees.

When I put them on the floor, I don't like the mids or the bass, it seems to get lost somehow, but when their up high the bass hits so hard I can feel it in my bones.
They also don't seem to come alive here like they did at the old house. There they were mounted on a 14" tall ledge along one wall, the rear wall was stone, and the rest of the room was wood paneling. Now the room is drywall and half the size at best. I'm also thinking the multi-angle ceiling has something to do with what I hear.
They do 'wake up' at higher volumes, but not till the point they're likely doing hearing damage.
I switched over to a Yamaha Natural Sound receiver today, but the sound is the same. The Yamaha is less power, only 65w/ch. RMS, vs the Pioneer's rated 100w. The Pioneer drives them far better up high but they sort of 'kick in' at about 1/3 volume. With the Yamaha, they improve sound wise gradually as the volume is increased.

pitdogg2

Not many receivers will do them justice, and that's a fact Jack.

TCK

I found that if you disconnect a mid-driver or two, they become more efficient & are easier to drive if you are lacking the wattage &/or room conditions.

fullvolume

I have a few separate amps that I can use but the Yamaha and the Pioneer receivers sounded better. I've got three preamps, one is an older JVC 4vr-5446 receiver with preamp outs, which sounds just plain bad to me, I've got a Nakamichi RE-3 receiver which I can use as a preamp but the sound is too bland or sterile, something is missing, and I've got a late 80's Kenwood preamp but that just don't sound right either. The Kenwood was part of a rack system at one time.

I've got a Pioneer SA-8500, Crown DC-300, Adcom GFA-545, and a Niles 2125T, The SA-8500 doesn't have enough power, the Crown isn't much better and is noisy, the Adcom is ok but doesn't sound as good to me as the larger receivers, and the Niles doesn't seem to be anywhere near the 120w its advertised to be. The Niles has good clear sound with good separation but its weak compared to even the newer Pioneer receivers.
I have the following receivers here,
Pioneer SX 303S, VSX D504, VSX 503S, SA 1980, and a SA 1280.
Yamaha RX-V480, RX-V490
Nakamichi RE-3
Harmon Kardon 560, 630, 730 and a 930 (The 560 is my favorite)
Radio Shack STA-2100, STA-64
LXI 430(Sears by Sanyo)

I had actually picked up the Niles figuring it would give me some better quality sound than any of the older stuff but I haven't found a good preamp yet to make that work.

boston1450

A decent preamp on the 545 should be a good fit. 565 maybe-which usually can be had fairly cheap & has a decent phono on it

fullvolume

boston1450 wrote: »

A decent preamp on the 545 should be a good fit. 565 maybe-which usually can be had fairly cheap & has a decent phono on it

I've seen a few GFP465 preamps around but they've all been out of my price range. As it stands, most all of my speakers and equipment has come from yard sales, estate sales, and flea markets.
Sound wise, all the Pioneer receivers and amps sound the same to me, the Yamaha is right in that same bracket as well but with less power.

I did forget to mention that I've got an Onkyo A7 and an A10, both integrated amps, but they don't sound much different than the Pioneer receivers. The best sound in my opinion out of what I've got here comes from the Harmon Kardon 560, but that's only 40w/channel, although it seems a lot more powerful than what its rated at.

Power wise, the SX 1280 and VSX D504 are the strongest by far but they seem to lack detail in the highs and mids.

boston1450

Yupi hear ya. I took a look on the bay & those prices are more than i paid for my 555amp565pre.

