Can I add more power to an active subwoofer

[alphard]

Hi,

I have a B&W 610xp powered subwoofer hooked up to my integrated amp (NAD326bee) It's a 500w 10" sub but despite its very low frequency response, I feel like its not loud enough. The volume control is already at max and it's still a bit low for me.

Since I have a spare integrated amp (Rotel RA04), can I use it to increase my subwoofer's volume? So the setup will be the NAD amp's subwoofer out will be connected to the Rotel amp, and then to the active subwoofer.

Now I know you only use a separate amp for a passive sub and there are dangers of overloading, but in my situation, I just want to add a little more volume to it.

Thanks in advance!

 

[mike c]

it's not worth doing it IMO. you'd have to find a way to bypass the active sub's own amps but still use it's low pass filter. (that warrants advanced electrical know-how).

sell your RA04 and B&W sub and get a better subwoofer

 

[96cobra10101]

You need a bigger sub, or relocate the sub to a better sweet spot.

 

[Adam]

Welcome to the forum!

You mentioned that the volume control was on max, and I'm assuming that is the volume on the sub itself. Can you adjust the subwoofer level on the NAD? I looked through the manual and didn't see that mentioned, but most receivers will let you set speaker levels (although, I'm not that familiar with stereo receivers like yours).

I bring this up because you're asking if you can add more amplification to the signal being sent to the sub, and I'm talking about increasing the level of the signal before it gets amplified - having the same overall effect without trying to rig up an external amp to your sub. If you can't adjust it on your NAD, you could boost the signal going to the sub. I don't know how much that would cost you, and it might not be worth it.

Like cobra above, I also suggest looking into placement of the sub. You can check out articles on how to go about doing that on the Audioholics site here.

 

[TLS Guy]

Hi,

I have a B&W 610xp powered subwoofer hooked up to my integrated amp (NAD326bee) It's a 500w 10" sub but despite its very low frequency response, I feel like its not loud enough. The volume control is already at max and it's still a bit low for me.

Since I have a spare integrated amp (Rotel RA04), can I use it to increase my subwoofer's volume? So the setup will be the NAD amp's subwoofer out will be connected to the Rotel amp, and then to the active subwoofer.

Now I know you only use a separate amp for a passive sub and there are dangers of overloading, but in my situation, I just want to add a little more volume to it.

Thanks in advance!

That is a small 10" sub. You can not daisy chain amps. You will get no more power, and damage the sub amp. The input is not designed to feed from a power amp. In any case your current sub amp would be providing all of the power, and your Rotel no power.

A couple of point in addition to experimenting with position. I suspect you have the bass extension switch set to A (-6 db at 20 Hz). Since this is a sealed sub, that will waste a lot of amplifier power as the a sealed sub has to be equalized at 12 db per octave. The driver will roll off far too high on a sealed sub, so you have to equalize.

So set the bass extension to B (-6 db at 25 Hz.)

You will have most output (sub will be loudest) setting the bass extension to C (- 6 db at 30 Hz), but then it won't be truly a sub as it will be rolling off at 45 Hz. On be it will be stating to roll off at 37.5 Hz and on A it will be starting to roll off at 30 Hz.

The higher the roll off the louder the sub will play.

Now make sure you have the sunb optimally phased with your other speakers. A phasing error will really reduce bass.

The next point is that this problem may not be the fault of your sub, but your main speakers. What are your main speakers?

Most of what is actually perceived as bass is actually well above sub range, in the 80 to 180 Hz area. A lot of speakers have inadequate baffle step compensation and are very deficient in this part of the audio range. The temptation is to play the sub too loud to compensate.

Often what I find on my travels, is weak in the wind main speakers and a ported high Q sub spreading a seeming audio gunge over the whole room. Really quite ghastly and not accurate reproduction at all.

And this is my last point, your sub is a low Q design and not designed to bring attention to itself, which a good sub should not. It will just give a subtle underpinning to the program.

Pretty much all European subs are that way. The reason is because so many European houses have shared walls. If your neighbor complains, the police can confiscate your entire rig. So European subs generally don't produce high spl in the last octave.

 

[alphard]

it's not worth doing it IMO. you'd have to find a way to bypass the active sub's own amps but still use it's low pass filter. (that warrants advanced electrical know-how).

sell your RA04 and B&W sub and get a better subwoofer

Yeah I was afraid of that since I recently bought the sub based from a magazine review's recommendation. If the low volume still bothers me, then yeah, I'll sell it.

 

[Bassbinotoko]

Since you have a spare integrated amp, I suggest building another sub or two and using that amp to power it. $100 to $200 apiece should get you a worthy driver, probably vastly more capable than what's in your current sub. Check out the diy section at AVSforum.com for some ideas, or see what plans places like Madisound or Zalytron offer. Or Creative Sound Solutions' SDX10 and Trio12. creativesound.ca/products.php?category=Drivers&make=CSS
The Trio12 horn is very efficient, although possibly a bit large for some rooms.

