This is a what if question.
What are the problems or benefits of pluging in a different sub cabinet to the PAS. It it even possible or feasable. Say you have a 4 ohm 250 watt EV sub with a 15 in speaker and you pluged into it instead of the B1. What could you expect and is there any possible damage you could cause.
or could you use that instead of a second B1 for more bottom.
Thoughts??
Original Post
I won't attemp to go into details that might or might not be correct but, your sub lacks the "sensing" circuit that tells the PS1 whether it is one or two B1's, therefore I don't think the PS1 will recognize and deliver the same EQ and power as it would with two B1's.

I think that somewhere in this domain Cliff or Hilmar advised what value of resistor needed to be placed in that circuit to make the PS1 respond correctly, but I can't find it at this time.

Oldghm
DKrobath,
We have found that for the type of music we play (Rock and Roll including pop, alternative, and dance music), just 2 B1s can't quite satisfy the kick drum requirements. So we use a Mackie 1501 Subwoofer with our drummer's L1 instead of B1s. Due to the added power (600 watts), and the large speaker, we get a much bigger kick drum.

We have also found that, on indoor gigs, our bass player sounds way better with 2 B1s than playing through the Mackie/L1 Combo. So, IMHO, use the powered sub for kick drum only, and use it sparingly.

Like Oldghm mentioned, the units are set up to provide EQ for the B1 speakers, so it might be advantageous to include a single B1 if you are going bass line out into a powered sub. This should optimize the sound from the tower.

Hope that helps.

Jeff
http://www.theunmentionables.com
Its certainly not going to damage the PS1. The speaker needs to be able to handle the 250 Watt at 4 Ohm, which seems to be fine in your case.

However, one of the problems you may encounter is that the PS1 will not "detect" the EV sub and run the L1 down to about 110 Hz which is probably not what you want. The easiest workaround is to get a 1/4" plug (with no wire attached) and plug it into the "Bass Line Out" on the PS1. This will be detected and the PS1 will provide a flat 40 - 180 Hz signal through
the AMP3 Out.

Hope that helps

Hilmar
I am in a similar situation. I have two JBL 18" 300W powered subwoofers I want to try and compared with the B1s and keep what sounds best, in a dual PAS home theater/studio set up.

The JBL subwoofer frequency range (-10dB) is 38-300 Hz, and the frequency response (±3dB) is 50-300 Hz but you say the L1 will only pass 40-189 at best?

Will the PAS drive it correctly?

I know that some synching will not occur and it might not sound as tight, but those JBLs are not to be sneezed at. For one they are much bigger *active* subwoofers compared to the B1 smaller passive ones, not that size always translated to quality, but I need to A/B them, then I'll know.



Maybe I don't understand it, but why not just put the non-Bose subwoofer on the Bass Line Out (black)?

Many thanks
quote:
Originally posted by Tiglath:
I am in a similar situation. I have two JBL 18" 300W powered subwoofers.........

Maybe I don't understand it, but why not just put the non-Bose subwoofer on the Bass Line Out (black)?

Many thanks


Tiglath,

In your case, with powered subs, that would be the correct choice. "Bass Line Out" is a proper "line level" signal to send to the input of your powered JBL's.

In the case above for DKrobath, his sub is passive and needs the "AMP 3 OUT" to power his sub.

Does that make sense??

Oldghm
quote:
Originally posted by Tiglath:
I am in a similar situation. I have two JBL 18" 300W powered subwoofers I want to try and compared with the B1s and keep what sounds best, in a dual PAS home theater/studio set up.

The JBL subwoofer frequency range (-10dB) is 38-300 Hz, and the frequency response (±3dB) is 50-300 Hz but you say the L1 will only pass 40-189 at best?

Will the PAS drive it correctly?

I know that some synching will not occur and it might not sound as tight, but those JBLs are not to be sneezed at. For one they are much bigger *active* subwoofers compared to the B1 smaller passive ones, not that size always translated to quality, but I need to A/B them, then I'll know.



