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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB: The Classic Live Audio Board => Topic started by: Pierre Olivier on December 23, 2015, 10:25:36 AM
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Hi there!
First post here (I hope I'm in the right forum), but I'm really a veteran: I started doing live sound in 1976...
I recently been involved, with a friend, in the purchase of a used PA system consisting mainly of Meyer UPA-1A speakers, Ashly FET-500 amps, Transparence subs, and assorted crossovers and controllers.
I'm in the process of getting this system back in a good working condition, and I'm having a hard time!
Upon plugging everything, (fear not, I am using the required M-1A processor), the system sounds dreadful: complete lack of warmth (upper bass), and the mids just want to shred your ears. Is this normal?
Now we have extensively searched the internet seeking everything that mentions UPA-1A. We all know that Meyer is a top-notch company with highly regarded products and an obsession for quality. We read that these speakers should stand the test of time, but we have NEVER, EVER come up with some comment about the *sound* of these. Nor with a published frequency response plot! Everybody seems hush-hush when it comes to the sound of the UPA-1A, to the point that we feel we've just joined a sect, or that there may be a Meyer Gestapo!
That said, we have come to some sort of listenability with agressive EQing. I say this is not normal. We know about Meyer's in-factory service policy: we certainly don't have the money for that, so they won't be sent. I'd like to ask for advice here about somes issues we have, and comment by those in the know:
After 25 years, the foam "lens" in the horn is suffering from "foam rot", and is starting to desintegrate. Anybody got a tip as to where I can find appropriate material for a repair? How important are those "lens"?
One of the 12" LF drivers was behaving strangely. I thought it was some kind of bad contact, and then I found out that if I gently press the cone inward, the speaker cuts out!. Voice coil loses connection. Anybody familiar with that kind of failure? What can cause that? (that driver's been swapped for another MS-12 from another incomplete box).
Why do they sound so bad? What could be the cause? Is there something we ought to know?
Also, we got six Ashly FET-500 amps in that deal, all in different stages of disrepair. I already did a fair amount of work on these, but if anybody would care to share a service manual or readable set of schematics, that would be of great help!
Now before you ask, here are the technical details: the two boxes we use are equipped with the original MS12 LF and 1401A HF drivers. HF protecton network set to "flat" response.
Signal goes into TDM 24 cx-4 crossover, frequency set at 160Hz. mono sub output (I had to find out how the "mono summing" mode works by myself on 24 cx-4: NO ONE gives you the slightest clue) then goes to Ashly FET-500 amp with mono switch on, each channel driving one of the two 8 ohm 18" speakers in a Transparence TR-218 sub. (should get a proper amp for this if kit is put into service)
High outputs of the crossover goes into M-1A processors (safe and lo-cut switches off, VHF switch to CAL). Outputs of M-1A goes to inputs of Ashly FET-500 amp and outputs of FET-500 goes to speaker (and M-1A return lines).
That's about it for now. Take care of your ears!
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I will take this bait. It's 10 am and I've been drinking...er,..tea since 6am.
Ahem:
My car has been replaced 7x in 25 years (progress/choice/affect). My lawnmower 4x (wear/abuse). 2x snowblowers. Same wife 25+years (totally my happy choice).
WTF is your expectation here Pierre?!
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Any generation of the UPA will not win a casual speaker shootout - Meyer went for flat, not for "nice sounding".
Have you measured the frequency response of your UPA-1A's?
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Jim:
I have read in numerous instances that the UPAs are very well protected against abuse by the M-1A. They should threfore maintain their integrity for a long, long time. I have also read of old UPA installs that keep on delivering. Call me naive, but I keep on hoping that old stuff will consistently deliver the performance they originally delivered. We replace stuff mainly because thy become out of fashion (computers/electronics) or they break down (cars). I live with old stuff. My studio is full of old stuff, and I graciously live with the fact that they're not the fastest, shiniest, convenient devices there is, as long as they live up to their original performance. I know damn well these speakers will not last forever, but if they're not broken, I see little reason why they wouldn't deliver. And I see your comparison with cars a little far-fetched: Innumerable components in cars can break down, while in a speaker...
Scott:
Thanks for your input!
No, I don't really have a setup to measure frequency response. I'm trying to hack something with "audio tester", but the audio output on the PC portable I want to use is so shitty it's unuseable.
Pierre
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Innumerable components in cars can break down, while in a speaker...
Foam surrounds can rot, ferrofluid can dry out, capacitors can dry out, moisture can seep into the drivers and enclosures,...