 

[alphard]

You need a bigger sub, or relocate the sub to a better sweet spot.

Actually I do have a much bigger sub but it's not as "musical" as the B&W sub.

 

[alphard]

That is a small 10" sub. You can not daisy chain amps. You will get no more power, and damage the sub amp. The input is not designed to feed from a power amp. In any case your current sub amp would be providing all of the power, and your Rotel no power.

A couple of point in addition to experimenting with position. I suspect you have the bass extension switch set to A (-6 db at 20 Hz). Since this is a sealed sub, that will waste a lot of amplifier power as the a sealed sub has to be equalized at 12 db per octave. The driver will roll off far too high on a sealed sub, so you have to equalize.

So set the bass extension to B (-6 db at 25 Hz.)

You will have most output (sub will be loudest) setting the bass extension to C (- 6 db at 30 Hz), but then it won't be truly a sub as it will be rolling off at 45 Hz. On be it will be stating to roll off at 37.5 Hz and on A it will be starting to roll off at 30 Hz.

The higher the roll off the louder the sub will play.

Now make sure you have the sunb optimally phased with your other speakers. A phasing error will really reduce bass.

The next point is that this problem may not be the fault of your sub, but your main speakers. What are your main speakers?

Most of what is actually perceived as bass is actually well above sub range, in the 80 to 180 Hz area. A lot of speakers have inadequate baffle step compensation and are very deficient in this part of the audio range. The temptation is to play the sub too loud to compensate.

Often what I find on my travels, is weak in the wind main speakers and a ported high Q sub spreading a seeming audio gunge over the whole room. Really quite ghastly and not accurate reproduction at all.

And this is my last point, your sub is a low Q design and not designed to bring attention to itself, which a good sub should not. It will just give a subtle underpinning to the program.

Pretty much all European subs are that way. The reason is because so many European houses have shared walls. If your neighbor complains, the police can confiscate your entire rig. So European subs generally don't produce high spl in the last octave.

Thanks for the great advice! It was a real eye-opener for me especially the part about playing the sub too loud to compensate a speaker's deficiency. My speakers are the B&W 685 so it "should" match the 610xp. Now I'm thinking if I should get floorstanders instead like the 684 haha.

And yes you're right. I do have the EQ at A since I get the "feel the sub" experience more. But in some cases, I don't feel them at all when I know I should with certain tracks I'm listening. I mostly listen to movie scores and a few jazz and classical.

Maybe I'm just expecting too much bass when it really shouldn't be too much, I don't know. If a subwoofer is intended to be "musical", should the bass be as subtle as possible?

 

[timoteo]

Are your 685s set to small or large? If large then you may be asking too much from the speakers & not letting enough bass go to the sub! Or you may have them crossed over wrong. I have the 685 as well & ive crossed them over between 80hz-100hz.

Also, like mentioned definately try both phase settings & see which gives you more output.

2 words "Bass Crawl"

Honest though it sounds like the sub just cant make you happy....new sub soon?

 

[Bassbinotoko]

Setting a sub level by ear is tricky. When I dusted off the SPL meter, I found mine were set at lest 10 dB louder than flat. Maybe you can hook a mic to a laptop, run some RTA software, play pink noise and see at a glance if there's holes in the response. Or go the other way, using 1/3 octave pink noise from a CD, DVD, or software and watching the needle of an SPL meter.

I think there are arguments for 2nd order (sealed) subs being more musical than ported subs. The gentler rolloff blends better with the room gain which is also second order. Sealed usually has a better transient response. A lot of current sub drivers can be used in either ported or sealed boxes, if you want to make some sawdust. Maybe it's my selective memory, but it seemed like in a lot of sub comparisons, the ported boxes won on loudness, but the sealed ones sounded better for music.comparisons.

 

[alphard]

BTW, I forgot to mention about "break in". I bought the sub last June and I haven't really used it for many hours. Is it possible that it needs more time for the woofers to loosen up or is breaking-in just a placebo effect?

 

[j_garcia]

Placebo. The sub was broken in the first day you used it. Placement is critical for a sub to do well in a given room, so I agree completely with the "crawl" method as well as proper calibration. After you've tried that and you are still not happy, either a second one or a better sub would be the next step.

 

[lsiberian]

Actually I do have a much bigger sub but it's not as "musical" as the B&W sub.

It's either a better sub or not. "Musical" is often nonsense used to justify a poorly constructed ported sub.

B&W subs are terrible. Their speakers are solid though.

If you want a real sub look at SVS, HSU, Epik, Elemental Designs and real sub companies. The main disadvantage to ported subs is size, but if it's ported properly it won't matter as much.

If you need a great sealed sub you can also consider the JL Audio line. These are amazingly well built.