New Theatre Room Build 2020

[Guest niterida]

No build thread or photos of my build unfortunately.

I bought 2nd hand car subs. Just try and get the subs with the highest xmax and mms specs that you can find/afford.

Since the platform is sitting on isolators there is reduced transmission direclty in to the floor structure.

You can use tennis balls, wheel barrow tubes etc instead of proper (expensive) isolators, but whatever you use has to be really really wobbly.

You do get SPL form them but it is reduced and you can turn the sub output down at night and still feel it through the couch.

[hopefullguy]

hmm so this replaces bass shakers in effect. can it be retrofitted to a 13" riser i already have? sorry i looked at avs link and lately all this stuff goes over my head.

 

what powers it? my shakers run off an old yammy avr.

[almikel]

Hi Justin,

 

Just an idea - you could turn your study/alcove into an effective "bass" trap with some absorption where you have the curtain.

 

Not many people have the opportunity to have an absorption trap big enough, with enough air gap behind to operate at low frequencies - your alcove is perfect.

 

You could even mount the absorption on wheels like you've done with the AT screen (nice idea BTW  ).

 

Let's just say you had a big absorption panel mounted on wheels to close off the alcove, say 200mm deep.

 

Polymax XHD would likely be easiest, as it's nearly self supporting, and a light frame may be sufficient.

Better would be ordinary fluffy, but you'd need something to keep it in place, say slats in a 1D BAD diffusion pattern, or black builders plastic on both sides (or both).

 

Here's the modelling for 200mm depth of Polymax HXD vs fluffy closing off that alcove with 1800mm of air gap behind using the porous absorber calculator http://www.acousticmodelling.com/porous.php

Blue is Polymax XHD (gas flow resistivity of approx 12000), green is ordinary fluffy poly insulation (gas flow resistivity of approx 5000)

Adding builders plastic (ie a membrane) on either side of the fluffy option for the mechanical reason of keeping the fluffy in place could improve the bass performance, and not absorb treble...useful if wheeling your trap out of the way to get access to the study, but it remains in your listening room (eg straddling the rear right corner behind the couch.

 

The first thing I thought when looking at your original post was that alcove could make a "proper" bass trap, but how to keep the space usable?...?

...After seeing your inventive mounting of your AT screen...you had the answer...

 

cheers

Mike

[Guest niterida]

1 hour ago, hopefullguy said:

hmm so this replaces bass shakers in effect. can it be retrofitted to a 13" riser i already have? sorry i looked at avs link and lately all this stuff goes over my head.

 

what powers it? my shakers run off an old yammy avr.

Yes it will replace your shakers - although the Tactile Repsonse (TR) loonies on AVSForum run these as well as shakers and buttkickers !!

 

You don't need much power (60-80w depending on our drivers) so an AVR may suffice.

 

For an existing riser just mount the drivers facing up (you may have to use spacers if the depth of the driver exceeds the depth of the riser), Get 4 tennis balls and glue them to the corners of the riser, inflate some bicycle tubes to a few psi only (fat tubes work better)  and place them around the drivers (individually or in groups depending on the size of the driver and tubes), put a sheet of ply on the tubes and your seating on top of that.

[almikel]

 

On 10/12/2020 at 5:14 PM, niterida said:

The latest version is a riser platform with the subs mounted in it facing up, bike tubes around the subs and a platform floating on the tubes with your seats on the platform - gives the ultimate response but adds a bit of height.

The simpler version is a sheet of ply with the subs mounted facing down, tubes between the platform and the floor and then the seats on top of the platform - much lower and more discreet and for normal people probably good enough.

Essentially home made bass shakers - very cool

14 hours ago, OzJustin said:

So these riser setups really don't transmit the bass through the floor, walls etc into the rest of the house the way a normal sub does?

My SVS sub has the sound isolation feet but you can still very much feel the bass from our ground floor theatre in the upstairs rooms of the house.

The drivers are decoupled from the house structure, and like bass shakers are designed to transmit physical/tactile vibrations to the listing seat rather than acoustic sound waves.

 

14 hours ago, OzJustin said:

So these riser setups really don't transmit the bass through the floor, walls etc into the rest of the house the way a normal sub does?

My SVS sub has the sound isolation feet but you can still very much feel the bass from our ground floor theatre in the upstairs rooms of the house.

Your SVS sub is producing bass acoustically - and that bass will transmit widely through the rest of the house.

The solution Ken is discussing transmits vibrations physically to the listening couch to produce a tactile effect.

If the drivers are mounted as open baffle (ie they produce no change to the overall pressure in the room), and the baffle isn't connected to the structure of the house, then there won't be much "acoustic" bass created inside the room, just a tactile vibration at the listening couch.

