Electro-Voice PXM-12MP report

greiswig said:
My one remaining gripe with these speakers is part of the compromise EV had to make to create such a light cabinet. There is definitely a reason that many cabinets are made with 18-ply birch plywood, which is bloody heavy. I'm sure the panels on these PXM's is a fraction of that thickness, and probably MDF.

Anyway, there is some noticeable panel resonance that occurs, even at moderate volumes. I think the bottom is the primary culprit, since you can knock on it and hear a ring right around the area that I hear a boxiness in the response of the cabinet that is not present on my studio monitors...400Hz or so. There are also two side panels that rang pretty well when you struck them, too.

I quick trip to Home Despot to get some 3/8" dowel rod, and I fixed that issue.
View attachment 92759

Basically, I used a trick I've used on subwoofer cabinets I used to make, creating some scaffolding inside the speaker to counterbrace opposing panels and break up resonances...or at least push them higher in frequency and force a lot less amplitude.

I also added a little more batting in one corner. I'm very pleased with the results. I used to have to notch a bit at that 400Hz area, and now it sounds great without it. It seems to have a bit more oomph in the lows and low mids, too, but that could be imagination. In any case, it was a pretty easy modification with excellent results.
Click to expand...
Cool. Did you just force-fit those in there? Glue them? Screw them in from the outside (which seems like an error prone PITA)?
 
Dave Merrill said:
Cool. Did you just force-fit those in there? Glue them? Screw them in from the outside (which seems like an error prone PITA)?
Click to expand...
They are pretty well force-fit, because they have to put some tension on the panels. But they're secured in place with hot glue to keep them from falling off. Trickiest one is that long vertical one connecting the top corner to the base; getting that one to not interfere with the speaker as it goes in was a little tricky.

Nothing irreversible here, either.
 
greiswig said:
My one remaining gripe with these speakers is part of the compromise EV had to make to create such a light cabinet. There is definitely a reason that many cabinets are made with 18-ply birch plywood, which is bloody heavy. I'm sure the panels on these PXM's is a fraction of that thickness, and probably MDF.

Anyway, there is some noticeable panel resonance that occurs, even at moderate volumes. I think the bottom is the primary culprit, since you can knock on it and hear a ring right around the area that I hear a boxiness in the response of the cabinet that is not present on my studio monitors...400Hz or so. There are also two side panels that rang pretty well when you struck them, too.

I quick trip to Home Despot to get some 3/8" dowel rod, and I fixed that issue.
View attachment 92759

Basically, I used a trick I've used on subwoofer cabinets I used to make, creating some scaffolding inside the speaker to counterbrace opposing panels and break up resonances...or at least push them higher in frequency and force a lot less amplitude.

I also added a little more batting in one corner. I'm very pleased with the results. I used to have to notch a bit at that 400Hz area, and now it sounds great without it. It seems to have a bit more oomph in the lows and low mids, too, but that could be imagination. In any case, it was a pretty easy modification with excellent results.
Click to expand...
Interesting.

I'm not ready to do that yet. Last week, because there was a ridiculous low frequency rumble, I did a SYNTH block sweep of mine on the stage extension where I place them, and found a resonance/rattle from the stage at about 96Hz, cut it with the global output PEQ, which made a big difference. I can probably tweak it further but that was good enough for the moment.
 
greiswig said:
My one remaining gripe with these speakers is part of the compromise EV had to make to create such a light cabinet. There is definitely a reason that many cabinets are made with 18-ply birch plywood, which is bloody heavy. I'm sure the panels on these PXM's is a fraction of that thickness, and probably MDF.

Anyway, there is some noticeable panel resonance that occurs, even at moderate volumes. I think the bottom is the primary culprit, since you can knock on it and hear a ring right around the area that I hear a boxiness in the response of the cabinet that is not present on my studio monitors...400Hz or so. There are also two side panels that rang pretty well when you struck them, too.

I quick trip to Home Despot to get some 3/8" dowel rod, and I fixed that issue.
View attachment 92759

Basically, I used a trick I've used on subwoofer cabinets I used to make, creating some scaffolding inside the speaker to counterbrace opposing panels and break up resonances...or at least push them higher in frequency and force a lot less amplitude.

