Subwoofer Bottoming Out When It Shouldn't

H

Hermitian777

Audiophyte
So I purchased a used 15" subwoofer on ebay (locally). It is a Paradigm Servo 15a. It is about 15 years old but was originally a $1,500 dollar subwoofer so I am thinking this thing will be pretty nice.

With music it sounds great, no problem. But at moderately loud movie volumes it sometimes bottoms out with a POP sound during loud booming parts. I am thinking that it may be very low frequencies? Obviously I am not too happy.

The strange thing is that the subwoofer it is replacing (a Paradigm PDR-10, about the same age) is much smaller and cheaper and does not have this problem. It may not play as many of the low frequencies, but it doesn't bottom out at least!

Any suggestions? I am wondering if something may be wrong with electronics? Maybe it is not pulling itself back as it should?

Thank you for your help!

Edited to add: It is sealed instead of ported. I don't' know if that makes a difference.
 
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lovinthehd

lovinthehd

Audioholic Jedi
You did reset/recalibrate your system for the new sub? Might not be it but hard to know since you don't mention any specifics as to what you've done to set it up and if you just plugged and played.....

What is "moderately" loud particularly? Can you play bass sweeps and determine the frequencies that are causing this?
 
TLS Guy

TLS Guy

Audioholic Slumlord
So I purchased a used 15" subwoofer on ebay (locally). It is a Paradigm Servo 15a. It is about 15 years old but was originally a $1,500 dollar subwoofer so I am thinking this thing will be pretty nice.

With music it sounds great, no problem. But at moderately loud movie volumes it sometimes bottoms out with a POP sound during loud booming parts. I am thinking that it may be very low frequencies? Obviously I am not too happy.

The strange thing is that the subwoofer it is replacing (a Paradigm PDR-10, about the same age) is much smaller and cheaper and does not have this problem. It may not play as many of the low frequencies, but it doesn't bottom out at least!

Any suggestions? I am wondering if something may be wrong with electronics? Maybe it is not pulling itself back as it should?

Thank you for your help!

Edited to add: It is sealed instead of ported. I don't' know if that makes a difference.
Servo is just one way of Eq a sealed sub. However a sealed sub is just not going to reproduce low frequencies at power. The sub obviously needs a steep high pass filter at 25 Hz, or it will be a dead deceased sub, off its mortal coil and bereft of live. I think you know the story. (Hint Parrot).
 
lovinthehd

lovinthehd

Audioholic Jedi
FWIW when I looked up the sub it indicated it had a slot vent.....or is "a" designating a sealed version?
 
mazersteven

mazersteven

Audioholic Warlord
According to Stereophile review of that sub it was meant for small to medium rooms
 
John Parks

John Parks

Audioholic General
Servo is just one way of Eq a sealed sub. However a sealed sub is just not going to reproduce low frequencies at power. The sub obviously needs a steep high pass filter at 25 Hz, or it will be a dead deceased sub, off its mortal coil and bereft of live. I think you know the story. (Hint Parrot).
So you are saying it will be an... ex-subwoofer?
 
H

Hermitian777

Audiophyte
You did reset/recalibrate your system for the new sub? Might not be it but hard to know since you don't mention any specifics as to what you've done to set it up and if you just plugged and played.....

What is "moderately" loud particularly? Can you play bass sweeps and determine the frequencies that are causing this?
I did do the recalibration with the new sub. After it was complete I did pump the level up a little to be a bit closer to the old sub's volume (From a -10db level to a -5db) because it just seemed so much quieter.

I guess I just felt like something must be wrong because I have never bottomed out my smaller/cheaper sub and this monster is struggling at what seems to be similar volumes. As I said, I do notice that it plays lower frequencies than my old, but the actual volume is not high.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Warlord
Also. There’s no way of knowing how much abuse, intentionally or accidental it suffered over 15 years. Could’ve been sold because it was problem for the old user. Not saying that for sure, but it’s definitely possible.
How much was it? Imo it was overpriced at 1500 at any point in time. If the idea was to get more performance at lower cost from the used market, that’s definitely valid. However there are many subs today that will do better for far less than 1500, and probably less than you think.
 
S

shadyJ

Speaker of the House
The suspension on your sub might have loosened up so much over the years that the electronic limiters that these type of subs normally have may not be enough to protect it anymore. If I were you, I would put some kind of high-pass filter on it, a 2nd order slope at maybe 25 or 30 Hz should do the trick.
 
timoteo

timoteo

Audioholic General
I hate to have to say this but most likely the servo in the amp is going bad. I had the EXACT same thing happen to a Jamo 15” sealed sub I previously owned. The sub was also approx 15 years old. It would “fart” at moderate volume when allow bass would hit. With music it was fine but if I played a movie at anything over -25dB (calibrated by AVR) it would make a nasty pop or clunk noise. It was the servo :(

If you purchased it used the previous owner may have been dishonest & sold you a damaged sub. Sorry dude.

This of course only a guess on my part. Tho the issue sounds to me to be exactly what I experienced.
 
G

gettingloud

Audiophyte
So I purchased a used 15" subwoofer on ebay (locally). It is a Paradigm Servo 15a. It is about 15 years old but was originally a $1,500 dollar subwoofer so I am thinking this thing will be pretty nice.

With music it sounds great, no problem. But at moderately loud movie volumes it sometimes bottoms out with a POP sound during loud booming parts. I am thinking that it may be very low frequencies? Obviously I am not too happy.

The strange thing is that the subwoofer it is replacing (a Paradigm PDR-10, about the same age) is much smaller and cheaper and does not have this problem. It may not play as many of the low frequencies, but it doesn't bottom out at least!

Any suggestions? I am wondering if something may be wrong with electronics? Maybe it is not pulling itself back as it should?

Thank you for your help!

Edited to add: It is sealed instead of ported. I don't' know if that makes a difference.
hello there.... I'm having the same issue with my paradigm15a sub..... does anyone knows how to fix it?
Thank you in advance for your help.....
 
TLS Guy

TLS Guy

Audioholic Slumlord
hello there.... I'm having the same issue with my paradigm15a sub..... does anyone knows how to fix it?
Thank you in advance for your help.....
I doubt it is fixable. That may be the way those subs are. Subs have made massive strides over 15 years. Otherwise it likely needs a new driver and quite likely electronics as well. You could install a high pass filter at 25 Hz, that is the only thing I have to suggest. Realistically though that sub is probably at the end of the road.
 

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