Alesis 8 track mixer to FBT X lite 12

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Alesis 8 track mixer to FBT X lite 12

Post by gragham »

Hi, My Alesis mini Mixer only has 2 main line outs & similar Control room outs (L/mono & right) whist my FBT X light speakers only have one stereo XLR line/Mike (switchable) in, & 2 X 1/4" (L/mono & right) line ins for direct instrument connection. Should I connect the mixer to the existing instrument line ins or buy a (twin) 1/4 jacks to 1 stereo male XLR cable? Would this be better from an impedance perspective for a Digital piano / keyboard that I need to eq accurately to get the best possible sound?
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Re: Alesis 8 track mixer to FBT X lite 12

Post by resistorman »

It’s a bit confusing because of this, but the XLR out is a switchable connector to send a mono balanced or stereo unbalanced signal from the stereo inputs. While this might be useful in some circumstances, I’ve not seen it before, I think they should have had separate jacks.

Presumably the stereo inputs are summed to the individual speaker, so use whichever one is appropriate for you.
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Re: Alesis 8 track mixer to FBT X lite 12

Post by Mike Stranks »

Connect your mixer and speakers as shown here:

Image
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Re: Alesis 8 track mixer to FBT X lite 12

Post by gragham »

Thanks for all replies, Can I safely connect the L & R 1/4"" jack outputs of the Alesis mixer to the XLR line in via a twin (TS) jack plug to single XLR male lead, on only one FBT X Lite 12 & would this carry across to a second FBT in stereo?
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Re: Alesis 8 track mixer to FBT X lite 12

Post by James Perrett »

No - that wouldn't work. Connect the XLR's directly to each speaker. The FBT may offer some kind of stereo linking but it is always best to use standard practice where possible to avoid confusion. One of my pet hates, as a sound engineer, is to get to a gig and find that the PA has been wired up in some 'clever' way which takes all of the setup time to decipher. Once you've learned the standard way of working you'll be able to walk up to most PA systems and get going immediately.
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Re: Alesis 8 track mixer to FBT X lite 12

Post by gragham »

My question is really how best to sum the Left & right Jack plug outputs of my Alesis mixer to just 1 FBT X Lite 12. Should I use a twin Jack plug (TRS) male, to single XLR lead, to connect into the FBT XLR line in dedicated mixer impedance input, or simply connect to the two dedicated Jack socket instrument inputs, which I believe are not really optimised impedance wise for a Mixer to be fed into them, ( They sound great with just my Keyboard connected, but I also need to connect at least 1 or 2 microphones but I don't want the sound, even in Mono through 1 FBT, to be too 'middly' & poor quality purely due to an impedance mismatch! Why oh why can't my Mixers have an XLR line out? ( I also have a 12 channel Studiomaster, but it still only has Jack Line output sockets!) !! 😱
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Re: Alesis 8 track mixer to FBT X lite 12

Post by James Perrett »

The XLR is just a mono input so won't work for what you want to do. The jack inputs are best for what you want to do - I can't see why they wouldn't work as well as the XLR inputs as they're just normal line inputs as far as I can see. They appear to be balanced from Mike's picture so you would be best off using TRS to TRS cables (assuming the mixer output is balanced).
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Re: Alesis 8 track mixer to FBT X lite 12

Post by gragham »

On a slightly different tack, I see that FBT are bringing out a revised X Lite range in September with an added Bluetooth input & a 'supposedly' more powerful 1500 watt (1200 LF+ 300 HF) Amplifier against the present 1000 Watt (800 LF + 200 HF). However the 1000 watt amp is quoted as 'RMS', whereas The 1500 watt is quoted as 'Dynamic', (in an Italian advert!) so I wonder if FBT have sadly gone down the overquoting power output route, with 'peak' 'Dynamic' & other basically misleading figures, so beloved of some other speaker manufacturers, & all you are actually getting is the extra Bluetooth input?
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Re: Alesis 8 track mixer to FBT X lite 12

Post by James Perrett »

gragham wrote: Mon Aug 16, 2021 4:37 pm ... all you are actually getting is the extra Bluetooth input?

If they measure their dynamic power in the same way as another Italian manufacturer whose products I own, then they may well be fitting smaller amplifiers in the new version.
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Re: Alesis 8 track mixer to FBT X lite 12

Post by gragham »

The continuous/Peak SPL on the new version FBT X lite 12 is quoted as a 124/131 as against a single figure of a continuous 127 quoted for the current version. What is going on?
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Re: Alesis 8 track mixer to FBT X lite 12

Post by Hugh Robjohns »

gragham wrote: Tue Aug 17, 2021 3:21 pm The continuous/Peak SPL on the new version FBT X lite 12 is quoted as a 124/131 as against a single figure of a continuous 127 quoted for the current version. What is going on?

Can you provide a link for context?

If it is quoted as you say the likely meaning is that the max rating for a continuous output is 124dB SPL, while the transient peak maximum is 131dBSPL.

As to why there might be a difference for peak ratings of 127 and 131dB SPL, the peak figure depends a lot on the duration of the peak when tested, as well as the reservoir capacity of the amplifiers, so perhaps the measurement format has been changed or the amplifiers are different!
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Re: Alesis 8 track mixer to FBT X lite 12

Post by gragham »

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Re: Alesis 8 track mixer to FBT X lite 12

Post by Hugh Robjohns »

Doesn't help... I think the two figures confusing you are simply the SPLs for the speaker making a continuous sound, and for a brief transient sound -- the latter being a few decibels higher than the former.
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