Great idea to put all the monitors on a DCA Dan, Thanks so much 
Yeh I know what you mean about getting to know. It has been very helpful. Many, many thanks.
This is me on Facebook. Redirecting...
With a couple of pics of the shows and bands Iām involved in.
Yes, Waiheke is an island with about 14k permanent residents just off Auckland, NZ.
Where are you guys based?
I think that everyone from the forum should come visit Waiheke!!
xyz,
what ānew remote controllersā do you speak?
Waiheke,
WOW a beautiful place to live
I am in St. Louis, Missouri USA
IP6 & 7
I read it on a brochure somewhere?
Mind you there is the iPad
The iPad saved my bacon last night at an outside job.
Ran out of setup timeā¦ musicians were mucking around on stageā¦ had not sound checked anything.
Ipad in hand I was able to do it all from stage!
12k right. Phew!!!
Thank you A & H for a wonderful App.
The app is very useful eh Likes to chew battery though-- I use a battery pack on a cable in my pocket and keep it plugged in
I do have one question about the AUX fed subs-- i read about how changing the relative signal of the tops and sub mid performance changes the crossover point and phase and is to be avoidedā¦
I suspect that this only really matters in large systems ā to me its more important whether it sounds ok- but what is that about?
Changing the level of the subs is not going to effect phase of either the subs or the tops.
My suggestion is donāt worry about things like thisā¦ in other words, donāt sweat the small stuff
I am not suggesting to disregard the phase of all your speakers, but not to worry about changing the level of the subs. Absolutely everything has to be in phase, but it will not sound phasey or anything if you alter the level between subs and tops, just run the subs where they need to be for the music genre and audience.
By the way, for years JBL refused to use what I refer to as the industry standard for polarity for their speaker components,
they made no bones about it, if you bought a JBL 15 inch woofer, it had a warning tag on the speaker terminals that went something like thisā¦
positive voltage applied to the BLACK terminal creates a forward cone movement.
Of course this was completely opposite of just about every other speaker manufacturer in the world.
Red is always positiveā¦ so, since your JBL sub is, well , a JBL,
I would suggest calling JBL and ask them point blank, is your sub the same polarity as other brands or check it with a phase checker if you have one.
I will leave this thread alone shortly
But I just wanted to add for anyone still reading this saga ā I did some investigation on using the GEQ as a HPF to emulate the slope of a cross over. It is not designed for this and is not really great-- even if I drop all the sliders up to and including 80Hz it still passes a lot of lows (as low as 40Hz) to the tops-- this is because the GEQ only attenuates -12db max per band. It is better than nothing but a cross over with a 24db slope is better I think.
Incidentally I did this test by enabling the signal generator on one of the spare mix outputs and physically patching it back into one of the channels ā you can then send this incoming tone to the Main LR and Aux Sub mixes and have a listen to each and together as you sweep it. Very interesting to see what freq range your speakers do actually handle.
Oh- thanks Dan I just saw your post. Yep - Iām not really sweating it-- just curious really.
Um-- I donāt have a phase checker. I will see if I can get anything out of JBL. Meanwhile I guess I flip the phase switch and see which sounds best at the next show.
Looking forward to giving the AUX fed subs a whirl at a show. Looking like New Yearās eve unless something comes up before then.
Thanks once again man.
All the best.
Hi,
Reading this thread with interest as just about to try out the sub aux Send option this weekend.
Regards using the GEQ to simulate a HPF on the main LR output why not use the actual HPF available on each channel? More time to setup but surely more effective.
The Mix feed to the sub can be setup to ignore any HPF settings on the original input channels. I plan to do it that way and only use the LPF on my active subs. Iām only using a single sub to take a bit of the load off the tops so they will be running down into the same region as the Sub save maybe the last 30Hz (itās for Pub Rock so not super critical). My tops only have a 100Hz HPF and so need it to be more like 80Hzā¦
Also, when you setup a DCA to control the level of the LR and sub Mix, would you just put that fader into the Custom 1 layer say to the left of the main LR fader. You then ignore the main LR fader on the right hand side of the screen (unless you want to adjust the relative LR and sub levels)
Hi,
Glad the thread has been useful. Certainly was useful to me.
Regarding your comment
"ā¦ using the GEQ to simulate a HPF on the main LR output why not use the actual HPF available on each channel
Regarding the use of HPF on the input channels. You can do that and you should anyway on relevant channels because most 12" or 15" tops will go down pretty low and you donāt want rumble and plosives in the tops any more than you want them in the subs.
The idea of using the GEQ was to achieve the crossover but I think I get a better result when I use a crossover rather than the GEQ to high pass to the tops. The GEQ does not really shelve the signal all that well. Also I think I like the sound more when I use another crossover with the same slope and crossover frequency as the one feeding the tops on the AUX Sub channel to low pass to the subs. It is a wee bit more wiring and gear but I think it sounds better. This is think is the ārecommendedā way to do it.