Maybe I don't understand it, but why not just put the non-Bose subwoofer on the Bass Line Out (black)?

Many thanks


Oldghm has certinaly the correct advice. You can easily connect any active sub to the "Bass Line Out". You may have to play around a liltte with the level control on the sub to get the spectral balance, other than that it should be plug and play.

Personally, I'm not a big fan of going deeper than 40 Hz, since in nearly all live cases it just adds some indistinct rumble and makes things muddy.

There is virtually no recorded music out there with any appreciable spectral content below 40 Hz. The only exception are movie sound tracks, but there it is mainly used for sound effects and not in any musical way.

You do NOT need 30 Hz to adeqautely reproduce the low B string of a 5-string bass. In fact most of the energy is in the harmonics an not the fundamental frequency and you get much better bass definition by going easy on the very low frequencies.
I agree with Hilmer on the sub-bass issue. Most deep bass setups I've experienced lack the clean, defined sound that you get from b1's.

I only commented because of Tiglath's comment about "Home Theater" usage, Of which the pas should be excellent just as it is.

I have experienced very few full range systems that adding a sub-woofer to helped, and many other systems where it only created what I call Low frequency "Grunge"

Happy experimentation!
Hi Tiglath - I've done a LOT of bass reinforcement experimentation with our systems over the past year or so. What I've found is that the B1's, as designed, are the most musical sounding with the system...they have a great tone that just "fits". That being said, there is not always enough (exaggerated) "thump" for certain musical styles. My rock band ended up using a Yorkville 2-10" 600 watt powered sub to supplement the bass guitar (a little) and the kick drum (a lot) in addition to the double bass PAS that they share. It works great for us.

There are some tricky things going on in the processing of the PAS that you'll need to understand to get the JBL's integrated with the system and working to their full potential. Here's the (not so) short list:

1) The L1: The L1 "tower" is rated down to 110Hz if NO B1's are connected, and there is NO plug in the "Bass Line Out". If there is ANY cable connected to the "Amp 3/Bass Out" or the "Bass Line Out" jack, the processor senses that and kicks the crossover to the L1 "tower" up to 180Hz, and sends everything below 180Hz to the sub(s). I mention this because many third party powered subs have their crossovers set more in the 120Hz area, which could leave a "hole" in the lower mids/upper bass (120 to 180Hz). You may get better results running the lines from your mixer into the subs first, and then out of the sub's crossover to the PAS'(which will be running to 110 Hz with NO B1's attached). That will get you closer to the "full range" potential of the L1. There are also other benefits to this, which are discussed below.

2) The B1: The B1 EQ curve works great on the B1's. It's an EQ boost in the lower frequencies (around 60-80Hz, I think) that makes those little 6" B1 speakers sound MUCH bigger than they are. Unfortunately, when you apply that curve to a 15" or 18" speaker, it can turn to mush pretty quickly. Moral of the story - I've found that you're better off WITHOUT the B1 curve activated for your larger third party sub(s). If there are NO B1's connected to the Amp 3 out, the Bass Line Out will give you a flat eq, but you'll still get the 180Hz crossover point. If there ARE B1's connected to Amp 3 out, you'll get the eq curve, plus the higher crossover point PLUS a reduction in SPL output. I told you that there was a lot going on in there. That brings us to...

3) The PS1: The PAS is designed as an integrated system. All the smart processing is intended to make the system sound perfect as you keep adding to it. This works great as long as you're adding B1's. The processor "senses" how many B1's are being used, and adjusts itself with a reduction in bass output - to add headroom, but maintain the spectral balance. If a single B1 is used, it's at full throttle. If a second B1 is added, it drops the output. If a plug is plugged into the bass line out, it drops the output again, assuming more B1's are being added. This works great for the integrated system as designed, but not so well for third party subs. Also, if your sub does not have a volume control, there's no way to control the mix coming from the bass line out - you just have to take what it gives you. With my band, we've found that bypassing the bass line out altogether yields the best results with a non-Bose sub. This is why I suggested that you try running your signal from the mixer to the JBL's first - you won't have to deal with the funky EQ curve, the high crossover point or the reduction in bass output.