fullvolume

Way back in the early 80's when I was really into buying stereo stuff, I had listened to various set ups at a few of the local hi fi stores around at that time, the way it went was Polk, JBL, Advent, Pioneer, Onkyo, and Kenwood were the names I saw, speaker wise it was a toss up between the JBL and Polk speakers for me and my tastes would go back and forth.
Amp wise, there as also Nakamichi and Carver in the mix, and if you had real money, maybe McIntosh. Names like NAD, Adcom, Crown, and such were usual sort of a side line. The systems you heard set up in the sound rooms tended to be big receivers with their best speakers. Separates were few and far between.
For the most part, other than places like Sears, these brands were hi fi dealer only names. I think I paid close to a grand for my SX 1980, I was in high school at the time and it took a lot of side jobs to buy that one, the SX 1280 was a hand me down from a buddies brother and it got retired when I bought the SX 1980. A number of years later I discovered Harman Kardon after I was given the 630, the sound detail was so much cleaner than the big Pioneers but it didn't have the big bass that I got from the big Pioneer. I first bought a set of Montior 5jrs, then a set of Monitor 7's, then I moved to the Monitor 10's. The 5jrs and the 7's were my favorite then.
The Polks went with the HK, the JBLs went on the big Pioneer.
When I bought the Monitor 12s in 1990, I had already retired the big Pioneer for the most part in favor of an Onkyo A10 that a buddy brought back from Japan. That powered the Polks and my JBL L100's, which were set up on a four way speaker switch. I bought the A7 and another set of Monitor 10's off a buddy who was going into the Navy back around that time.
I bought everything he had, at that time except the Sony CD player he wanted to keep. It all sounded fantastic at his place, which was basically a converted garage apartment. I set it all up in my living room at the time, but with a newer Pioneer CD changer. It never sounded the same here, the speakers sounded under powered or lacking that mid bass kick they had at his place.
I sort of get the same thing with the Monitor 12's here, they were amazing at the old place, but here they sound sort of weak or distant. They lack crispness.
I've tried several CD players, and several receivers and even the one Onkyo integrated amp but nothing seems to make much of a change.
Before I brought them back here, I had them wired up in the storage building for a bit and they sounded great there, in a metal building with concrete floors.
Here I've got low ceilings, and wall to wall carpet.
What I get is a very narrow sweet spot for listening to them. If I'm not pretty much at the center of the optimum triangle for listening, they sound pretty bland.
They do sound better up high, on the floor they seem to loose that mid bass punch I like. I dug out my Monitor 5jrs and they sound better, but they don't have enough mid bass for me. At lower volumes, their easier to listen too.

My Adcom amp has pretty much sat over the years because I've never found the right combo to get what I felt was good sound from it. The big Pioneer receivers always trumped it power wise when it comes to bass. The Adcom was bought used, a buddy bought three of them to get a matched pair to run bridged, and I got the third one. He's running a tube preamp from China.

Is there any particular brand of amp or receiver that works better with the Monitor 12's? If I have an idea what may work better, I know what to look for in the flea markets and yard sales around here.

F1nut

I'd be a bit afraid to tilt them forward, they're a bit top heavy and when they were sitting on the plush carpet, they were a bit tippy.

Since you are sitting higher than normal, tilting the speakers is not required or advised.

You have to spike any speaker that is on carpet. In fact, any speaker sitting on a floor, carpeted or not should be spiked. Spiking also lessens the amount of bass transferred to the floor and cleans up the mids.

You're chasing a problem with different power gear when the problem is the crossovers. It's way past time for them to be upgraded.

Not to insult, but you could sell all of that so-so gear (except for the SX 1980} and put the funds towards a really good newer integrated amp or separates. If the SX 1980 hasn't been recapped/serviced, you should have that done.

fullvolume

The SX -1980 had an issue with one channel cutting out after it played for about four hours about seven years ago, at that point I hunted down a full set of replacement output transistors and a full set of poly caps for it, it fixed the issue at hand, but didn't change the sound in any way.
I pulled the cross overs in my Monitor 5jr's, and the 12's, all but one cap appears to be a poly cap already, I separated and tested the remaining electrolytic cap and both were within spec.
I wasn't leaning toward it being a crossover issue since they sounded good in the old house, and they sounded good in the storage building.
The ceiling is slanted to one side, there's a low side and a higher side and one point that drops down a bit. The overall space narrows as it reaches the mid point since the living room is wider than the dining area.