Fix them if you want to, but don't complain to us that your 25-year old boxes show signs of being 25 years old.
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Jim:
I have read in numerous instances that the UPAs are very well protected against abuse by the M-1A. They should threfore maintain their integrity for a long, long time. I have also read of old UPA installs that keep on delivering. Call me naive, but I keep on hoping that old stuff will consistently deliver the performance they originally delivered. We replace stuff mainly because thy become out of fashion (computers/electronics) or they break down (cars). I live with old stuff. My studio is full of old stuff, and I graciously live with the fact that they're not the fastest, shiniest, convenient devices there is, as long as they live up to their original performance. I know damn well these speakers will not last forever, but if they're not broken, I see little reason why they wouldn't deliver. And I see your comparison with cars a little far-fetched: Innumerable components in cars can break down, while in a speaker...
Scott:
Thanks for your input!
No, I don't really have a setup to measure frequency response. I'm trying to hack something with "audio tester", but the audio output on the PC portable I want to use is so shitty it's unuseable.
Pierre
Consider the fact that a loudspeaker is a MECHANICAL device-just like your car. You have to replace things on your car to keep it running.
It is amazing to me that they (loudspeakers) last as long as they do.
Also (has been pointed out) foam-due to its construction will rot over time-and that time is not real long.
No piece of electronics can provide "protection" over environmental issue (that cause foam rot).
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How do they sound without the TDM?
I assume you have 2 M1A & 2 FET-500, one for each speaker?
The Meyer UPA should sound very good on it's own, and I would just use the low-cut function when adding subs rather than an additional crossover ahead of the M1A.
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How do they sound without the TDM?
I assume you have 2 M1A & 2 FET-500, one for each speaker?
The Meyer UPA should sound very good on it's own, and I would just use the low-cut function when adding subs rather than an additional crossover ahead of the M1A.
Thanks for your useful input Andy!
Yes, I have two M1A, and I have run the kit without the TDM. unfortunately it does not sound any better (no bass to speak of). Besides I would need the TDM to roloff the highs from the subs, and to obtain a mono sum of the bass...
Pierre
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That's about it for now. Take care of your ears!
Im using UPA´s for about 30 Years now, in lot of Applications, and it was always one of my preferred PA Devices ... if they sound like something you describe, then clearly there is something broken/worn out etc. I also had various Meyer Boxes been overhauled by Meyer and they always do a good Job ... so the only thing you could do is ..
... spend the Money on a Repair, dealing with Meyer or somebody who can repair them for you .. i bet its not getting cheap, bit if they sound as they sound, you have no other choice ... maybe i would listen to something i Buy FIRST before buying and not rely on a "big name" and buy used worn out crap ....
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Fair enough.
Everyone's opinions on what "sounds good" are different, but I always liked the way they sound and I've not heard anyone ever say that the UPA sounded bad. So I would have to think something is very wrong with the gear. What that problem is, I can't tell without seeing and hearing it for myself.
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You'll have to use a HF boost in the M1-A controller to get the correct HF response in the UPA-1C. Never tried that on the A-model, you might want to give it a try. It did wonders on the C-model. You'll fint the boost described in the M1-A manual.
Sent from my iPhone using Tapatalk
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Consider the fact that a loudspeaker is a MECHANICAL device-just like your car. You have to replace things on your car to keep it running.
It is amazing to me that they (loudspeakers) last as long as they do.
Without major abuse I see no reason why a plywood box with metal grille shouldn't last nearly forever. However recone&re-diaphragm the drivers and replace any electrolytics in the passive networks and you should be good to go.
-I'm that guy who's newest car is older than a UPA -but also understands many of the parts in that car are new or rebuilt. The original straight-6 has also been replaced with a new smallblock back in the early 2000's.
So with that being said, look into replacing the amps and processing with some DSP, surely the Meyer M1a was an analog device with component aging issues too?
Someone on this board has to have DSP settings that will make the UPA happy? (yes I know there's loop-back sense lines but are they for more than just limiting?
-and if not, could modern DSP coupled with newer power amps make up for their lack?
(Ashly 500's are a good amp but relatively underpowered by modern standards -especially for your subs)
Also (has been pointed out) foam-due to its construction will rot over time-and that time is not real long.
I don't remember the UPA having any foam surrounds, just the foam covering over the grille. They run fine without that and can easily be replaced if you feel they are necessary.
