Help with weird issue for Alto TS412 powered speaker

[Jumbotronic]

OK, so I got a used Alto TS412. Plugged it in and I'm having a problem with it. When I plug into inputs 1 or 2, I get a weird low-end distortion. This happens no matter what I plug in--I've tried acoustic-electric guitar, acoustic-electric guitar with a Baggs preamp, vocal mic, line out from my Tech 21 TM60, and mixer in (tried running acoustic-electric, vocals, and Tech 21 into the mixer).

I don't think I'm running anything in hot enough to clip it, and I get the distortion no matter how much gain I throw in. It seems to help a little bit if I cut the low end eq dramatically from the mixer, but it's still there (and annoying).

It doesn't seem to matter how I've got the TS412 set. I get the distortion on all their various EQ settings, and I used the app to make a custom setting where I cut all the low end. I also get the distortion no matter what sub size I select (Even if I select "no sub").

Edit: when I first posted, I thought the bluetooth input didn't have the problem. But now I did some more experimenting and I think it does. If I run a bass-heavy song through there, I can hear the distortion.

So what's going on? Am I doing something incompetent? Blown speaker? Any help is great!!

 

[cousinpaul]

Bought used? It may have been damaged by the former owner. You could try contacting Alto via the official website for troubleshooting and support.

 

[Jumbotronic]

Bought used? It may have been damaged by the former owner. You could try contacting Alto via the official website for troubleshooting and support.

Yeah, I've got a ticket in with them, so good idea.

I ran some more tests today and determined that the preamp section seems to be fine. If I run the XLR out into another amp, I don't get any distortion (and the Alto's level control controls that output too, so it's not in there).

I'm increasingly leaning toward blown speaker. I'll look into a refund, but my suspicion is that given it was shipped used from the other coast, it's going to be cheaper for me to get a replacement speaker than it is to ship it and get a refund. I guess I got hosed on this one.

But this brings me to another question for anybody out there. I wrote Alto about this too, but is there a good value replacement speaker for it anybody can recommend? Stock speaker is 12", 2 ohm, 800W RMS.

 

[PhredE]

tock speaker is 12", 2 ohm, 800W RMS.

100% sure it's a 2ohm driver?
Sorry, just want to confirm. I 'll poke around on Parts Express and see if they have something that matches. A 2ohm 12" woofer is a pretty rare find these days, maybe, just maybe, they'll have something that fits.

Edit:

Found a 12" Subwoofer (PRV) @ 2ohms $400 (!)

CLEARANCE PRV Audio 12SW6000BP-2 Brazilian Punch 12" Subwoofer Driver 2 Ohm

PRV Audio 12SW6000BP-2 Brazilian Punch 12" Subwoofer Driver 2 OhmPRV Audio 12SW6000BP-2 Brazilian Punch 12" Subwoofer Driver 2 OhmThe Brazilian Punch is an efficient woofer crafted for systems that require high performance in the low midbass range, delivering clean sound with impressive sound...

www.parts-express.com

I'll check some other retailers and brands.. in progress.

There's an assortment of 12" 2ohm subwoofers out there on Amazon and other online retailers. I recommend to do some searching and have a look for yourself what replacement options are available. Generally speaking, they seem to be mid-grade auto type drivers (as opposed to pro/PA type replacement units). But, by no means, is that summary set in stone. Have a look for yourself as well.

 

[cousinpaul]

What about mechanical vibration? Can you get in there and see if there's a loose nut or something not tied down snug?

 

[Jumbotronic]

100% sure it's a 2ohm driver?
Sorry, just want to confirm. I 'll poke around on Parts Express and see if they have something that matches. A 2ohm 12" woofer is a pretty rare find these days, maybe, just maybe, they'll have something that fits.

Edit:

Found a 12" Subwoofer (PRV) @ 2ohms $400 (!)

CLEARANCE PRV Audio 12SW6000BP-2 Brazilian Punch 12" Subwoofer Driver 2 Ohm

PRV Audio 12SW6000BP-2 Brazilian Punch 12" Subwoofer Driver 2 OhmPRV Audio 12SW6000BP-2 Brazilian Punch 12" Subwoofer Driver 2 OhmThe Brazilian Punch is an efficient woofer crafted for systems that require high performance in the low midbass range, delivering clean sound with impressive sound...

www.parts-express.com

I'll check some other retailers and brands.. in progress.

