a/d/s/ HT12ps subwoofer

across

New Member
Hi All, I have searched the web over and over and the ADS page for any insight or experiences with the giant a/d/s/ HT12ps subwoofer. I recently bought one on Craigslist for 180.00 in good condition. I found the manual online and set it up. Anyway this thing is a BEAST 81 lbs and monstrous bass, maybe more than I need. I have it hooked up to a Accuphase e 202 which and also a P 300 power amp. Speakers I am running are mains from the e202 ScanDynas and from the p300 ADS L 810s. The inefficient Scandynas are probably no match for the sub. Regardless I was just looking for anyone else out there who may have some experience with the ADS subs advice etc. I love ADS speakers, but I am not overwhelmed by the sub yet. Thoughts?
 
I own both the HT12ps and smaller HT10ps (model # references the woofer diameter as you'd expect).

I was also the product manager at the time these were launched, thru the point where all a/d/s/ products were discontinued. :tears:

The HT subs are bandpass designs and were tuned to support as much low frequency output as we could get out of them within the constraints of size/weight/things coming loose or getting noisy (port noise for one). You might say we didn't quite stay within the confines of the size/weight part, lol - mostly because the engineers had to use enough port to prevent whistle that the cabinet internal dimensions expanded a little more than we had originally intended.

My experience is that while they CAN be used effectively for music in a 2.1 system, they take a LOT more tweaking to blend reasonably well than a lot of other powered subs, including the smaller & less expensive C10ps/C12ps which are conventional sealed cabinet designs. However, they come into their own for home theater use, where the higher LF output works really well for big/bang/boom sound effects - so much so that I use the smaller Ht10ps for my A/V system because the HT12ps makes parts of my house vibrate that I really don't want to try and fix.

The key part is managing the onset and phase of the bass output, but I think if you can run the stereo pair low enough you will be able to get the woofer to match up to it pretty well, though you may still find that combination is a little peaky on material with lots of low end - hard to mask when all of a sudden there's a massive amount of additional sonic energy in the room.

Funny, I just saw one of these subs listed for sale locally at a halfway reasonable price - if anyone in the SoCal area is interested, take a look on CL.

John
 
I spent sometime with it last evening, and tweeked the bass volume and phase and was able to get a really sweet spot for music. The sub actually really needs very little volume output to get the job done. That is really interesting you were a product manager for ADS, what was the history on this sub? Doesn't seem like many were made when I search for them for sale or for insight on other owners etc. Do they have any unique repair issues that you know of?
I was at my local Hi Fi shop and told them about my score and they mentioned trading for a Sunfire sub, so this ADS must be somewhat in demand.
I wanted to stay with ads since I had the ADS L810s and had Richard So rebuild them and I am invested. I have tried other subs but this one seems to have a pretty smooth bass extenuation if that makes sense. Some of the other subs I have tried had a more clinical thin bass. Anyway lots of info but I love chatting about this stuff.
 
Funny you mention unique repair issues... since my HT12ps fried itself last night - guess I am about to find out.

Getting to the drivers is interesting as I recall, have to go in through the bottom after removing the baseplate. I won't have to do that to service the amp, will for now just pop the amp from my NOS HT10ps into that one (same amp used for both) and should be able to service the blown amp given I have a second working one and - I think - schematics, somewhere.

I will post back after looking at the amp, it's possible these suffer from defective Chinese electrolytic capacitor syndrome. They were produced around 2004-2005 or thereabouts, seems to me that was at the peak of the period where bad caps were showing up everywhere in China. If so you might want to do some preventative replacement.


John
 
Well, the good news is that these amps do not appear to have defective caps in them, saw no signs of leaking or bulging parts inside the one I thought was dead.

The other good news is I am an idiot, the only reason it wasn't working was that the OTHER end of the RCA cables connected to it was left disconnected back around the Super Bowl when that A/V receiver got yanked to fix a nasty intermittent protection issue (failing solder joints). It's obvious now that I am hearing it again but I totally missed that the sub wasn't playing for the past couple of months - the crossover point from the front surrounds is pretty low, so the system sounded quite good w/o the sub. Works perfectly now that I've reconnected it, though.

And the burning electrical smell that prompted all this? Traced that to the handle of a pot on the stove that had been left too close to the heat coming up from a second burner that was also in use at the time. Didn't melt it but got it so hot it produced the same smell you get from fried transistors and diodes... which I know all too well from years of repairing car amps in particular. So, if you ever want to F with someone, take the handle from a Revereware pot and throw it on their BBQ when they aren't looking - will make the whole neighborhood think they have an electrical fire somewhere.

Anyway all is well.


John
 
So, closing the circle on this... I've been inside the amp for the HT12ps and saw NO evidence of failing caps whatsoever. In fact, it is working fine... problem turned out to be horribly soldered lead wires at the actual woofer inside the box, making the woofer intermittent (mostly off). They were so bad I can't imagine how it ever played, but it did! For years in fact. They were captive inside the terminal posts but only because the cold solder blobs on the ends were too big to slip back out of the little cylinders the leads route thru where they emerge towards the cone. I put a bunch of heat on the terminal sleeve and flowed the joints properly, should hold up forever now.