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Craig, EVERYTHING I have read says omitting the M1A is an heresy: they're essential for the protection of the drivers and the good sound of the speaker. It cannot be replaced by DSP.
Also, there's not much that can deteriorate in the M1A: there is simply NO electrolytic capacitors in tha unit! (apart from the PSU filters- no audio goes through them). I have however encountered problems with the "sub in" jack that have contacts go dirty and do not let the signal go through them well.
I'm aware that the Ashly is not the ideal amp for the sub, but that's all I got for the moment.
No, there's no foam surround in the UPA-1A, and I'm not talking about the grille either: there's a foam pad in the throat of the HF horn that's supposed to act as a "lens".
Pierre
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Craig, EVERYTHING I have read says omitting the M1A is an heresy: they're essential for the protection of the drivers and the good sound of the speaker. It cannot be replaced by DSP.
Also, there's not much that can deteriorate in the M1A: there is simply NO electrolytic capacitors in tha unit! (apart from the PSU filters- no audio goes through them). I have however encountered problems with the "sub in" jack that have contacts go dirty and do not let the signal go through them well.
I'm aware that the Ashly is not the ideal amp for the sub, but that's all I got for the moment.
No, there's no foam surround in the UPA-1A, and I'm not talking about the grille either: there's a foam pad in the throat of the HF horn that's supposed to act as a "lens".
Pierre
I wonder if they actually dont have the correct hi drivers but somebody nhas fitted the Radian "equivelent" ignore the stickers on the back who knows what's been done to them in the past, try something for me, reverse the polarity on the high driver and see what happens and yes keep the M1A in line trying to match it with a DSP is a futile excersise IMO G
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I thought about that, Gordon. One of the boxes we got has an other-than-1401A driver, and it sounds very different (much brighter). But it's the LF drivers that actually bothers me the most. Why the quasi-absent bass?
Pierre
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Woofers can get "tired" - when our MSL4's started having weak bass we ended up replacing the low frequency drivers. Something like a 3dB or more difference between old and new.
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Woofers can get "tired" - when our MSL4's started having weak bass we ended up replacing the low frequency drivers. Something like a 3dB or more difference between old and new.
across their spectrum?
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Woofers can get "tired" - when our MSL4's started having weak bass we ended up replacing the low frequency drivers. Something like a 3dB or more difference between old and new.
How old were they?
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If I remember correctly the original HF driver was made by Yamaha, the diaphragm no longer available but a replacement from Radian is. Determine what's in each HF driver and if the jumpers have been removed. I believe the M1A is required as the crossover point varies with level. When properly maintained there are few small boxes that sound as good..even better than current product.
I have a fanatical client who continues to use them every week...paired with Chevin power.
Where are you ?
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How old were they?
Probably 10 years, I'd guess. And to answer your other question, the SPL loss was roughly even across the driver's spectrum. Maybe more loss off the bottom, don't remember exactly.
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Warning:
Satirical picture saves 1,000 words
http://img04.deviantart.net/52e6/i/2011/187/e/1/rusty_mercedes_benz_200_d_by_flame_cze-d3l6p7e.jpg
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Yes, Mike, I have read all about the different origins of the drivers, and how they are NOT interchangeable with the Meyer-modified units. I have personally removed the jumpers on the HF protection network in the two boxes we use. We are located east of sherbrooke, Quebec.
One thing I have observed is that the cones in the MS-12 tend to be quite "outward". Maybe it's from the years of beign suspended in the air with a slant towards the ground. I tend to think this would place the voice coil in a not-so-optimal place relative to the magnetic field...
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One thing I have observed is that the cones in the MS-12 tend to be quite "outward". Maybe it's from the years of beign suspended in the air with a slant towards the ground. I tend to think this would place the voice coil in a not-so-optimal place relative to the magnetic field...
Cone sag can happen when drivers are mounted like that.
The old Maryland Sound Clams were notorious for that. Half the drivers would be "out" and the other half "in"
I have never measured the sonic effects due to the coil being not centered in the gap.
I am sure there would be a measurable difference. How much is the question.
With cones that are "out" there would be a greater chance of the driver jumping out of the gap and getting physically damaged when pushed hard or below the tuning of the cabinet.
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If I remember correctly the original HF driver was made by Yamaha, the diaphragm no longer available but a replacement from Radian is. Determine what's in each HF driver and if the jumpers have been removed. I believe the M1A is required as the crossover point varies with level. When properly maintained there are few small boxes that sound as good..even better than current product.
I have a fanatical client who continues to use them every week...paired with Chevin power.
