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Subwoofer Crisis: Replace Velodyne DD18 or buy 2 new 12" (SVS, Rythmik, or...?)

MediumRare

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I have a vintage Velodyne DD18 subwoofer that just died. :facepalm::eek: Its prodigious 18" cone and 1,250 watt digital servo controlled output was clean (like 2% distortion) down to 15 hz or below. At 120 lbs, it's a monster and understandably provided amazing deep LFE in my 18' x 27' x 9' room. (4,400 cu ft). But it's dead and cannot be repaired. The DSP board died and those famously are impossible to repair.

Aside from the weight and size, there is one major drawback to the DD18: With just one sub I did have a mode problem, even after using REW and Velodyne's sophisticated DSP system. I am only interested in listening to music and I love to feel that slam in my guts. And I do like to play loud on occasion, especially for parties.

So I have a few options and I'd appreciate some expert help in deciding what to do:

1. Buy a replacement plate amp/board from Velodyne
and I'm back to where I was. Cost about $2,500 but just guessing. https://www.audioholics.com/subwoofer-reviews/velodyne-dd-18
2. Buy 2 SVS-2000 Pro subs - 12" aluminum cone/1,500 watts. They don't go as low (still maybe 18 Hz?) or have digital servo but have a good app for integration and with 2 subs would help the mode problem. Cost $1,710 before negotiation. https://www.svsound.com/products/sb-2000-pro
3. Buy 2 Rythmik L12 subs - 12" paper cone/smaller amp not comparably reported. Has digital servo control so easily down to 15 Hz and very low distortion, but no sophisticated DSP for integration. Cost $1,320 https://www.rythmikaudio.com/L12.html https://www.audiosciencereview.com/forum/index.php?threads/rythmik-l12-subwoofer-review.12140/
4. Other ideas?
 
I have a DD10+, the later model. Mine also died out of warranty. I was at least able to get a complete new board. Cost was A$1500 installed about 10 years ago. Been working 100% every since. "Other ideas" may depend on what DSP could do the same job elsewhere, as good or better than the Velodyne tools.
 
You don't need the DSP on the Velodyne. DSP is better implemented upstream, i.e. between the source and the DAC(s).

If you choose to implement the DSP elsewhere, then all you need to replace is the plate amp on your Velodyne. If your Velodyne is dead anyway, you could consider removing the plate amp and replacing it with an aftermarket amp from Dayton like this. It will be a bit ugly since it won't fit. The first thing I would do is to open it up and check that the drivers still work by connecting it to one of your existing amps and playing a test signal.

You WILL lose the servo feature on your Velodyne if you go with an aftermarket plate amp though.

My usual recommendation with subs is: buy multiple smaller subs, as many as you can afford and you can place (minimum 2, maximum 4). Sacrifice cone diameter if necessary. The only exception is if you have a very large room, then you will need cone diameter. Ensure you budget for DSP of some kind.
 
I had the plate amp of my Velodyne 12" sub die on me. It has a regular bass driver (no servo stuff). I just gutted the amp (left everything required to seal the subwoofer case and removed everything else) and hooked up the driver to an external Nobsound G2 Pro amp. Works splendidly.

I'm not sure whether that's an option with a servo-controlled driver, do they have extra contacts for "telemetry"? I also have a dead Martin Logan sub, the driver of which as two pairs of terminals. Not sure what to do with that, otherwise I would have given it the Nobsound treatment, too.
 
My 2011 vintage DD18Plus needed a new plate amp (which I understand includes the servo and DSP functionality) in 2021, which cost about $1000 including shipping. I also had to ship the old plate amp back to Velodyne at a US address. I have no doubt the price for the plate amp has risen substantially since 2021, but the Euro to $US exchange rate has changed in favor of the dollar. I doubt a new amp is $2500. I'd guess more like $1500, unless Velodyne has gone nuts with prices.

The repaired DD18Plus has worked flawlessly since then. If the price is reasonable I'd probably recommend fixing it.
 