For maximum control of blending the low to high ratio, here's another thought for you, based on how I've set my sub up in my band. You can run your main left and right out of your mixer to the two Bose systems - in this configuration it doesn't matter if you have B1's connected to them or not... your personal taste. Take a pre-fade AUX from your mixer (most manufacturers make aux 1, and sometimes aux 2 "pre-fade" - this means that whatever you do with the channel fader/slider has no affect on the aux signal and vice-versa) and run that into your sub. I agree that you may find you only need one of the JBL subs. In most live sound situations, even if the "mains" are run in stereo, the subs are summed at the crossover and run in mono, due to the omnidirectional nature of those low frequencies. If your JBL's have a "thru" jack, you can always just run from that into the second sub if you really want to rattle the rafters. So, let's say you've got your cd player running into a stereo channel on your mixer - we'll call it channel 11/12 - with left and right out to PAS #1 and #2, and Pre-fade Aux #1 send to the JBL sub. Now you can control the highs and lows individually. The channel fader on ch 11/12 will control the volume to the Bose towers, and the aux knob on that channel strip will control how much goes to the JBL sub. This way, if you're not getting enough bass in relation to the highs, you can turn the PAS' down a little (with the channel fader) and crank the sub up (with the aux knob). With this set up, every channel on your mixer that has something plugged into it - vocal mics, guitars, whatever - can have a tailored amount of that signal going to the sub if you desire...just by turning the aux knob on that particular channel. It works great for us.
That's not advisable. The EV sub has 4 Ohms and a single B1 8 Ohms. The resulting impedance of the combo would be around 2.7 Ohms. That's a little low for the power amp in the PS1 and it might shut down temporarily if you are pushing it hard.

A safer (but less elegant) way of getting the B1 EQ activated is to modify a Speakon cable so that there is a 5k or 10k resistor between the 2+ and 2- pins of an NL4 plug.

The easiest way to do that is to run normal speaker wire or lamp cord from 2+ and 2- to a banana plug like this
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=274-717.
You can then take make up two more banana plugs with a 10k resistor like this

http://www.radioshack.com/basket.asp?sku=%2C271%2D1335%2C&iGo=

across the pins. By simply cascading none, one, or two of the "resistor plugs" you can get three different EQ curves and check which one you like better.

That's a little do-it-yourself project but requires only a screwdriver, some parts, and a little patience.

Hope that helps

Hilmar
Hi DKrobath - Your initial post said the EV was a 4 Ohm/250 watt sub. Does that mean it is a powered/active sub, with a 250 watt power amp in it, or are you saying that it's a passive cab and the speaker is rated for 250 watts? That's the biggest issue here. If the sub has a power amp in it, you have no choice but to just run a 1/4" cable from the bass line out to the input of the sub. If it is NOT a powered sub, and you want to run it from the Amp 3 out, I think you've still got issues with the Ohm rating if you want to run it WITH a B1. I'm sure Hilmar can clarify that for you, but I think the power amp in the PAS is rated at 4 Ohms total, which would mean you could run EITHER the EV(4 Ohms) by itself or the B1 (8 Ohms) but not both together. Hilmar?
quote:
Originally posted by gittar-jonz:
There are some tricky things going on in the processing of the PAS that you'll need to understand to get the JBL's integrated with the system and working to their full potential.

If there ARE B1's connected to Amp 3 out, you'll get the eq curve, plus the higher crossover point PLUS a reduction in SPL output.

All the smart processing is intended to make the system sound perfect as you keep adding to it. This works great as long as you're adding B1's. The processor "senses" how many B1's are being used, and adjusts itself with a reduction in bass output - to add headroom, but maintain the spectral balance. If a single B1 is used, it's at full throttle. If a second B1 is added, it drops the output. If a plug is plugged into the bass line out, it drops the output again, assuming more B1's are being added.


Very tricky, this has been discussed before, and I'm still not sure I understand.