The one thing I like about my other large speakers, primarily those with 12" or larger woofers is that they do impart the bass on the room, but they lack the sharp mid or upper bass that the M12's are so good at.

F1nut

Poly power supply caps in the Pioneer?

Those are mylar caps in the Polk's. Film and foil caps, such as Sonicap, even in the shunt circuit are far superior. Upgrading the resistors to Mills will help clean up the sound as well.

fullvolume

The filter caps are stock type , they came from Japan, a buddy there sourced them for me. He's restored a handful of these and pretty much supplied me with a blueprint of what to change and what to modify.
His background was in military contracting, mainly in communications and had a good bit of the parts on hand.

Do you have a parts list for replacements for the xover in the M12's?

F1nut

Ok, they are electrolytic as they should be. There are only so many Japanese cap makers and while some are better than others when it comes to power supply caps, Mundorf and Kendeil are the best, IMO. Stick either of those in there and you will hear the difference.

There does not appear to be a schematic available for your speakers, but it's always best to get the values off the crossover itself. If you don't know what the printed info on the caps and resistors mean I'd be happy to help.


Reading back, I need to clarify something. The comment I made about not tilting your speakers was referring to them being on end tables. If they were on the floor with you sitting at bar height, then yes, tilting them back (not forward) would be an excellent idea.

fullvolume

The largest cap is yellow, its marked only with E-0012-1 & 12J10CV + made in Mexico.
The two smaller caps are marked 4.2 and 4.4 uF, and there's two more that have no visible markings, these are lighter blue and glued directly to the board.
I see one ceramic or cement resistor that's piggy backed atop a pair of caps.
The markings on one of these resistors are smudged by the hotglue melted over top of them. The resistor on the other cross over has no visible markings, unless their underneath.

I have a cap tester, two actually, one newer digital model and an old BK tester.
I don't doubt that the caps aren't what they once were but the sound issues I'm having aren't present in another location. These sounded really good in the storage building, which is basically a steel structure 6 car garage with a concrete floor. When I fired up these speakers there they were sitting atop an old desk, I hooked them up to the same receiver they're hooked to now in the house and they lack separation and detail, if they sounded bad in the storage building, I'd have left them in storage. When I had them playing there they were bright and clear.
I've even gone as far as checking line voltage at the wall outlet here which is fine at 117v.

F1nut

The largest cap is yellow, its marked only with E-0012-1 & 12J10CV + made in Mexico.

That one is a mylar, it's a 12uF 100 Volt. The "C" in 10CV is actually a zero. The "J" indicates a +/- 10% tolerance.

The two smaller caps are marked 4.2 and 4.4 uF

Ok, likely to be either 50V or 100V. All new film and foil crossover caps are at least 100V, so no worries.

there's two more that have no visible markings, these are lighter blue and glued directly to the board.

They will have the values on them. You'll have to remove them. Use denatured alcohol to loosen the glue, remove it by peeling it off, then desolder the caps.

The markings on one of these resistors are smudged by the hotglue melted over top of them. The resistor on the other cross over has no visible markings, unless their underneath.

You'll have to remove the glue and possibly remove the other resistor to see if the value is on the bottom.

Forget testing them, even if still in spec they are crap.