Also found out (re-learned might be a better description) that my HT12ps is a total prototype. I remember vaguely rescuing it from being thrown away, and that the ports weren't 100% finished internally but after taking the cabinet apart to remove & service the woofer I really see the non-production details now - including a bolt that was supposed to be holding the woofer in (one of eight) that was hot-glued in place! Apparently the captive nut came loose from the MDF and rather than pull the woofer to service that (the captive nuts install from inside the smaller sealed chamber at the top of the woofer, so the only way to get to them is with the woofer completely removed) someone just hot-glued the bolt head so it wouldn't rattle (which worked, amazingly). I fixed that, also fixed the damaged thread that made it bind up and come out in the first place, and resoldered the leads correctly.

The woofer in this one is actually not production either, it has a big old Ground Zero driver in it - looks like one we might have had made locally during the development project. Damn thing vibrates the whole house again now that it's fixed though - time to go on a hunt for more drywall screw heads popping out. Definitely run circles around the HT10ps I had in there temporarily, and that one is no slouch either.

John
 
Thanks for the post John. Great to know about the solder, but likely only on your prototype. I run an ads MS4u with my Polk SDA 3.1TLs when I feel like really rattling the house. I checked the amp before and it appears well soldered. Coincidentally, an a/d/s HT10ps popped up on my local CL recently, for $50. (No affil.) Sounds like it'd be worth checking out if one was looking.
 
$50? I would jump all over an HT10ps at 3x that price.

I don't imagine anyone else will run into that solder problem on the woofer but thought it was worth mentioning that the amps don't show any signs of being infected with bad Chinese cap virus.

John
 
John what was the timeline of the ADS produced sub's, I have an SW500 myself another rather large
band pass design.
 
I'd have trouble with that one... I was a 12V guy and only got involved with the brand at the manufacturer level after the ADST acquisition by Directed. At that point the only models in sight were the HT- and C-series which were still being developed at the time. We shipped those the following year, so I know the story behind those for the most part. As I recall those series were replacing another series they'd had some problems with that had BASH amplifiers... some finger pointing going on between the amp supplier and the driver supplier as to which was blowing up the other, according to the story I head. Might have that chronology wrong though... don't recall any powered subs being available at the time of the acquisition but the first year or so that was being done from Phoenix and I wasn't involved so might have had other models still being produced in small quantities.

The guy you'd want to ask about earlier models is Soundmotor... he was around for a bigger chunk of that period. I have one other powered sub model myself and it's a big bandpass design, can't remember which model though. Has a conventional amp on it and looks like it might have been designed to be mounted between studs and vented into a room - all of the sound comes from small vents at one edge of the cabinet, and the cabinet is not finished to any real degree of quality.

John
 
Hello,

Sorry to bump up an old thread, please let me know if I should just start a new one.

I have an ADS HT10PS that in the past year or so stopped working. It powers on with a green light and I can hear a faint hit of the driver when I plug in the RCA connections. But I get no sound whatsoever from playback. I've hooked the driver up directly and it works fine, so I believe the problem is with the amp. Fuse isn't burnt out, I looked all over the board and I can't find anything fried anywhere..

So in the meantime I'm going to be replacing it with my ADS C10PS, but my question (especially to John aka jdurbin1) is if you know what impedance the HT10PS runs? I am torn between trying to get the amp repaired and just replacing it with another plate amp. Right now I have it hooked up with the backplate on but the amp removed (passive speaker only).

Just looking for general advice. I don't really want to buy another new sub when I already have these two plus a custom passive sealed Image Dynamics 12" that I built sitting in the garage.

I'm sure I'll be perfectly happy with the C10PS as a replacement, but the HT10PS was really the sub that I bought for my HT setup and it's a shame to let such a beautiful speaker go to waste.

Very Respectfully,
Hoy
 
Soundmotor where art thou?

~1981

PB1500 (2x10" w/ 2x100W)

~1987

SW5 (1x12" w/ 350W iirc)
SW4 (1x10" passive bandpass)
SW2 (1x10" passive bandpass, fit between studs)

~1990

SUB12 (1x12: bandbass w/ ~400W iirc)
SUB10 (1x10" bandpass w/ ~250W iirc)
SUB5 (1x10" passive bandpass)

~ 1993

MS3 (1x10" bandpass w/ ???)
MS2 (1x8" bandpass w/ ???)
MS1 (1x7" bandpass w/ ???)

~1994

MS4 (1x12" bandpass w/ ???)
 
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I don't offhand, would have to go dig thru archived engineering files to get to that level of the component specs - or get to the wires in my own HT10ps, which is boxed up at the moment.

Could be the latter will happen, as I have three broken C12ps amps I'm working on starting with the one from my office system that I just got opamp replacements for. Same amp as used in the HT10ps, so if I have to pull that good one to have it for reference when I work on the other three, I'll be able to measure the wires going to the woofer.

You might be able to drop the C10ps amp in but it's half the wattage of the other three models (150 vs. 300) - but fits the same, as I recall.

I'll post back anything I learn on the amp repair (the larger 300 watt model), have seen enough that failed with the same symptoms that I would lean towards commonality for the root cause & what to do to repair them.

John
 
Do you have a pic of it?

Poor old picture.

Yes it is an SW500 had it for some time around 100lbs




ads%2520sub.jpg
 
Could be, the pedestal design in the front is not dissimilar to the HT-series subs which were the last ones designed (2000/2001):

HT-series subs.jpg

John
 
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