Do a google search of this site for "yellow paint" to get Hilmar's explantion.

Oldghm
quote:
Originally posted by Hilmar-at-Bose:
That's not advisable. The EV sub has 4 Ohms and a single B1 8 Ohms. The resulting impedance of the combo would be around 2.7 Ohms. That's a little low for the power amp in the PS1 and it might shut down temporarily if you are pushing it hard.

A safer (but less elegant) way of getting the B1 EQ activated is to modify a Speakon cable so that there is a 5k or 10k resistor between the 2+ and 2- pins of an NL4 plug.

The easiest way to do that is to run normal speaker wire or lamp cord from 2+ and 2- to a banana plug like this
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=274-717.
You can then take make up two more banana plugs with a 10k resistor like this

http://www.radioshack.com/basket.asp?sku=%2C271%2D1335%2C&iGo=

across the pins. By simply cascading none, one, or two of the "resistor plugs" you can get three different EQ curves and check which one you like better.

That's a little do-it-yourself project but requires only a screwdriver, some parts, and a little patience.

Hope that helps

Hilmar

I am really just curious here... I understand that it wouldn't a good idea to add a 4 ohm load to a B1. What would the result be if you added an 8 ohm load to a single B1?
Would the PS1 remain in "1 B1" mode, or would it sense the overall 4 ohm load and switch to "2 B1" mode?
Combining the a single B1 with an external 8 Ohm subwoofer is technically okay. You would get the same curve as fo a single B1, so it may be a little bass heavy. We are not measuring the actual impedance of the speaker but use an external resistor on the 2+, 2- pins of the B1 Speakon connector.

However, I'm not a big fan of mixing subs. Different speakers tend to have different phase responses and that could lead to the two subs start fighting each other at some frequencies. To avoid that, you can physically separate them, but than you loose the beneift of "acoustic coupling" which gives roughly an extra 3dB of efficiency.

Hope that helps

Hilmar
quote:
Originally posted by Hilmar-at-Bose:
Combining the a single B1 with an external 8 Ohm subwoofer is technically okay. You would get the same curve as fo a single B1, so it may be a little bass heavy. We are not measuring the actual impedance of the speaker but use an external resistor on the 2+, 2- pins of the B1 Speakon connector.

However, I'm not a big fan of mixing subs. Different speakers tend to have different phase responses and that could lead to the two subs start fighting each other at some frequencies. To avoid that, you can physically separate them, but than you loose the beneift of "acoustic coupling" which gives roughly an extra 3dB of efficiency.

Hope that helps

Hilmar

Ok, I tried this last night just because I am curious. I used a 15 inch, 8 ohm sub with a B1. It was very bassey, which I guess some people like. Sounded ok most of the time but every now and then this setup produced some really strange results. I reduced the volume a little more (reduced some to begin with) and it sounded better. Still too much bass for me, but better. I was able to tweak the sub placements/positions and get some really good sound out of it. But I still like the results the best from the "All BOSE" solution.
My conclusion is: BOSE knows best so if I want more low end I will buy more B1s..
I realize this discussion is mainly for drummers and bass players, but as I said, I was just curious as to the results.
I had my two PAS in my basement for two nights and I have been experimenting a little.

The POD XT sounds great. I don't think I am going to sell my Marshall and Dr. Z amps, but they are going to get played little now. The Taylor T5 sounds made for the PAS.

As a stereo system, the clarity is outstanding, quite a leap from my powered 15", The top end is a bit harsh though, maybe it's the bare walls, I have to roll back treble and mids quite a bit soften it.

Being accustomed to 18" subs, the two B1s just don't produce enough bass. The bass they give is good and tight but not enough. The best combination is to turn the 18" powered subs down to 60% and play the B1s alongside. I don't know if getting two additional B1s would better that.

I got my two PAS at the Guitar Center but they don't have a blue-labeled speaker socket. Does that mean that I got obsolete units? If so, what can I do about it? The DVD firmware update looks like a pain I can do without. I should not have to do that on units bought two days ago.