 

cheers

Mike 

 

[OzJustin]

On 23/12/2020 at 1:05 PM, almikel said:

Hi Justin,

 

Just an idea - you could turn your study/alcove into an effective "bass" trap with some absorption where you have the curtain.

 

Not many people have the opportunity to have an absorption trap big enough, with enough air gap behind to operate at low frequencies - your alcove is perfect.

 

You could even mount the absorption on wheels like you've done with the AT screen (nice idea BTW  ).

 

Let's just say you had a big absorption panel mounted on wheels to close off the alcove, say 200mm deep.

 

Polymax XHD would likely be easiest, as it's nearly self supporting, and a light frame may be sufficient.

Better would be ordinary fluffy, but you'd need something to keep it in place, say slats in a 1D BAD diffusion pattern, or black builders plastic on both sides (or both).

 

Here's the modelling for 200mm depth of Polymax HXD vs fluffy closing off that alcove with 1800mm of air gap behind using the porous absorber calculator http://www.acousticmodelling.com/porous.php

Blue is Polymax XHD (gas flow resistivity of approx 12000), green is ordinary fluffy poly insulation (gas flow resistivity of approx 5000)

Adding builders plastic (ie a membrane) on either side of the fluffy option for the mechanical reason of keeping the fluffy in place could improve the bass performance, and not absorb treble...useful if wheeling your trap out of the way to get access to the study, but it remains in your listening room (eg straddling the rear right corner behind the couch.

 

The first thing I thought when looking at your original post was that alcove could make a "proper" bass trap, but how to keep the space usable?...?

...After seeing your inventive mounting of your AT screen...you had the answer...

 

cheers

Mike

Hi Mike,

 

Apologies, I think I overlooked your Dec 2020 post until now. I think your design suggestions are going a little over my head. So you're suggesting I create a moveable false wall to seal the gap in my study alcove and have one or more subs pointing out of the wall into the main listening room? That would be roughly 2m wide x 2.2m tall so sounds a bit beyond my humble multi-purpose space. Forgive my ignorance but what are the benefits of going such a large design? Wouldn't the sub placement be an issue (even with elaborate bass management/EQ)?

[almikel]

On 07/02/2021 at 9:15 PM, OzJustin said:

So you're suggesting I create a moveable false wall to seal the gap in my study alcove

No requirement to "seal" anything...just build a movable panel of say 200mm deep "fluffy" absorption to place across the alcove the same size as the alcove opening.

"Bass traps" using absorption need to be large with a decent air gap to work at low frequencies - your alcove provides an opportunity for an air gap deep enough for an absorption trap to actually be effective <150Hz or so.

 

On 07/02/2021 at 9:15 PM, OzJustin said:

and have one or more subs pointing out of the wall into the main listening room?

My post above made no reference to sub placement - place them as needed for the smoothest "in room" bass

 

cheers

Mike

[almikel]

On 07/02/2021 at 9:15 PM, OzJustin said:

Forgive my ignorance but what are the benefits of going such a large design?

for absorption to be effective at low frequencies they need to be large/deep, with the absorption placed where air particle velocity is highest.

Absorption works based on slowing down air particle velocity - which is highest at wavelength/4 from a rigid boundary.

At low frequencies (say <150Hz), wavelengths are long - Velocity = frequency x wavelength, where velocity is the speed of sound (343m/s).

• Traps need to be big, otherwise the long wavelengths just go around them.
• Traps need to be deep to slow the air particles
• Traps need to be placed where air particle velocity is high, which requires large air gaps to place the trap closest to wavelength/4 from a boundary if wanting to absorb lower frequencies

cheers

Mike

[OzJustin]

Hi all

 

I wanted to provide a further update on my theatre room. I've recently added some automation (via a universal remote) and made the jump up to a Dolby Atmos setup - now running a 7.1.4 arrangement.

 

First up, I was having issues with my stock remotes being unable to penetrate my blockout curtains to control my receiver, UHD player etc in the rack located behind the curtains. After a bit of research, and some good Xmas sales, I ended up purchasing a Logitech Harmony Campanion. This utilises a universal remote that talks to a wifi based hub which then also sends a signal out via a Logitech blaster to IR etc devices. This allowed me to place the Logitech hub on my front right speaker in the main theatre room and then run the blaster behind the curtain pointed into my study room and gear rack (see photos below). This was a good option to solve my curtain issue. It is a nice setup although I find the Logitech software and having to configure devices based on three 'activities' very restrictive and confusing. Perhaps it's just me being new to the Logitech Harmony range of universal remotes but it took me a good while to get three basic activities configured and I'm still finding the options and button assignments very limiting. I can at least turn on/turn off my projector, receiver and Panasonic UHD player with a single button press. Some of the custom button assignments e.g. particular buttons while in Netflix, controlling certain options in the receiver, and ending an activity without it shutting down devices etc have been troublesome though. I find I'm often using a combo of the Harmony remote and the Anthem iphone app to control most things. I'd give the Harmony Companion a 6-7/10.

