I expected my new rig to be louder!

[ClarkW]

I don't know if this post is just a request for comments, or asking for advice, or just venting.

 

My old combo: SWR Workingman 12. 100 watts through the built-in 12" (I think) cone. Not sure about the impedance. I normally set it at halfway on the input gain and halfway on the master output, then set the volume on my bass's active preamp to about 3 or 4, and that's plenty loud for practicing. For jamming with a band, I can set the gain and master to 6 or 7 and it gets pretty loud. I've never turned it all the way up, as that would be just damned loud.

 

My new rig: Avatar 2x10 and 1x15. 2x10 is rated at 700 watts at 8 ohms, the 1x15 is something like 600 watts at 8 ohms. The power amp is a Mackie M1400i. The specs are as follows:

 

1400 watts @ 4 ohms bridged

1000 watts @ 8 ohms bridged

700 + 700 watts @ 2 ohms stereo

500 + 500 watts @ 4 ohms stereo

300 + 300 watts @ 8 ohms stereo

 

The back of it looks like this: http://www.mackie.com/home/showimage.html?u=/products/m1400/images/1400iback.JPG

 

So, since I have a single input source coming from my preamp, I plug that in Channel 1 Input, set the amp to Mono mode, and then run a TSR (standard instrument cable looking cable) from the Channel 1 out to the 2x10, and from Channel 2 out to the 1x15. The results were, shall I say, disappointing.

 

The difference between 3 and 10 on my bass preamp is very minimal in overall sound. I set the Channel 1 and 2 volume dials on the front to halfway, and it was less than anemic. Barely louder than a speaking voice. Cranking it up all the way to nearly full, it was perhaps a little louder than a shout.

 

The front looks like this:

http://www.mackie.com/home/showimage.html?u=/products/m1400/images/1400ifront.JPG

 

Turning the bass's active preamp all the way up and cranking the Mackie's volume to full then thumping the strings as hard as I dared, I managed to barely light up the "-20" lights on the front, not even getting it remotely close to clipping. Moreso, I was standing right in front of the stack, and the volume was still bearable, though it was approaching "loud."

 

But had I been pushing my old combo amp like that, the walls would have been shaking and the neighbors would be calling. Why so anemic?

 

Is it because in that mode, I'm going at 300 watts at 8 ohms per speaker, and that's just not enough to drive the hungry Avatar cabs?

 

Do I need to bridge it and run the speakers in series to get down to that 1400 watts at 4 ohms potential? If so, exactly what kind of speaker connection goes on those red and black poles? The Mackie manual indicates that in bridging mode, you go out from the Channel 1 red pole, and back in on the Channel 2 red pole, and you don't use the black poles or the TSR jacks.

 

Help a feller out, please!

[...]

Originally posted by ClarkW:

"Turning the bass's active preamp all the way up and cranking the Mackie's volume to full then thumping the strings as hard as I dared, I managed to barely light up the "-20" lights on the front..."

This act should have destroyed the universe... or, at the very least, you and everything within 10 city blocks.

 

Sounds to me like your preamp send signal is really low. Mackie amps like a fairly hot signal from their source. Perhaps your preamp has a gain control/pad on the back of it that is currently set way too low?

[SteveC]

I think (correct me if I'm wrong guys) if you want the most power and sound, you should run the amp in bridge mode and connect your speakers in series. Your two 8 ohm cabs will draw a 4 ohm load when run in series, thus using 1,400 watts from the amp.

 

Connect a speaker cable (make sure it is for speakers, not instruments) with a banana end (I can never remember the real name) to the 2 red speaker outs on the Mackie. Run that into your 2X10. Then run another cable from your 2X10 to the 1X15.

 

I think that should rock your world.

[...]

Originally posted by SteveC:

I think (correct me if I'm wrong guys) if you want the most power and sound, you should run the amp in bridge mode and connect your speakers in series. Your two 8 ohm cabs will draw a 4 ohm load when run in series, thus using 1,400 watts from the amp.

