2x Otops + 2x T60 slims + Crown xTi4000

[metaverse]

Hey all,

I just sat down for the first time with the xti4000 manual and started to get a little bit lost in the settings.

I'm attempting to run both Otops on 1 channel and both subs off of the other channel.

Does anyone have any experience with a setup like this that can potentially pass on a quick settings list ??

big thanks as always,
~ E

[metaverse]

[Gregory East]

It's mono any way you do it as you have only one amp, you have a choice of sending the amp a mono feed into channel 1 or having the amp sum the inputs.

You need to download Bandmanager software and set up the amp with your PC or Mac.

Set your high pass and crossover so subs are on channel 1 and tops on channel 2. You can throw in some best guess EQ presets based on the "reverse" of the EQ sensitivity charts and save them also, this will gibe you less work to do to Eq the system in each room.

I set up my 4 t48 and 4 dr250 to run 2 of each off 2 amps, you basically have half of that.
I can't say what worked for these will work for yours but may be a decent starting point:

Highpass at the plans point, LR48dB and 0db gain (blue channel 1) after the crossover
crossover at 100Hz with LR24dB again zero dB gain for channel 2 (red)

You must set limiters before plugging in speakers. You get options at 0, -3, -6 etc dB. I set mine at -3 with XTi2000 and got to 53V in "overdrive the bejezus out of it" condition so called it good. Yours will be set a bit more down I would guess. It's very important to get the limiting right as too much will not let your punchy dynamics come through but too little will blow your drivers to kingdom come!

[metaverse]

It's mono any way you do it as you have only one amp, you have a choice of sending the amp a mono feed into channel 1 or having the amp sum the inputs.

Hey greg ... Currently i'm running 2x TRS to XLR cables to channel 1 and channel 2 of the amp. Is it better to just sum the inputs or to simply just run 1x TRS to XLR cable to the amp channel 1 from the mixer ??

You need to download Bandmanager software and set up the amp with your PC or Mac.

I'm downloading System Architect 3 from the HiQnet site right now ... this is the same thing, right ??

Set your high pass and crossover so subs are on channel 1 and tops on channel 2. You can throw in some best guess EQ presets based on the "reverse" of the EQ sensitivity charts and save them also, this will give you less work to do to Eq the system in each room.

Ok so ... Subs on channel 1 ... Tops on channel two ...

General rule of thumb is LP subs @ 80hz , HP tops @ 80 hz ... BUT ... You're saying to reverse the EQ sensitivity chart.

My question is then what db margins do I start with ?? In other words how do I know how much to bump it up or down - its relative to what point ... 90 db ??

I set up my 4 t48 and 4 dr250 to run 2 of each off 2 amps, you basically have half of that.
I can't say what worked for these will work for yours but may be a decent starting point:

Highpass at the plans point, LR48dB and 0db gain (blue channel 1) after the crossover
crossover at 100Hz with LR24dB again zero dB gain for channel 2 (red)

lost me a bit ...

I understand HP and LP points from my car audio experience ... However the LR48db vs the LR24db and blue channel vs red channel and i'm ?

You must set limiters before plugging in speakers. You get options at 0, -3, -6 etc dB. I set mine at -3 with XTi2000 and got to 53V in "overdrive the bejezus out of it" condition so called it good. Yours will be set a bit more down I would guess. It's very important to get the limiting right as too much will not let your punchy dynamics come through but too little will blow your drivers to kingdom come!

I'm very afraid of blowing my babies to kingdom come ... I'm a complete virgin to pro-sound so i'm treading cautiously like an 8 year old.

"overdrive the bejezus out of it" ... hahaha ... i'm guessing this is the gain cranked 90 percent or better while just barely licking the reds ??

[Gregory East]

I believe Bandmanager is a kind of a subset of the amp management functions in System Architect. They are pretty compatible but they messed up a little in that they don't show the amps in the correct order in your rack when you plug them all in at once, no matter to you with one amp.

It should hopefully do the blue channel, red channel thing also...all will become clear when you get it up and running. In my case I thought I had entered The Matrix, but I'm dumb like that and soon got a handle on the menus and relating them to the BFM instructions.

If you only run one input cable you do "a to y". If you run dual you need to set up the input for a+b sum to mono. My short term recall of this sort of stuff isn't so great these days so I forget the exact terms, but I do remeber it was self explanatory inside the program, I'm just prompting you to click the input menu box.

re limiter, I ran mine up to +3dB on the desk and it was 52V. Then clipped everything to the max and made sure the input on the amp was showing overdriven and it went to 53V, I'd call that limited less than 60V and some safety margin for extended pounding.

iirc otop12's don't make such good 70 to 90Hz, so you might want to raise your crossover some and let them play loud and proud at what they are good at before they distort.