 

 

 

 

 

Next up was my step up to Dolby Atmos. This is something I've wanted to do for years so I was pretty excited to push this project along. My biggest issue was working out speakers to suit my space. I was not remotely interested in the ceiling bounce kind, and while I did consider in-ceiling speakers, it wasn't really a legitimate option for me given the lengthy wiring involved and limited ceiling depth. About the only speakers that may have worked (without fabricating unsightly boxes on the ceiling) for my existing build were the Krix Helix which have a very shallow mounting depth. They do not have directional tweeters though so I was a little hesitant with that option. At the top of my list were the SVS Prime Elevation speakers which seemed to have very good reviews and lots of flexibility with mounting them on the wall or ceiling. Unfortunately the AUD isn't great so buying new was going to be expensive and second hand sales of them seemed to be very few and far between.

 

This led me to investigate other local options. I looked at a few of the Krix range like the Phonix 45 but they were a bit expensive for me. Then I started thinking outside the box at the Tropix which are actually marketed as an outdoor speaker but are surprisingly similar in design philosophy to the SVS Prime Elevation. They utilise a 165mm bass driver and 26mm dome tweeter and have a very elegant bracket mounting solution that provides heaps of flexibility for installation. The bracket can be tilted virtually any angle so you can achieve a perfect angle for your listening position. For the price, warranty and supporting an aussie business, I don't think there is much else that can compare for a flexible Atmos setup. Needless to say, I ended up with a set of four of the Krix Tropix speakers and set to work with mounting them on my ceiling pointing directly at my main listening position.

https://www.krix.com.au/tropix/

https://www.krix.com.au/phonix-45/

 

 

 

 

 

 

 

I ended up using two of these 'GripIt 15mm Yellow Plasterboard fixings' per speaker. They are rated to hold 40kg each so it gave me plenty of confidence that they would hold the sub 4kg Krix speakers to the ceiling without them falling on anyone's head. The fixings are highly recommended from my perspective.

https://www.bunnings.com.au/gripit-15mm-yellow-plasterboard-fixing-4-pack_p2260676

 

Then came all the extra wiring which was the most difficult part of the install. I continued to use my cable hide strips but I can tell you now that running 5-6 14AWG speaker wire runs is about the limit in terms of sizing, particularly when dealing with tight 90 degree bends around corners. I managed to make it work and look reasonably neat (not much of an issue when the lights are out). For the furthest away Atmos speakers, I used a thinner cable hide strip as only a single 14AWG wire was running to these.

 

 

 

 

So how does it sound?

Well I was pleasantly surprised by the Krix Tropix speakers. They obviously are never going to match my large floorstanding VAF DC-X35 speakers but they certainly hold their own and produce a nice smooth, detailed sound. Dialogue and instruments sound good although the bass is somewhat lacking given the small plastic enclosure. My SVS sub and large floorstanders can manage that so I'm not particularly worried about the limited bass. The first Dolby Atmos movie I fired up after recalibrating ARC on my Anthem receiver was impressive. My system has gone from a flat 2D sound to a 3D bubble of sound. It really feels like you're sitting 'in' the scene now. It's subtle but certainly a noticeable improvement in immersion, at least for those movies/shows that have a soundtrack in Atmos/DTS:X. After some further reading, I've also discovered that I can utilise all 11 speakers for 5.1 and 7.1 channel content by selecting the 'Dolby Surround' or 'DTS Neural X' setup on my Anthem receiver. From my brief viewing to this point, the Dolby Surround seems to offer a more natural height effect, while the DTS Neural X offers a more punchy blockbuster feel to content. I'm very happy with the upgraded setup.  

 

My next step will be looking for a larger 4 seater 3m wide leather couch (my current is only a 2.5 seater at 1.9m wide) so more of the family/friends can come over to enjoy the system. I have considered moving to two rows of three seats but I think that will be more difficult to calibrate, reduce the useability of the room and be a bit tight around the doorway unless I move to a riser setup with rollers, in a similar vein to what I did with my moveable screen. I could add some recessed subs into a platform under the couch(es) though...  

[Krix Loudspeakers]

Thanks for the update @OzJustin, it looks great!

I've found similar results with Dolby Surround and Neural:X.

 

Cheers, Michael

[OzJustin]

It's been a couple of months since an update on my build. Only a few tweaks to report as I've just been enjoying the room.

 

I sourced an Apple TV 4K (2019 era so not the latest gen) and am loving it so far. So much more flexibility to access content (Kayo, Binge, Netflix, SBS etc) although as expected it doesn't seem to offer quite the performance of physical media. It will still be 4K/Blu-rays for my box office favourites.

