New sub-Questions???

[copperband]

Got my new sub Jamo sub 650, found this video:

www.youtube.com/watch?v=MazwNR9CFqE

I took off the grill trying to see if my unit will vibrate like the one in the video, but most of the sources I played do not. Questions:

-is the vibration in the video normal?
-is it because the sources I played do not have enough low frequency?
-does volume level(both sub itself & UMC) play a role, meaning the higher the volume, the more it vibrates?
-sub needs break in?

My old sub is Jamo sub 300 which is 10", 50% less power than my new one sub 650, which is 12". So far I don't hear much improvement, which is disappointed as I expect a big step up. When I get close to the woofer and touch the woofer I felt its vibration and hear its sound.

I tested 2 channels cd with USP-1 with the sub on & with the sub off. To my surprise there is not much difference. It seems that I hear most of the bass from my front speakers...something do not look right. Crossover of USP-1 is around 80hz

[creimes]

Could be a placement issue, as more experienced people chime in I'm sure they will tell you the same thing, I was playing around with my Ultra Sub10 tonight even though I'm not in my house yet I had to play around with it a bit, just moving around would change the presence of it, just can't be put in an optimal position right now...heh but still fun, look into the sub crawl placement method.

[DYohn]

All I see in that video is a normally operating subwoofer. But they only move like that when reproducing low frequencies at relatively high volume levels.

[The Mad Norseman]

Loved the way it moved across the floor too!

But it didn't sound like a track that had much bass to it - what was the crossover point to the subwoofer? - 250Hz?

[copperband]

Oct 7, 2012 11:05:21 GMT -5 The Mad Norseman said:

Loved the way it moved across the floor too!

But it didn't sound like a track that had much bass to it - what was the crossover point to the subwoofer? - 250Hz?

Crossover point at subwoofer is 150hz, which is the highest, range is 40 to 150hz. By the way, there is a knob called "boundary gain compensation". How to set it? I tried different setting but it does not seem to make a difference.

[AudioHTIT]

Here's what THX says about BGC, don't think all the logo money goes for naught.

Boundary Gain Compensation (BGC)
Sitting near a wall may result in distorted bass response. BGC corrects the way low frequency sound is perceived when seated near a wall. This results in a more true and accurate bass response.

In case that didn't make it perfectly clear there's a picture that will flatten your understanding.
www.thx.com/consumer/thx-technology/thx-av-receiver-features/

[jamrock]

To be totally honest with you, the highest X/O for subs is approximately 80Hz. Above that that it might mean that your speakers are under performing and your subs over extending with possible localization. Also, regardless of dB output, your sub should not move an inch. You might need better isolation (soft rubber) feet for it. My U-12s have bass extensdion to -3dB @ 22Hz and they don't move regardless of output, and I drive them very hard

[flamingeye]

To really see your sub in action a highspeed camera should be used then played back in a slower mode

[copperband]

Oct 7, 2012 17:03:48 GMT -5 jamrock said:

To be totally honest with you, the highest X/O for subs is approximately 80Hz. Above that that it might mean that your speakers are under performing and your subs over extending with possible localization. Also, regardless of dB output, your sub should not move an inch. You might need better isolation (soft rubber) feet for it. My U-12s have bass extensdion to -3dB @ 22Hz and they don't move regardless of output, and I drive them very hard

When I first joined this forum, Bob from Victoria Canada and a few other people all say to set the sub at the highest hz level while UMC-! should be set around 80hz....

My sub is currently on a Auralex Gramma so isolation should not be a problem.

As I said at the beginning, when listening two channels with USP I set USP at around 80 and USP instruction says to set sub at the highest level

[DYohn]

Oct 7, 2012 22:02:42 GMT -5 copperband said:

Oct 7, 2012 17:03:48 GMT -5 jamrock said:

To be totally honest with you, the highest X/O for subs is approximately 80Hz. Above that that it might mean that your speakers are under performing and your subs over extending with possible localization. Also, regardless of dB output, your sub should not move an inch. You might need better isolation (soft rubber) feet for it. My U-12s have bass extensdion to -3dB @ 22Hz and they don't move regardless of output, and I drive them very hard

When I first joined this forum, Bob from Victoria Canada and a few other people all say to set the sub at the highest hz level while UMC-! should be set around 80hz....

My sub is currently on a Auralex Gramma so isolation should not be a problem.

As I said at the beginning, when listening two channels with USP I set USP at around 80 and USP instruction says to set sub at the highest level

That is correct.

[copperband]

Oct 7, 2012 17:02:57 GMT -5 AudioHTIT said:

Here's what THX says about BGC, don't think all the logo money goes for naught.

Boundary Gain Compensation (BGC)
Sitting near a wall may result in distorted bass response. BGC corrects the way low frequency sound is perceived when seated near a wall. This results in a more true and accurate bass response.