 

Connect a speaker cable (make sure it is for speakers, not instruments) with a banana end (I can never remember the real name) to the 2 red speaker outs on the Mackie. Run that into your 2X10. Then run another cable from your 2X10 to the 1X15.

 

I think that should rock your world.

While that will rock his world, this isn't his problem. I'd bet large sums of money that his preamp signal isn't hot enough. I have a Mackie 1400i as well, and I've experienced this same problem when the preamp send signal didn't have it's +4db pad engaged. I had a serious lack of volume, even when everything was seemingly set to Nuclear Holocaust.

[Soundcrafter]

Yeah, the Mackie amps, and pro audio power amps in general are designed to accept line level signals, which electric basses provide anything but. You need to boost the signal output of your bass somehow.

[73 P Bass]

I don't know about hot signals, but don't you want to run the cabs. parallel to load the amp down to a higher wattage?

 

Also I believe some speakers and amps are more efficient than others; I have a 225w combo 2 x 10

that's louder (and more defined) than a 350w head and a 2 x 10 cab. that I have.

[ClarkW]

I tried it through an ADA midi preamp that I got from my bass teacher, then also through a Korg Pandora 3B. I guess I could try it straight from the bass and see what kind of a difference that makes.

[hags2k]

If you're not clipping your power amp with the amp cranked, then you definitely need to get more juiced INTO the power amp. It sounds like there is not nearly enough signal going into the power amp to give it anything to actually amplify. If you had a hot enough sigal going in, chances are you'd be clipping the power amp and getting some crazy/mad/insane distortion from your power amp and shaking walls for miles.

[ClarkW]

Well, I'll have to take a look at the manual to get more juice out of the ADA preamp, because the "Output Level" knob does absolutely nothing. I did buy it used, so it's possible that knob is broken? Otherwise, it's a midi-controlled preamp and not very user-friendly at all, so I'll have to break the book out.

 

I used the Korg Pandora to plug straight into the Mackie, and cranked the Korg's master level all the way up and managed to get some reasonable volume. With the Mackie channels both at halfway, it was getting to the realm of "loud" but cranked all the way up it still wasn't quite as loud as I might have expected it to be. I mean, I'm not trying to start my own demolition business here, but I'm used to having enough power at my disposal that I never dare turn things up over halfway.

 

I'll see if I can get some banana connectors or something and see if putting it in bridged mode will cook things up.

 

Gets a nice low B, though, when I can hear it.

[alexclaber]

You definitely haven't got a hot enough signal driving the poweramp. If all you're getting is the -20dB LED lighting up at max power then the Mackie will be putting out a mere 15W into each cab - that's why it doesn't sound loud. Your bass on its own will not drive the Mackie hard enough, nor will your Pandora, because neither have pro-level (i.e. +4dB) outputs. However, your ADA preamp *should* be able to drive the Mackie comfortably so I suspect something's wrong with your preamp.

 

Alex

[BenLoy]

One big thing I'm noticing in your original post:

 

So, since I have a single input source coming from my preamp, I plug that in Channel 1 Input, set the amp to Mono mode, and then run a TSR (standard instrument cable looking cable) from the Channel 1...

I've never heard of a "tsr" cable...but I have heard of a "trs" or "tip-ring-sleeve" cable. These are cables that can be used to either carry an unbalanced stereo mike or line-level signal or a balanced mono mike or line-level signal. This is not the type of cable you should be using to connect your power amp to your speakers.

 

You need a real 1/4" speaker cable. They look just like instrument cables, but they use two conducting wires connected to the tip and sleeve instead of a single wire and a sheild.

 

I'll also echo that your preamp should be sending a +4db line-level output.