 

Raven door drop seals were installed this weekend. A bit fiddly to install but seem to be working well. The room is pretty well sealed now. Anybody know how long o2 will last in a room of my size before I have to start think about running the AC or opening a door?  

 

 

 

 

I was also able to finally source a 4 seater recliner lounge. This is a much better fit for my room. It allows me to still utilise the walkway area between rooms but also have more friends/family over to enjoy the space. I've left the old 2.5 seater in the room against the back wall for now. If I were to keep it longer term then I would have to think about some kind of riser setup on wheels. Seating for 7 currently!  

 

 

Next up will be trying to optimise the setup via some acoustic treatment etc. I'm brand new to this area so will start a separate thread to seek advice.

[OzJustin]

Over the last few months, but particularly over the Christmas break, I've had some time to do some more work on the theatre room so time for an update.

 

I've had these two separate threads running covering acoustic treatment advice and subwoofer upgrade options so thought I'd cross-link to them for some of the back story:

Room treatment

 

So first up was some digging into the acoustic performance of my room. I have no problem admitting that until probably 12 months ago I had no idea what frequency response was, the purpose of Room EQ Wizard (REW) software, miniDSPs etc. This has been a VERY steep learning curve for me and I'm genuinely only scratching the surface of this area. It is fun learning about how sound works, what affects it etc, but it is a challenge finding the time given the busy stage of my life.

 

Initially I was going to make some acoustic panels (combo of absorber and diffuser panels), but upon further investigation it appeared I would benefit more from some bass treatment. With the guidance of some kind forum members, I've since been building two large bass traps to fill the alcove/study area of my room when the room is in 'theatre mode'. They extend floor to ceiling and are approx 430mm deep. I've built one so far and just about finished stapling on the fabric cover. I'm yet to finish the second one as I've been waiting 4-5 weeks so far for the insulation to come back into stock locally. Once that is done I'll get them both finalised and stapled up. I also managed to source some small 18mm fixed drawer castors that I've attached to the bottom of the traps to allow them to be moved more easily. Here's a few pics to show the progress and design.

 

 

In terms of performance, here's an ARC Genesis screenshot showing the before and after with about 30% of the alcove space filled with insulation batts. You can see that it reduced the volume approx 3dB @ 20Hz and then increased some peaks and nulls at the 80 and 120Hz mark. 

 

 

Also included is a later REW measurement showing the frequency response change after installing one of the near complete bass traps (green line). It has actually done the opposite of earlier - boosting approx 5dB @20Hz and then some other adjustments from 30-200Hz. I'm not too fussed above my crossover point of 80Hz.

 

Subwoofer upgrade

 

I've been running a single SVS PB-2000 sub for the last few years and was considering transitioning to a pair of either Rythmik FV15HP/F18 or REL 1508 Predator subs. Like many products at the moment, stock shortages and delays meant I wasn't able to secure either of those options for several months. As luck would have it, a pair of SVS PB-2000 Pro subs popped up locally in the For Sale section and I jumped on them as an economical way of being able to jump into dual sub experimentation.

 

Moving to dual subs has really encouraged me to learn more about the performance of my room and how best to dial in my equipment. As part of this, I purchased a miniDSP 2x4 HD and Umik-1 to allow me to take measurements in REW and investigate further than my current Anthem microphone and ARC Genesis software have allowed me to date.

 

 

As a starting point, I decided to measure the response of all positions in my room that could house a sub. I ended up with 16 positions, plus I also experimented with the driver facing in different orientations, moving the sub away from walls 15cm etc. To make this tedious measurement process easier, I placed one of my SVS subs on a garage dolly with plywood so it could be wheeled around the room easier. I'm happy to send my REW measurement file to any members should they want to take a look or offer any advice on best placement in my room for dual subs. Funnily enough I discovered that the previous two locations I had placed my PB-2000 sub were actually not performing very well with some large nulls. I ended up choosing position 4 and 13 of the 16 spots in my room. See below photo (not to scale) to give you an idea of all the measured positions (took a few hours!) - one sub is now located in the front behind my screen to the left of my centre channel, and the other sub is located at the back wall just slightly to the right of centre. The front sub driver faces the left wall, while the rear sub driver faces the right wall. I level matched the subs and ran individual measurements and then combined the subs and took a measurement. Strangely the combined measurement didn't initially match the predicted combined curve generated by REW. This is where I found the SVS app quite beneficial. I took some measurements adjusting phase and polarity and was able to get a better combined response by reversing the polarity on just the rear sub and leaving phase at 0 degrees on both subs. These Youtube tutorials from Home Theatre Gamer were very helpful for this basic sub position measuring in REW:

https://www.youtube.com/watch?v=rm4FIbKzqvk&t=402s

https://www.youtube.com/watch?v=H48jmexIP9k

 

 

The response is all over the place throughout the room! I ended up picking the two spots with the flattest response 20-50Hz and 50-100Hz and then combining them for a reasonably flat overall response throughout the room. I don't think more than two subs are necessary for my space? The next flattest response was in position 3 which had very similar characteristics to position 4 that I've gone with.

