Should I downgrade my subwoofer size

[almikel]

20 hours ago, mloutfie said:

I've simulate different multi sub using rew the current position is the most smooth response. So look like other than using minidsp my options are quite limited

I've never used the REW simulation...

 

23 hours ago, mloutfie said:

 

 

but looking at the graphs, the dip between 40-70 Hz moves in frequency for each of the curves - so could be speaker boundary interference response (SBIR) not modal - and the REW sim is likely only looking at modes - I still think it's worthwhile experimenting with placement...including lifting the subs off the floor to change the SBIR from the ceiling bounce (but potentially introducing floor bounce...always compromises)

You could run some sims using an SBIR calculator from an SNA member I haven't seen here in a long while - Ken Tripp

http://tripp.com.au/sbir.htm

 

cheers

Mike

[mloutfie]

Just doing measurement now with one more sub (REL T1) found one locally for decent price so why not. and I decided to sell the small T3 this will be the last chance I can do any sort of comparison

 

First Up Rel T7i black VS REL t3 purple on the corner T7i edges the t3 a bit it's slightly noticeably better punch but if you don't do side by side you won't be able to tell in a 4x5m room both on this setup do feel more punchy compared to the next setup

second setup middle of the room 1.7m from the wall and only 1m infront of listening possition (using this value because REW room simulator shows this is the most balanced freq response for the room) this is where the t7i shines much more balanced and still having loads of authority with bigger driver and more powerful amp sure it's less thumping than corner position but because of the the dip between the peak and though of the freq response it felt much more neutral the graph might be not that clear but in the corner t7i top to bottom dif difference is 25db where in centre position top to bottom difference is 20db

Now the new comer the T1 in the centre does have an even more balanced frequency response and also feel more natural and even though when spl matched at 80hz it is less punchy at the bottom end compared to t7i which kinda shows in the graph. To me this T1 sub is even better candidate to use with room correction because the swing in frequency is even better. It also has the most power reserve, driver size and cabinet size.

 

 

@jgunner this might interest you yesterday when I said t3 can't keep up with t7i I forgot to say in which condition, if the planned position in your room will be in the corner yes it can keep up with t7i just fine. not as good but not that far behind either

 

[jgunner]

@mloutfie cheers mate and thank you for sharing. i have done some research myself and sub placement like speaker placement is essential to get the best performance (in relation to where your listening position is)

 

so now big question for you? which one are you selling? 

 

[mloutfie]

@jgunner that would be decided after I get my DSP sorted. But raw power wise T1 which is the old version T9 just trumps t7i massively it's quite a bigger and heavier sub also this is the three of them together

 

 

Edited July 1, 2020 by mloutfie

[jgunner]

@mloutfie have you done any acoustic treatment to your room? it will make a big difference if you have not

Edited July 1, 2020 by jgunner

[mloutfie]

@jgunner the room was built planned as listening room/office. Wall and ceiling was insulated with soundshield bats and I've got absorbtion panel that handles 120hz and up. Planned to put some diffuser panel on the wall behind speaker. Was thinking to get bass trap but has never have problem with boomy bass. I think the insulation between the drywall and bricks handles that already

 

Edited July 1, 2020 by mloutfie

[Irek]

It's funny how people judge Rel T7i without ever hearing it in stereo system. 

Those who actually heard it are saying the same thing- excellent integration, musicality and speed.

I would add few more acoustic panels, behind speakers as well and place floor rugs in front of speakers. 

Also I would set the volume on subwoofer to my liking not to get best measurements.

If I have to replace T7i I would go with 2 x T5i.

[Cloth Ears]

On 28/06/2020 at 2:55 PM, mloutfie said:

but the dip at 40-80hz is still there. Is this just room effect that I can't ever beat? so no matter what I do I can't boost the dip? or is this something you fix with room treatment like bass trap?

On 28/06/2020 at 4:48 PM, almikel said:

individual sub placement can assist, as can individual EQ/delay control over each sub with something like Multi Sub Optimizer (MSO)

 

Looking at your sub placement, I'd be guessing that the 50Hz dip is something to do with your sub placement. Having them in pleasing symmetry (physically) is generally something that would cause your room to have bass hot-spots. Maybe you could try moving them around with your software to see if that helps with the dip (and a 15dB is quite large). Or, if you're fit, moving them around physically to see if the measurements change at all.

