If you have full range main speakers can a single sub be enough?

[blueone]

Really? It is the biggest sub they made at the time, but very old now. I have been using it to fill in below 23Hz iirc

Perhaps I'm confusing it with another REL sub I've encountered. Possible; senility might be setting in. If it goes to about 20Hz it should work.

 

[andreasmaaan]

I suppose what I am really asking is if anybody knows if there is something which is likely to be better than what I have now.
Devialet have just come up with a way of adding room compensation filters for its DSP engine, so I may well try that first.

Do you already have the capacity to take measurements and then set filters to manually implement room correction using whatever DSP you have now?

If I were you I would basically take measurements and then implement a manual correction filter that you can tweak both by measurement and by ear (the latter primarily to adjust overall bass level to your preference). Sorry if that's already obvious But I would tend to believe you will ultimately be able to do a more satisfactory job manually than by using any automated tool.

 

[Frank Dernie]

Do you already have the capacity to take measurements and then set filters to manually implement room correction using whatever DSP you have now?

If I were you I would basically take measurements and then implement a manual correction filter that you can tweak both by measurement and by ear (the latter primarily to adjust overall bass level to your preference). Sorry if that's already obvious But I would tend to believe you will ultimately be able to do a more satisfactory job manually than by using any automated tool.

Thanks, that is what I feared the things I have tried so far have not been better.
I have just downloaded REW and bought a UMIK-1 to try doing it manually but wanted to see if there was anything easier.
I am unlikely to persist if the dicking about eats up too much listening time.

 

[andreasmaaan]

Thanks, that is what I feared the things I have tried so far have not been better.
I have just downloaded REM and bought a UMIK-1 to try doing it manually but wanted to see if there was anything easier.
I am unlikely to persist if the dicking about eats up too much listening time.

Don't take my word for it, as I've always done these things manually. So I'm not the person to categorically say manual is always better. But it's my hunch

 

[Frank Dernie]

Perhaps I'm confusing it with another REL sub I've encountered. Possible; senility might be setting in. If it goes to about 20Hz it should work.

The output has not started to roll off at all by 20Hz, I have not measured lower. I have it set with a low pass at 22Hz to fill in below the main speakers but it can go up to 80Hz so with a bit of phase and amplitude manipulation I was hoping I could use them to fill in some hollows, the peaks are no more than 5dB anyway.

 

[Soniclife]

I am unlikely to persist if the dicking about eats up too much listening time.

The as is measurement of your system will show how much of an issue you have now, and how much you have to gain.
Are you intending to connect the two Rel using the high level or low level connections? The devialet DSP is not active on the sub out, but EQ on just the mains where they overlap in excess could work.

 

[FrantzM]

They will work well as long as you get them in phase with each other via time alignment or phase adjustments (not just a polarity adjustment). Anytime you have multiple speakers playing the same frequencies you have the same issues.

I have read this a few times here at ASR. The reality is: Not necessarily so... It is because it takes us, human beings a bit of time to process, bass signals. For example it takes us up to 50 ms to recognize a 50 Hz signal. In simple terms, down low, we are more susceptible to overall frequency response rather than to timing issues. Combining multiple subwoofers, involves getting smooth, FR, first and foremost. This is often achieved by playing with level, phase and placement or a combination of those, for a smooth response i-e to keep the variations of levels within reason, say + or - 5 dB before Equalization. In other terms a good steady state Frequency Response. EQ cleans it further ... It explains why a subwoofer in the back can work rather well. Of course if you can manage to time align it while having a smooth FR , the better but this is in no way a requirement wihtin certain limits.

Now to answer of Frank. It is possible. The only problem is that you would not have much control over the 2 full range speakers low bass response. It would be quite dependent on their placement in the room. Earl Geddes ( a luminary BTW in many things audio) postulates this as a good problem to have: Multiplicity of low frequency radiators in a room increase the likelihood of smooth bass response. The lone control would be a properly DSP'd subwoofer, more difficult than individually adjustable low frequency radiators ( aka subwoofers) but feasible.

 

[Jdunk54nl]

I have read this a few times here at ASR. The reality is: Not necessarily so... IT is because it takes us, human beings a bit of time to process, bass signals. For example it takes us up to 50 ms to recognize a 50 Hz signal. In simple terms down low, we are more susceptible to overall frequency response rather than timing issues. Combining multiple subwoofers, involves getting smooth, FR, first and foremost. This is often achieved by playing with level, phase and placement or a combination of those, for a smooth response i-e to keep the variations of levels within reason, say + or - 5 dB before Equalization. In other terms a good steady state Frequency Response. EQ cleans it further ... It explains why a subwoofer in the back can work rather well. Of course if you can manage to time align it while having a smooth FR , the better but this is in no way a requirement wihtin certain limits.