Many thanks
Tiglath,

I won't be the one to say the only difference is the software and blue paint, but I don't think they have changed enough to make the V.1 equipped PAS obsolete.

A phone call to 877-335-2673 will get you the upgrade kit, and it really is a simple process. Give em a call.

Oldghm
Hey Tiglath,
quote:
The POD XT sounds great.
Are you using the XT's 'Bose PS1' output mode? Studio Direct?
quote:
Being accustomed to 18" subs, the two B1s just don't produce enough bass.
Are you currently running one B1 for each of your two systems?
quote:
Does that mean that I got obsolete units?
There are no obsolete units. The latest batch from the factory (with the blue paint at the Amp 3 Out connector) already have the v2 presets. These are just now starting to show up at Guitar Centers. Oldghm pointed you in the right direction for getting the latest and greatest presets. It's pretty straight-forward, but let us know if you run into any snags along the way...
quote:
Are you using the XT's 'Bose PS1' output mode? Studio Direct?


Bose PS1 mode. It's the first time I hear the POD just like with the headphones. Previous attempts to play it though my PA or amps turned out crappy sound. With the POD patches being so excellent the need for the proverbial tube tone to sound good is all gone.



quote:
Are you currently running one B1 for each of your two systems?


I have to to capture the stereo image. I use the dual PAS as a stereo sound system and as a band practice system, in the latter role I play backing tracks (mono) on one PAS and the live instruments on the other. I can switch modes with a mixer without touching any cables.


What's the difference between the channel trim at the unit and the level knob on the remote?
Hi Scottie Mack,
It is my understanding that you are correct about the 5k & 10k resistors, plus the option of NO connection across 2+ & 2- (I believe you probably meant this, but it wasn't explicit so I included it for clarity and completeness). This will result in three different possible curves.

...Mark
quote:
Originally posted by Scottie Mack:
So let me jump in here then.
If I take my custom JBL 12" 4ohm bandpass subs and run 1+ and 1- to the voice coils and place either a 5K or 10K (1/4watt?) across pins 2+ and 2-, I should be able to run those subs using the power base and the different EQ curves?


Scott - Mark is right. You will be able to access the different EQ curves for the bass output this way.

But, and the big but is, those 5k and 10k EQ curves are made specifically for the B1's. Generally, when I have connected third party or homebrew subs, I have not wanted the B1 eq curve on there.

Can't hurt to try, but don't be surprised if it doesn't sound good.

Mike
No problem. I just wanted to make sure that the 1+/1- was for power and 2+/2- was for sensing circuit before I started plugging things in. Didn't want to get anything wrong. Smile
I'll experiment.
Thanks again.

Side note, When I bought my L1's from Guitar Center one of them had no cover over the mixer portion. They just said contact Bose and they can get me one. I suppose that will cost me extra? They didn't know where the one that was originally on it had gotten to. (I bought it anyway)
Alrighty. Then the 5K resistor is just built into the box to tell the base that a B1 has been connected and that placing 2 B1's (while doubling resistor value) does not make the powerbase do anything different.
So...in theory, I should be able to use 1+/1- for power to voice coils and a 5K 1/4 watt across 2+/2- and I should be able to run tests on my custom JBL's.

Thanks.
Hi Scott,

My guess looking at the information provided so far in this thread is that each B1 has a 10k resistor across +2/-2. Connect two B1 in parallel and the PS1 now sees 5k at the +2/-2 of the Speakon connector. (Two 8 ohm speakers in parallel = 4 ohms. Two 10k ohm resistors in parallel = 5k ohms.)
So:
0 ohms = no B1 connected, low crossover point for the L1 speakers is 110 HZ.

10k = 1 B1 connected, 8 ohm load at sub amp, low crossover point for the L1 speakers is 180 HZ.

5k = 2 B1 connected, 4 ohm load at sub amp, low crossover point for the L1 speakers is 180 HZ.