 

 

 

[mloutfie]

2 hours ago, Cloth Ears said:

Looking at your sub placement, I'd be guessing that the 50Hz dip is something to do with your sub placement. Having them in pleasing symmetry (physically) is generally something that would cause your room to have bass hot-spots. Maybe you could try moving them around with your software to see if that helps with the dip (and a 15dB is quite large). Or, if you're fit, moving them around physically to see if the measurements change at all.

 

on a 4x4.5 sized room the dip will always be there no matter the sub position from what I tried

[almikel]

On 01/07/2020 at 10:52 PM, mloutfie said:

Was thinking to get bass trap but has never have problem with boomy bass. I think the insulation between the drywall and bricks handles that already

gyprock with insulation behind soaks up low bass nicely - the gyprock acts as a membrane/pressure trap

 

On 02/07/2020 at 2:54 PM, mloutfie said:

on a 4x4.5 sized room the dip will always be there no matter the sub position from what I tried

with 2 subs and positioning only, you "should" be able to improve it...but it's laborious (shift/measure/repeat)...and be careful of your back !

 

Are any of those measurements with both subs running? Obviously the chief benefit of multiple subs is a smoother bass response at the listening position.

You can easily do your head in (and others in the household) with lots of measurements...and the interpretation of the curves is the hard bit  , but I'd be surprised if you couldn't make it better (and worse) with positioning of individual subs...the making it worse bit is part of the journey.

 

Good note taking is essential along the way - especially with 2 subs - pref add the notes to each REW measurement.

Measure each sub individually then combined...move a sub (not both at once) /repeat...as I said very laborious.

 

On 02/07/2020 at 12:50 PM, Cloth Ears said:

Having them in pleasing symmetry (physically) is generally something that would cause your room to have bass hot-spots

^this - symmetry is something you want to avoid with bass integration - but keep in mind you room will always have bass hot spots/cancellation spots - you just want to avoid them at the listening position/across the listening couch...it doesn't matter if the bass is boomy/cancelled outside of the listening zone. I have too much bass standing in front of my laptop compared to at the listening couch.

 

This is normal unless you live in a tent or an anechoic chamber - the goal being to get smooth bass at the listening position/across a listening couch...

 

...or much harder still, multiple rows in a home cinema, where 4 subs are often deployed, but the "critical seats" are usually prioritised, as you can't have "great bass" everywhere (the exception being a tent...everyone's listened to great bass at outdoor gigs...the bass doesn't change much as you move around as it's not being reflected off boundaries other than the ground).

 

For typical rooms with boundaries that bounce the bass around, something like Multi Sub Optimizer (MSO) takes a lot of the repetition/trial/error out of the process of achieving smooth bass at the listening position - but you need individual EQ/Delay control of each sub for MSO to work.

 

cheers

Mike

[TerryO]

On 01/07/2020 at 10:52 PM, mloutfie said:

@jgunner the room was built planned as listening room/office. Wall and ceiling was insulated with soundshield bats and I've got absorbtion panel that handles 120hz and up. Planned to put some diffuser panel on the wall behind speaker. Was thinking to get bass trap but has never have problem with boomy bass. I think the insulation between the drywall and bricks handles that already

 

Just because the room doesn’t sound boomy doesn’t mean it won’t benefit from bass traps and as others have said decent sized rugs in front of your speakers would be good..
 

The best money I have invested in my system that has given me the greatest improvements in sq and listening enjoyment has come from professional room measurement and treatment, not in upgrading gear. Without first treating the room properly all one ends up doing is chasing your tail,.

 

I actually sold my sub once I had the room treated properly. Good luck with it, some rooms can be a real pain to correct.

 

cheers,

Terry
 

Edited July 11, 2020 by TerryO

[mloutfie]

On 12/07/2020 at 4:09 AM, TerryO said:

Just because the room doesn’t sound boomy doesn’t mean it won’t benefit from bass traps and as others have said decent sized rugs in front of your speakers would be good..