 

Here is where I've landed as my base calibration for the dual SVS subs. This is based solely on the best positioning for the subs in my room and then very basic tweaking of polarity in the SVS app. Frequency response is reasonably flat from 20 - 80Hz where my crossover is set. I then ran Anthem ARC Genesis and it further smoothed out the response, especially the 90-100Hz null (see below).

 

Even with me only being about 50% calibrated at this point, the difference is night and day compared to my previous single sub. The dual subs are much better balanced and even throughout the listening positions, less boomy and noticeably more output. I've watched Godzilla vs Kong (only a compressed Netflix stream) and Dunkirk (proper 4k disc) and the revised sub setup hits much harder. It is much cleaner but there is still some minor muddy boominess that I would like to dial out if possible. Otherwise I may consider moving to the Rythmik or REL subs down the track as from what I've read they are much faster, tighter and more musical, while the signature SVS sound is more slam and boom.

 

Home Theatre Gamer also has a series of five tutorial videos to properly configure and take advantage of a miniDSP to fine-tune subwoofer setups. This will be next on my list when I have the bass traps finalised and some more time. I'm hoping to sort a 'house curve' that starts high at 20Hz and then tapers off very gradually down to 100Hz. I may also investigate Multi-Sub Optimiser (MSO) as I've read it can be even more effective for optimisation, although I'm not looking forward to the learning curve. I do wonder if I'd benefit integrating subs to mains for my combo theatre/music use...

 

Here's my current Anthem ARC Genesis results if interested. I'm still confused why ARC seems to want to set my centre channel crossover at 250Hz. The frequency response seems a little funny too. It seems to taper off from about 300Hz.

ARC Genesis Results 7.1.4 MRX1120 301221.pdf

 

Tactile response / HoverEze

 

I've also made some decent progress on my tactile response semi-riser setup that will house four 12" Alpine Bass Series subwoofers on a suspended platform under my four seater recliner lounge. I have a 2250 x 600 x 30mm (thick) plywood sheet as my base (should be zero flex!) and some 20" thornproof tubes for the hover component. A Behringer NX3000 amplifier (with Noctua fan mod to quieten it down - wow was it loud like a cyclone in stock form!) will power the four drivers, again when they come back into stock early in 2022. I've been waiting months for the Alpine or JBL drivers to become available locally again at a good price. More updates on this once I've been able to mount the drivers and get a base calibration done on the miniDSP. I do wonder what effect the Alpine drivers may have on my overall room response once all the subs are setup. Crossing my fingers it won't affect things too much.

 

 

More to come soon, but any feedback appreciated on my measurements, sub placement, calibration etc to date.  

[jamiebosco]

Justin, send me the mdat file and I'll have a look at it

 

Great work here mate, once you have your bass response and room acoustics dialed in - you'll be in heaven!

[The One Demon]

I had a post written out but my browser decided that I'm not allowed to type, or even the page to respond...

 

Basically I've tried the PB2000 vs the Velodyne SPL-1000 in the same room, Velodyne is much cleaner and tighter bass, but less overall volume, the PB2000 has that muddiness or boominess you talk about that doesn't exist with the SPL-1000, the PB2000 seemed to extend the driver an extra couple of times. I noticed this before testing the side by side. (My brother has the PB2000)

 

Last time I checked, Audio Salon, the local dealer for Rythmik had the E15HP2 in stock. That was a couple months ago though, so might be worth checking if they have anything in stock atm, or what can be ordered that Rythmik have in stock.

 

I'm waiting on the G25HPSE to arrive (SE is just because it's gloss black). That's a dual 15" sealed sub with opposed drivers. Some delays from the manufacturer recieiving stock so probably going to be 3rd week of Jan unfortunately by the time it gets here..

[The One Demon]

Going back through my emails, the E15HP2 is only $50 less than the F18 (sealed 18" $3,150 through Audio Salon no stock on hand likely though) so either that or the FV18 (ported, not sure on pricing locally and likely no stock on hand I'd guess) would be my go to. I'm partial to sealed myself lol. Idk how the pricing worked out like that, but

Edited January 3, 2022 by The One Demon

[WatchDoc]

Great progress on the room! 
acoustic treatments and dual subs definitely make a difference!

 

did you try putting the sub on your couch and doing the subwoofer crawl before moving it around on a dolly to all those positions??

[hopefullguy]

i would guess using REW +umik-1+mini DSP would be on a far higher level than any sub crawl, especially with 2 subs

 

as for your final location.. who knew? thats my first/go to placement in every room for 2 subs.

