Thanks vm for the input Pallas. Much of what you say resonates very clearly with me.
I too live where I need to take others (neighbours on both sides) into account. The archetypal 'house on the hill' it isnt!
So I definitely don't need significant levels, but I do want to experience smooth and quality bass. The end result of your 3 sub set up there, looks like it would meet my needs really well.
It's good to hear you had success with a similar Peerless based 'primary sub'. Right now I feel I'll likely stick with the SB12. I do have some additional thoughts that I'll put in another post shortly - would appreciate your input there too.
Am also planning to use miniDSP, I'll probably dial in the subs as best I can first, then choose a good fit from the miniDSP range.
Had a look Omholt thanks. If I added one of those to my setup here, the one thing thats guaranteed is that i'd be shot 😀
Earl,
That's a good guess for a 95 dB 1w 1m sensitivity B&C sealed sub at around 100 Hz, but I'd guess about 10-15 dB too high at 40 Hz, unless your room has a lot of LF "cabin gain".
Art
Understood Earl.
As I say in my reply to Pallas, I listen at what I think of as low levels, so am hoping will be well within overload/clip levels.
Separate amplifiers is something i'm keen to avoid for space/box reduction reasons, whilst recognising the irony in pursuing a multi sub approach 🙂
Appreciate that the proof of my sub selection will be in the playing!
It seems to me that as a single EQ is applied to all 3 subs as one '3 sub system', then this might be an argument for the 3 subs to be similar in output capability?
So in my specific case, instead of subs 2 & 3 being less capable, then they could be 2 additional SB12s and so spread the load? (There are some on sale currently from the SVS UK distribution chain)
Having said that, although the EQ is the same for all 3, from a headroom/clipping perspective, the onboard amp gain setting is relevant - right?
If the sub amps are set so there's more output from sub 1, than from subs 2& 3, then lower spec subs could be used without necessarily overloading them, as per Pallas's set up in his previous post?
Last edited:
Thanks Octavia.
Not sure they're available yet in Europe/UK - can't see them on the Elac site.
Not to add to the complications ...but... has anyone tried an open baffle sub like MJK's H frame subwoofers in multiples? It seems the open H frames don't load the room in the same way and may be more acceptable for those of us with next wall neighbors.
I have never done a situation where all the subs had the same EQ. I see no reason not to do this as it is so easy to do.
In my setups, there is always one sub that is "master". This sub is usually setup first and blended with the mains as best as can. Then the second sub is added and adjusted for smoothest response as a combination with everything else. This sub invariably has lower gain. Finally a last sub, usually the one closet the listener. The same thing is done and again I usually find this sub the lowest output of the bunch.
How one would setup 3 identical subs all with the same EQ, I really don't know. I don't think that it would work well enough to justify not EQ each sub separately. Remember "EQ" means gain, phase, even delay sometimes, everything that gets manipulated.
let me clarify what I meant sorry.
use the individual controls on each of the 3 subs to 'best' fit with the goal of smooth response. As you say this will mean, adjusting gain, phase and roll off controls on each individual sub.
When I used the phrase EQ above, I meant the use of something like miniDSP to remove any peaks/troughs that remain, after those adjustments, so long as they're not nulls.
The reason I said explicitly that this would be done for all 3 together, was a discussion I'd had on the miniDSP site that had suggested that was their standard approach for a multi sub set up.
Would you agree, or suggest that each sub be fed a differently EQ'd input?
Late here/typing on phone so might need to review tomorrow!
I think that the whole multi-sub idea may be compromised if the EQ were common among the subs. Its the individual nature of the problem that gives you enough degrees of freedom to conquer any situation. With three common subs that happening would be pure luck. Individual subs is complicated, but it is the ideal and if you can do it, and you can with a MiniDSP then you absolutely should take the time and trouble to do it right.