I believe that the only other difference (beside the EQ curve MikeZ mentioned) between having a 5k or 10k resistance is in the way the PS1 keeps the power balance in perspective between the sub amp and L1 amps when considering the 4 or 8 ohm load. (An amplifier's output rating changes depending on the load connected to it.) If I was connecting a sub other than a B1 to the PS1 I would try a 5k resistor if the sub is 4 ohms and 10k if the sub is 8 ohms.

Don't confuse EQ curve with crossover point. I would assume that there is EQ adjustments within the 40 Hz to 180 Hz band specific to the B1 that are active when one or two B1 subs are connected to the PS1.
Tested it out this morning (I'm sure my neighbors liked that)
It did hit lower into the bass registers well. the techno and hip-hop was very good compared with the B-1's
For most all weddings I'll use the Bose bins and when doing schools I'll swap out for the JBL's.
Thanks for all the help.
quote:
Originally posted by Le5:
Hi Scott,

My guess looking at the information provided so far in this thread is that each B1 has a 10k resistor across +2/-2. Connect two B1 in parallel and the PS1 now sees 5k at the +2/-2 of the Speakon connector. (Two 8 ohm speakers in parallel = 4 ohms. Two 10k ohm resistors in parallel = 5k ohms.)
So:
0 ohms = no B1 connected, low crossover point for the L1 speakers is 110 HZ.

10k = 1 B1 connected, 8 ohm load at sub amp, low crossover point for the L1 speakers is 180 HZ.

5k = 2 B1 connected, 4 ohm load at sub amp, low crossover point for the L1 speakers is 180 HZ.

I believe that the only other difference (beside the EQ curve MikeZ mentioned) between having a 5k or 10k resistance is in the way the PS1 keeps the power balance in perspective between the sub amp and L1 amps when considering the 4 or 8 ohm load. (An amplifier's output rating changes depending on the load connected to it.) If I was connecting a sub other than a B1 to the PS1 I would try a 5k resistor if the sub is 4 ohms and 10k if the sub is 8 ohms.

Don't confuse EQ curve with crossover point. I would assume that there is EQ adjustments within the 40 Hz to 180 Hz band specific to the B1 that are active when one or two B1 subs are connected to the PS1.


Almost...the scheme is:

Each B1 has 10k across 2+/2-. So when two are connected the resistors are indeed in parallel.

open/infinite resistance = no B1 mode - L1 goes to 110Hz.
10k = 1 B1 mode
5k = 2 B1 mode (-6db from 10k/1 B1 mode)


MikeZ
So if I leave the resistors off I will get a full output up to 110.
If I run a 10K, I bump that up to 180 and if I run a single 5K I bump up to 180 but LOSE 6DB?

If that is the case then running no resistor and leaving the 4 Ohm 12inchers to handle 40 to 110 shouldn't be a problem. Asking my subs to go out to 180 isn't my greatest option. Still waiting on my Speakons to arrive. Thanks,
quote:
Originally posted by Scottie Mack:
... a single 5K I bump up to 180 but LOSE 6DB?...

Just for clarification, you don't lose 6DB in overall "maximum output"...
The 10K output is "assumed" to be an 8 ohm load, and the 5K output is assumed to be a 4 ohm load from two 8 ohm speakers in parallel. Thus, the "5k" output at the same settings is reduced by 6db so the bass volume stays balanced whether it has one 8 ohm load or two in parallel. What that does is allow that "balanced sound" to stay balanced as the Master volume is increased.

You don't "lose" 6db: roughly speaking, it's 125W into 8 ohms; 250w into 4 ohms.
I'm just wondering what will happen, if I'll take a cable from "Bass-Line OUT" into "Amp-3 IN" with an external sub attached to the "Bass Module" (Amp-3 OUT)?

I know, the low crossover point for the L1 speakers then will change from 110 Hz to 180 Hz.

I'm assuming, that this way I would get a flat bass signal instead of the EQ'ed for the B1 on the "Bass-Line OUT" up to 180 Hz. - But I'm not shure.

Could someone from Bose chime in and confirm or reject my assumption please?

Wolfgang

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