Home Theatre Speakers - do you really need a sub, if you have full range?

[dlaloum]

Been giving this some thought....

Many lower end subs have a frequency range and loudness capability that very closely matches the bottom end of full range speakers.

If you have 2 full range front speakers (L & R) you therefore effectively have 2 subs

If you have additionally 2 full range surround speakers - you now have 4 subs... with a 7.x setup you would have 6 subs in the room

If your setup allows for full range speakers, are we better off seeking out full range, rather than taking the now "normal" aproach of a Sub / Satellite configuration?

My current speakers:

Anthony Gallo Reference 3.2 L / R
Anthony Gallo Reference AV C
Anthony Gallo Nucleus Micro surrounds/heights
Anthony Gallo TR1 10" Sub

Note: the TR1 was designed to match with Gallo satellites to make a full range music system, not so much for HT, it purportedly uses the same driver as used in the full range reference 3.2 and has the same low frequency -3db point (24Hz) - so one can argue, that this is not a SubWoofer per-se, but a seperate woofer.
This type of configuration and capability seems to be quite common (Kube 8b lower limit 34hz, Kube 10b lower limit 24Hz, Klipsch R100SW lower limit 32Hz, etc...)

Given the many advantages of a multi-woofer multi position configuration - and the benefits to bass SPL of having 4 or 6 woofers - should we be trying for full range speakers, rather than trying to integrate more subs?

 

[ernestcarl]

What about the dedicated LFE channel?

I know some AV processors can be set to redirect it to some select channel(s) — usually the front LRC. Theres a way to do this manually in a HTPC with JRiver as well… However, the best placement for the mains doesn’t always hold true for low frequency bass.

 

[dlaloum]

What about the dedicated LFE channel?

I know some AV processors can be set to redirect it to some select channel(s) — usually the front LRC. Theres a way to do this manually in a HTPC with JRiver as well… However, the best placement for the mains doesn’t always hold true for low frequency bass.

Quite - the LFE can by on most AVR's be redirected to the mains... I am not sure whether strictly speaking that means all the main layer speakers, or L / C / R or L/R.

Dirac have been working on a piece of software to "tune" all of a rooms speakers as a single system - rather than the current speaker by speaker EQ... something similar to what is currently being done in software for multi-sub configurations. - So there is a software answer to that question coming...soon (?).

The hardware based answer is different - the speakers would be positioned for optimal midrange imaging - which is unlikely to be optimal for bass - on the other hand, the more bass driver locations you have the more even the overall room response will end up - so they may not be optimal, but they are still likely to be better... (better vs best - the battle continues!)

This article discusses the new software - rumours were that it was due for release in January 2022.... but we are all still waiting! - I believe the intent is to first launch it on AVR's in partnership with one or more of the hardware manufacturers... (Onkyo?)

The Arrival of Spatial Room Correction Technology - Dirac

This article describes an approach to the challenge of applying DSP room correction to complex multichannel setups, intended for immersive audio reproduction. Instead of one...

www.dirac.com

 

[ernestcarl]

Quite - the LFE can by on most AVR's be redirected to the mains... I am not sure whether strictly speaking that means all the main layer speakers, or L / C / R or L/R.

You're probably right. I have never used an AVR so don't know how common this feature really is...

I think it may be recommended to add either only in one or a combination of the front mains to avoid any potential phase induced cancellation/issues. *Though, an additional reason may be surround channels also usually have less bass headroom.

In my case, there's no reason to ditch the subwoofer, and so my experiments were only at extending the LFE signal higher up to make it more or less "full-range" for MCH A/B concert disk comparisons or LFE soloing purposes. I haven't found a need for it anymore so just leave it disabled.

I do not quite remember the exact SPL level gain I used prior, but it should vary depending on number of channels used.

 

[ppataki]

Most people in this forum will tell you to use at least 3 subs with MSO (Multi Sub Optimizer)
That will allow you to even out the frequency response in your room and would provide less distortion and higher SPL in the sub-bass range

That is all true, however if I were you I would first make some measurements to see how bad the situation is
It might not be that bad at all - it all depends on your room and the placement of the speakers in your room

In my experience, if you have enough driver surface and if you can correct some dips with EQ (again, most people will advise you not to do, but I would say to try it first and see/hear the results) you will not need a sub (or subs)

Really cool thing is that these days one can simply run measurements and decide based on those which direction to proceed + one can try many different things and some of those might actually work out well

Don't be afraid to experiment since that will yield the best learning curve possible
Just my 2 cents

 

[FeddyLost]

Given the many advantages of a multi-woofer multi position configuration - and the benefits to bass SPL of having 4 or 6 woofers - should we be trying for full range speakers, rather than trying to integrate more subs?

If everything would be free, yes.
But:
1) good placement for imaging is often bad for bass (see multi-sub arrays and their placement)
2) bigger and more expensive speakers are required
3) more powerful fullrange amps of good quality are required
4) really good DRC for proper integration of this mishmash is required
5) speaker design will be really .. industrial with at least 10" woofers and WAF will be lower

So, this concept .. will not have big commercial success at least.

