Passive subwoofer speaker wire

Midnite Mick

Do you guys think there would be significant differences in how a passive sub sounds with differing speaker wire. I currently have a passive 15" Adire Tumult run by a QSC pro amp at 830 watts bridged. Sometimes I think that the sub is a little out of control. I am not sure if this is just my perception, or reality as I have no experience with subs, especially one that goes as low as this thing. I am currently just using 12 gauge 1.29Cdn a meter Home Depot inwall speaker wire and am wondering if I am limiting the performance of the sub because of this. Thanks guys as you have all been great.

Mike

Midnite Mick

Nothing Yet?:( Please somebody atleast say Hello.:)

capecodder

Uhhh hello. Unfortunately I don't have a clue other than I'd be surprised if you could really hear a noticeable difference as long as you are using "quality" speaker wire. Sorry.

schwarcw

Mike,

What exactly do you mean by "out of control"? Is the sound too boomy or too loud compared to the main audio? I too doubt the speaker wires would be a big problem like capecodder stated.

Planenutz

Did the sub ever sound good?

Midnite Mick

Sound is not boomy at all (non-ported). I am not sure how to describe it. Just sounds sloppy and not tight at times (kind of rubbery). Maybe this is how it is supposed to sound, I am not sure (little experience with subs). Could it be that it is just so low that I am perceiving it as sloppy. Maybe it is just too loud like you say. How is a sub like this supposed to sound as I guess I am a little confused.

Mike

Planenutz

What is your source? Phono, CD,etc. I once had a problem of my turntable picking up feedback from my "boomy" speakers that would escalate violently!

Eric

michael_w

It might sound a little better but I highly doubt the 'out of control' sound you're getting is due to the wire. Maybe you're pushing it too hard or it's in a bad spot in your room. Try moving it around your room some and if it's in a corner move it more near the center if possible. I don't think you're overdriving it because it's a beast of a sub but you never know

McLoki

Mine sounded the same way with 16 guage wire. I upgraded to 10 guage wire from blue jeans cable and the sub sounded much better. Tighter or more in control would be the best description of it.

The wire was only a 7' run, but the additional size made a world of difference in my case. (sub is run off one channel of my Cinepro - I assume the wire I was using was not allowing as much current through as the new wire is.)

I would have assumed that the 12 guage wire should have been large enough, but at only .59 / foot (or so) it is cheap enough to try it out and see for yourself.

Michael

Dennis Gardner

How much gain are you using on your BFD? I would hate to think you are clipping your amp at over 800 watts, but if you are pumping tons of power into a room null, it can happen.

I doubt it is the wire gauge, but it sure would be cheap to try something heavier.

Midnite Mick

I don't know if I am pushing it too hard. I have the gains set to half on each channel of the pro amp. My pre/pro setup has bean run (SNAP) and it set it at -8db. In its current location it has been equalized with a BFD. I did have a nasty null at around 36 Hz that really had to be gained a lot using the BFD. Maybe it is still too loud I should try trimming it a bit on the processor.

Man this thing is a beast for sure. Gotta be close to 150 lbs. (2.5 cubic foot, doubled up 3/4 MDF, bottom firing). The thing shakes everything.

McLoki sorry which speaker wire were you refering to that I should try for myself. Didn't fully understand you last statement.

I only use it for home theatre

Thanks everybody.

Mike

Planenutz

http://www.polkaudio.com/forums/attachment.php?attachmentid=8283&d=1112831981

Midnite Mick

Yes Dennis when I first ran the Sherwood Newcastle setup (SNAP) I had the gains turned all the way up on the amp and it was clipping quite easily. What a horrible sound that was. It sounded like someone was jackhammering in my living room. I then turned the gains down to half on the amp and now the clipping lights don't even blink and no sense of distortion at all.

The thing that I find strange about the whole procedure was that when the gains on the amp were set at max the Sherwood setup put it at +1db. When I ran it again at half gains on the amp the Sherwood setup put it to -8db. I would think that it would have been the opposite.