[almikel]

On 03/01/2022 at 10:44 PM, WatchDoc said:

did you try putting the sub on your couch and doing the subwoofer crawl before moving it around on a dolly to all those positions??

 

On 04/01/2022 at 6:40 AM, hopefullguy said:

i would guess using REW +umik-1+mini DSP would be on a far higher level than any sub crawl, especially with 2 subs

@WatchDoc meant moving the mic to all those positions with sub1 at the listening position (ie propped up on the couch where your head would be).

Then put the sub2 in the best spot (eg position 4 or position 13) and re-measure with the mic in other spots to find the position for sub1.

 

@OzJustin - awesome progress !...

...measuring/tweaking/rinse/repeat gets very tedious ...and the family quickly tires of hearing the woop woops !

 

Mike

 

[almikel]

Hi Oz - coming along nicely - lots of progress !!

 

On 02/01/2022 at 11:01 PM, OzJustin said:

I've been running a single SVS PB-2000 sub for the last few years ...... As luck would have it, a pair of SVS PB-2000 Pro subs popped up locally in the For Sale section and I jumped on them as an economical way of being able to jump into dual sub experimentation.

 

Does that mean you have 3 x SVS subs now? I'd try all 3 together before considering moving to other subs.

 

With multiple subs there is no requirement to run identical subs - they can all be different. What's important is that you keep all subs well within their driver excursion and amplifier power limits .

 

Integrating 3 subs does add further complexity  , but if that allows you run each sub with less gain/cone excursion that may remove the "minor muddy boominess" you can hear...

...but with further tweaking of room/position/EQ/delay with just the 2 x SVS PB-2000 Pro subs I reckon you should be able to get rid of any "minor muddy boominess" 

 

On 02/01/2022 at 11:01 PM, OzJustin said:

Otherwise I may consider moving to the Rythmik or REL subs down the track as from what I've read they are much faster, tighter and more musical, while the signature SVS sound is more slam and boom.

Your SVS subs are very capable - spend the time getting the integration right and you'll be happy!

Good integration and keeping driver excursion/amp power well within limits are way more important than the brand of sub!

...although I will say that now you've headed down the path of miniDSP/EQ, I would avoid Rel subs - their main marketing push is to use "speaker level" inputs on their subs...for great reasons based on good science you've gone beyond their approach 

 

On 02/01/2022 at 11:01 PM, OzJustin said:

I'm hoping to sort a 'house curve' that starts high at 20Hz and then tapers off very gradually down to 100Hz.

You'll likely continue to tweak your house curve for ages, including having more than 1 house curve you can select between - I typically run my house curve full range - about 6dB boost at 20Hz shelving down slowly to 0dB around 10kHz (I think - I haven't mucked with it in a while...it could be -3dB at 10kHz).

 

On 02/01/2022 at 11:01 PM, OzJustin said:

I may also investigate Multi-Sub Optimiser (MSO) as I've read it can be even more effective for optimisation, although I'm not looking forward to the learning curve. I do wonder if I'd benefit integrating subs to mains for my combo theatre/music use...

I've never used MSO - as I've never made sawdust for a 2nd sub...the bass in my room is pretty good with my single sub (dual Rythmik 12" T20 tapped horn)...and the lazy DIYer in me takes over...

...but with your dual sub setup + miniDSP providing individual EQ and delay control over each sub - MSO could be the easiest path to getting your subs integrated with the room and your main speakers - especially for optimising the bass across your listening couch!

IMHO well worth the learning curve...but that's easy for me to say given I've never mucked with it 

 

On 02/01/2022 at 11:01 PM, OzJustin said:

 

 

The response is all over the place throughout the room! I ended up picking the two spots with the flattest response 20-50Hz and 50-100Hz and then combining them for a reasonably flat overall response throughout the room. I don't think more than two subs are necessary for my space? The next flattest response was in position 3 which had very similar characteristics to position 4 that I've gone with.

It's entirely expected that the bass will change significantly at the listening position when the sub/s are moved around the room - get it as smooth as you can at the primary listening position just by moving subs - then tune using tools like MSO.

 

On 02/01/2022 at 11:01 PM, OzJustin said:

I then ran Anthem ARC Genesis and it further smoothed out the response, especially the 90-100Hz null (see below).

Nice!

FYI - you likely can't hear that null between 90-100Hz - it's way to narrow/steep...and it was pretty narrow steep before, so you may not have heard it before either...but less likely now 

The really steep/sharp changes on a frequency response "look" terrible on a graph, but the ear is not that sensitive to short/sharp dips or peaks in the frequency response - the ear/brain just ignores short/sharp peaks/dips and is far more sensitive to broader changes in the frequency response - like a house curve - you will easily hear changes to your house curve.