Regarding your room problem... when I ordered the DD18Plus I was going to order two, and the dealer recommended I order one at first, see how the system & room responds, and order the second one only if necessary. When I got the DD18Plus, I played with the system for days. Moving the sub, moving the L/R speakers, adjusting the DSP, everything. I wasn't completely pleased, so I was going to order the second sub. Then it occurred to me, rather than using a high-pass filter for the mains, which are Revel Salon2s, which are good to nearly 20Hz, what if I ran the Salon2s full-range and used the sub just for fill-in? After much more fiddling around, I had a smooth, no significant modes frequency response down to 20Hz. And I used the same strategy when we moved to the current house in 2015, again not needing a second sub. So if your mains are good to below 30Hz, you might try running them full-range and see what happens.

In case you're wondering, getting smooth bass from the Salon2s alone in both of my rooms required placements that I didn't like for various reasons. (Both were large, oddly shaped rooms.) However, if the DD18Plus fails again, I won't repair it a second time. I'll purchase two smaller subs and go with a more conventional set-up to achieve smooth bass.
 
Regarding your room problem... when I ordered the DD18Plus I was going to order two, and the dealer recommended I order one at first, see how the system & room responds, and order the second one only if necessary. When I got the DD18Plus, I played with the system for days. Moving the sub, moving the L/R speakers, adjusting the DSP, everything. I wasn't completely pleased, so I was going to order the second sub. Then it occurred to me, rather than using a high-pass filter for the mains, which are Revel Salon2s, which are good to nearly 20Hz, what if I ran the Salon2s full-range and used the sub just for fill-in? After much more fiddling around, I had a smooth, no significant modes frequency response down to 20Hz. And I used the same strategy when we moved to the current house in 2015, again not needing a second sub. So if your mains are good to below 30Hz, you might try running them full-range and see what happens.

In case you're wondering, getting smooth bass from the Salon2s alone in both of my rooms required placements that I didn't like for various reasons. (Both were large, oddly shaped rooms.) However, if the DD18Plus fails again, I won't repair it a second time. I'll purchase two smaller subs and go with a more conventional set-up to achieve smooth bass.
Great comment, as usual, @blueone. In fact, I do run my mains full-range for just that reason, though they are really only good to 42 Hz or so. Also, I tried using the DD18 to provide the high pass for the mains and I found it to be noisy, so I didn't want to compromise my mains, either.
 
Great comment, as usual, @blueone. In fact, I do run my mains full-range for just that reason, though they are really only good to 42 Hz or so. Also, I tried using the DD18 to provide the high pass for the mains and I found it to be noisy, so I didn't want to compromise my mains, either.
That's a bad sign, a noisy high-pass filter. Your amp may have been bad since the start. If you still have room modes that annoy you, and you're already running the mains full-range, I suspect you're a good candidate for multiple smaller subs. Why postpone the inevitable?
 
I have a vintage Velodyne DD18 subwoofer that just died. :facepalm::eek: Its prodigious 18" cone and 1,250 watt digital servo controlled output was clean (like 2% distortion) down to 15 hz or below. At 120 lbs, it's a monster and understandably provided amazing deep LFE in my 18' x 27' x 9' room. (4,400 cu ft). But it's dead and cannot be repaired. The DSP board died and those famously are impossible to repair.

Aside from the weight and size, there is one major drawback to the DD18: With just one sub I did have a mode problem, even after using REW and Velodyne's sophisticated DSP system. I am only interested in listening to music and I love to feel that slam in my guts. And I do like to play loud on occasion, especially for parties.

So I have a few options and I'd appreciate some expert help in deciding what to do:

1. Buy a replacement plate amp/board from Velodyne
and I'm back to where I was. Cost about $2,500 but just guessing. https://www.audioholics.com/subwoofer-reviews/velodyne-dd-18
2. Buy 2 SVS-2000 Pro subs - 12" aluminum cone/1,500 watts. They don't go as low (still maybe 18 Hz?) or have digital servo but have a good app for integration and with 2 subs would help the mode problem. Cost $1,710 before negotiation. https://www.svsound.com/products/sb-2000-pro
3. Buy 2 Rythmik L12 subs - 12" paper cone/smaller amp not comparably reported. Has digital servo control so easily down to 15 Hz and very low distortion, but no sophisticated DSP for integration. Cost $1,320 https://www.rythmikaudio.com/L12.html https://www.audiosciencereview.com/forum/index.php?threads/rythmik-l12-subwoofer-review.12140/
4. Other ideas?