[JD_dup2]

The input sensitivity on the Mackie 1400 is adjustable. This is what makes this amp so popular for use with the SansAmp Bass Driver DI. You are probably set at +4 dB and are feeding it with a -10 dB instrument level signal. This results in a 14 dB loss of signal. Get out your manual and change the dip switch.

[alexclaber]

Originally posted by JD:

The input sensitivity on the Mackie 1400 is adjustable. This is what makes this amp so popular for use with the SansAmp Bass Driver DI. You are probably set at +4 dB and are feeding it with a -10 dB instrument level signal. This results in a 14 dB loss of signal. Get out your manual and change the dip switch.

It is? I used to own one of these and never found that DIP switch and I've just looked through the manual and can't find it there either! Are you thinking of the right amp?

 

Also, as BenLoy said, you should be using speaker cable, not instrument cable. If you haven't got any speaker cable handy, mains cable will do a pretty good job. Instrument cable just isn't designed to carry that amount of current.

 

Alex

[getz out]

Originally posted by BenLoy:

One big thing I'm noticing in your original post:

 

So, since I have a single input source coming from my preamp, I plug that in Channel 1 Input, set the amp to Mono mode, and then run a TSR (standard instrument cable looking cable) from the Channel 1...

I've never heard of a "tsr" cable...but I have heard of a "trs" or "tip-ring-sleeve" cable. These are cables that can be used to either carry an unbalanced stereo mike or line-level signal or a balanced mono mike or line-level signal. This is not the type of cable you should be using to connect your power amp to your speakers.

 

You need a real 1/4" speaker cable. They look just like instrument cables, but they use two conducting wires connected to the tip and sleeve instead of a single wire and a sheild.

 

I'll also echo that your preamp should be sending a +4db line-level output.

Nice, Benloy, that's the first thing I noticed, too. If you're using a TRS cable in place of a speaker cable, you will mostly likely melt something in short order. Go to the store, buy two, heavy gauge SPEAKER cables. Make sure they're short (like 6' or less).

[rumpelstiltskin.]

Originally posted by JD:

You are probably set at +4 dB and are feeding it with a -10 dB instrument level signal. This results in a 14 dB loss of signal.

actually, it's a little less than 12dB difference. i know this is largely irrelevant to the discussion, but i like to clear up misconceptions whenever i can.

 

here's the reason: +4dBu has a different reference point than -10dBV. anything with "u" after its "dB" is referenced to 0.775V. anything with "V" after its "dB" is referenced to 1V. so +4dBu is actually equal to about +1.8dBV.

 

-10dBV is about 0.316V, whereas +4dBu is about 1.228V. plug that into the handy dB equation:

 

dB = 20 * log (1.228 / 0.316) = 11.8dB (or dBV)

 

so what you're seeing is that just because it has "dB" after it, it isn't necessarily the same kind of dB. you have to pay attention to what its reference point is.

 

robb.

[ClarkW]

Well, looks like I'm gonna have to go smack the bastid at the music store what sold me instrument cables instead of speaker cables!

[ClarkW]

Part of the mystery has been solved.

 

It turns out that the ADA preamp has a switch on the Direct Out for pre and post, and when set to Pre, the direct out is at instrument level and bypasses the preamp's modeling and shaping channels. Setting it to post engages the preamp and sets the output at line level. It had, for some reason, been set to Pre. I wondered why all of the buttons I pushed on the amp didn't seem to be having any effect.

 

Once I got it set to Post, I was quite pleased with most of the factory preset tones (unlike on many FX processors I've tried), and got a lot more sound out of the amp. Like I expected, setting the Gains to halfway was plenty loud with my Cirrus's preamp volume set to about 3. Setting my bass at full was just too loud for that little room, which is good.

 

I'll have to check on the speaker cables though. After further review of the Mackie manual, I will correct my mistake. The speaker outputs are for 1/4" TS (tip-sleeve) connectors, which is what an instrument cable is. However, I'm not sure if instrument cables are heavy enough gauge to handle the duties of amp->speaker connections, are they?

