f-113 subwoofer woofing too much!!!

[DrWho]

Btw, how do you know you're bottoming out the driver?

Usually,

slapping the voice coil against the back plate sounds more like a

clacking sound. Or if you're really pushing it hard it's a loud crack

(like breaking a baseball bat). If you're nearing the limits of the

suspension, sometimes the cone will rock and the voice coil will hit

the side of the gap. This sounds like scraping sound.

I have to

wonder if the sound you're hearing isn't just suspension noise - which

will sound like woofing whooshing sound. The Sunfire subs are notorious

for this sound too (hmm...they're small drivers in small cabinets too).

To find out for yourself, you could just remove the woofer from the

cabinet and blast some sine waves to get the woofer moving over its

full excursion. Being out of the box, the woofer should make absolutely

no noise whatsover - any noise you do hear is the distortion in the

speaker. You might be surprised how many mechanical sounds there are

when you're pushing the full xmax. Btw, don't do this if you don't know

what you're doing...there's a lot of potential for blowing up stuff.

One last comment....how loud are you listening? I wonder if you don't

have some mega suckage with the room acoustics? Cranking the sub up as

much as you are doing seems a bit insane. One other possibility would

be an impedance mismatch between your pre/pro and the subwoofer amp.

You wouldn't be the first situation where I've seen this happen.

[Roc Rinaldi]

It looks to be a great product, with lots of positives. Perhaps a little tweaking and adjusting. I run my Velodyne's volume level on "4" never needed any more than that. Adjusment on the preamp is typically at "0" or +1 crossed at 80Hz. Bring the crossover point to 80Hz and you will get more output out of it and back the volume control down to about 6-7 you should be fine.

I think your advice is accurate. Here is what the JL Audio technicians wrote to me about my noise.

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

" Of course it can be (and probably is) distortion, anything can be <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

overdriven, misused or abused.

A rapping sound would be a reasonable description of a

subwoofer being severely overdriven. Extremely low frequencies present the

greatest demand upon the subwoofer.

This system sounds as though it is completely

mis-adjusted. Everything set to maximum? ELF is a room optimization

tool. It sounds as thought the customer is using it and all other controls

simply to drive more energy from the subwoofer. ELF should be set/adjusted

to the acoustics of the room only and virtually never is there reason to

boost this region. Normally set ELF at zero or cut for the subwoofer to integrate

properly to the rooms acoustics depending upon room gain characteristics.

If the customer wants/needs more output than a single f113 is

capable of producing properly then logically he needs to purchase

more subwoofers. Subwoofer of the year or not, no product has infinite

output. Maybe he needs one or two more f113s or even a pair of Gothams.

It sounds as though he likes a lot of bass and there is nothing wrong with that, he

just needs to purchase more equipment.

Why would the crossover on the receiver be set to 60 Hz? The

Dolby standard (which is applied to all DVD mixing/mastering and authoring)

calls for an 80 Hz crossover point and that is the default for virtually all units

shipping from their manufacturers. Please advise to change to 80Hz.

Again, this all sounds quite self-explanatory, he is overdriving the

product. I imagine that he has the EQ on the receiver and the subwoofer

feed turned up as well. Controls on all equipment are for adjusting, they

are not a turbo boost feature and it is the Dealers job to educate the customer

and help set these controls. "

My advice is; Turn the ELF to zero, change the crossover frequency

on the receiver to 80 Hz, set all speaker and LFE levels and EQ settings on the

receiver to zero. Set all of the controls on the f113 to zero as well and with all of

these changes things should improve dramatically. Most importantly, buy

at least one more sub as the customers needs exceed his systems abilities. Remember

small adjustments up or down on all settings in the system to achieve balance and

not to be used as additional sources of gain which will certainly cause overload

throughout the entire system. Once these adjustments have been made, the consumer

should listen to the system and decide if he needs to purchase more equipment

to achieve a higher level of output. "

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -

My main concern is to make sure that my sub is not defective. I can easily turn down the sub's volume control, and I guess, buy a second f-113 if I need more volume which I do.

[Roc Rinaldi]

"You are overdriving it and bottoming the woofer out on the backplate! JL Audio is way overrated in the car audio world and they have been making home subwoofers how long now? A year. Gimme a break! That is a 13W7 car audio woofer adapted into a home cabinet with a JL Audio Plate amp regardless of the specs and what it can do. At $3K there are other and better choices. We'll see how well it works in the next 5 to 10 years.

My Velodyne's (They have been making subs for more than 20 years) won't do that since they are Servo controlled, the cone movement is measured thousands of times a second and any inconsistencies corrected. Loud, Deep and really, really low. No 60Hz Boom here!"