In a building like that I'm sure they were bright with reflections bouncing everywhere. Not what one would call a good room or sound. Perhaps, you need to adjust to the way they sound in a better room. Bright is not a positive attribute.

agfrost

I believe this is the schematic for the Monitor 12 Series 2: Note the SL2500 tweeter on the schematic, this should indicate the Series 2. Has your parts list on the bottom; looks like there are matches to what you've seen (12.0uF mylar, 4.2uF electrolytic). It's probable that the 4.4uF cap you're seeing is paralleled with a 12uF cap, giving the 16.4uF value that the schematic IDs as 'C1', in the woofer circuit.

https://us.v-cdn.net/5021930/uploads/attachments/4/6/7/2/8/18782.pdf

F1nut

Good find Jay, that's it.

westmassguy

The original and revised schematics both show a SL2500 Tweeter. On the revised schematic, a Polyswitch and Shunt cap were added to protect the tweeter. The Polyswitch should be replaced with a new, equivalent RXEF090 TE Polyswitch. It cannot be eliminated or replaced with a fixed resistor, like we do with other models.

agfrost

westmassguy wrote: »

The Polyswitch should be replaced with a new, equivalent RXEF090 TE Polyswitch. It cannot be eliminated or replaced with a fixed resistor, like we do with other models.

That's interesting. Can you explain why that is? (Please read that as an honest question, not any sort of challenge.)

westmassguy

Best guess, Polk added the Polyswitch and Shunt Cap to protect the Tweeter from being over-driven. If the current exceeds the Polyswitch's rating, it opens. All the signal now flows through the Shunt Cap. When the 4.2uf Shunt Cap is added in series with the 12uf Cap downstream, the Capacitance is lowered to approximately 3.1uf, and the Crossover Frequency is raised. This, in theory, would prevent excessive coil movement, saving the Tweeter.

agfrost

In light of Dave's (westmassguy) post, check the other schematic to see which matches your crossover, the original, or the revised.

The presence or absence of the polyswitch will likely be the easiest way to determine which schematic is appropriate for you. (A simple "parts count" isn't foolproof because sometimes Polk used multiple caps in parallel to achieve the capacitance indicated by a single cap on the schematic.

There's pictures of some of Polk's polyswitches in the first post of this thread. Yours, if present, will look similar if not identical.

fullvolume

I attached a few pics of one of my crossovers, the parts list appears to be as follows,
a pair of 12uF-50V caps, one is piggy backed with a 4.4uF cap, and the other with a 2 ohm/10% resistor, plus one 4.2uF cap (piggy backed with a poly switch) , and one 12uF-100V cap.

Is there an advantage of using two caps vs one larger one? (Other than cost.)
Is Sonicap the best choice here?

agfrost

Sonicap and Polk crossovers are a proven combo. (I've used them in my two crossover projects). They're also a nice company to work with; you can order custom values from them very simply (phone call). They stock both 16uF and 17uF, either of which are within the 10% tolerance, but you could call and ask them to make a pair of 16.4's if you're OCD, but probably not necessary.

Others have used *cheaper* (Dayton, Jantzen) or *different* (Clarity ESA); but I cannot comment there.

No benefit to you to have two values of caps paralleled. From your picture, I assume the stack that includes the darker blue small cap is the 12uF + 4.4uF--You'd just want to add a single cap of 16.4 (16 would likely be OK). I just imagine Polk had a zillion of the 12uF caps back stocked in the factory back in the day, and would parallel whatever value with it that the particular model of speaker needed. Here's a picture of the original crossover of a RTA11TL I re-did several years ago:



I just replaced the two yellow mylars with a single 16uF Sonicap.

westmassguy

You have the Revised Monitor 12 Crossovers, not the originals.

fullvolume

I just priced out the cost of rebuilding two crossovers with Sonicaps and a Mills Resistor, plus a new Polyswitch, including shipping, and I'm looking at over $160.
Does this sound right?
I figured on a one for one replacement to get exact values as per the schematic, thus two caps to achieve the 16.4uF rating for the one cap. Am I right that the big yellow 12J100 cap will get replaced with a 12uF Sonicap Gen1 200v?
In other words, I need three of the same 12uF caps for each xover, plus the 4.4 and 4.2uF caps?

I'm looking at over $300 in caps alone just to rebuild four cross overs, (two M12's, and two 5jr's). I could save some money using a single cap to replace the two that make up the 16.4uF stack.