It may benefit more from bass trap. But it is sort of treated already bass absorption is already handled by soundsheild insulation between the wall and gyprock and this insulation actually cover both wall and roof. Larger rug is already in place now but I think it need to be thicker

[almikel]

5 hours ago, mloutfie said:

It may benefit more from bass trap. But it is sort of treated already bass absorption is already handled by soundsheild insulation between the wall and gyprock and this insulation actually cover both wall and roof. Larger rug is already in place now but I think it need to be thicker

Only measurements will tell you if you have enough room treatment - and it's usually never enough to manage the bass response of the room, unless you live in a tent.

 

In lightly constructed rooms the low bass leaks out (great from an "in room" sound perspective - less great for your neighbours) - @mloutfie - you've got brick veneer, ie a rigid boundary behind the gyprock, so some bass will reflect back in - somewhat absorbed by travelling twice through the gyprock and the insulation...

5 hours ago, mloutfie said:

But it is sort of treated already bass absorption is already handled by soundsheild insulation between the wall and gyprock and this insulation actually cover both wall and roof.

You can only determine if "bass absorption is already handled" based on room measurements - IME it never is - and further bass management within the room is always required.

Waterfall plots are useful in this regard - seeking even decay below 250Hz is a target - but virtually impossible

 

Below 150Hz treatment gets way too big, and EQ is the best answer - but the more rigid your room, the less successful this approach will be - it's vastly easier to manage the "in room" bass in a lightly constructed room compared to a concrete bunker, where the bass bounces around forever.

 

Room bass management IMO should be the primary focus - get it right and everything else is a bonus

 

6 hours ago, mloutfie said:

Larger rug is already in place now but I think it need to be thicker

this is irrelevant for room bass control - if the treble is a dentist drill then you have other issues - otherwise ignore the rug and focus on managing room bass

 

cheers

Mike

[mloutfie]

@almikel this is the waterfall of my room what do you reckon?

 

[almikel]

On 13/07/2020 at 7:26 PM, mloutfie said:

@almikel this is the waterfall of my room what do you reckon?

it looks like it could do with some more broadband absorption.

Decay is reasonably even above 500Hz or so, which is likely where those panels are having an effect.

Below that the FR and the decay is more uneven.

 

Can you get away with more absorption targeting that 150Hz - 500Hz range?

As large and deep as possible - min 200mm deep, min 600mm wide, floor to ceiling, straddling corners is the sort of size required...several of those would clean up 150Hz - 500Hz substantially.

 

Below that I've found a few bands of parametric EQ cut helps a lot, and in some cases (where the room is "minimum phase"), some broad EQ boost can help also.

 

Just noticed your sig, "Vinyl, tubes and electrostatics nothing else to add now"...except room treatment

 

cheers

Mike

[mloutfie]

5 hours ago, almikel said:

required...several of those would clean up 150Hz - 500Hz substantially.

My panels does clean up 140hz and above. But I have reservation how much improvement with more panel considering I actually considering its quite good response above 150hz there is actually looks good to my eye.

 

5 hours ago, almikel said:

Just noticed your sig, "Vinyl, tubes and electrostatics nothing else to add now"...except room treatment

I would say I have spent quite a bit in room treatment

[POV]

On 02/07/2020 at 2:25 AM, Irek said:

It's funny how people judge Rel T7i without ever hearing it in stereo system. 

Those who actually heard it are saying the same thing- excellent integration, musicality and speed.

I would add few more acoustic panels, behind speakers as well and place floor rugs in front of speakers. 

Also I would set the volume on subwoofer to my liking not to get best measurements.

If I have to replace T7i I would go with 2 x T5i.

 

I find this is an interesting thing with subs, where folks seem to be more interested with manufacturer published specs than actual experience.  I don't know how many people have told me that SVS SB2000 is a better sub than the REL T7i,  so I bought one and tried it out for weeks in both my systems and found that on balance that the REL sounds superior in almost every way.  I do think folks get a bit caught up in the SPL at sub 30 hz but realistically I find that there's not much going on in most music below 35 hz (yes it exists in some classical and electronic music) and really people should worry about the performance of the sub between 35 hz and 80 hz.  It's in this range that the Rel kicks butt.

 

IMHO the Rel T7i is a verifiable bargain.