Just because a company has been building a product for years does not mean they make a state of the art product. Look at any of the big 3 automakers compared to the european and japanese cars. No contest.

In fact, my f-113 is a replacement sub for a Velodyne CT-120.

[Roc Rinaldi]

And BTW I have yet to bottom any of my subs...maybe I am more aware when to stop...

I'm learning when to stop.

JL Audio overrated...you are joking.Their $3300 retail price makes the velo DD18 $4999 look like a joke. And the JL Audio uses better parts from A to Z,the only departament where the Velo gets the nod is lower distortion and built in SMS-1.

Price Increase effective June 1, 2007 - f-113 - $3,500. Last day to order at the $3,300 price is May 31.

The JL Audio subs are far more capable down deep,cubic inch for cubic inch. Also one f113 moves more ait than two of your Velo subs and comes close to three units! Some people simply have large rooms and listen loud,plus placement and sitting are less than ideal.

I have a large room. I listen very loud. My speaker placements and seat locations are less than ideal.

What Roc was doing is pushing the sub beyond its limit,and BTW I can ruin any sub by overdriving the unit with sine waves...and roast any driver VC. I have seen voice coils in Velo,Klipsch ...roasted. Anything can be overdriven.Even the stoutest pro sub can be tortured to where ovearheating will get the better.

I believe that I was pushing the sub beyond it's limit. However, in my defense, the heat sinks never got more than slightly warm to the touch.

[Roc Rinaldi]

Big is a problem?!?

*sigh*

"Hoffman's Iron Law"

What is the "Iron Law"?

How about a slide from a lecture?

Basically, for a given motor strength the loudspeaker engineer has 3 main degrees of freedom:

-Size of the Cabinet

-Low frequency extension

-Efficiency of the system

Hoffman's Iron Law is a series of equations that describe the relationships between each of the above design criteria. Ignoring the math (unless you wanna get into it), "improving" any one of the design criteria to satisfy the desires of the market requires that you make sacrifices in other areas. For example, if you make the cabinet smaller and want to keep the efficiency the same, then the low frequency extension of the system moves higher. Or basically, you cannot make the system play lower without either increasing the size of the cabinet or reducing the efficiency. But if you don't mind a large cabinet, you can have the same efficiency AND the low frequency extension. This is why infinite baffle subs work so well.

Another important thing to keep in mind is that most all distortion is a result of the movement of the driver. If you can reduce the amount of movement for the same SPL, then the system is going to have less distortion. Since SPL is tied to the amount of air displaced, the only way to reduce the cone excursion is to increase the total driver surface area. This is another reason why infinite baffles work so well.

When you've got a small 12" driver in a small little cabinet, you've got all the variables working against you. Obviously, JL Audio has done some sick stuff with their motor to achieve their performance, so don't let me imply that you're hearing absolute crap. But it's still an iron-fisted approach, and for the amount of money and engineering put into that motor, I can't help but wonder what kind of performance they could be achieved in a cabinet twice or even four times the size. Heck, move to a 15" driver and now you need half the cone excursion for the same displacement! Double the size of the cabinet with a single 15" driver and you'd readily obtain 6dB more output all around. That can also read that you'll have 6dB less distortion at the same output levels. Of course, you could always purchase two units and achieve the same, but it's gonna cost way less when you've got a single driver in a single cabinet than multiple drivers in multiple cabinets.

I know I'm looking at the problem like an engineer and I'm well aware that there is no JL Audio motor mounted to a larger driver in a larger cabinet, and that you probably feel like you purchased the best product that matches your criteria...and that may very well be the case (I can't think of anything off the top of my head that isn't DIY). That said, I think it helps to be aware of the huge hurdles the design is trying to leap over when wondering why the system doesn't meet expectations. In my eyes, you might as well purchase a wave runner designed to travel up waterfalls when it would be way easier to take an elevator built into the side of the mountain...

This was very helpful. Thanks Mike.

[Roc Rinaldi]

Btw, how do you know you're bottoming out the driver?

Usually, slapping the voice coil against the back plate sounds more like a clacking sound. Or if you're really pushing it hard it's a loud crack (like breaking a baseball bat). If you're nearing the limits of the suspension, sometimes the cone will rock and the voice coil will hit the side of the gap. This sounds like scraping sound.

I have to wonder if the sound you're hearing isn't just suspension noise - which will sound like woofing whooshing sound. The Sunfire subs are notorious for this sound too (hmm...they're small drivers in small cabinets too). To find out for yourself, you could just remove the woofer from the cabinet and blast some sine waves to get the woofer moving over its full excursion. Being out of the box, the woofer should make absolutely no noise whatsover - any noise you do hear is the distortion in the speaker. You might be surprised how many mechanical sounds there are when you're pushing the full xmax. Btw, don't do this if you don't know what you're doing...there's a lot of potential for blowing up stuff.