I advised my friend to get a SVS SB-1000 Pro. It is very good for the price, and reallly helped elevate the performance of his system. But, in comparison to my 18" Velodyne, it is not anywhere close, and even with two I don't think they will be on par. The SB-2000 Pro is a small step up from SB-1000 Pro, but I still don't think two of those will get you to what you had with the Velodyne. That is based on me comparing the specs for the SB-2000 Pro to the SB-1000 Pro, and I could be wrong. Nonetheless, multilple subwoofers are better than one at addressing room modes.

Rythmik subs have caught my eye as a potential replacement for my Velodyne if/when it ever dies. I have never heard one, but the reviews I have seen for them tend to be good.
 
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I have a vintage Velodyne DD18 subwoofer that just died. :facepalm::eek: Its prodigious 18" cone and 1,250 watt digital servo controlled output was clean (like 2% distortion) down to 15 hz or below. At 120 lbs, it's a monster and understandably provided amazing deep LFE in my 18' x 27' x 9' room. (4,400 cu ft). But it's dead and cannot be repaired. The DSP board died and those famously are impossible to repair.

Aside from the weight and size, there is one major drawback to the DD18: With just one sub I did have a mode problem, even after using REW and Velodyne's sophisticated DSP system. I am only interested in listening to music and I love to feel that slam in my guts. And I do like to play loud on occasion, especially for parties.

So I have a few options and I'd appreciate some expert help in deciding what to do:

1. Buy a replacement plate amp/board from Velodyne
and I'm back to where I was. Cost about $2,500 but just guessing. https://www.audioholics.com/subwoofer-reviews/velodyne-dd-18
2. Buy 2 SVS-2000 Pro subs - 12" aluminum cone/1,500 watts. They don't go as low (still maybe 18 Hz?) or have digital servo but have a good app for integration and with 2 subs would help the mode problem. Cost $1,710 before negotiation. https://www.svsound.com/products/sb-2000-pro
3. Buy 2 Rythmik L12 subs - 12" paper cone/smaller amp not comparably reported. Has digital servo control so easily down to 15 Hz and very low distortion, but no sophisticated DSP for integration. Cost $1,320 https://www.rythmikaudio.com/L12.html https://www.audiosciencereview.com/forum/index.php?threads/rythmik-l12-subwoofer-review.12140/
4. Other ideas?
That is a great subwoofer. There are people who specialize in Velodyne plate repair.

You can look on the internet for DD18 failure modes. Usually it is the power supply. That is an easy fix.

It is possible for the power supply failing to destroy the small signal parts, or the digital parts. Different servicers will have different capabilities, on up to the original manufacturer fixing it all.

If you replace it, perhaps in the decision-making equation is how long the maker says they will maintain it.
 
Have a 15 inch Velodyne subwoofer for my home theater system.
I just bought 2 Rhytmik LV12M subs for my music system and they go deep. Use REW and Dirac for room correction . Listen to mainly classical and some jazz. My room is 20x20x 8
It sounds great.
 
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I'd also recommend looking into the HSU VTF-3 Mk5. Would definitely have more output than the Velodyne and sound better doing it.
 
I'd also recommend looking into the HSU VTF-3 Mk5. Would definitely have more output than the Velodyne and sound better doing it.
Thanks for the suggestion. I guess a ported sub is expected, all things being equal, capable of being louder than sealed. But the DD18 isn't "all things being equal"; it's measured louder than the Mk5 HP, even at 16 Hz. And I expect with substantially less distortion. So I'm not sure how you reached that conclusion. Can you expand on your comment?
 
Thanks for the suggestion. I guess a ported sub is expected, all things being equal, capable of being louder than sealed. But the DD18 isn't "all things being equal"; it's measured louder than the Mk5 HP, even at 16 Hz. And I expect with substantially less distortion. So I'm not sure how you reached that conclusion. Can you expand on your comment?
Sorry, I meant via a pair of them. I should have made that more clear.
 
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