Powering a B360

[still4given]

I was given a B380 by a friend. I am trying to decide how best to power it. He gave me the crossover/splitter box that goes with it.

Here's my question. The power amp I have to use with this is a Carvin DCM 600. Here are the specs;

DCM600 Power Amp
600W bridged 4 ohms, 450W bridged 8 ohms.
• Continuous RMS per CH: 8 ohms 125w, 4 ohms 225w, 2 ohms 300w.
• Not rated "pulse power" or at 2 ohms for a few minutes like some amps
• THD 20-20kHz @ rated 90% output: 0.1%, 50% ouput 0.03%.
• High transparent 45v/us slew rate. Studio quality 100 dB S/N ratio.
• INPUTS: 1/4" balanced and female XLR balanced.
• OUTPUTS: 5-way binding post, Speakon(tm) and two 1/4".
• Switches: limiters, ground lift, paralleling inputs, bridge mode.
• Recessed level attenuators, clip, signal, protect and power on indicators.
• Soft-start, DC SpeakerGuard(tm), thermal and short circuit protection relays.
• Variable speed fan. Heavy-duty all steel construction.
• Dynamic low frequency punch with transparent high-end for uncolored sound.
• 2U rackmount 3.5"H x 10"D x 19"W, WT: 19 lbs.

Should I be using this amp in bridged mode?

I am using this in conjunction with a pair of Event 20/20 passive nearfields powered by a Hafler TA-1600.

Any and all suggestions are welcome. I want to use this sub in it's most useful way.

Thanks, Terry

[4313B]

Strap that amp and punish that 2235H! :die:

It should be fine as long as you don't exceed a continuous input above 300 watts.

*****

Oh, and remember the three most important rules of successful single sub use. Location, location, and location.

[still4given]

So by strap, you mean bridged?

Also, you mention location. The Nearfields sit on my mixing desk which sits in the center of my small studio, a room about 10' wide and 13' deep. I have a pair of 4412's on mounts up near the ceiing on the wall facing me, about 6-7' away. Should I place the B380 on the floor , centered between the 4412's, This is going to be used mostly for referencing while mixing and mastering. I wasn't planning on using the B380 in conjuntion with the 4412's as much as with the 20/20's but I could.

Thanks, Terry

[4313B]

Yes, strapped = bridged.

Try placing the B380 so you get roughly equal energy at something like 30 Hz and 60 Hz at your listening location and it should be ok.

[Zilch]

Originally posted by still4given
I was given a B380 by a friend. I am trying to decide how best to power it. He gave me the crossover/splitter box that goes with it.

Any and all suggestions are welcome. I want to use this sub in it's most useful way.


Terry: If the "crossover/splitter box" you got with it is BX63(A), you're one lucky dude. Those are hard to come by these days. Be sure to use it, as it provides requisite equalization for the B380.

Check out this delicious article (http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm) for more info on your fortuitous windfall!

:rockon1: :bouncy:

ps: Once you get it going, do NOT let your friend hear it. Heh, heh....

[still4given]

Thanks a bunch.

I'll try that.

Blessings, Terry

[still4given]

Hi Zilch,

Yup, it is the BX63. I wasn't sure what the model was and I am at work. This just gets better and better. Thanks so much for the link. I will read it in it's entirety as soon as I get a chance.

Blessings, Terry

[boputnam]

Originally posted by still4given
...Nearfields sit on my mixing desk OK, OK!!! Enough jive about JBL's for a second! :rotfl:

Tell us more about the desk, what you're using in your racks, etc., and what you use it all for. There's a few of us out here besides me and Oldmics who thrive on this stuff!

