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Martin cabs
garryrockdj
Posts: 22
Can anyone help me with Crossover settings and slopes for Martin F12 tops, with Martin s18 Bass speakers.
I am running then with Crown XTI 4000 X 2 Amps.
I am running then with Crown XTI 4000 X 2 Amps.
0
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45hz (maybe 40) BW18
100 - 110hz LR24
Tops:
100 - 110hz LR24
Are you going to bridge either amp?
DRA
Um... the tops are 300/600/1200 watts... you are supplying them with 650 watts stereo 8 ohms, or 1600 watts (per cab) @ 4 ohms mono... too little.. in stereo (for any headroom) and too much (without a pretty stiff limiter) power in bridged.
As for the subs (reports from the PSW have the XTi 4000 as a poor amp for subs) the rating is 750/1500/3000 so stereo isn't a good match and in bridged the subs are only getting 1500 watts...
So... Dra's suggestions are good.. I'd suggest even 118hz LR24 if your going to run stereo...I'd definately suggest running bridged on the subs at least...
G
I am running 4 x f12 in stereo so 4ohm for the tops and 2 x S18 in Summed so 8 ohm for bass.
Both on XT1 4000 Amps.
I will bridge the bass and see how it goes.
Thanks for your help.
It is generally best to run separate lines to the sub boxes, but if you use large wire and the jumper is only a couple of feet it should be OK. Just be aware that in bridge mode there is a lot of 4 ohm power traveling down the main line and then splitting to the 8 ohm loads.
Maybe Gadget will clarify.
DRA
DRA
Yes, you would then have 1600 watts per sub instead of 650 watts
The bridged operation is outlined in the manual...and no you don't hook to both outputs.. Perhaps the best way would be to use the 2 red binding posts.. otherwise it's the one NL4 marked Channel 1 out and you would need to wire pin 1+ and 2+ on the amp end, and the other end (speaker) would be 1+ and 1- so mark them appropriately so as to not get it backwards... then the other sub would need top be jumpered out of that speaker.
Gadget
viewtopic.php?f=61&t=959
and realize that if you rely too heavily on the limiters to protect your system you may find that you have burned them up with the limiter...
Here is a math method:
viewtopic.php?f=60&t=2242
But the best way to do it is to make sure you NEVER clip the amps. The gain structure method will let you know when your close...
Limiters are best used for OOPS protection... dropped mics... pulled cables...
If your going to use limiters use the ones in the amps.
Gadget
I have set the amp to Bridged Mono , but do I enter bridged in the DRPA+, or just use mono to the bass amp.
Just running down one input to the amp of course.
:roll:
Next I would download "band manager" from the driverack downloads site:
http://hiqnet.harmanpro.com/bm_download.php
and then you can set up your amps limiters and PEQ's easily, and graphically...
Use the Limiters and PEQ's in the amps as they are better then those in the driverack.
I would start with a PEQ on the sub amp @ about 60hz and 100hz with a "Q" in the 3.5 area...for the front loaded sub (where typical front loaded subs are most efficient ) and usually involves cuts of varying amounts to tighten up the sub sound.
Also one that is broader @ 350hz with a "Q" in the 1.0 area for control of inside low mid buildup (howl) and again cuts of varying degrees...
And another high shelf in the 3.5K area with a slope of 6dB/oct as a hi "tone" control and this one could be a cut or boost...
Gadget
I have System Architect installed will that do the same job.
Please explain the sequence in a bit more depth.
What is the "Q". AND P eq.
Please could you try to explain this in an idiots guide to me, as I would like to try and set it up
Bass amp set to bridge mono.
If so do BOTH amps show up and are you able to identify which is which? (sub amp/tops amp)
If so you need to open one amp at a time.. start with the sub amp...double click on the icon. you can name this as the sub amp later.
Double left click on the top [EQ} on the opened control surface. you will then see [sub synth] [low shelf filter] [Eq filters] [ High shelf filter] This is the filter section and it has an LPF, and HPF and 6 parametric filters...
Make sure the [enable] is [enabled] then set the first filter @ 60 hz ...easiest way is to click on the first slider and drag it down till you see the 1...and the box under it in red... then click on the box and drag it down to 60 hz..You see the circle and the square box on either side? the square boxes control the "Q" and you can click and drag either one to achieve the "Q" your looking for...then use the slider to adjust just how much cut you will apply...do the same for other filters you want to place in the amp.
You can also watch the amp temperatures.. and input and output status from this screen.
report back once you have mastered this.
Gadget
Do I need to enable all the filters near the sub synth area.
How do I control the two bands of eq together in the software, there must be a way to stero link the Chanel's ??
as for the other things like HPF/LPF and sub synth, I would leave them alone for now and use the DRPA for those functions...
Your just going to have to set the system up and play with it and see what the various things we talk about do to the sound...play some music through the system and try various things. Turn off the tops and just play with the subs and the HPF and LPF and see what happens as you change them.. also add the filters as specified and more them around, add and subtract gain and listen for the changes, with and without tops, do the same for the tops... note what happens when you change the "Q" from narrow to wide on the PEQ I suggested you try @ 350 hz.
The only way your going to get a grasp of this stuff is by working with it.
G
I enabled the Sub Synth and don't think I should have done..
I got a load of really deep bass and not much kick in it...
I did not get chance to experiment, as the punter's were turning up so ripped out all my leads and went back to stereo tops and bass
and set the eq myself...
I did not think to uncheck the synth at the time, do you think that's what the problem could have been.
Also I have gone through the gain structure on here, but find I am having to run at around 85% vol setting on my desk to get decent volume.
No, the subs have a lot of really nice low end, you can add low ends with the crossover gain or amp control... but don't exceed the gain set in the gain structure, you'd be better off LOWERING the tops volume..
Do you realize that when the mixer clips, the amps are still NOT clipping, and if your having to crank the system up that loud you probably don't have enough system....
G
Earlier in this post you suggested a cross over point of around 100 / 110 between bass and tops.
When you read the Speaker spec's the bass bin is a 2k crossover, and f12 120khz ??
What are the crossover frequencies they are talking about.
So, in the tops, the crossover built in crosses the woofer to the horn @ 2000hz (2khz)
The subs are probably capable of ~35-2000 hz or so,, but what they are telling you is were only going to use up to 120hz.. NOT 120khz...
G