 

I might get some with bananan connectors so I can set the amp to bridging and really get some juice out of it, but for now I think it will work all right with just 300watts at 8 ohms going through each channel.

[_Sweet Willie_]

Originally posted by ClarkW:

However, I'm not sure if instrument cables are heavy enough gauge to handle the duties of amp->speaker connections, are they?

 

NEVER use instrument cables to connect amp to speakers. NEVER! Go get yourself some speaker cables!

[coyote]

Just an offhand comment:

 

Why did you toss the Workingman? You've indicated it was plenty loud - did you dislike the tone? If so, did you ever experiment with extension cabs? I have a Crate BX100 which sounds pretty good with its built-in 15", but as soon as I added a 4x10 extension cab it sounded GREAT! And 100 watts provides enough stage volume for almost any situation unless you're competing with Marshall stacks.

[BenLoy]

Using an instrument cable as your speaker connection, especially when using a high-current amplifier, is a bad bad bad bad idea. An instrument cable's sheild was not designed to carry current like that, and the slightest short can fry your amp. I'm talking smoke and fire.

 

Use a speaker cable.

[music-man]

Originally posted by ClarkW:

The speaker outputs are for 1/4" TS (tip-sleeve) connectors, which is what an instrument cable is. However, I'm not sure if instrument cables are heavy enough gauge to handle the duties of amp->speaker connections, are they?

OK, this may have already been driven into the ground, but just to make sure it's crystal-clear ... you're right, 1/4" instrument cables and 1/4" speaker cables have the same type of connectors . But the problem with using instrument cables is in the conductors, not the connectors.

 

Instrument cables use one conductor to shield the other to eliminate RF interference (which causes hum and buzzing). Speaker cables run both conductors side by side. Because the two conductors in instrument cords are not the same (often they're made of different materials, are of different tolerances, etc.), and the shielding conductors are usually not designed to carry full "amp-level" current loads, as BenLoy says, you're asking for serious trouble by connecting your amp to your speaker with a guitar cable.

 

And it's really not worth it, when a few bucks will save you a TON of trouble.

[_Sweet Willie_]

Short, heavy gauge speaker cables -- that's what you want.

 

Did anyone mention this yet?

 

ClarkW, keep us posted on the rumble factor of your rig as you get all of this straightened out!

[ClarkW]

About the speaker cables: I figured as much. That's why I haven't been playing through the rig. You think GAS is bad? How about having just bought all your new toys but getting home late every night so all the music and electronics stores are closed!

 

To answer Coyote, I'm not actually tossing the Workingman. Since I have the funds to keep it around right now, I will. The tone is generally pretty good; I did need a little more flexibility on tones since I just joined a progressive rock band, and I've been unsatisfied with the Korg floor pedal and Pandora for most situations.

 

But you actually guessed the second reason. I am competing with a Marshall stack! Full stack, two 4x10s I think it is, from the guitarist in my new progressive band.

 

And finally, rehearsing a total of 4 to 6 times a week with three different bands, it was getting to be too much of a pain lugging the Workingman everywhere. Now, I can leave the stack at the progressive band practice space, the workingman at another band's practice space, and I always just go through DIs into the PA system for the third band. Much less loading time at all the gigs!

 

Thanks for your advice, folks. I'll pick up speaker cables tonight and be rocking out till the sun goes down (or the doors autolock at the storage facility where the band practices, more likely)!

[fantasticsound]

Glad you found the signal strength problem. But a few misconceptions need to be addressed.

 

Originally posted by ClarkW:

...Do I need to bridge it and run the speakers in series to get down to that 1400 watts at 4 ohms potential?

Running speaker cabinets in series increases the load, resulting in lower power output from your amp. Two 8 ohm speaker cabinets in series would result in a 16 ohm load, not a 4 ohm load.