[Robh3606]

Hey Bo

Why you letting him off so easy. Where are the pictures. Come on don't be shy he's right we live for this stuff:)


Rob:)

[still4given]

OK, no pictures yet but I will take some this weekend. Basically, I am in the process of building up my little home studio. I also have a PA system for live work.
Anyway, here's a list off the top of my head. Most of the gear s in SKG cases for portability

Mics;
Shure KSM32
Shure SM58 - 4 each
Shure SM86 - 2 each
RODE NT 1000
RODE NTK
Audix OM5
Studio Projects B1
Marshal MXL 57V
Marshall MXL 603 - 2 each
Oktava MK-012-01 - 2 each
Oktava MK319

Mic Preamp/Mixer;
M-audio DMP3
Mackie 1604 VLZ
Behringer MX802

Compressors;
DBX 266xl - 2 each
Behringer Multicom Pro MDX4400

Headphones/amps;
Sony MDR 7506
Behringer HA 4600 Headphone amp

Recorders;
Panasonic SV-3800 DAT
Panasonic SV-3700 DAT
Tascam 112 MKIII tape deck
Denon DN790R tapedeck

Monitors;
HHB Circle 3 - nearfields
JBL 4412 - mid fields
Yamaha NS1000 - mid fields
Event 20/20
JBL 4425
JBL B380 w/ BX63

Amplifiers;
Hafler TA-1600
Carvin DCM600

DAW;
Compaq P4 1.7
Win XP Home
512 SDRAM
20g apps disc
80g audio disc
Samsung CDRW/DVD
Memorex USB2 CDRW
Delta 1010 sound card

Software;
N-Track
Fl Studio
GigaStudio24
Easy CD Creator
Delta Logic

Instruments;
Fender Deluxe Nashville Power Tele w/Bill Lawrence L280 pickups
Fender Blonde Blues Jr.
Ovation Balladeer
Gibson Grabber Bass
Peavey Fury V Bass
Fender BXR 200 combo
Behringer V-Amp 2
Midiman Radium 61 MIDI controller

Pedals;
VS Route 66
VS H20 Chorus
Dunlop Crybaby

Other rack gear;
Denon DN-650F CD Player
Phonic PEQ 3600 1/3 octave Stereo EQ
Rane 2/3 octave Stereo graphic EQ
Behringer Virtualizer Pro DSP1000
RackRider Power Conditioner

PA speakers;
JBL EON Power 15 - 2 each
EV S80 - 2 each

Blessngs, Terry

[johnaec]

Sounds like a great bunch of gear! Also, JBL made a BX63 and a BX63A. I'm not sure of the difference, but the "A" version seems to be more in demand.

BTW - what's your impression of the 4425's vs. the 4412's, primarily in the mid/hi ranges?

John

[Zilch]

Originally posted by johnaec
JBL made a BX63 and a BX63A. I'm not sure of the difference....

BX63A has adjustable frequency. BX63 is fixed at, ummmmm, 63 Hz.

Hee, hee. The B380/BX63 made it onto the gear list purty quick! ;)

[boputnam]

Hey, Terry...

:drool: OK, I made that up, but we need a smilie for it, right?

Quite a line-up. Couple things came to mind, one gear junkie to another:

If you ever go to CD-R (rather than to harddrive) you might give the Sony CDRW66 a lookie. Phenomenal workhorse. Sony's SBM technology is amazing. The CDRW66 is much the standard, I've noticed, both in road racks and in built-ins.

And, a few friends I've turned onto Nero, find it superior in many ways to CD Creator. CD Creator has lately added features that bring it closer to Nero, but the latter I still prefer.

Now, I gotta go over that list of yours, again... :drool:

[still4given]

johnaec,

I'm not sure which one I have, I'll have to look when I get home. I know it only has on knob and a big paddle switch on the front. It the BX63A has two, that I don't have it.

Not really sure about the 4425 vs the 4412 yet. Haven't had the 4425's long enough. My room is not really set up well enough yet to be very discriminative. I've got to do some more acoustical treatment before I would make a judgment about that. I like both of them. I don't think the 4425's go as high as the 4412's but for some types of music that is a good thing. IMO

Truth is, on some things, my Yamaha NS1000's sound fabulous.