Mike

Midnite Mick

sub wired nominal 4 ohm

15 foot run---12 gauge wire (just cheap home depot inwall though)

Mike

McLoki

BJC Ten White (5T00UP) (White jacket, 10 AWG) 0.61/f When I purchased mine it was the same price for white or Grey (.57/foot)

Like I said - my run was only about 7' so I should have been fine with 16guage wire according to the chart that was already posted in this thread, but there was a big increase in performance when I went to the 10 guage wire.

Michael

BTW - this is from a post here - last november when I first replaced my sub cable.

McLoki wrote:

I replaced my generic 16 or 18 guage lamp cord (don't remember the exact guage) with 10guage wire from Blue Jeans cable. (is running both in wall and in a plenum so I thought it prudent to purchase plenum grade wire - the 10ga. is)

Biggest difference in my setup was in the 7' run from my amp to my sub. Much better control of the sub and much crisper bass. This is from a 500 watt amp to a 4 ohm sub and even though it was a short length - the cable was definately limiting the performance of my sub. (now even at loud volumes, the sub never seems close to bottoming or stepping out of line.)

Michael

Midnite Mick

Thank you very much McLoki.

I did something just now that I think that I need your guys's education on. I ran a test tone cd. It sounded pretty solid and quite controlled on the test tones at lower volume levels. Kind of funny seeing all the lights going on the amp and BFD but I can't even here it though. Anyways, I shut off all my speakers amps and ran the test tone on LFE+SW mode. I played it in the -20 to -15 range on the sherwood (lower volume level than I would watch a movie). Now in doing this would the sub get a lot more input in this situation than watching a movie? I ask this because on certain tones (that I could hear) there was distortion from the sub (that jackhammer sound). When I would turn it down a little the distortion goes away. If I turn it up or down using the gains on the amp the distortion goes up and down as well. I Would get distortion even at half gains on the amp and not even a flicker of the clipping light. Isn't this telling me that the distortion is not coming from the amp, but at the tumult? This sub is supposed to be able to handle up to 1000 watts this should not be happening. Am I right? Could it have something to do with the speaker wire then restricting current possibly? (hope all this made sense)

Mike

McLoki

I would try and do this....

Run your BFD with all cuts. (rather than try and boost a null - cut every other frequency or if the null is narrow - just live with it)

Then turn your amp all the way up. (obviously rebalance your sub volume after doing this) What frequency was the distortion happening at? Is it possible the BFD was clipping rather than the amp? (you can set the gain on your BFD - was the sub level indicators pretty high (on the BFD) when the distortion was happening?

I would say based on what you are saying - it is not the amp, but it could be either direction from it. Downstream (the sub) or upstream (the BFD or pre-amp)

Michael

Midnite Mick

McLoki wrote:

I would try and do this....

Run your BFD with all cuts. (rather than try and boost a null - cut every other frequency or if the null is narrow - just live with it)

Then turn your amp all the way up. (obviously rebalance your sub volume after doing this) What frequency was the distortion happening at? Is it possible the BFD was clipping rather than the amp? (you can set the gain on your BFD - was the sub level indicators pretty high (on the BFD) when the distortion was happening?

I would say based on what you are saying - it is not the amp, but it could be either direction from it. Downstream (the sub) or upstream (the BFD or pre-amp)

Michael

I didn't realize that the BFD could clip? Yes the sub level indicators on the BFD were maxed out when the distortion was happening. Unfortunately, I have to further figure out how this BFD works, get an SPL meter and figure this thing out. It is all new to me as I didn't set it up. Thank you.

Mike

michael_w

Those were my thoughts as well. Perhaps you actually clipping things by trying to fix that null with the bfd? The sub would have to worked that much harder in order to fill that null, in which it would begin to be overdriven and sound like crap.

Midnite Mick

In order to find that out maybe I should try really turning up the test tones that are far from the null?

Mike

Dennis Gardner

A true room null is an anomoly of the room not your equipment and can't be fixed without many 1000s of watts or many more drivers. You just can't boost a true null enough to get rid of it without reaching the limits of your equipment. Add some boost to smooth it out, within the limits of the Bfd/amp and call it good. Then calibrate your sub and rest of your system to a level you can live with within your systems newly found limits.

Most of us think that 800 watts would be plenty, but unless all pieces are within their limits, distortion still rears its ugly head.