There's an assortment of 12" 2ohm subwoofers out there on Amazon and other online retailers. I recommend to do some searching and have a look for yourself what replacement options are available. Generally speaking, they seem to be mid-grade auto type drivers (as opposed to pro/PA type replacement units). But, by no means, is that summary set in stone. Have a look for yourself as well.

Yeah, 2 ohms is kind of unusual, but as per the Alto's TS412 page:

Low-Frequency Driver: 12.0” driver, 2.5” (63 mm) high-temperature voice coil. 1 x 800 W RMS @ 2 Ω.

I found this, which is a QSC replacement, and has comparable specs: https://reverb.com/item/65250200-ne...0060-00-woofer-2-ohms?utm_source=pocket_saves. That's currently the leading contender.

I've also found some car subs, such as this one: https://www.skaraudio.com/products/sdr-12-inch-car-subwoofer?variant=SDR-12 D2. The thing I don't get about that is that it's dual ohms. If anybody knows what that means, I'm all ears.

I'm hoping Alto has a reasonably priced replacement I can get from them, but I'm not holding my breath.

What about mechanical vibration? Can you get in there and see if there's a loose nut or something not tied down snug?

Yeah, I popped off the grill, and nothing loose there. No loose speaker screws either. I suppose before I order a new speaker, I should take the current speaker off and look inside to see if I can find something in there loose. That would be a cheap fix! Unfortunately, it doesn't sound like a loose kind of rattle, but more a speaker thing. But I should definitely check.

 

[Peegoo]

You can remove the speaker and run some music from a different speaker-level source through the speaker and listen for similar noise. If there is none, you'll know the fault is either in the Alto amp circuit or something going on with the cabinet.

 

[cometazzi]

Yeah, 2 ohms is kind of unusual, but as per the Alto's TS412 page:

Low-Frequency Driver: 12.0” driver, 2.5” (63 mm) high-temperature voice coil. 1 x 800 W RMS @ 2 Ω.

I found this, which is a QSC replacement, and has comparable specs: https://reverb.com/item/65250200-ne...0060-00-woofer-2-ohms?utm_source=pocket_saves. That's currently the leading contender.

I've also found some car subs, such as this one: https://www.skaraudio.com/products/sdr-12-inch-car-subwoofer?variant=SDR-12 D2. The thing I don't get about that is that it's dual ohms. If anybody knows what that means, I'm all ears.

I'm hoping Alto has a reasonably priced replacement I can get from them, but I'm not holding my breath.

Yeah, I popped off the grill, and nothing loose there. No loose speaker screws either. I suppose before I order a new speaker, I should take the current speaker off and look inside to see if I can find something in there loose. That would be a cheap fix! Unfortunately, it doesn't sound like a loose kind of rattle, but more a speaker thing. But I should definitely check.

You could also set this speaker onto a different one that you can send sound through. The Alto isn't powered on or anything, but if you can send the same frequencies through the case and make it rattle, you know it's not electrical.

 

[PhredE]

Thanks @Jumbotronic

Still researching some things..

I like Peegoo's suggestion to try to get a different speaker to put out some signal.

Specs from Sweetwater listing:

https://www.sweetwater.com/store/detail/TS412--alto-professional-ts412-2500-watt-12-inch-powered-speaker

(just for specs)

Ya know, one thing I wonder about is since it's a Class D onboard power amp, and a high-powered one at that, if it might have been overheated and damaged in the past. I have a couple amps that are Class D based designs. One has a dedicated cooling fan and the other has good airflow (vents)+heat sink. In the absence of a good cooling design.. (hmmm?). Seems that most Class D failures somehow involve heat/cooling related problems. ..Just my 0.02. Will keep monitoring and researching here though..

 

[Jumbotronic]

You can remove the speaker and run some music from a different speaker-level source through the speaker and listen for similar noise. If there is none, you'll know the fault is either in the Alto amp circuit or something going on with the cabinet.

You could also set this speaker onto a different one that you can send sound through. The Alto isn't powered on or anything, but if you can send the same frequencies through the case and make it rattle, you know it's not electrical.

Nice. These are the same suggestion, right?

I also thought of wiring up a 1/4" jack to the speaker and powering it up with another amp. Then I realized I have nothing that will drive 2 ohms. But taking the speaker out and pushing it with another--neat trick! I'll have to take the speaker out anyway to check for loose stuff in there, so easily done.