Hee, hee. The B380/BX63 made it onto the gear list purty quick!

Yeah, I tried to remember all the equipment I have presently, not that I know how to implement it all properly. :D


Hey, Terry...

:drool: OK, I made that up, but we need a smilie for it, right?

Quite a line-up. Couple things came to mind, one gear junkie to another:

If you ever go to CD-R (rather than to harddrive) you might give the Sony CDRW66 a lookie. Phenomenal workhorse. Sony's SBM technology is amazing. The CDRW66 is much the standard, I've noticed, both in road racks and in built-ins.

And, a few friends I've turned onto Nero, find it superior in many ways to CD Creator. CD Creator has lately added features that bring it closer to Nero, but the latter I still prefer.

Now, I gotta go over that list of yours, again... :drool:

I do have 3 CDRW/DVRW drives on my DAW. Hard to imagine them keeping up with the data transfer required in digital recording. The one I use the most for burning CDR's is a Lite-On unit. They have "SafeBurn" technology and I have yet to burn a coaster with it. I'll look into that Sony you're talking about.

I have Nero and Easy CD Creator. I like them both. Nero has a normalization feature so if I'm in a hurry and don't have time to normalize it elsewhere, I will use Nero. I can get around in Easy CD Creator better so I usually go to it first.

Blessings, Terry

[still4given]

Hey guys,

OK, I bridged the Carvin and when I turned up the system a bit I started hearing a bunch of poping or slapping sounds coming from the B380. I think the speaker was bottoming out. :confused: Too much power? I'm not too familiar with sub woofers. This 2235 has a lot of movement! I used to use D140's for bass and they didn't move in and out like this thing can and I drove them pretty hard. It sounds fine if I don't push it that hard. Am I just over driving it?

I went back to using just one side of the amp. Seems fine, but I keep hearing about the dangers of using too little power. Not sure if that applies to sub woofers though.

As I said earlier, I am driving two Event 20/20 passive nearfields with a Hafler TA-1600 which is only about 60 watts per side. It didn't seem as though I was playing it all that loud. My room may be fooling me though. I have furniture blankets hanging on all the walls.

So, what do you think?

Blessings, Terry

[Alex Lancaster]

Terry:

For sure You are bottoming out, I done it many times; I don´t remember exactly how the BX63 works, but it seems You need a low cutoff, or high pass, at about 16Hz, 24 dB/oct, I run my 4 2245H´s with a 15Hz 24 dB/oct at the electronic xover, an M552, and then an 8Hz 24 dB/oct at the amp in cascade, before using the 15Hz, I promptly drove the coil out of one gap, getting too crazy with Telarc´s 1812.

There are all kind of electronics for that.

Alex.

[Zilch]

BX63 has the low cut, if I recall. I've never bottomed a 2235. Even a single plays plenty loud in a small room....

Terry: Are you using the BX63? Remember, there ain't a lot of intelligible program content down below 63 Hz, typical. It's supplemental SUB woofing you're doing there and not gonna sound like D140's crossed higher. The primary purpose is to rattle stuff, LOL.

[still4given]

Yes I am running it through the BX63. I sounds fine now that I'm only using one channel on the Carvin. I think bridging it was just too much power. I haven't heard it bottom out since I change it back to one channel. More than enough bass with my Events.

It's good to know that it has a bass cut down low.

Thanks for all the help.

Blessings, Terry

[4313B]

Originally posted by still4given
I think bridging it was just too much power. I haven't heard it bottom out since I change it back to one channel.Some amps act screwy when strapped. From your description it sounds like the 2235H was "driving" the amp and the amp lost control. It happens...

[still4given]

Originally posted by Giskard
Some amps act screwy when strapped. From your description it sounds like the 2235H was "driving" the amp and the amp lost control. It happens...

Could you elaborate on that a bit. That doesn't make sense to me. How does a speaker drive an amp?