 

[Peluvius]

I believe so, yes. The sub/s provide playback of LFE along with placement flexibility not possible if only fronts are present. Placement of the sub is one of the most critical aspects of reproduction in the room. The only real complication I have found is the integration of the sub with the rest of the speaker system.

 

[alex-z]

Trying to run without a subwoofer for home theatre is silly.

The LFE channel is inherently 10dB higher than all other channels, and can have content below 20Hz. Your speakers would need to be -3dB at roughly 15Hz to match good quality subwoofers, and be capable of 115dB at the listening position to hit reference level.

Ignoring the fact that virtually no speakers are actually that capable, including yours, it is still a bad idea. If the woofers in your speakers are having to work that hard, it will drive up multi-tone distortion through the mid-bass and mid-range regions, worsening overall sound quality.

Because most AV receivers lack more than 2 subwoofer outputs, an external DSP solution is an easy route. You can blend 4 or even 8 subwoofers into a seamless response, then let Dirac, or other room correction software treat them as a single simplified sub. Software like Multi-Sub Optimizer exists for this purpose.

Multi-Sub Optimizer Freeware for Multiple Subwoofers

Optimize bass performance of multiple-subwoofer audio systems. Reduce seat-to-seat frequency response variations.

www.andyc.diy-audio-engineering.org

 

[Peluvius]

Trying to run without a subwoofer for home theatre is silly.

The LFE channel is inherently 10dB higher than all other channels, and can have content below 20Hz. Your speakers would need to have an -3dB of roughly 15Hz to match good quality subwoofers, and be capable of 115dB at the listening position to hit reference level.

Ignoring the fact that virtually no speakers are actually that capable, including yours, it is still a bad idea. If the woofers in your speakers are having to work that hard, it will drive up multi-tone distortion through the mid-bass and mid-range regions, worsening overall sound quality.

Because most AV receivers lack more than 2 subwoofer outputs, an external DSP solution is an easy route. You can blend 4 or even 8 subwoofers into a seamless response, then let Dirac, or other room correction software treat them as a single simplified sub. Software like Multi-Sub Optimizer exists for this purpose.

Multi-Sub Optimizer Freeware for Multiple Subwoofers

Optimize bass performance of multiple-subwoofer audio systems. Reduce seat-to-seat frequency response variations.

www.andyc.diy-audio-engineering.org

The suggestion that reference loudness is important in a domestic environment is questionable. I would love to hear how many of us actually listen or watch at reference levels, it is offensively loud to my ear.

 

[Frgirard]

The suggestion that reference loudness is important in a domestic environment is questionable. I would love to hear how many of us actually listen or watch at reference levels, it is offensively loud to my ear.

The lfe is cut at 120 Hz. The mixing choice determines if the lfe channel can be dispatched on the L/R.

 

[polmuaddib]

Your speakers would need to be -3dB at roughly 15Hz to match good quality subwoofers

Not many subs reach that low. In fact, they are usually very big and expensive.
And for the best possible result, you are right. That's the way to go.
BUT, I don't think that was OP's question and he made it clear that he might not be looking for the best possible outcome.
His premise is sound in my opinion, because usual subwoofers reach only at 30hz or so. And many tower speakers reach that low also.
So, if you have 5 or 7 full range speakers arranged around the MLP, you should be able to get reasonable LFE channel response. I think...
Should be an option for this situation in AVR/AVPs...

 

[Peluvius]

The lfe is cut at 120 Hz. The mixing choice determines if the lfe channel can be dispatched on the L/R.

I do not believe even the most capable of floorstanders will play clean LFE at the same time as the rest of the soundtrack without compromise.

 

[Frgirard]

Not many subs reach that low. In fact, they are usually very big and expensive.
And for the best possible result, you are right. That's the way to go.
BUT, I don't think that was OP's question and he made it clear that he might not be looking for the best possible outcome.
His premise is sound in my opinion, because usual subwoofers reach only at 30hz or so. And many tower speakers reach that low also.
So, if you have 5 or 7 full range speakers arranged around the MLP, you should be able to get reasonable LFE channel response. I think...
Should be an option for this situation in AVR/AVPs...

Operation at the limit.of the sub at 30 Hz impacting 200 Hz or higher?
Same thing for the full range impacting 200Hz or higher?

 

[Sancus]

Quite - the LFE can by on most AVR's be redirected to the mains... I am not sure whether strictly speaking that means all the main layer speakers, or L / C / R or L/R.

In what way can the LFE be redirected to the mains? This isn't possible on Denon AVRs at least, not sure about others. Sometimes the downmix will include the LFE, sometimes not, it depends on codec and implementation, but the user has no control over it.