One last comment....how loud are you listening? I wonder if you don't have some mega suckage with the room acoustics? Cranking the sub up as much as you are doing seems a bit insane. One other possibility would be an impedance mismatch between your pre/pro and the subwoofer amp. You wouldn't be the first situation where I've seen this happen.

All that I can say to describe the noise is that it sounds like a rapping or thrapping sound. This noise definitely shouldn't be there. It is not a part of the special effects. You could describe it as a clacking or a loud crack (like breaking a baseball bat). It does not sound like a scraping sound.

[Roc Rinaldi]

....To find out for yourself, you could just remove the woofer from the cabinet and blast some sine waves to get the woofer moving over its full excursion. Being out of the box, the woofer should make absolutely no noise whatsover - any noise you do hear is the distortion in the speaker. You might be surprised how many mechanical sounds there are when you're pushing the full xmax. Btw, don't do this if you don't know what you're doing...there's a lot of potential for blowing up stuff.

I'm not doing this because I don't know what I am doing.

And, Yes, I have unintentionally blown stuff up before.

[Roc Rinaldi]

One last comment....how loud are you listening? I wonder if you don't have some mega suckage with the room acoustics? Cranking the sub up as much as you are doing seems a bit insane. One other possibility would be an impedance mismatch between your pre/pro and the subwoofer amp. You wouldn't be the first situation where I've seen this happen.

Well I bought an f-113 so I expect to hear it play. I expect it to be quite loud. I listen loud. My wife complains. I continue to listen loud. My wife continues to complain and suggest that I go get a hearing test.

The listening room is somewhat on the dead sounding side but I can't imagine that it is sucking all of the bass out of the room.

Can you elaborate on your "impedance mismatch" comment? Thanks.

[wstrickland1]

I have a similar problem with my car radio. It sounds just terrible. I have it turned up as loud as it can go and I hear alot of distortion, almost as if the speakers are buzzing and rattling more so than reproducing music. I also have the bass and treble turned all the way up. Does anyone have any suggestions?

[sivadselim]

What does it mean to be "running hot"?

It has nothing to do with temperature.

It means you are running it at a higher volume level than it should be run if properly calibrated.

For example: "Joe is running his subwoofer 6 dB hot".

In your case, you're probably running it way too hot. Calibrate it properly!

[SWL]

I have a similar problem with my car radio. It sounds just terrible. I have it turned up as loud as it can go and I hear alot of distortion, almost as if the speakers are buzzing and rattling more so than reproducing music. I also have the bass and treble turned all the way up. Does anyone have any suggestions?

That's not nice.........lol

[Roc Rinaldi]

I have a similar problem with my car radio. It sounds just terrible. I have it turned up as loud as it can go and I hear alot of distortion, almost as if the speakers are buzzing and rattling more so than reproducing music. I also have the bass and treble turned all the way up. Does anyone have any suggestions?

Lower your listening standards.

[Roc Rinaldi]

What does it mean to be "running hot"?

It has nothing to do with temperature.

It means you are running it at a higher volume level than it should be run if properly calibrated.

For example: "Joe is running his subwoofer 6 dB hot".

In your case, you're probably running it way too hot. Calibrate it properly!

If I follow all of the suggestions given, then the sub bass volume is too low. I think I need a second f-113. I wasn't expecting this because I figured that at 2,500 rms, wpc, I would have plenty of volume to spare. Apparently not so. I am learning as I go. Good, solid, deep bass doesn't come cheaply now does it?

[Jay481985]

if you went by just spare wattage, you shoulda brought yourself a space heater...... watts mean nothing except how much the voicecoil will start burning up unless you get a decibel per watts aka sensitivity

[Roc Rinaldi]

if you went by just spare wattage, you shoulda brought yourself a space heater...... watts mean nothing except how much the voicecoil will start burning up unless you get a decibel per watts aka sensitivity

If I play it loud enough I can have both a loud playing sub AND a space heater.

[TheEAR]

Rocky,

Take your prescription pills,you are starting to mutate into a JacksonBart...[]

[Macho Nacho]

Ahh the Ear is still blowing his mono horn. Chill wiz

[TheEAR]

NatchosTacos,

What? You again!

[Duke Spinner]

I have a similar problem with my car radio. It sounds just terrible. I have it turned up as loud as it can go and I hear alot of distortion, almost as if the speakers are buzzing and rattling more so than reproducing music. I also have the bass and treble turned all the way up. Does anyone have any suggestions?

Yeeeouch ...!!!!!

[SWL]

Yo Duke.....................No subs???