Where are you ?
The xover point does not vary by level. That's a long standing myth. IIRC Apogee used a variable xover, but I'm not certain.
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The xover point does not vary by level. That's a long standing myth.
I first read about the "shifting xover w/freq in Meyer processors" back in the 80s.
I "think" it was the Audio Cyclopedia-but not sure.
As I "understood it", the HP on the HF driver would go higher so less power and excursion was going to the HF driver (the limiting factor)
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I first read about the "shifting xover w/freq in Meyer processors" back in the 80s.
I "think" it was the Audio Cyclopedia-but not sure.
As I "understood it", the HP on the HF driver would go higher so less power and excursion was going to the HF driver (the limiting factor)
I would like to measure one to be sure.
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The OP mentioned a host of issues in the OP, but doesn't understand what is wrong. Amps needed repairs, one woofer has a known issue, seems like there are a host of issues.
If you are going to keep these I would say get them factory serviced and up to spec. Otherwise there is really no point. Obviously something is wrong, UPA-1A sound quite nice and flat typically.
Problem is it sounds like could be speakers, processor, or amps. I would want to narrow down by sweeping the speakers with a known working amp and no processor, then adding the processor and sweeping again, then add the newly repaired amp. At some point you will notice a difference OR the speakers themselves will turn out shot.
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I would like to measure one to be sure.
Of course-just because it is in print does not mean it is true.
It was just a little one or two line statement. I don't remember the section it was in-other than the loudspeaker section.
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The OP mentioned a host of issues in the OP, but doesn't understand what is wrong. Amps needed repairs, one woofer has a known issue, seems like there are a host of issues.
If you are going to keep these I would say get them factory serviced and up to spec. Otherwise there is really no point. Obviously something is wrong, UPA-1A sound quite nice and flat typically.
Problem is it sounds like could be speakers, processor, or amps. I would want to narrow down by sweeping the speakers with a known working amp and no processor, then adding the processor and sweeping again, then add the newly repaired amp. At some point you will notice a difference OR the speakers themselves will turn out shot.
You got a point. I'm working on a setup so I can measure the frequency response. I did try to get the system as straight as possible before conducting listening tests: I checked the electronics for proper operation, and made sure the two speakers had identical components and were setup the same.
I would tend to rule out amps and processors, because (1) I have tested them, and (2)both sides sound the same. TDM crossover has been bypassed, and that has changed nothing. Defective speaker has been replaced. So yes, I must now conduct frequency tests to know more. What I had hoped to learn by posting here is: are there known issues with those speakers that can lead them to deteriorate and not sound good.
As for sending them for service, as much as I'd like to do that, it won't happen: Just to send them speakers to California from Quebec will cost more than what we paid for the kit...
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OK, we have sweeps. I jury-rigged a setup with a portable PC running "Audio Tester 3", Tascam "FireOne" firewire audio interface and MKH-40 microphone. Microphone was one Meter from speaker, mid-point between woofer and horn. Output of FireOne was fed into input of M1A controller. We have two sets of graphs, one made with a 200-point sine sweep starting at 100Hz, 2dB grid. The other with pink noise, 5dB grid.
Looks like the two horns are holding up reasonnably well, except in the upper octave where the left channel's peak at 11K is quite mean. Both sides sharply fall off after that: I wonder if that had somethinh to do with the (deteriorating) foam lens.
Crossover seems good, but below that the woofers really don't perform very well: Quite different from side to side, a dip between 700-1K, and an apparent 2-4dB lack of output especially on the left channel, more evident on the sweep graph. The left channel's woofer is the one with the "outward" cone.
Please excuse the low quality of the graphics, this was hastily done.
Comments?
Words of Wisdom?
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This is just a cursory observation but it looks like you might have a polarity flip on one side. There is quite a dip in response at the crossover region on the right.
Do these drivers use ferro fluid? If so, a loss of fluid might account for the hi freq spike.
The foam in the throat of the hi driver is there to help smooth out the beaming (in my understanding)of the high end of the horn's bandpass.
You mentioned they were breaking down so take it out of both and re- measure.
Also, measure each driver separately, that is low only then horn only. This will test the drivers without interaction.
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OK, we have sweeps. I jury-rigged a setup with a portable PC running "Audio Tester 3", Tascam "FireOne" firewire audio interface and MKH-40 microphone. Microphone was one Meter from speaker, mid-point between woofer and horn. Output of FireOne was fed into input of M1A controller. We have two sets of graphs, one made with a 200-point sine sweep starting at 100Hz, 2dB grid. The other with pink noise, 5dB grid.