 

Fortunately for you, speaker cabinet inputs are almost universally wired in parallel. Daisy chain your two 8 ohm cabs will result in a 4 ohm load.

 

Originally posted by ClarkW:

...If so, exactly what kind of speaker connection goes on those red and black poles? The Mackie manual indicates that in bridging mode, you go out from the Channel 1 red pole, and back in on the Channel 2 red pole, and you don't use the black poles or the TSR jacks.

Most amp manufacturers use this set up, or provide a separate Speakon connector solely for bridging mode. In bridging mode, one of the two red poles is the + and the other is - . It is stated on the back of your Mackie amp that, in mono bridge mode, the + is speaker channel 1's red post, and - is speaker channel 2's red post. This is important because you want your speakers pushing outward (+) first. The downside to bridging your amp for extra power is that your speaker cabs are not identical, and you'll have no control over the balance between the two.

 

In dual mono mode, you can control the balance between the cabs with the level controls on the amp.

[JD_dup2]

Originally posted by C.Alexander Claber:

It is? I used to own one of these and never found that DIP switch and I've just looked through the manual and can't find it there either! Are you thinking of the right amp?

 

Also, as BenLoy said, you should be using speaker cable, not instrument cable. If you haven't got any speaker cable handy, mains cable will do a pretty good job. Instrument cable just isn't designed to carry that amount of current.

 

Alex

I have not personally used the Mackie amp but was going on what another bass player told me. He uses the SansAmp Bass Driver DI pedal as his preamp and he told me he adjusted the input sensitivity of his Mackie 1400 to get full operation. I will, of course, defer to your direct experience with the amplifier. I use QSC amps for my power needs which are adjustable.

[JD_dup2]

Originally posted by robb.:

Originally posted by JD:

You are probably set at +4 dB and are feeding it with a -10 dB instrument level signal. This results in a 14 dB loss of signal.

actually, it's a little less than 12dB difference. i know this is largely irrelevant to the discussion, but i like to clear up misconceptions whenever i can.

 

here's the reason: +4dBu has a different reference point than -10dBV. anything with "u" after its "dB" is referenced to 0.775V. anything with "V" after its "dB" is referenced to 1V. so +4dBu is actually equal to about +1.8dBV.

 

-10dBV is about 0.316V, whereas +4dBu is about 1.228V. plug that into the handy dB equation:

 

dB = 20 * log (1.228 / 0.316) = 11.8dB (or dBV)

 

so what you're seeing is that just because it has "dB" after it, it isn't necessarily the same kind of dB. you have to pay attention to what its reference point is.

 

robb.

I had thought about using a voltage comparison but thought that might be too confusing. Your analysis of the different input levels is right but a little hard for some to understand. I just tried to keep it simple.

[_Sweet Willie_]

Hey ClarkW,

 

Make any progress on this yet? Got the rig sounding large?

 

Peace.

[ClarkW]

Well, here's a little story about how the wicked Time Gremlins gobbled up 80 minutes of my Saturday rehearsal time.

 

On the way to Saturday's practice with the new prog rock band, I was already late because of a previous engagement. Practice is from 11 to 2, and I told them to expect me at 12, which was cool because the guitar and keyboard had some work to do without me there.

 

Here it is about 11:30 or 11:40, and I realize that Van Wagenen's is on the way to rehearsal. See, there's no pro audio shop down here in Utah Valley, and none of the music shops actually carried speaker cables (what is wrong with these people!), so instead of driving just under an hour up to Salt Lake to hunt down a pro audio shop, I was told that VW's gun and pawn shop actually had a pretty sizeable audio section and a competent guy running it.

 

Both of those were true. They did have a fair amount of music and audio equipment, as the guy seems to be a Behringer sales rep or something, and the guy DID know what he was talking about and got me exactly what I needed.

 

However, I failed to remember one of the immutable laws of the universe:

 

14) Thou shalt not go to a pawn shop on a Saturday, especially if thou art pressed for time.

