ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1] 2 3  All   Go Down

Author Topic: Help with my DSR112  (Read 4085 times)

Steve Garris

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1457
Help with my DSR112
« on: March 21, 2019, 07:50:45 PM »

Sunday's Paddy gig at the Wilde Rover:
Guitar player calls me to the stage, my monitor sounds weird. I checked everything in the back and stuck my head in front of each speaker, seemed ok to me and both horn and bass driver were producing sound. There was liquid spillage on some of my monitors including this one, but not that much. Next day I decided to pull the grills and clean them all up. This box showed no sign of liquid getting in to the horn, but another one did - I have (4) total.

After cleaning I did some A/B comparisons, using a mono sound track and just flipping the mains left/right to compare. After just a bit of time I did think one of them was weak in the 2.5-4k area. Today I decided to swap the horn in this one with another. Upon doing this, they both sounded the same to me. Did I get one of the 4 mixed up? Not sure...

I swapped the outputs from my board, twisted the knobs, cycled all of the buttons, still sounded the same. Next I brought the other 2 boxes back in and did the same comparison, and found that one of them sounded weak in the 2.5-4k range. Perhaps this is the one that my guitar player was using?

I have them all marked now, and did some additional testing with my limited tools and knowledge. Using a pink noise generator, and a program called Octive on my iPhone, I measured the response in each cabinet (hand holding the iPhone, not very scientific I know).  After this I laid them out again and compared all of the boxes, and I still heard less high frequency in this box #4. Next I used a tone generator set at about 3.4k, and box #4 measured about 5 db less at this frequency. Something is definitely up with this box.

Could this be from beer or liquid spillage? I've never had a symptom like this before. Or would this be some issue with the amp module?

Pictures show each box with pink noise - ignore the colored bars as they were jumping around a lot.
Logged

Steve Litcher

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 621
    • MixMasters Podcast
Re: Help with my DSR112
« Reply #1 on: March 21, 2019, 09:29:18 PM »

I would look into some sine sweeps while trying to capture the transfer responses you can.

Wish you were located closer; I’d bring my Smaart rig over and we’d know for certain.

That said, it’s semi-telling when you mentioned that swapping the horns changed the sound between the cabinets.



Sent from my iPhone using Tapatalk

Steve Garris

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1457
Re: Help with my DSR112
« Reply #2 on: March 21, 2019, 09:36:28 PM »

I would look into some sine sweeps while trying to capture the transfer responses you can.

Wish you were located closer; I’d bring my Smaart rig over and we’d know for certain.

That said, it’s semi-telling when you mentioned that swapping the horns changed the sound between the cabinets.



Sent from my iPhone using Tapatalk

What does the "sweep" do? I have that on my tone generator but not sure what to do with it.

I just set the quiet one (#4) next to another, and using a tone generator pumped 3.4k through them. Using my db meter, at 3.4k, #4 is 98.5 db while the others are 102 db (meter against the grill centered over the horn). I am now about to swap these horns out.
Logged

Steve Garris

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1457
Re: Help with my DSR112
« Reply #3 on: March 21, 2019, 09:59:26 PM »


I just set the quiet one (#4) next to another, and using a tone generator pumped 3.4k through them. Using my db meter, at 3.4k, #4 is 98.5 db while the others are 102 db (meter against the grill centered over the horn). I am now about to swap these horns out.

I can now confirm it is the horn driver. I just swapped the 2 above out and the problem moved along with the driver.

I'll contact Yamaha tomorrow and see what my options are.
Logged

Peter Kowalczyk

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 318
Re: Help with my DSR112
« Reply #4 on: March 22, 2019, 12:21:53 PM »

I had a similar issue last summer.  We have 10x DSR112s, purchased at various times from various sources.  During a shop day, I used Smaart to verify all of them.  9 of them were spot-on identical, but one had a substantial hole in its frequency response.  I don't have the data available now, but I recall it was in the lower end of the compression driver's range - somewhere around 2kHz.  By swapping polarity and horn/driver assemblies with a 'known good' unit, I confirmed that it was, in fact, a bad compression driver.  I contacted Yamaha support and they sent me a new one promptly under warranty. 

Sounds like you've confirmed it is the driver itself; Yamaha should be able send you a replacement.  Good luck!
Logged

Steve Litcher

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 621
    • MixMasters Podcast
Re: Help with my DSR112
« Reply #5 on: March 22, 2019, 12:37:13 PM »

What does the "sweep" do? I have that on my tone generator but not sure what to do with it.