Looks like the two horns are holding up reasonnably well, except in the upper octave where the left channel's peak at 11K is quite mean. Both sides sharply fall off after that: I wonder if that had somethinh to do with the (deteriorating) foam lens.
Crossover seems good, but below that the woofers really don't perform very well: Quite different from side to side, a dip between 700-1K, and an apparent 2-4dB lack of output especially on the left channel, more evident on the sweep graph. The left channel's woofer is the one with the "outward" cone.
Please excuse the low quality of the graphics, this was hastily done.
Comments?
Words of Wisdom?
The right speaker looks closer to reality than the other, that dip in the 1k range still makes me suspect a polarity thing going on somewhere try reversing the horn and re-measure it.
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The right speaker looks closer to reality than the other, that dip in the 1k range still makes me suspect a polarity thing going on somewhere try reversing the horn and re-measure it.
Isn't the crossover F supposed to be 1.6K? If so that region looks pretty smooth...
Yes, there is supposed to be ferrofluid in the HF driver. What would be the effect of loss/drying of ferrofluid?. I hoped I would not have to dismantle the HF drivers. And then what do I do, add some ferrofluid? Where do I find that?
I'm a little stuck here, as these are the only 2 working woofers I got. I was thinking maybe recone both (I have seen recone kits for the MS12) but I have no idea how it's gonna be relative to the originals. At least they would sound the same...
As for the foam lens, I'm waiting 'till I have found a proper replacement material before I take them out.
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Isn't the crossover F supposed to be 1.6K? If so that region looks pretty smooth...
Yes, there is supposed to be ferrofluid in the HF driver. What would be the effect of loss/drying of ferrofluid?. I hoped I would not have to dismantle the HF drivers. And then what do I do, add some ferrofluid? Where do I find that?
I'm a little stuck here, as these are the only 2 working woofers I got. I was thinking maybe recone both (I have seen recone kits for the MS12) but I have no idea how it's gonna be relative to the originals. At least they would sound the same...
As for the foam lens, I'm waiting 'till I have found a proper replacement material before I take them out.
Are you SURE the measurements were equal?
Meaning no reflections that would be in one but not in the other.
The BEST way is to measure 1 speaker, then remove it from its position and place the other speaker in the EXACT same place.
Reflections will cause notches in the response.
There are many different types of Ferro fluid. And the different formulas will affect different speaker adhesives differently..
I you use the wrong type-it could cause the drivers to fail
Do you have any phase traces? That could be very telling.
I would also try disconnecting the other drivers in the cabinet and measure each driver individually.
Also MAKE SURE you use the same input into each speaker-to help eliminate any electrical differences.
This is a matter of "divide and conquer", so you have to use several pieces of information to come to the correct result.
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Are you SURE the measurements were equal?
Meaning no reflections that would be in one but not in the other.
The BEST way is to measure 1 speaker, then remove it from its position and place the other speaker in the EXACT same place.
Reflections will cause notches in the response.
The speakers were in their respective places and I moved the measurement setup. As I went I said to myself: maybe I should do this differently...
So you are right, next time I do this I'll do as you say: keep the same electronics and the same measurement spot, and just switch the speakers. I also hope I will master "Audio tester" better next time.
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If I get a chance I'll do a quick blast on one of mine to-morrow and post it I thought I had some traces hiding on an old computer but alas no From memory the crossover slopes overlap quite dramatically so it wouldn't suprise me to see that sort of dip in the response, take the time to look through ALL the wiring not just in the cabinet check the interconnects as well. My speakers are UPA1C models and are a little different but who knows what version of drivers are in yours now, there are also several types of filter card that were supposed to be fitted with whatever driver was in the horn. Generally the main issue I see is that dip in 700-1k range which as keith has said and I agree would seem to be a polarity thing.
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The speakers were in their respective places and I moved the measurement setup.
Nope!
You have now found out, do not move the test equipment and move the speakers into a clearly marked position.
When testing you need to reduce, to a maximum, any variables or the test results can be skewed.
As mentioned before, if you really want these speakers to sound the way they should, get Meyer to repair the drivers.
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Only to echo what Ivan's saying......
As I've been trying learn to use smaart, one set of boxes I keep measuring is pair of upa-1ps.
Indoors, the speaker and mic placement have to be so damn identical to get the two boxes to look alike...well, it's almost demoralizing...
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Only to echo what Ivan's saying......