Re eq, it depends on the chart response, and how flat you want it. The Architect programme is probably same as BM. If you make a EQ overlay to equally shift areas above and below 0dB that will preserve your overall gain, possibly not so necessary in the digital age, but good practice.

[metaverse]

Just downloaded Band Manager from the site ... I missed it the first time around.

Gonna tinker around and post back.

Thanks a million for your help man.

[metaverse]

OK

My speakers haven't exploded

I accidently had the Tops connected to channel 1 and the Sub on channel 2 , with no limiters , and turned the amp on with them all connected ... All I heard was mostly a hiss though so I think I'm still ok.


I decided to run a single TRS to XLR cable to channel 1 input.

Input is set to "Y". (i'm assuming this is why All of the speakers go up when I notch up the gain on channel 1 and none go up when notching channel 2 ??)

EQ : Haven't touched it.

XOVER is set :
[blue channel 1] = HP @ 25hz , LP @ 110hz , 48dbLR butterworth , 0gain
[red channel 2] = HP @ 110hz , LP @ 19khz , 24dbLR butterworth, 0gain

LIMITER : -6db , both channels


I wasn't sure what the best starting point should be when setting crossovers from looking at the SPL charts ...

So I chose 100db ... and thats why the crossover is at 110hz ... Is this right / wrong , why ??

What sensitivity at what frequency defines the appropriate place to cross over ... Or is it just where the slope begins to even out most ??

Thats why I haven't even touched the "EQ" setting just yet ...


Also ... for the moment ... I'm only running 1 T60slim because the other is being finished up. I'm assuming this means i'll have to put a -12db limit on this channel until I get the 2nd one running along side it on the same channel ??

[Dave Non-Zero]

I wasn't sure what the best starting point should be when setting crossovers from looking at the SPL charts ...

So I chose 100db ... and thats why the crossover is at 110hz ... Is this right / wrong , why ??

What sensitivity at what frequency defines the appropriate place to cross over ... Or is it just where the slope begins to even out most ??

Thats why I haven't even touched the "EQ" setting just yet ...

the tops have a point where they start to drop off dramatically and the driver would have to work much harder. around the 100-110 range is fine for you. its not really a sensitivity number.

Also ... for the moment ... I'm only running 1 T60slim because the other is being finished up. I'm assuming this means i'll have to put a -12db limit on this channel until I get the 2nd one running along side it on the same channel ??

No. each speaker connected in parallel gets the same voltage from the amp, so the limiter setting is the same if you had one cab or 4 on the same channel.

[Gregory East]

Anyone know what -6dB is worth for volts from a overdriven XTi4000? Not too much hopefully.

[metaverse]

Hey dave,

Thanks for the input!

Currently the two Otops are connected parallel on the channel 2 output via speakons and the single T60 is on channel 1's speakon.


@ Greg

So the more it limits , the more db it minus' , the greater the output voltage ??

In other words ... would it be safer for me to run it at -3db?

[Gregory East]

Hell no. -6dB is 6dB less than the rated output when driven up to 0dB. What I don't know is what the XTi considers to be zero. It's always a Bad Thingtm to plug amps into subs without testing what the limited output actually is.

In your case I'd say its beyond mandatory to do the test since you are struggling with the concepts of dB and whatnot.

[metaverse]

I just recently started getting random DPC latency spikes / audio drop-outs from my Traktor Kontrol S4 and / or Laptop while running my bfm system ...

Gotta love it man ... two steps foward , 1 step back ... as always ... F@CK.

Will post back after properly testing voltage which will probably be after I find a replacement for my S4 = double F@CK.

PS. I understand what -3db vs. -6db is in relation to zero ... what I didn't understand was whether or not the actual action of "limiting" itself created more voltage to counteract the sound "spilling" over the point where the "limit barrier" resides.

[el_ingeniero]

I just recently started getting random DPC latency spikes / audio drop-outs from my Traktor Kontrol S4 and / or Laptop while running my bfm system ...

Gotta love it man ... two steps foward , 1 step back ... as always ... F@CK.

Will post back after properly testing voltage which will probably be after I find a replacement for my S4 = double F@CK.

PS. I understand what -3db vs. -6db is in relation to zero ... what I didn't understand was whether or not the actual action of "limiting" itself created more voltage to counteract the sound "spilling" over the point where the "limit barrier" resides.

Sawbucks to donuts (inflation, you know) it's a recent software change.

[metaverse]

Hello again,

Its been a while and I'm back with an odd question ...


With the "Y" input setting selected the audio is Mono - However - all 4 speakers (both tops and both subs) are set to the same gain knob. The channel 1 gain knob adjusts all 4 speakers at the same time and the channel 2 gain knob does nothing.

This is a problem because the tops start screaming before the subs do. How can I set it so that I can adjust the gain on the channel 1 knob (subs) independently of channel 2 (tops) ??

thanks

[Gregory East]

Set input to SUM A + B , instead of Y.