Edited July 18, 2020 by POV

[almikel]

 

On 18/07/2020 at 7:41 PM, mloutfie said:

My panels does clean up 140hz and above. But I have reservation how much improvement with more panel considering I actually considering its quite good response above 150hz there is actually looks good to my eye.

Maybe your current treatment is cleaning up 140Hz and above - it's difficult to determine with the variation in your frequency response above 120Hz or so...filling those dips may bring a bunch of those resonances forward in time...ie not as damped as the graph shows.

 

The panels visible in your room photos IME would have reducing effect below 500Hz or so - they are too small/thin to have much effect below that. 

 

On 18/07/2020 at 7:41 PM, mloutfie said:

I would say I have spent quite a bit in room treatment

Based on the photos I've seen of your room, and the measurements you've shared, you have no treatment targeted at bass frequencies.

My approach to room treatment is to target bass frequencies first - large/deep/gapped corner absorption treatment, using EQ below that (as treatment gets too large) to get the room's bass under control.

 

Along the way of managing the room's bass response you could easily find you've added too much absorption of the top end...usually avoided by treatment being placed straddling corners, but you can bring back treble into the room with slats/membranes etc in front of the absorption.

 

Once the room's bass is under control, you're >80% done with room treatment...and I'm happy to stop with any 80% solution.

 

Your current room treatment only absorbs the top end - IMO the wrong place to start with room treatment.

 

cheers

Mike

 

[almikel]

On 18/07/2020 at 10:33 PM, POV said:

really people should worry about the performance of the sub between 35 hz and 80 hz.

IMO people should focus on good integration between sub/mains/room - good integration is way more important than what sub...

 

[davewantsmoore]

On 01/07/2020 at 10:52 PM, mloutfie said:

Was thinking to get bass trap but has never have problem with boomy bass. I think the insulation between the drywall and bricks handles that already

No, that won't change the bass in room at all.

On 13/07/2020 at 12:40 PM, mloutfie said:

Larger rug is already in place now but I think it need to be thicker

A rug will do literally zero for the bass.   It is too thin (even a 50mm thick one) not absorbent enough ("flow resistance") and it is against a room boundary where the efficiency of abosrbtion drops to zero.

[davewantsmoore]

On 02/07/2020 at 12:50 PM, Cloth Ears said:

Looking at your sub placement, I'd be guessing that the 50Hz dip is something to do with your sub placement.

There's too much smoothing on the charts to tell.  With 1/12 octave smoothing, there is only 24 points making up the entire chart (2 octaves).

 

On 13/07/2020 at 7:26 PM, mloutfie said:

this is the waterfall of my room what do you reckon?

It looks great.

 

I might ask to see a little bit deeper (ie. down further in level in thewaterfall).... we can see about 45dB now... which is usually enough (so I'd probably be nit picking).

 

The uneven decay below 200Hz isn't caused by lack of absorbtion, as much as it's showing standing waves (modes) in your room, which are also responsible for the uneven frequency response.

 

If overall you are happy with the sound decay level (ie. it's not too "live") then I'd say do nothing.... find a good spot for your subwoofer(s), and then get something which can bass manage them (ie. cross them over to your mains, and EQ them to they are flat/to taste).

[davewantsmoore]

22 minutes ago, almikel said:

IMO people should focus on good integration between sub/mains/room - good integration is way more important than what sub...

 

Yes, the way the subs were being tested in this thread isn't very helpful.   The differences in their frequency response aren't inherent to the subwoofers (unless are bad/broken) it's juts part of where they are located and pointed.

 

They'll all sound identical when postioned identially, EQed flat, and not being over-driven.

[mloutfie]

On 23/07/2020 at 6:01 PM, davewantsmoore said:

If overall you are happy with the sound decay level (ie. it's not too "live") then I'd say do nothing.... find a good spot for your subwoofer(s), and then get something which can bass manage them (ie. cross them over to your mains, and EQ them to they are flat/to taste).

Yeah at the moment I'm happy with the setup since moving from t7i to T1 . In the end the answer for my question is actually going larger rather than smaller.

 

REL crossover has proven to be really good in my system better that my old sub and minidsp ever integrate with my speaker. I will investigate minidsp sub integration in the future when I have a better power supply for it. At the moment any power supply I try for it inject to much noise to the Yamaha ns1000m