Right. And so there's good reason to go heterogeneous in getting different subs and matching locations and EQ to get it best. With the identical units, you're just asking to multiply their common shortcomings instead of averaging them out.*
Ben
* yes, I know how that kind unsymmetry must pain some people
Ben
* yes, I know how that kind unsymmetry must pain some people
Attachments
Understood that treating the 3 subs as a system removes their independence which is key to the overall approach. In terms of the practical implementation of the 3 channel EQ, I'm a bit unclear. For example;
If I adjust the controls on sub 1 and integrate it with the mains as best I can, then use a miniDSP channel to EQ lets say a prominent 10 dB peak at 40Hz and a broader 6dB dip at 90Hz.
(I don't EQ the mains as Marcus's write up excludes them - presumably as they're the base response that our combined subwoofer signal is to be integrated into.)
If I then integrate sub 2 with sub1 + mains as best I can, it may be that the 40Hz peak or 90Hz dip would have been 'useful' in compensating for some limitation of sub 2 response. But since they're no longer there…
Perhaps the process needs to be iterative in this area, i.e. if you spot that an earlier EQ can be reduced / amended in some way to help with a later stage, then you need to step back to that stage and then revisit any subsequent work?
Alternatively integrate all subs without EQ, then use the channel independent EQ, to address the remaining peaks / dips. How then to choose the 'correct' channel of the 3 to address a given peak / dip?
I see the ability to use different subs as an advantage - invest more in the primary with a focus on it's performance parameters, potentially at the expense of domestic acceptability.
Accepting that sub 3 and to a lesser extent sub 2 can be less capable, then more focus can be given to 'looks' - assuming this matters to you (or to someone else who's opinion counts)
In fact as I think about it, it may be that in my case I initially attempt to use my SB12 as the primary. If it proves to be lacking in performance, I can 'downgrade' it to sub 2 or 3 and get a more capable sub that takes the primary role.
In some parts of the UK, you can rent a room not much bigger than that sub for several hundred of £s / month!
You are correct that the ideal would be to iterate all the parameters of all the sources to find the best solution. That is what my computer program does, but that is not public domain (at least not yet.) But without that capability it is best to start with one (no EQ or HP on mains) and then add others iterating to your hearts content, until you are satisfied or exhausted.
Ok thanks Earl - will go ahead with the iterative approach.
I look forward to the launch of your computer program too.
Just some links.
Hi Y'all,
Nothing new, but the link in Post #5 doesn't seem to work reliably, so I typed "markus multisub geddes" into Google in Google Chrome, and the first link that came up is:
https://www.google.com/?gws_rd=ssl#q=markus+multisub+geddes
and it works in Chrome (but not IE8), the wonders never seize. Another link that right now seems to work (in Chrome and IE8, old Win XL laptop) is this one:
Serious Audio: Two Great Articles on Multiple Subwoofers by Dr. Earl Geddes
Grab 'em while they work. 🙂
Regards,
Hi Y'all,
Nothing new, but the link in Post #5 doesn't seem to work reliably, so I typed "markus multisub geddes" into Google in Google Chrome, and the first link that came up is:
https://www.google.com/?gws_rd=ssl#q=markus+multisub+geddes
and it works in Chrome (but not IE8), the wonders never seize. Another link that right now seems to work (in Chrome and IE8, old Win XL laptop) is this one:
Serious Audio: Two Great Articles on Multiple Subwoofers by Dr. Earl Geddes
Grab 'em while they work. 🙂
Regards,
I've been running this multiple sub approach for a while now with a stereo setup and no separate EQ on the subs other than the cutoff/level/polarity settings on the subs' plate amps. I'm looking to jump to multi channel. I noticed the newer DCX's have 3 inputs while it seems some of the older ones only had two. Looking through the DCX manual you can set up a SUM signal based on two of the three inputs. It's not clear to me but it seems like it's possible to route the SUM signal to three of the outputs and route the third input to the other three outputs. Anyone know if this routing is possible? Most subwoofers with plate amps have separate left and right inputs that are summed so you could then get a sum of all three channels if that's the case right?
Dan