I also added a little more batting in one corner. I'm very pleased with the results. I used to have to notch a bit at that 400Hz area, and now it sounds great without it. It seems to have a bit more oomph in the lows and low mids, too, but that could be imagination. In any case, it was a pretty easy modification with excellent results.
Click to expand...

Wouldn't MDF be heavier than plywood?
 
Greg Ferguson said:
Interesting.

I'm not ready to do that yet. Last week, because there was a ridiculous low frequency rumble, I did a SYNTH block sweep of mine on the stage extension where I place them, and found a resonance/rattle from the stage at about 96Hz, cut it with the global output PEQ, which made a big difference. I can probably tweak it further but that was good enough for the moment.
Click to expand...
I carry these just in case of a bad low freq resonance:
https://auralex.com/subdude-ht/?utm...tAFjeCFf8LUJNf0RtbDoTOd4oIJ9DUsEaAkSBEALw_wcB
 
I had mine up on stands today! (Yorkville SKS-02B mini's) They sounded pretty good though I did notice a rumble but though it might the keyboard player. He was running through a pair of EV ZLX we both were running in a backline fashion. @greiswig Interesting fix for the cab flex I might give that a try!
 
greiswig said:
There is definitely a reason that many cabinets are made with 18-ply birch plywood, which is bloody heavy.
Click to expand...
One of the things that’s never really made sense to me is that heavy cabinets necessarily meant well made or that they were good musically or sonically. It’s definitely been a trend.

I’m a big fan of Mark Bartel, the designer of the ToneKing amplifiers, who now is doing his own line called Bartel Amplifiers. When he left ToneKing, he spent several years digging into different circuit and cabinet designs. Both studies turned up some really interesting ideas that he turned into his new line. On the cabinet design he’s treating the cabinet as part of the overall sound similar to a cello or violin, not just the thing that holds the speaker. He tunes the cabinet to respond with the speaker, and everything I’ve heard has been very good.

So I’m wondering if EV isn’t doing something similar, deliberately allowing a lighter cabinet to resonate. I like the sound of mine, I just don’t like how the stage floor reacted to the sound, and since I can’t change the stage I changed the speaker’s output to counter the stage resonance.
 
Greg Ferguson said:
One of the things that’s never really made sense to me is that heavy cabinets necessarily meant well made or that they were good musically or sonically. It’s definitely been a trend.

I’m a big fan of Mark Bartel, the designer of the ToneKing amplifiers, who now is doing his own line called Bartel Amplifiers. When he left ToneKing, he spent several years digging into different circuit and cabinet designs. Both studies turned up some really interesting ideas that he turned into his new line. On the cabinet design he’s treating the cabinet as part of the overall sound similar to a cello or violin, not just the thing that holds the speaker. He tunes the cabinet to respond with the speaker, and everything I’ve heard has been very good.

So I’m wondering if EV isn’t doing something similar, deliberately allowing a lighter cabinet to resonate. I like the sound of mine, I just don’t like how the stage floor reacted to the sound, and since I can’t change the stage I changed the speaker’s output to counter the stage resonance.
Click to expand...
The only problem with that is if the cabinet is resonating at certain frequencies or frequency would seem to be an unwanted effect based on your findings. If Mark Bartel has found a way for a cabinet to resonate at all frequencies then he would definitely be on to something. Based on what I have seen and read his cabs look like they have been designed so the speaker has a fairly rigid bond to the bafel.

Other than wood choice Pine and hog vrs Birch ply and construction practice Bafel and box vrs a single piece box/bafel with a hog retainer mount. I would like to hear one of those amps in person to see if there really is a difference!

With a full range cab how would one account for phase and standing wave? By nature of how a speaker cabinet is built, using materials that are not as stiff different surfaces will resonate at different frequencies with different amplitudes. With the given space between the driver and surfaces would phasing not become an issue in the inclosure?

I'm not an audio engineer by any stretch but based on my limited knowledge I would think inducing resonance to a full range cabinet would not be a good thing!

Just throwing that out there.
 
Sixstring said:
The only problem with that is if the cabinet is resonating at certain frequencies or frequency would seem to be an unwanted effect based on your findings. If Mark Bartel has found a way for a cabinet to resonate at all frequencies then he would definitely be on to something. Based on what I have seen and read his cabs look like they have been designed so the speaker has a fairly rigid bond to the bafel.