 

[cometazzi]

Nice. These are the same suggestion, right?

I also thought of wiring up a 1/4" jack to the speaker and powering it up with another amp. Then I realized I have nothing that will drive 2 ohms. But taking the speaker out and pushing it with another--neat trick! I'll have to take the speaker out anyway to check for loose stuff in there, so easily done.

They are close, and very similar. For starters, one is about 3 minutes faster than the other one.

The first suggestion is using a different amplifer to connect to the speaker in the Alto. This effectively bypasses all the amplification parts of the Alto. Play music through it (that would make the noise). If there is no noise, then you know the speaker is ok, and there's nothing rattling in the cabinet. If there IS noise, then the opposite.

The second suggestion is using a different speaker cab to vibrate the Alto's cab, so you can hear something rattling. This is less thorough than the first suggestion, though it would be definitive about crap rattling around in the case. You can possibly test that by shaking it too, but it can yield a false negative.

When in doubt, listen to Peegoo.

 

[schmee]

"1 x 800 W RMS @ 2 Ω" that appears to be an amp rating. ....?
Maybe it is the speaker though. Pretty unusual. I guess that's how they get their amp wattage rating so high ... with a 2 ohm load!
Before you buy a speaker I would measure the speaker resistance... But I also wonder if it's something loose inside. However, clD amps are not the most reliable thing in the world, even if they are JBL!

It does kinda sound like an amp issue.

 

[Jumbotronic]

I ran some tests this afternoon (with my 9-year old son--fun family project!). I couldn't find anything loose or obviously vibrating. I pulled the speaker and did what I'm going to call the "cometazzi test"--and lo and behold! When I put the speaker up in front of my bass cab with a very clean sound dialed in, I got distortion. So I think, pretty decisively, that the speaker is the issue. So thanks everybody for helping me figure that out!

It's definitely 2 ohm (got the multimeter on it). I just have to find a suitable replacement. That one I found on reverb seems like a solid choice--specs are right--but I'm going to wait for Alto as well to get back to me to see if I can get a replacement right from them. There's an Alto dealer around here, which might be helpful.

 

[PhredE]

It's definitely 2 ohm (got the multimeter on it). I just have to find a suitable replacement. That one I found on reverb seems like a solid choice--specs are right--but I'm going to wait for Alto as well to get back to me to see if I can get a replacement right from them. There's an Alto dealer around here, which might be helpful.

Hey, congrats on the progress. Was going to throw out one idea before you go any further: maybe ask the ALTO if you can substitute a 4ohm woofer instead of a 2ohm unit(?) You have MANY more options going with a 4 ohm woofer than the 2ohm unit. (Of course, it goes without saying that if you could use an 8ohm woofer, you'd have exponentially that many more as well).

My hunch is, they offer to send out another of their drivers (free? at discounted cost..?) to replace it (or maybe nothing, who knows??). If it were me, I would probably do some deep research on a quality 4ohm driver with appropriate specs and take a chance and put it in and give it a shot. Another reason that might actually work better, is because many of the 'high-powered' woofers (especially in the 2ohm variety..) tend to be low efficiency; so they can handle a large power input without self-destructing, at least in theory. Whereas, many 4 ohm units may have lower power handling but also be greater efficiency. So the net effect is that what power does get to the woofer is expressed in a more efficient manner -- so you don't need to turn things up as much to get the same overall output volume. (it's a tradeoff buried in the specs of the relative drivers essentially).

 

[PhredE]

TS412

2500-WATT 12-INCH 2-WAY POWERED LOUDSPEAKER WITH BLUETOOTH®, DSP & APP CONTROL

www.altoprofessional.com

From the link above:

• "Powerful and efficient class D amplifiers with fanless cooling design to run cleaner, quieter and with greater long-term reliability
• 2500 W peak (1600 LF + 900 HF) 1250 W continuous RMS (800 LF + 450 HF)"

So, we can deduce a couple things about the guts of this unit.

An active crossover is used to segregate the output into relative 'low' and 'high'er frequencies. The woofer (LF) is getting everything below a set threshold (often for units like this, it's something like 2000hz, 2500hz, 3000hz). The tweeter or horn (HF) is getting all the rest (higher frequencies above the threshold). Fair enough, pretty standard configuration.