As I've been trying learn to use smaart, one set of boxes I keep measuring is pair of upa-1ps.
Indoors, the speaker and mic placement have to be so damn identical to get the two boxes to look alike...well, it's almost demoralizing...
At least I had a directional microphone...
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At least I had a directional microphone...
Measurement mics are omni.
A "Directional mic" will introduce all sorts of "distortions to the response" of its own.
The only thing a directional mic could be good for is comparative measurements. NOT absolute.
So it "could" help a little bit-by reducing some of the reflections, but the notch (if it was a reflection) just below 1KHz would to small for the for the directional characteristics of the mic to help.
The IMPORTANT thing when comparing 2 products is to make SURE there is only 1 variable (the product) and not some thing else. Like reflections-electronics etc
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Measurement mics are omni.
A "Directional mic" will introduce all sorts of "distortions to the response" of its own.
The only thing a directional mic could be good for is comparative measurements. NOT absolute.
The IMPORTANT thing when comparing 2 products is to make SURE there is only 1 variable (the product) and not some thing else. Like reflections-electronics etc
Would you care to elaborate on this?
Why exactly are measurement microphones omnidirectional?
I don't quite understand how a directional mic would introduce "distortions to the response"...
I used a Sennheiser MKH40, which is known for its ruler-flat response.
I am aware that I'm very far from beign able to claim absolute results. Relative results will satisfy me!
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Would you care to elaborate on this?
Why exactly are measurement microphones omnidirectional?
I don't quite understand how a directional mic would introduce "distortions to the response"...
I used a Sennheiser MKH40, which is known for its ruler-flat response.
I am aware that I'm very far from beign able to claim absolute results. Relative results will satisfy me!
I don't know about that mic, but the very action that produces a cardioid (or other pattern) is CANCELLATION, which means response "distortion".
Distortion is NOT just THD, but anything that changes the original signal.
When measuring (for other than comparative results), you want was little as possible to enter into the measurements.
That is one reason the mic capsules are very small. Large diaphragm mics will alter the signal being received-simply due to their physical size.
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Would you care to elaborate on this?
Why exactly are measurement microphones omnidirectional?
I don't quite understand how a directional mic would introduce "distortions to the response"...
I used a Sennheiser MKH40, which is known for its ruler-flat response.
I am aware that I'm very far from beign able to claim absolute results. Relative results will satisfy me!
Measurement mics are omni mostly because all directional mics have proximity effect, with means that directional mics are LESS sensitive to low frequencies on a distance.
This means that your MKH-40, wich is an excellent sounding microphone for a lot of applications, is tilting your measurement considerably off in the low end of the spectrum.
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Omnis, like the word implies, are "immune" to rotation. The same evidently can't be said for directional mics. So mic positioning and orientation becomes much more critical. Another variable complicating things.
Also D/R values are different for directional mics compared to omnis. Angle of incidence for direct sound is the same but not for ER and the "homogeneous" distributed reverberation field.
Verzonden vanaf mijn iPad met Tapatalk
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While the comments made about test mics are true, in Pierre's case, he is testing relative not actual frequency response.
He wants to see if 2 different speakers exhibit similar response patterns given the terst method and equipment are the same.
Should be fine with the mic he has.
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Hey, I've got another mystery for you!
I was going over the documentation of the M-1A and B-2A, and now I'm puzzled as ever!
Says in the m-1A operation manual:
Lo Cut Switch. This switch introduces a 6dB/octave high pass filter at 160Hz. It is designed to provide an alternative crossover slope when using Meyer Sound subwoofers, but can also be used to compensate for the proximity effect of cardioid microphones. This filter is automatically inserted when the Sub Input is used.
Then I read the Operation manual of the B-2A, and the crossover frequency is stated as 95 Hz.
Knowing that I should connect the "high" ouput of the B-2A (that contain 95Hz up) into the "sub in" of the M-1A (which implements a lo-cut of 160Hz), WTF happens to our clients 95 to 160 Hz????
(of course, that is all theoretical, as I don't have a B-2A. I DO have however a crossover and subs).
In other words, what frequency the crossover between the subs and the tops should be??? I assumed it was 160 Hz, but now I'm confused.
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Knowing that I should connect the "high" ouput of the B-2A (that contain 95Hz up) into the "sub in" of the M-1A (which implements a lo-cut of 160Hz), WTF happens to our clients 95 to 160 Hz????