 

[dlaloum]

Most people in this forum will tell you to use at least 3 subs with MSO (Multi Sub Optimizer)
That will allow you to even out the frequency response in your room and would provide less distortion and higher SPL in the sub-bass range

That is all true, however if I were you I would first make some measurements to see how bad the situation is
It might not be that bad at all - it all depends on your room and the placement of the speakers in your room

In my experience, if you have enough driver surface and if you can correct some dips with EQ (again, most people will advise you not to do, but I would say to try it first and see/hear the results) you will not need a sub (or subs)

Really cool thing is that these days one can simply run measurements and decide based on those which direction to proceed + one can try many different things and some of those might actually work out well

Don't be afraid to experiment since that will yield the best learning curve possible
Just my 2 cents

Indeed - many will suggest that a multi-sub setup is optimal.

But the key with resolving harmonic peaks and troughs - is having bass drivers in multiple, non room-symmetrical (ie: not in positions that would generate the same harmonic peaks and troughs) positions.

Typically our listening rooms are not sufficiently symmetrical for the speaker positions to be a bass problem - and having 4 woofers would result, without any EQ, in a more even bass response in any case (on average!)

In terms of SPL - 4 woofers will inherently provide +3db per additional woofer beyond the 1st... net result +9db with just full range speakers!

 

[dlaloum]

If everything would be free, yes.
But:
1) good placement for imaging is often bad for bass (see multi-sub arrays and their placement)
2) bigger and more expensive speakers are required
3) more powerful fullrange amps of good quality are required
4) really good DRC for proper integration of this mishmash is required
5) speaker design will be really .. industrial with at least 10" woofers and WAF will be lower

So, this concept .. will not have big commercial success at least.

Multi woofer, provides better result than single sub... placement - well still, multiple will be more even than single (Better vs Best)

Speakers would need to be full range - so additional speaker cost - but you are saving the cost of subwoofers!

Amps - the subwoofers come with amps built in - which are a cost built in to their price! - improve the main system instead?

DRC - yes... I think this is key - and I don't know how well current DRC with its focus on Sub/Satellite configurations, would deal with it - hence it may require the new software from Dirac...

Speaker design.... yep lifestyle issues can be an issue - along with WAF - but you are talking to someone who once had an all Electrostatic full range surround setup.... which sounded very good indeed!!

 

[dlaloum]

Trying to run without a subwoofer for home theatre is silly.

The LFE channel is inherently 10dB higher than all other channels, and can have content below 20Hz. Your speakers would need to be -3dB at roughly 15Hz to match good quality subwoofers, and be capable of 115dB at the listening position to hit reference level.

Ignoring the fact that virtually no speakers are actually that capable, including yours, it is still a bad idea. If the woofers in your speakers are having to work that hard, it will drive up multi-tone distortion through the mid-bass and mid-range regions, worsening overall sound quality.

Because most AV receivers lack more than 2 subwoofer outputs, an external DSP solution is an easy route. You can blend 4 or even 8 subwoofers into a seamless response, then let Dirac, or other room correction software treat them as a single simplified sub. Software like Multi-Sub Optimizer exists for this purpose.

Multi-Sub Optimizer Freeware for Multiple Subwoofers

Optimize bass performance of multiple-subwoofer audio systems. Reduce seat-to-seat frequency response variations.

www.andyc.diy-audio-engineering.org

each additional woofer increase the SPL by 3db - having an additional 3 provides a 9db boost - so close to the +10db in the spec, that it might as well be the same!

With regards to 15Hz.... probably 80%+ of the sub sold on the market, don't even get close to achieving 20Hz let alone 15Hz !! Hence my examples in the OP (Kube 8b lower limit 34hz, Kube 10b lower limit 24Hz, Klipsch R100SW lower limit 32Hz, etc...).

Yes one or more dedicated subs would be required to extend below circa 24Hz (which is pretty much where most 10" subs are at based on a cursory inspection of main brands subs... ).

But given where the main massmarket sub options are at, and what their specifications indicate.... it doesn't seem to me that using Full range speakers would be any worse - and depending on the speakers, may well be substantially better!

And current AVR's all have EQ for the main channels - even if they only have a single LFE channel - so tuning would be easier.

 

[dlaloum]

I do not believe even the most capable of floorstanders will play clean LFE at the same time as the rest of the soundtrack without compromise.

With 3 additional channels working on the LFE - you have an additional 9db of SPL without additional pressure (ie: with the speakers running at their base levels, and not needing to overdrive woofers)

If you run 6 full range (ie 7.x) - then you would have an additional 15db SPL in the bass.... - so that would indicate there should be no compromise (assuming your full range speakers can provide bass quality equivalent to the more critical midrange... so yeah they need to be halfway decent)

 

[dlaloum]

Operation at the limit.of the sub at 30 Hz impacting 200 Hz or higher?
Same thing for the full range impacting 200Hz or higher?

Perhaps - but does that simply indicate a flawed full range speaker?

Or are we talking about amp strain, then impacting the rest of the frequency range - a common issue - but also indicative of an underspecced amp for the capability of the main speakers!

 

[Dal1as]

I guess if you wanted a really bad sounding mono 7 speaker system you could make it work. Otherwise just a sonic mess.

So no.