The sweep just lets you see exactly where the issue is; the energy is consistent, rather than "busy" like it is with pink noise. Easier for doing A-to-B comparisons because the signals are identical and singular.

Scott Harris

  • Subwoofer forum
  • Sr. Member
  • *
  • Offline Offline
  • Posts: 257
  • Worcester, MA
    • Running Sound
Re: Help with my DSR112
« Reply #6 on: March 23, 2019, 01:22:26 PM »

You might want to skip right past the beer spillage part when speaking to Yamaha.
Logged

Chris Grimshaw

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1822
  • Sheffield, UK
    • Grimshaw Audio
Re: Help with my DSR112
« Reply #7 on: March 24, 2019, 07:09:03 AM »

Just a quick FWIW, I once ended up using a coaxial stage monitor as a lawn fill (still in stage monitor position - they just wanted a bit of clarity outside the tent and I didn't have any stands) and then the rain started. Turned out the tent was positioned just so that it would direct plenty of water into the stage monitor.

Sounded pretty bad after that - 6dB hole between 2-5kHz. EQ'd it back in to get through the gig.

Got back to the shop, opened it up, pulled the HF driver, and found there was quite a lot of water on the diaphragm and in the magnetic gap. Presumably, stopping the diaphragm moving much at the bottom of its range.
Went around it all with kitchen roll, got all the water out. Re-assembled, and it sounded fine again.

Something similar might've happened with your cabs, and simply cleaning out the HF driver might rescue it. I can certainly imagine that dried up beer would leave residues that would upset a HF driver.
If you get sent another one, clean the old one and you've got a spare.

Chris
Logged
Sheffield-based sound engineering.
www.grimshawaudio.com

Steve Garris

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1457
Re: Help with my DSR112
« Reply #8 on: March 24, 2019, 12:55:21 PM »

Just a quick FWIW, I once ended up using a coaxial stage monitor as a lawn fill (still in stage monitor position - they just wanted a bit of clarity outside the tent and I didn't have any stands) and then the rain started. Turned out the tent was positioned just so that it would direct plenty of water into the stage monitor.

Sounded pretty bad after that - 6dB hole between 2-5kHz. EQ'd it back in to get through the gig.

Got back to the shop, opened it up, pulled the HF driver, and found there was quite a lot of water on the diaphragm and in the magnetic gap. Presumably, stopping the diaphragm moving much at the bottom of its range.
Went around it all with kitchen roll, got all the water out. Re-assembled, and it sounded fine again.

Something similar might've happened with your cabs, and simply cleaning out the HF driver might rescue it. I can certainly imagine that dried up beer would leave residues that would upset a HF driver.
If you get sent another one, clean the old one and you've got a spare.

Chris

I would like to try this myself, but I've never really taken a horn driver apart. Is there anything I need to look out for? I suppose I should look at some Youtube videos. Also, what is "kitchen roll"?
Logged

Chris Grimshaw

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1822
  • Sheffield, UK
    • Grimshaw Audio
Re: Help with my DSR112
« Reply #9 on: March 24, 2019, 01:08:24 PM »

Kitchen roll is what we in the UK call the heavy-duty paper tissues used in the kitchen. It's absorbent, and doesn't break down when wet.

When it comes to dismantling HF drivers, they're pretty simple. Take your time, don't force anything. When it comes to reassembly, be gentle. You want the HF coil to line up with the gap perfectly - most HF drivers have some kind of pin or hole around the edge to help things line up better.
When everything is back together, tighten the screws so they're just about touching the back cover, and then torque them up a bit at a time (moving to different screws each time) so the pressure applied is nice and even across the diaphragm.

Bear in mind that diaphragm is made of titanium, and can take a little abuse. However, they're not indestructable.

If you get stuck, take pictures and post them here. Chances are at least one of us has seen the problem before, and knows what to do.

Chris
Logged
Sheffield-based sound engineering.
www.grimshawaudio.com

ProSoundWeb Community

Re: Help with my DSR112
« Reply #9 on: March 24, 2019, 01:08:24 PM »


Pages: [1] 2 3  All   Go Up
 



Site Hosted By Ashdown Technologies, Inc.

Page created in 0.056 seconds with 20 queries.