 

Some tips for applying EQ:

1. always broad, never narrow - the narrower the EQ the more it will work at only 1 position in the room
2. use cut as a preference to boost - but if using boost refer tip 1
3. learn when not to use EQ - speaker box diffraction, Speaker Boundary Interference Response (SBIR), and deep nulls from Room Modes are examples where EQ should not be used

I love EQ! but it's been said many times before, EQ can do great evil! - which is absolutely true!

 

When carefully/appropriately applied, EQ can do great good to your room sound - I wouldn't be without it!

 

Some other other ideas a bit left of centre:

• I'm sure you're already over measuring at different sub positions - but don't discount the option of putting a sub into the alcove. Just because you're using the space as a big bass trap doesn't mean it won't produce great room response with a sub in it !
• What is the cupboard at the back left of the room used for? to the left of position 11?
  - Fill it with clothes or bed linen and it becomes a reasonable bass trap 
  - don't leave it empty, or much worse - filled with stuff that rattles  
  - easy pitch to the boss - "hey honey, let's use this cupboard for all the winter doonahs and blankets"

cheers,

Mike

[almikel]

On 02/01/2022 at 11:01 PM, OzJustin said:

I do wonder what effect the Alpine drivers may have on my overall room response once all the subs are setup. Crossing my fingers it won't affect things too much.

I expect not much if any - all their energy is going into moving the couch - IMO you'll get no change to your room response above 20Hz based on the wobble board.

 

Mike

[OzJustin]

On 03/01/2022 at 10:00 AM, The One Demon said:

Going back through my emails, the E15HP2 is only $50 less than the F18 (sealed 18" $3,150 through Audio Salon no stock on hand likely though) so either that or the FV18 (ported, not sure on pricing locally and likely no stock on hand I'd guess) would be my go to. I'm partial to sealed myself lol. Idk how the pricing worked out like that, but

 

Thanks for the suggestions. I was on the list for a Rythmik FV15HP or F18 for many months but there were significant stock delays. In the end I jumped on the pair of SVS. A much cheaper but still very capable option! I now have three SVS subs to play around with which should be plenty of output.

On 03/01/2022 at 10:44 PM, WatchDoc said:

Great progress on the room! 
acoustic treatments and dual subs definitely make a difference!

 

did you try putting the sub on your couch and doing the subwoofer crawl before moving it around on a dolly to all those positions??

 

I did a 'subwoofer crawl' very early on in setting up my room with a single sub but have not tried the other approach Mike figured you were meaning above. I'm pretty happy with the measurement approach I've followed and have graphs coming out my ears of over 16 potential spots in the room now. So many to choose from in determining a 'summed' response.

On 04/01/2022 at 6:40 AM, hopefullguy said:

i would guess using REW +umik-1+mini DSP would be on a far higher level than any sub crawl, especially with 2 subs

 

as for your final location.. who knew? thats my first/go to placement in every room for 2 subs.

 

Since my last post, I've actually shifted from positions 4 and 13 to position 9 and 14 as that is predicted to provide for a better house curve in the 50-80Hz range. 18-50Hz is also quite similar. That is only with the two subs too. I may dable with adding the third sub in but it looks like I should be able to achieve a smooth response and plenty of output with just the two PB-2000 Pro subs.

6 hours ago, almikel said:

 

@WatchDoc meant moving the mic to all those positions with sub1 at the listening position (ie propped up on the couch where your head would be).

Then put the sub2 in the best spot (eg position 4 or position 13) and re-measure with the mic in other spots to find the position for sub1.

 

@OzJustin - awesome progress !...

...measuring/tweaking/rinse/repeat gets very tedious ...and the family quickly tires of hearing the woop woops !

 

Mike

 

 

Thanks Mike. I think I'm hearing the chirps and woop woops in my sleep now! I think I've done close to 100 sweeps in the last few days   

2 hours ago, almikel said:

Hi Oz - coming along nicely - lots of progress !!

 

 

Does that mean you have 3 x SVS subs now? I'd try all 3 together before considering moving to other subs.

 

With multiple subs there is no requirement to run identical subs - they can all be different. What's important is that you keep all subs well within their driver excursion and amplifier power limits .

 

Integrating 3 subs does add further complexity  , but if that allows you run each sub with less gain/cone excursion that may remove the "minor muddy boominess" you can hear...

...but with further tweaking of room/position/EQ/delay with just the 2 x SVS PB-2000 Pro subs I reckon you should be able to get rid of any "minor muddy boominess" 

 

Your SVS subs are very capable - spend the time getting the integration right and you'll be happy!

Good integration and keeping driver excursion/amp power well within limits are way more important than the brand of sub!

...although I will say that now you've headed down the path of miniDSP/EQ, I would avoid Rel subs - their main marketing push is to use "speaker level" inputs on their subs...for great reasons based on good science you've gone beyond their approach 

 

You'll likely continue to tweak your house curve for ages, including having more than 1 house curve you can select between - I typically run my house curve full range - about 6dB boost at 20Hz shelving down slowly to 0dB around 10kHz (I think - I haven't mucked with it in a while...it could be -3dB at 10kHz).