In case that didn't make it perfectly clear there's a picture that will flatten your understanding.
www.thx.com/consumer/thx-technology/thx-av-receiver-features/

Thanks. So how do I determine how much to turn on the knob for BGC? There are 6 dots on the knob

[AudioHTIT]

Oct 8, 2012 0:40:24 GMT -5 copperband said:

Oct 7, 2012 17:02:57 GMT -5 AudioHTIT said:

Here's what THX says about BGC, don't think all the logo money goes for naught.

Boundary Gain Compensation (BGC)
Sitting near a wall may result in distorted bass response. BGC corrects the way low frequency sound is perceived when seated near a wall. This results in a more true and accurate bass response.

In case that didn't make it perfectly clear there's a picture that will flatten your understanding.
www.thx.com/consumer/thx-technology/thx-av-receiver-features/

Thanks. So how do I determine how much to turn on the knob for BGC? There are 6 dots on the knob

That would have to be something gleaned from the manual. If I designed the knob, the counterclockwise position would be little or no BGC, and it would increase clockwise. This would mean clockwise if you sit near a wall and counter clockwise if your in the middle of the room ... but I didn't design it.

Edit: Here's a review on AVS, I just scanned and saw he mentioned BGC, don't think he used it but might be worth a read.
www.avsforum.com/t/1425552/jamo-sub-650-omnimic-frequency-response-graphs

[Nemesis.ie]

Copperband: If you are playing at moderate levels in a smaller, sealed room, you may not need (or be taking advantage of) the headroom provided by the bigger/more powerful sub.

Unless it is providing more extension in the lower frequencies, it may not be giving you anything different to the old one and you obviously need to play things with content at the lower end to observe that.

How does it sound in movies, e.g. the sonic canon in the the Hulk movie or the end scenes in "How to train your dragon". Do you have access to a mic and REW software so you could measure the response?

Buying another one of the original subs (depending on price) may have been a better option, what were you hoping to gain from the upgrade, i.e. what was lacking from the single old sub?

BTW, looking at the Jamo web site and comparing the current models (360 and 660) the bigger one only has 4Hz lower FR, i.e. 24Hz instead of the 360's 28Hz (neither of which is particularly low). So as I mention above, you may not notice much difference, especially if it's a smaller room.

Looking at the pic of the BC control, all the way clockwise appears to give the highest output and if you have the sub close to the wall and find it "boomy/over-powering" it would seem you turn it anti-clockwise to reduce the lower frequencies. From what you are saying it sounds like you may want it at max clockwise to get the most output in the lower frequencies - if it's too much you can then turn it down bit by bit.

One thing that struck me as REALLY strange is that there is no gain control on the sub? It looks like the BC control is a gain control that only works below 40Hz. This will mean you'll have to adjust the sub level to match the speakers in the processor only.

Did you adjust the gain in your processor since swapping in the new one? It likely needs to be level matched again and may even have a different gain (lower) to the smaller one as it has more headroom so could be playing quieter than the old one for the same processor volume setting if the trim was not adjusted.

www.jamo.com/images/common/SUB660/addl/SUB660_3.jpg

The 360 doesn't even have the BG control so is a fixed gain sub - this is the first time I've seen such a thing on a self-powered unit.

Not trying to be funny, but I hope you didn't pay something like this for it:

www.amazon.com/Jamo-SUB-660-Subwoofer/dp/B0099J2IV2

The C80 and D600 look like the only units in the range that actually extend down to 20Hz.

[copperband]

Thanks all for the replies so far.

Nemesis.ie

To answer your questions, reasons to buy a new sub:
-My old sub just don’t have enough punch on movies,
-wants to try a sealed sub as most say sealed sub is good for music listening. I do listen to music/pop songs/concerts a lot. My old sub is a slotted port design
-thinking of using two subs, that’s why bought the same brand
-$300 for a 12” 650 watts I thought that’s a pretty good buy?

I don’t have REW software.

My old sub model is 300 and new model is 650. It is interesting Jamo makes so many subs with close/similar model number
The gain control of my 650 is at top right front, just like my old 300.

I did change the gain level on the fly with UMC remote a few times. I think I need to check on the gain level, as you suggested.

My room is about 16’ x 25’, big wall behind TV and big wall 15” behind my seating area, one side is windows with full size curtain, one side is open to a hallway.
I play around 50 for UMC-1-movies, and ¼ for USP-1 for music/songs/concerts

NO I didn’t pay 900, paid $300. I know there are many better choices at 900, but just don’t want to spend that much at this time.

More inputs are appreciated.