My understanding would be that they are gently rolling off from 160Hz towards 80Hz where they will be 6db down from the corner freq of 160hz. Probably to help the acoustical summing of the UPA and sub be flatter and have a better phase response. Neither of these speakers are going to fall off a cliff response wise at 95Hz.
Apologies for my less than technical musings.
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My understanding would be that they are gently rolling off from 160Hz towards 80Hz where they will be 6db down from the corner freq of 160hz. Probably to help the acoustical summing of the UPA and sub be flatter and have a better phase response. Neither of these speakers are going to fall off a cliff response wise at 95Hz.
Apologies for my less than technical musings.
I agree with John about the acoustical summing.
65 Hz is not really al that much and the slopes of the crossovers are probably not all that steep.
As I recall from listening to Meyer 650s, the low pass slope is rather shallow.
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Hey, I've got another mystery for you!
I was going over the documentation of the M-1A and B-2A, and now I'm puzzled as ever!
Says in the m-1A operation manual:
Lo Cut Switch. This switch introduces a 6dB/octave high pass filter at 160Hz. It is designed to provide an alternative crossover slope when using Meyer Sound subwoofers, but can also be used to compensate for the proximity effect of cardioid microphones. This filter is automatically inserted when the Sub Input is used.
Then I read the Operation manual of the B-2A, and the crossover frequency is stated as 95 Hz.
Knowing that I should connect the "high" ouput of the B-2A (that contain 95Hz up) into the "sub in" of the M-1A (which implements a lo-cut of 160Hz), WTF happens to our clients 95 to 160 Hz????
(of course, that is all theoretical, as I don't have a B-2A. I DO have however a crossover and subs).
In other words, what frequency the crossover between the subs and the tops should be??? I assumed it was 160 Hz, but now I'm confused.
In almost every case, the ACOUSTICAL and ELECTRICAL crossovers are NOT the same.
This is due to a couple of factors.
One is the fact that very very few speakers are actually flat-around crossover point.
Full range products tend to be a bit low in level and subs tend to be a bit high in level.
Also consider that subs are typically run higher in level, means that the electrical crossover point for the subs will be a lot lower than the acoustical crossover to the full range speaker.
So while it may "appear" to be a hole in the response-there is not and in many cases there is actually a HUMP in the area you "think" there is a hole.
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The biggest thing between me and great sound is the exchange rate on the US to CDN $$ :o KILLING ME!
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In almost every case, the ACOUSTICAL and ELECTRICAL crossovers are NOT the same.
So while it may "appear" to be a hole in the response-there is not and in many cases there is actually a HUMP in the area you "think" there is a hole.
Yeah. and War is Peace.
(sorry, I couln't resist)
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Hey!
I got new measurements taken today.
"les deux" shows the two speaker's curves, red is right. As before, the horns track pretty well, but the woofers differ. Left channel is more linear, while right shows a descending curve. both show weak output below 170 Hz.
And for those who said crossover was wrong, the other curve shows left channel with the horn polarity reversed. Easy to see the original setup was OK...
What I'd REALLY like to see is a graph of a new UPA-1A (or at least one in good shape) so I can compare with what I've got.
More listening tests today, and the region where an EQ cut is most effective is around 650Hz.
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Hey!
I got new measurements taken today.
"les deux" shows the two speaker's curves, red is right. As before, the horns track pretty well, but the woofers differ. Left channel is more linear, while right shows a descending curve. both show weak output below 170 Hz.
And for those who said crossover was wrong, the other curve shows left channel with the horn polarity reversed. Easy to see the original setup was OK...
What I'd REALLY like to see is a graph of a new UPA-1A (or at least one in good shape) so I can compare with what I've got.
More listening tests today, and the region where an EQ cut is most effective is around 650Hz.
So it appears the position was the problem with the different response.
In looking at the response, it is +/- 1dB (model to model) Not bad for any speaker-much less an old speaker.
Now whether this is what it is "supposed to be" I have no idea-but the fact that they are that close means that they are VERY close in the same sound.
It is hard to say what you are hearing.
Are you feeding both of the THE SAME signal when you are listening to them? and not listening in stereo?
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What I'd REALLY like to see is a graph of a new UPA-1A (or at least one in good shape) so I can compare with what I've got.
More listening tests today, and the region where an EQ cut is most effective is around 650Hz.
You are in the same province as a very large Meyer shop if you're looking for a newer one for comparison. Offices in Montreal and Quebec City. Starts with S.
Might be worth a phone call.
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Does your analysis software include a phase display? That would provide some significant detail on the characteristics of the speakers.