That would be my bad in my original response. I assumed the EQ will be taken care of to achieve the desired response and correct for room nodes, after that it comes down to getting them to getting them in phase with each other to constructively interfere instead of destructively interfere with each other.

To the OP, Audyssey or Dirac or ARC are the usual suspects in software outside of using REW, SMAART, etc and some sort of DSP that you can manually control (could be Audyssey, ARC, or dirac if you have sub correction capabilities with them, not all versions do)

 

[Absolute]

Yes, Dirac's new bass management will treat each source as a separate "sub" and EQ levels and phase to sum in the best possible manner.
I'm sure Trinnov has the same capability as they were responsible for implementing the Sound Field management system from JBL in the higher end Synthesis-line for a while. That is basically the same thing.

I don't know if multi-sub optimizer can do that, but could be. You'd need a minidsp capable of running the software.

 

[Frank Dernie]

The as is measurement of your system will show how much of an issue you have now, and how much you have to gain.
Are you intending to connect the two Rel using the high level or low level connections? The devialet DSP is not active on the sub out, but EQ on just the mains where they overlap in excess could work.

I only have one sub and two full range speakers.
I did run the sub from the Devialet sub output for years but now have it connected to the .1 channel of the surround sound system. Audyssey shows the uncorrected output rising at 20Hz, iirc the Studio goes down to 16Hz.
Neither the peaks nor the nulls are that bad since the speaker position was chosen for even bass response without the sub.
In fact Amir's favoured bass response in his Audyssey review is a higher level, and sounds it when I tried it - awful- than I get in room with my carefully positioned speakers. I thought by running a wider frequency range on the sub and some sort of DSP I may be able to fill in nulls.
I will have a play around with REW and Sweet Room to see what I can get.
I have really got an interest in this only because of the enthusiasm for room compensation in this forum, not because I am disatisfied by the SQ in my room (rather the reverse) and so far have not been impressed.

 

[March Audio]

As per the title, can a single sub added to a pair of full range speakers be set up to behave like a system with 3 subs, and if so which software would do it best?
I realise in such a system two of the "subs" will have a fixed location.

I assume the objective is to do the same job as multiple subs and cancel room modes?

In theory I dont see why not, but the low frequency response of the sub and the mains will need to be very similar.

 

[mitchco]

As per the title, can a single sub added to a pair of full range speakers be set up to behave like a system with 3 subs, and if so which software would do it best?
I realise in such a system two of the "subs" will have a fixed location.

Yes, Audiolense XO can do it and time align the sub(s) with mains so that the direct sound from all locations are arriving at your ears all at the same time. Ideally you would use Audiolense XO and employ digital XO between the mains and sub(s) crossed between room modes (Pro tip). The reward is the ultimate in transient response, in addition to accurate sound. I guarantee you will be impressed

 

[Frank Dernie]

Yes, Audiolense XO can do it and time align the sub(s) with mains so that the direct sound from all locations are arriving at your ears all at the same time. Ideally you would use Audiolense XO and employ digital XO between the mains and sub(s) crossed between room modes (Pro tip). The reward is the ultimate in transient response, in addition to accurate sound. I guarantee you will be impressed

I gave away my PC when I retired 10 years ago so no chance for Audiolense

 

[Deleted member 65]

Yes, Audiolense XO can do it and time align the sub(s) with mains so that the direct sound from all locations are arriving at your ears all at the same time. Ideally you would use Audiolense XO and employ digital XO between the mains and sub(s) crossed between room modes (Pro tip). The reward is the ultimate in transient response, in addition to accurate sound. I guarantee you will be impressed

In a similar situation as @Frank Dernie, single Elac Sub2050 with Automatic EQ and Evolution Acoustics MicroOne speakers.
Integrated Norma amp, sub connected to low level output. RME ADI-2 DAC. Playing Tidal thru Roon.
Can I use Audiolense in this setup?

 

[bigjacko]

The main speakers sometimes placed at places that have severe dips because of SBIR, that is what multiple sub placed at different location will fix. Room modes cannot be fixed by multiple subs, but adding "enough" sub you can still bring up the low frequency by brute force. If there is no severe dip and you are satisfied with the subbass you don't need a sub. Whether adding two or just one depends on what you want, better sub bass or good enough and cheaper.

 

[ernestcarl]

Thanks, that is what I feared the things I have tried so far have not been better.
I have just downloaded REW and bought a UMIK-1 to try doing it manually but wanted to see if there was anything easier.
I am unlikely to persist if the dicking about eats up too much listening time.