Thanks, Terry

[4313B]

Back EMF. Big JBL's are famous for it.

[boputnam]

Originally posted by Giskard
Back EMF. Big JBL's are famous for it. That's where "damping factor" comes in...

[4313B]

Yeah, but we don't want to go there... ;)

[boputnam]

Ha! I admit - the hesitation did occur...

[still4given]

Looks like an inside joke going on here :p

You're discription is a little vague. Am I going to look foolish if I ask what EMF means?

I really would like to understand what may be causing this.

Thanks, Terry

[4313B]

"Am I going to look foolish if I ask what EMF means?"

Not that I know of. Questions are for the asking.

You should be able to find plenty of information on the Internet. Look up back-EMF.

[4313B]

A quick look brought this up:

Back-EMF, Back Electromotive Force
Describes the phenomenon found in all moving-coil electromagnetic systems, i.e. a speaker cone, whereupon, after the electrical audio signal stops, the speaker cone continues to move, creating a new voltage that tries to drive the output of the power amplifier. It does not sound good when loudspeakers do this, so amplifier manufacturers try to present a zero-ohm "dead short" to the loudspeaker. See Damping Factor.

Damping Factor
Damping is a measure of an audio power amplifier's ability to control the back-emf motion of the loudspeaker once the signal dissipates. When, for instance, a speaker cone continues to move after the electrical audio signal stops, it tries to drive the output of the power amplifier, resulting in less-than-pleasant effects. Designers of power amplifiers thus try to present a "dead-short" to the loudspeaker: the damping factor is defined as the ratio of the loudspeaker's nominal impedance to the total impedance driving it (amplifier + speaker cable). A high damping factor states that an amplifier's output impedance can absorb the electricity generated by the speaker cone motion, which will thus stop the loudspeaker's vibration. Effects of damping are most evident at lower frequencies; well-damped loudspeaker systems sound "tighter" at the low end because the woofer is not allowed to resonate after the electrical impulse is gone.

How on earth did humans ever exist without "cut and paste"? It must have been utter hell! :p

[still4given]

Thanks Giskard!

You the best!

Looks like I should get a better amp to drive that B380. I'll keep the High damping factor in mind when I do.

Who said and old dogs can't learn new tricks? :D

Blessings, Terry

[4313B]

Originally posted by still4given
Looks like I should get a better amp to drive that B380. I'll keep the High damping factor in mind when I do.If your current amp is working fine in stereo mode you'd probably be better off spending money adding a second B380. Single subs are notoriously difficult to employ.

[still4given]

Originally posted by Giskard
If your current amp is working fine in stereo mode you'd probably be better off spending money adding a second B380. Single subs are notoriously difficult to employ.

Does that mean I'd need a second BX63 as well? It doesn't have two outputs for the sub. A "Y" cord maybe?

Thanks, Terry

[Zilch]

Does your amp have an unbridged mono mode? If so, one input drives both channels, one B380 on each....

[Alex Lancaster]

If not, the "Y" would be fine; What freq and slope is the low cut on the BX63?.

[4313B]

Originally posted by Alex Lancaster
If not, the "Y" would be fine; What freq and slope is the low cut on the BX63?. The BX63 has the high pass bump filter set at 26 Hz. It falls 12 dB/octave below that. The low pass is set at 63 Hz and falls at 12 dB/octave above that.

[still4given]

I just looked at the amp and it has a "parallel inputs" button that I think gangs the inputs. I will try it and see.

However, I just tried pumping up the power with one channel only and I'm still getting that pop sound on the hardest hits. Not sure if it's bottoming out or maybe there is something wrong with the speaker. Not sure where to go from here. I cranked up my 4412's to the same volume as I'm running the Events and the B380 amd don't have any problems in the low end. It seems as though that the 2235 is just traveling too far. I just got an old D140. I'm going to try hooking it up and see if I get the same pop sound. I'll let you know how it goes.

Thanks again, Terry