Midnite Mick

I was able to get distortion levels on all the test tones both with the amp gains all the way up and half way up.

I guess another question that shows my ignorance. Is it normal when running a test tone cd to experience distortion at reasonable volume levels because it is only one frequency? Wish I had an SPL meter so I could communicate better what are reasonable levels.

Mike

McLoki

Midnite Mick wrote:

I didn't realize that the BFD could clip? Yes the sub level indicators on the BFD were maxed out when the distortion was happening. Unfortunately, I have to further figure out how this BFD works, get an SPL meter and figure this thing out. It is all new to me as I didn't set it up. Thank you.

Mike

Here is a long quote from a great BFD setup page....

Our sources (DVD Players, CD Players, Satellite Tuners, etc.) usually have fixed outputs and they are in the audio chain prior to the pre/pro or receiver. The BFD is in the chain after the pre/pro or receiver. Plus we are not setting this on auto pilot and letting it search out frequencies to destroy feedback (as the name of the unit would imply... it can cut a feedback frequency by up to 48db), we are using it as a parametric equalizer to tame frequency peaks... we surely don't want to eliminate them completely. Thus, we have to set the input level on the BFD so that during our maximum listening volume, it doesn't clip.

On the top right front of the unit you will see the "IN/OUT" button. Press and hold this button for a moment until the button light blinks. You are now in the "BYPASS" mode with no filtering active. You can only monitor the setting of the input level in the "BYPASS" mode. The input level is monitored by the LED's in the far left section of the display window. If the unit is not in the "BYPASS" mode then the LED's will monitor the output level. Play a CD or DVD with some good deep bass (U-571 is a good one to use if you have it). Play the source at the maximum level you would listen to it. You should notice the green LED's moving up and down. You may only see part of or all of the green LED's lit or you may see all of the green LED's lit up along with the yellow and the red LED at the top lit (they will vary with input). The red LED at the top is labeled "CLIP". Your goal is to see the yellow LED close to the top blink on loud bass sections of the music or movies. It is okay if the red LED blinks occasionally as well... as long as it's not constantly lit. Remember... there's a reason it's labeled "CLIP". To adjust how far up the LED's blink you will adjust your sub output level on your pre/pro or receiver's speaker level menu or sub level control. (Your volume control on your sub has nothing to do with the input level.) I had my pre/pro sub level set to zero initially. After I connected my BFD I raised the sub output level to +3. This allowed the yellow LED and occasionally the red LED to blink during the loudest scenes of movies. Remember, the input level of the BFD should be set in the "BYPASS" mode (the "IN/OUT" button will be blinking). Once you have set the output level on your pre/pro or receiver you can then adjust the output level (volume control) on your sub to equal your mains. I used the AVIA DVD to match the levels of my speakers. AVIA instructions are easy to follow and the DVD will give you a host of other tools to use for video and audio calibrations. There are other DVD's and CD's available for this... another DVD is VIDEO ESSENTIALS. You will also need to repeat the reset of the sub vs. main levels once you later complete the filter setups. You may find that once you have smoothed out peaks that your sub level doesn't seem loud enough. I had to turn my sub volume up for my taste. I now measure my sub output at about 10db louder than my mains.

NOTE: When the BFD is in its normal filtering mode and you are watching a movie or listening to music, pay close attention to the LED's for a few days. A continuous red LED indicates the unit is near clipping. You will need to revisit your initial input level settings and decrease your pre/pro or receiver's sub output level. If you do, you will need to again level match your sub vs. mains, but when doing so, make sure you use your sub volume for matching and not your pre/pro or receiver's sub level.

Read and enjoy....

Michael

Dennis Gardner

Sounds like it is about finding a balance within the limits of each piece. I've found that my Adire Shivas are great within all limits, but exceed any part of the chain and it can get ugly. Mine has more to do with being tuned EBS at 17 hz. The really deep stuff can get to my sub pretty easy since the tuning point is so low that they don't roll off fast enough to stop the subsonic stuff with no rumble filter in use. I have to watch the gain on really dynamic movies.

Midnite Mick

Great link McLoki. Thank you.

Mike