If you’re already happy with what you had before then you probably should just leave it be(?) Taking measurements with REW can be a fun and curious exercise though... just don’t try to think of it as a chore that has to be absolutely done for the sake of achieving some kind of theoretical state of audio perfection. Measurements can often look much worse than they really are to our own human ears and brain perceptually. I’ve been using REW and automated solutions a few years ago and sort of have on and off given it up several times. Only started delving back to learning more about it due to having a bit more free time. Of course, I’d rather enjoy listening to music than muck about with software and audio measurement gear — but the two activities aren’t necessarily mutually exclusive.

 

[sfdoddsy]

I've posed a similar question elsewhere here:

https://www.audiosciencereview.com/...ge-speakers-how-to-measure.16976/#post-550937

The problem is not doing it. Earl Geddes recommended running mains full range in his initial investigations into multi-subs.

And the problem is not bass depth. Mult-sub configurations do not need every sub to be able to play loud below 20Hz. The room response benefit is higher up in the modal region.

So, in my case, I have a sub capable of 20Hz bass at the levels I listen to (Rythmik) and I have speakers capable of playing flat to 35Hz at the levels I listen to.

The sticking point is bass management, measurement and EQ.

My amp (Anthem) normally has very good bass management and excellent EQ.

But it does not have a setting that allows me to run my mains full range and my sub to overlap (Double Bass or LFE+ on some prepros).

Fortunately, my Rythmik sub does thanks to seperate LFE and line inputs, plus the ability to adjust sub low pass when using the line inputs.

So I can run three bass sources in different positions, and adjust volume and phase.

But the problem is objectively getting it right, and then EQing to taste.

I normally measure speakers and subs individually, and then EQ each.

A multi-sub approach means you have measure everything together. I use REW which means a L+R setting.

And when doing such a measurement the overall response is indeed better than a simple 80Hz xover to the sub without any EQ.

But it is most definitely not as good as that same 80Hz crossover to the sub with Anthem's ARC EQ in action. Ditto, measuring each individual speaker 'full-range ' (ie main plus sub).

My room correction doesn't work on the multi-bass sources because it measures one source at a time.

I could theoretically add a MiniDSP into the chain to EQ the combined response after some REW measurements.

But it is added complication.

And I'm still not sure how to check whether doing this would be an actual improvement over Room EQ.

Mind you, I should probably have qualified all this by saying I'm trying to perfect one listening spot.

Mine.

My wife doesn't give a hoot what things sound like at the other end of the couch.

 

[blueone]

Thanks, that is what I feared the things I have tried so far have not been better.
I have just downloaded REW and bought a UMIK-1 to try doing it manually but wanted to see if there was anything easier.
I am unlikely to persist if the dicking about eats up too much listening time.

IMO, achieving bass octaves smoothness is always a PITA, so tighten your suspenders. One or more subs just gives you another set of variables to adjust to achieve smoothness. I've been measuring my systems and friends' systems for years, and everyone is always surprised by seeing their first set of listening seat response curves. A few friends have expressed disbelief, and I've shown them the in-room responses from Stereophile reviews, which are pretty terrible. (And I think Atkinson used something like 14 measurements that were averaged to produce even the terrible published graphs.) DSP EQ prior to amplification which "pre-distorts" the entire signal is the best solution for dealing with strong response peaks, but for dips we really need to move speakers and/or subwoofers around. To me, that's the big advantage of using even a single sub when in theory you shouldn't need one. You can position your L/R speakers for best imaging, try to position the sub(s) to fill in dips best, and then use a DSP-based correction system (Dirac, etc.) to smooth the entire response out. If you have the system in a room with a very large volume you might get by okay without the system-level DSP, but most people don't have very large rooms.

I know people who have contemplated placing four subs in their room, only to get dismayed at the reality of four line-level cables and four power cables to deal with. Or realizing a sub needs to go where some furniture already is. Or, my favorite, finding out the hard way that when the home was built the room they choose for their system has only one electrical circuit for the entire room, and their new HT system with a flock of subs exceeds the typical (in the US) 120v/15 amp breaker capacity.

 

[richard12511]

I think you really need to measure, and see exactly what's going on in the bass. Applying a generic house curve(like Amir did) is unlikely to sound good for your personal environment. Measure your speakers so you can see where your bass peaks and nulls are. You can then start knocking those peaks down, and maybe raise some of the nulls a couple db(depending on the cause). That should give you a more neutral sounding bass.

All of the room correction systems I've tried have never really worked great out of the box. To sound their best, they've all required me taking separate measurements and using those to inform the correction system and apply a custom house curve.

 

[Shike]

At what SPL?
At what frequency?
In what size room?

Just because a speaker can reach low in bass doesn't mean it can reach low + loud brining into question if it's really full range in practice. Xmax limits, compression, power handling, and distortion (to a degree) are real concerns. Hopefully you wouldn't hit them on a quality speaker under your usual listening conditions, but the point is it's not just a simple yes/no question.