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Does your analysis software include a phase display? That would provide some significant detail on the characteristics of the speakers.
I do think the software has phase measurement capabilities, but I don't know how to set it up for that yet. Bear in mind this measurement setup was very hastily put together with me beign unfamiliar with any of the three possible software packages, all running in "demo" mode... It has been some kind of "crash course".
Anyways, this project will be on hold for a little while, as we tore down this morning and put the equipment away to clear the hall for regular events. Next step will be to setup again with a good parametric EQ and bring in a band for a real-life test.
Aha! I always thought those S guys were acquainted with Meyer. We'll look into that file.
We made some listening in mono, and some in stereo to please ourselves.
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Frequency response is quoted from UPA-1A brochure "60-16000 Hz +- 4dB"
The ones at hand are more like 180-13000Hz +- 4dB
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I do think the software has phase measurement capabilities, but I don't know how to set it up for that yet. Bear in mind this measurement setup was very hastily put together with me beign unfamiliar with any of the three possible software packages, all running in "demo" mode... It has been some kind of "crash course".
Anyways, this project will be on hold for a little while, as we tore down this morning and put the equipment away to clear the hall for regular events. Next step will be to setup again with a good parametric EQ and bring in a band for a real-life test.
Aha! I always thought those S guys were acquainted with Meyer. We'll look into that file.
We made some listening in mono, and some in stereo to please ourselves.
If the program can show a phase display, then it HAS to have some sort of "delay locator", "ETC", "time arrival" etc.
If that is not set properly, then there is way of putting any sort of "confidence" in the measured response.
I would suggest reading the manual a bit more.
Just because you something to show up on a computer screen DOES NOT mean that it is even close to being "correct".
Yes it is "something", but on some platforms (like TEF), if you are off, the response can the wildly different, because the "window" is opening at the wrong time.
And every time you make a measurement-even of the same source, you will get a different result.
YES IT DOES MATTER. Especially if others are looking at your "data" and trying to help solve YOUR problem.
PROPER information is ESSENTIAL.
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Frequency response is quoted from UPA-1A brochure "60-16000 Hz +- 4dB"
The ones at hand are more like 180-13000Hz +- 4dB
Also didn't we determine you aren't using an actual measurement microphone, so other than the results allowing you to compare the two speakers, the graphs don't mean shit about what is actually happening? I'm just checking....
Sent from my iPhone using Tapatalk
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This thread reminds me of things I see in "Ferrari Chat": Some bloke purchases a tired 308 (or Testarossa) and discovers that comparative real-world performance is not there, and bringing it up to factory spec is costly.
If you aspire to Meyer performance send the units to Meyer or a Meyer specialist, who can confirm and identify the nonperformance issues. Then a true remedy will be offered.
This is ostensibly a "Pro Sound" forum, and we have taken the bait on this hobbyist question.
If anyone offered to satisfy a for-profit situation with the aggregate pile of gear offered here it would be rejected out-of-hand, at least in the NE corridor circles.
I rant, therefore I am.
Happy New Year all!
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Hey!
I got new measurements taken today.
"les deux" shows the two speaker's curves, red is right. As before, the horns track pretty well, but the woofers differ. Left channel is more linear, while right shows a descending curve. both show weak output below 170 Hz.
And for those who said crossover was wrong, the other curve shows left channel with the horn polarity reversed. Easy to see the original setup was OK...
What I'd REALLY like to see is a graph of a new UPA-1A (or at least one in good shape) so I can compare with what I've got.
More listening tests today, and the region where an EQ cut is most effective is around 650Hz.
This means nothing without phase. HIGHLY recommend along with everyone else to send off to Meyer.
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As a final conclusion, this issue has been resolved by changing the two woofers. I deduct cone sag might have been the problem.
They sounf fine now.
Thanks to all for nothing.
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Thanks to all for nothing.
I think you got at least your money's worth from this forum. Sorry you're unhappy with the forum, but glad you're happy with your repaired speakers.
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I think Pierre's very active participation on this board over the past 22 months since his initial thread was last posted upon indicates that he's been very happy with the knowledge here.
-Ray
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How about have Meyer repair just one of them?
Then you can compare a properly functioning speaker to the rest of them.
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How about have Meyer repair just one of them?
Then you can compare a properly functioning speaker to the rest of them.
Meyer does not do reconing or offer recone kits.
They only offer new drivers.
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Thanks to all for nothing.
Wow.....classy.
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Hey, they sounf great now! What else do you want?!?