[copperband]

Oct 8, 2012 0:50:31 GMT -5 AudioHTIT said:

Oct 8, 2012 0:40:24 GMT -5 copperband said:

Thanks. So how do I determine how much to turn on the knob for BGC? There are 6 dots on the knob

That would have to be something gleaned from the manual. If I designed the knob, the counterclockwise position would be little or no BGC, and it would increase clockwise. This would mean clockwise if you sit near a wall and counter clockwise if your in the middle of the room ... but I didn't design it.

Edit: Here's a review on AVS, I just scanned and saw he mentioned BGC, don't think he used it but might be worth a read.
www.avsforum.com/t/1425552/jamo-sub-650-omnimic-frequency-response-graphs

NO instructions from the manual.

[Nemesis.ie]

Oct 8, 2012 21:13:43 GMT -5 copperband said:

Thanks all for the replies so far.

Nemesis.ie

To answer your questions, reasons to buy a new sub:
-My old sub just don’t have enough punch on movies,
-wants to try a sealed sub as most say sealed sub is good for music listening. I do listen to music/pop songs/concerts a lot. My old sub is a slotted port design
-thinking of using two subs, that’s why bought the same brand
-$300 for a 12” 650 watts I thought that’s a pretty good buy?

I don’t have REW software.

My old sub model is 300 and new model is 650. It is interesting Jamo makes so many subs with close/similar model number
The gain control of my 650 is at top right front, just like my old 300.

I did change the gain level on the fly with UMC remote a few times. I think I need to check on the gain level, as you suggested.

My room is about 16’ x 25’, big wall behind TV and big wall 15” behind my seating area, one side is windows with full size curtain, one side is open to a hallway.
I play around 50 for UMC-1-movies, and ¼ for USP-1 for music/songs/concerts

NO I didn’t pay 900, paid $300. I know there are many better choices at 900, but just don’t want to spend that much at this time.

More inputs are appreciated.

Thanks for the detail, that helps.

Sealed subs generally will have lower output/slam for HT than ported (including via a slot), adding more of them helps.

My suggestion would be to put the new sub up front and try to integrate it well with the mains/centre. I'd then put the old sub behind your seating and integrate it to the rest and see how that sounds with the two running.

Another option might be to have the sub behind the seat only play the lower frequencies (e.g. 28Hz to 40Hz) for extra punch in the movies and/or maybe get a MiniDSP to try to tailor the sound to boost the lower frequencies.

Having the smaller sub closer to the listening position means it needs less power to get the same volume there versus further away, even though you will lose boundary gain.

Look up the HSU "Mid bass module" for more ideas along those lines.

Do you get more oomph with both subs running side by side (or on top of each other)?

Maybe you are just missing the <20-24Hz frequencies which are where a lot of the "feeling the sofa shake" comes from? Those subs just don't appear play that low.

At least it wasn't too expensive, maybe you can sell the two for enough to get something else?

Just to confirm the controls, I would set:

"Cut off" full clockwise.

"Phase" to full anti-clockwise

"BG" to full clockwise.

The mid position might be a good place to start with the gain and also check what is set in your processor, try maybe setting the sub trim there to the same as e.g. your centre and then adjust the gain on the sub so it integrates well. Additionally, is the distance setting in the processor correct for where the new sub is? If it is wrong, there could be phase differences causing cancellations.


Also, do you have both L + R inputs connected (via a splitter if needed), that often adds a bit of gain.

[copperband]

I am in the final week of testing the new sub Jamo 650 and I start to wonder if the unit could be defective as I don't get that extra punch I am expecting. I tried turning the volume at max and the output seems still low when compare to my old ported sub.

I do understand ported sub produces higher output/volume/punch than sealed sub, but 650 watts vs 300 watts(not in RMS) I thought should still generate a noticeable difference....

My final test: is there a way to check if a sub is defective? If so how? I have a few more days to return it for either refund or a replacement.

Thanks.

[hemster]

This might be obvious and covered already but could it be placement? Have you tried moving the sub or doing the "subwoofer crawl"?

[The Mad Norseman]

Oct 29, 2012 12:32:37 GMT -5 copperband said:

I am in the final week of testing the new sub Jamo 650 and I start to wonder if the unit could be defective as I don't get that extra punch I am expecting. I tried turning the volume at max and the output seems still low when compare to my old ported sub.

I do understand ported sub produces higher output/volume/punch than sealed sub, but 650 watts vs 300 watts(not in RMS) I thought should still generate a noticeable difference....

My final test: is there a way to check if a sub is defective? If so how? I have a few more days to return it for either refund or a replacement.
Thanks.

At this point, after you've already done so much experimentation and testing, I'd recommend that you call the dealer you bought it from and ask them.
At the very least you're then 'on record' (within the warranty period I mean), as reporting a suspected a problem.
But hopefully the dealer can solve the problem for you - good luck!

[Nemesis.ie]

Maybe put it in a smaller room of the house that has no openings with the door(s) closed and play some bass heavy stuff, if you are not then getting pounded, return it.