Other than wood choice Pine and hog vrs Birch ply and construction practice Bafel and box vrs a single piece box/bafel with a hog retainer mount. I would like to hear one of those amps in person to see if there really is a difference!

With a full range cab how would one account for phase and standing wave? By nature of how a speaker cabinet is built, using materials that are not as stiff different surfaces will resonate at different frequencies with different amplitudes. With the given space between the driver and surfaces would phasing not become an issue in the inclosure?

I'm not an audio engineer by any stretch but based on my limited knowledge I would think inducing resonance to a full range cabinet would not be a good thing!

Just throwing that out there.
Click to expand...
There are a number of videos on YouTube with Bartel discussing the design and construction and of people demonstrating them because they really like the amps, or search on the forum here for “Bartel” and you’ll find several threads with links.
 
Greg Ferguson said:
There are a number of videos on YouTube with Bartel discussing the design and construction and of people demonstrating them because they really like the amps, or search on the forum here for “Bartel” and you’ll find several threads with links.
Click to expand...
I did go and look on YT! Nice amps but at 5k are a little too spendy for me!
 
Greg Ferguson said:
One of the things that’s never really made sense to me is that heavy cabinets necessarily meant well made or that they were good musically or sonically. It’s definitely been a trend.

I’m a big fan of Mark Bartel, the designer of the ToneKing amplifiers, who now is doing his own line called Bartel Amplifiers. When he left ToneKing, he spent several years digging into different circuit and cabinet designs. Both studies turned up some really interesting ideas that he turned into his new line. On the cabinet design he’s treating the cabinet as part of the overall sound similar to a cello or violin, not just the thing that holds the speaker. He tunes the cabinet to respond with the speaker, and everything I’ve heard has been very good.

So I’m wondering if EV isn’t doing something similar, deliberately allowing a lighter cabinet to resonate. I like the sound of mine, I just don’t like how the stage floor reacted to the sound, and since I can’t change the stage I changed the speaker’s output to counter the stage resonance.
Click to expand...

I've built guitar cabinets made of antique pine for resonance. I've made cabinets with floating baffles that allow me to control how much float there really is. And yes, it can add some nice color to a cabinet. The floating baffle thing surprised me in that it didn't have as much of an effect as using a resonant wood for the rest of the cabinet, from what I could hear.

To me, the purpose of an FRFR cabinet is to avoid coloration while still having good, uniform dispersion. I seriously doubt that EV wants something they're targeting to be a stage monitor to add cabinet resonance. As I mentioned before, I would bet it is part of the compromise of "light and cheap."

This is something you can do friction-fit for the most part, so it would be completely reversible. Give yourself about 30 minutes to carve and angle the ends of the dowels and get the lengths right, and try it for yourself. If you don't like what you hear, pull the dowels back out. If you do, you can glue them. I have two of these, so I didn't really need to do a before/after. Just bouncing back and forth between them revealed what I needed. And I was able to dial the bass back a bit in the one with the supports, but it still sounded as beefy as the other...just without the low-mid honk that one resonance was causing.
 
Just stumbled across this over my (far too early) morning coffee, and am certainly appreciating the responses relating to use with the axe/fx so now lets off on a tangent..

I am wondering if anyone has tried these with vocals or acoustic guitar?..
 
Mystic38 said:
Just stumbled across this over my (far too early) morning coffee, and am certainly appreciating the responses relating to use with the axe/fx so now lets off on a tangent..

I am wondering if anyone has tried these with vocals or acoustic guitar?..
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Just last week! They sounded pretty much like a good monitor should sound. It's no Meyer but for a prosumer grade sub 1k monitor they are not bad. I would read through the entire thread as some are reporting of hearing a faint distortion with decaying low notes. Bosh is offering to fix the issue, personally have not heard that in the pair I have.
 
Yes, I've used them with an XR18 for a small gig with two vocals and me on acoustic guitar, set up as mains. One covered the small outdoor group of around 100 people quite well, and I like my acoustic to have some heft when I'm solo. I still prefer using one of my regular mains for this, even though it's overkill, because of the wide dispersion and clarity of the IG4T speakers. But they're in a different league.
 
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