I guess try what you are thinking. I think the recommended way is set up the AUX and with the same crossover slopes and balance the outputs of tops and sub then run all the aux sends at 0db (unity gain) with a DCA or group keeping the overall levels of sub and tops the same on changes to the master. This way it all works just like a normal - non aux - set up BUT with the advantage that the accumulated mud from vocal and other open mics with no useful low content physically canāt get to the subs because they are not routed to the subs.
This article explains quite well. https://totalproaudio.stevebunting.com/206/system-design/aux-fed-subs/
But it is what works with what you have thatās important eh.
Thanks for that link. Itās made me rethink a few things. Running the sub aux Send at unity gain is a great tip.
I think the HPF on the QU are 18dB/Oct so closer to the 24dB typically used in proper loudspeaker processors.
Iām really trying to avoid using a processor to keep the rig as simple as possibleā¦pub rock!
Andyoz,
āThe Mix feed to the sub can be setup to ignore any HPF settings on the original input channels.ā
This above statement is incorrect. The HPF is part of the input preamp and therefore any setting would effect that input regardless of where it is routed.
Also, I want to make sure that my posts above did NOT recommend the use of lowering low fequency graphic EQ faders as being the correct way to crossover tops and subs, as opposed to using a separate speaker processor/crossover if you donāt have a filter switch on your tops and an adjustable crossover frequency point on your powered subs. The separate processor will surely yeild better results, provided it is set up correctly. Using a graphic EQ instead is just a poor manās way of accomplishing something similar without a crossover but the slope of the GEQ faders is just not steep enough.
Waihekesoundieā¦
since you do not have usefull filters on your tops to eliminate lowe end, and a sub/s that do not have adjustable crossover point, you are choosing wisely by using your DBX processor, and it will provide better results.
I am honored and thrilled to have been part of this discussion and always enjoy helping when I canā¦ I just hope I didnāt step on any toes, besides ā¦
that hurts
Merry Christmas everyone!
TRUST YOUR EARS
Hi,
Regards this one:
āThe Mix feed to the sub can be setup to ignore any HPF settings on the original input channels.ā
I think the confusion had come from what was discussed in this thread. https://community.allen-heath.com/forums/topic/hpf-channel-settings
Band will only be using one mix feed and thatās for the sub (band doesnāt use monitors) so had planned to use the āPost Preampā setting in the āDirect Out Global Settingsā menu.
A bit of a fudge really.
Thanks guys,
Andy Oz-- Iām just learning but I think that perhaps if you donāt have outboard crossovers then maybe you are going to get a better result if you stick with stereo into your sub(s) and use the subās internal cross-over to route to the tops-- ie. forget Aux driven subs and control bass levels with EQ. This is what you do with the Aux fed subs anyway-- the only difference is that with the Aux approach you have only those channels with sub content physically routed to the sub.
I only say that based on messing around with a number of different configurations over the weekend over a variety of recorded material. My system sounds pretty good with a standard non-aux sub setup and sounded much less good with an aux fed sub config until I
a) used the same cross-over slopes for tops and subs (ie 2 crossover units- one on the LR mains and one on the Aux feed (mix 9/10) for sub;
b) Matched gain at the crossover point using a sinewave test tone
c) locked the topās and subās output masters together using a DCA on a fader in the custom layer.
Prior to this, the Aux fed approach sounded much more un-even and I was conscious of ābass vs topsā as opposed to an integrated sound presentation.
You havenāt said what you wanted to achieve by using Aux fed subs and maybe you can get what you want without above but thatās my 10cs. My stuff is pub rock as well but I often have DJs on the same night and it is this full range mastered material that shows up issues.
@DJDan
All good man-- thanks totally for your input.
Happy Christmas all.
Itās got a bit complicated as my tops (RCF TT25a ii) only have a 100Hz HPF whereas the sub I plan to order this week (RCF 8004) has LPF at either 80Hz or 120Hz. Iād prefer if the TT25ās had a 80Hz option. The rooms it will be used arenāt very big so the tops have plenty in reserve. So I was going to use the QU-SB HPF to mimic an 80Hz LPF or thereabouts. The rig will only used in a couple of different pubs and I should (hopefully) be able to the tops and sub to hopefully integrate well after a few trials, test tones and listening.
Feel like Iāve derailed thread a bit. Every days a school day for me anywayā¦
Very nice gear for āpub bandsā Prob worth the investment in a crossover,
You didnāt derail the thread-- it was an open discussion.
All the best.
we all learn from forums like thisā¦ this is one of the āgoodā things about the internet
or interwebs
Dan
Re. my post above, the QU has a 12dB/octave HPF and not 18dB.