 

When I got in there, he was in the middle of helping two guys who didn't really speak any English, which was complicated by the fact that he didn't speak much Spanish, either. These guys had apparently called in a special order a week or two earlier and came in to pick it up, then changed their minds on a bunch of things and wanted to try out different percussive instruments, stands and cables, and all sorts of crap. 30 minutes. 30 friggin' minutes he ran all over the place trying to get these guys a bunch of stuff that they seemed to need, but at the same time they had this demeanor like they couldn't give a crap whether they left the store empty-handed or not.

 

Of course, they weren't the only ones in line in front of me. 3 DJs were there. One of them needed a cheap PA rental. He wanted it cheap (he wasn't willing to spend more than the $40 bucks he had agreed to over the phone), but he kept trying to convince the guy to give him better equipment for the dirt cheap price.

 

Meanwhile, one of the other DJs had brought in two of his speakers because he had blown the coil in one of his compression horns or something. For a little over an hour (during the same time the aforementioned DJ was getting his rental gear and the two guys were equipping their entire band without saying more than about 10 words) he took apart his speakers, plugged them into different configurations of the test PA there, pulled different compression horns, magnets, etc. All the while complaining about how this was the second or third time he'd blown that particular speaker, and ignoring the pawn shop guy's recommendation that he spend $2 to put a better fuse in. Then, when it came time to buy the 39.95 coil, which came to $42 with tax, the kid tried to talk the guy down to $40, saying he didn't have $42. Worse yet, he pulled out a wad of cash and handed the guy two $20's, but still had at least 5 more bills that I could see. But he still wanted to get it for $40! Eventually the shop guy prevailed.

 

In the course of hauling his speakers back out to the car, the kid also managed to waste another 5 minutes of everyone's time by trying to get the shop guy to do some complicated soldering work on a broken jack for free, when the shop guy was insistent that he had done the same job the other day for $50. Then he wasted another 5 minutes by looking around at a couple of different mixer boards that he didn't really want to buy, just maybe get for free or something. Arg.

 

One more customer with a simple request later and he was able to get me two stinkin' speaker cables and a rack mount box big enough for my Mackie (that was the only reason I needed to talk to him). It was frustrating because it took him about 3 minutes to take care of me. I spent a total of 1 hour and 20 minutes in the store. I kept thinking "I'll just leave and use the Workingman for this practice" but then it would look like he was about finished with the two guys or the three DJs, so I'd stick around, and then it would take another 20 minutes.

 

ARG!

 

So, long story made long, I got the cables and worked out the signal chain and it sounds great now; I still need to get all the specs together on the Avatar cabs to set the compression horn thingamajig on the Mackie to see if that gives cleaner highs, but I have been pleased by the sound so far. The ADA gets nice sound, too.

 

Of course, when you're learning and shedding long eighth note unison melodic runs in 5/4 time at a fast tempo, or chordal tapping sections in Lord-knows-what-time-signature, your concentration isn't so much on nitpicking the sound of the new rig as it is on just playing one note after the other.

 

I was a little disheartened when we stopped for the day and the guitarist (and songwriter) said "Good, that's about our easiest song, so it's a start." When haven't even hit the 11/8, 17/8, or 9/8 + 9/8 + 4/4 sections yet.

 

But hey, the rig sounded good.

[A.P. Non-Prod.]

I run a Peavey Max preamp into a Mackie 1400i in dual/mono into two 4 ohm cabs, a Peavey BW 15' and a Carvin 2x10. It's nice being able to tweak the cabs volumes seperately. I usually crank the power amp full and adjust with my pre and post volumes on the preamp. And I usually have my preamp post gain between 3-5. You shouldn't have to worry about being heard. Enjoy feeling that bass!

[Mr. Phil]

I dunno if anyone else said this yet, but did you try to change your bass's preamp's battery???

 

That would defintely be a problem in volume...

 

~PHIL~