Unless you see a vented panel and/or the main chip mounted on a large heatsink I would have a great deal of cynicism about whether a powerful Class D chip operating at or near it's max capacity in an ENCLOSED box would have adequate cooling available. It needs some cooler ambient air circulating around it to stay [relatively] cool. I have a much smaller (much lower-powered Class D amp; 200w nominally) that has a dedicated cooling fan and it runs constantly (the fan speed appears to thermally be managed/dependent). Hopefully, it's just a blown speaker which is easily swapped out and nothing worse.

Let us know how it goes, good luck.

 

[Jumbotronic]

Hey, congrats on the progress. Was going to throw out one idea before you go any further: maybe ask the ALTO if you can substitute a 4ohm woofer instead of a 2ohm unit(?) You have MANY more options going with a 4 ohm woofer than the 2ohm unit. (Of course, it goes without saying that if you could use an 8ohm woofer, you'd have exponentially that many more as well).

My hunch is, they offer to send out another of their drivers (free? at discounted cost..?) to replace it (or maybe nothing, who knows??). If it were me, I would probably do some deep research on a quality 4ohm driver with appropriate specs and take a chance and put it in and give it a shot. Another reason that might actually work better, is because many of the 'high-powered' woofers (especially in the 2ohm variety..) tend to be low efficiency; so they can handle a large power input without self-destructing, at least in theory. Whereas, many 4 ohm units may have lower power handling but also be greater efficiency. So the net effect is that what power does get to the woofer is expressed in a more efficient manner -- so you don't need to turn things up as much to get the same overall output volume. (it's a tradeoff buried in the specs of the relative drivers essentially).

Good idea, about 4 ohm woofers. Yeah, there are a ton more of those! I know that running, for example, a 2 ohm speaker with a 4 ohm output is no bueno, but the other way tends to be fine. I'll see what Alto thinks, though I'd guess they'll want to push their own speaker on me (if they have replacements).

I took the unit apart pretty good today, and didn't notice any venting. Appears to be a sealed cab unless I missed something. Good point about the cooling. I've got a 500w class-D bass head, and that guy has all manner of vents and a fan. At the same time, I'd hope Alto's engineers know what the heck they're doing. I researched pretty well before buying, and it appears that Altos are (for powered speakers on the value end) supposed to be more reliable than most (e.g., Mackie), so presumably they're doing something right!

 

[PhredE]

An FYI for you as a footnote..

https://www.parts-express.com/pedocs/manuals/326-117-119--icepower-1200as-series-spec-sheet-manual.pdf

This is from the Ice power datasheet for the amp module 1200AS1 and 1200AS2 - (1200W class D amp module board from the most prolific maker of class D power amps / audio amps). I don't know that's the power for the TS412, but based on specs and if I were a betting type...

This quote struck me as interesting, P. 38, item 12.3
"12.3 Thermal Design
The ICEpower 1200AS module is designed with an integrated cooling system in the aluminum base plate. The module can therefore operate without any further cooling however at reduced power levels. Even though use of the module without further cooling is possible, it is recommended to add more cooling."

OK, I'll pipe down. Good luck. Please post back when you get a solution in the works.. (there may be people lurking that might also take an interest in the TS412 and related issues or problems..)

 

[Jumbotronic]

I heard from Alto. They think it's probably the speaker as well. What I have to figure out now is how to replace it. Options:

1) Exact replacement from Alto, $110 shipped + tax
2) Speaker with very similar specs, also 2 ohm: https://reverb.com/item/65250200-ne...-qsc-k12-2-powered-xd-000060-00-woofer-2-ohms. $99 shipped + tax
3) A 4 ohm speaker, as per PhredE's idea.

Anybody who wants to weigh in is welcome!

 

[schmee]

I heard from Alto. They think it's probably the speaker as well. What I have to figure out now is how to replace it. Options:

1) Exact replacement from Alto, $110 shipped + tax
2) Speaker with very similar specs, also 2 ohm: https://reverb.com/item/65250200-ne...-qsc-k12-2-powered-xd-000060-00-woofer-2-ohms. $99 shipped + tax
3) A 4 ohm speaker, as per PhredE's idea.

Anybody who wants to weigh in is welcome!

For $11 I'd buy the Alto correct speaker. But it's probably fine either 2 ohm speaker.

 

[cousinpaul]

Ditto.