 

I've never used MSO - as I've never made sawdust for a 2nd sub...the bass in my room is pretty good with my single sub (dual Rythmik 12" T20 tapped horn)...and the lazy DIYer in me takes over...

...but with your dual sub setup + miniDSP providing individual EQ and delay control over each sub - MSO could be the easiest path to getting your subs integrated with the room and your main speakers - especially for optimising the bass across your listening couch!

IMHO well worth the learning curve...but that's easy for me to say given I've never mucked with it 

 

It's entirely expected that the bass will change significantly at the listening position when the sub/s are moved around the room - get it as smooth as you can at the primary listening position just by moving subs - then tune using tools like MSO.

 

Nice!

FYI - you likely can't hear that null between 90-100Hz - it's way to narrow/steep...and it was pretty narrow steep before, so you may not have heard it before either...but less likely now 

The really steep/sharp changes on a frequency response "look" terrible on a graph, but the ear is not that sensitive to short/sharp dips or peaks in the frequency response - the ear/brain just ignores short/sharp peaks/dips and is far more sensitive to broader changes in the frequency response - like a house curve - you will easily hear changes to your house curve.

 

Some tips for applying EQ:

1. always broad, never narrow - the narrower the EQ the more it will work at only 1 position in the room
2. use cut as a preference to boost - but if using boost refer tip 1
3. learn when not to use EQ - speaker box diffraction, Speaker Boundary Interference Response (SBIR), and deep nulls from Room Modes are examples where EQ should not be used

I love EQ! but it's been said many times before, EQ can do great evil! - which is absolutely true!

 

When carefully/appropriately applied, EQ can do great good to your room sound - I wouldn't be without it!

 

Some other other ideas a bit left of centre:

• I'm sure you're already over measuring at different sub positions - but don't discount the option of putting a sub into the alcove. Just because you're using the space as a big bass trap doesn't mean it won't produce great room response with a sub in it !
• What is the cupboard at the back left of the room used for? to the left of position 11?
  - Fill it with clothes or bed linen and it becomes a reasonable bass trap 
  - don't leave it empty, or much worse - filled with stuff that rattles  
  - easy pitch to the boss - "hey honey, let's use this cupboard for all the winter doonahs and blankets"

cheers,

Mike

 

Thanks for the tips Mike. Yes I've got three SVS subs to play with now and still deciding whether I go with two or three subs. I'm going to be patient and see what I can achieve through this EQ process. I have noticed the bass is tightening up as I go which is very pleasing. I've generally avoided turning on the sub for much music listening as I always found it quite boomy, but once I've done this EQ and integrated with my other speakers, the bass may be more to my liking. No REL subs needed then!

 

From what I've read, adding any gain to the subs (if needed) should be done through the miniDSP rather than via the volume knob/SVS app on the sub itself?

 

I am yet to work out how to prevent Anthem's ARC from messing with my miniDSP house curve once I'm finished EQing. Will have to do some googling to see what the best approach is there.

 

Re the cupboard at the back left of the room - that is a storage cupboard with board games, sports equipment etc. I have actually noticed a rattle in the back corner of the room that I haven't tracked down yet.  

 

Re a sub in the alcove - I hadn't considered that option. The traps wouldn't cancel out the bass energy before it gets into the main room? Part of my positioning thinking now is working out how to get all the subwoofer cables to the miniDSP which I've chosen to place on a shelf against the left wall. I'm already having to be creative with 10-15m cable runs to keep things neat and hidden in the room.

1 hour ago, almikel said:

I expect not much if any - all their energy is going into moving the couch - IMO you'll get no change to your room response above 20Hz based on the wobble board.

 

Mike

 

It will be a big win if that is the case. I've read on the AVS forum that some members experience almost no SPL increase with the sealed platform setup, while others experience quite a bit. It seems very room and setup dependent. Time will tell. That project will happen after I have this round of EQ done with my 2-3 main subs.

[almikel]

On 05/01/2022 at 9:47 PM, OzJustin said:

In the end I jumped on the pair of SVS. A much cheaper but still very capable option! I now have three SVS subs to play around with which should be plenty of output.

 

On 05/01/2022 at 9:47 PM, OzJustin said:

Yes I've got three SVS subs to play with now and still deciding whether I go with two or three subs.

I reckon you can tune an awesome outcome with just 2 - but you have an extra on standby !

 

On 05/01/2022 at 9:47 PM, OzJustin said:

and have graphs coming out my ears of over 16 potential spots in the room now. So many to choose from in determining a 'summed' response.

yeah, understood - so much data you get "analysis paralysis" - apologies for mentioning putting a sub into the alcove!

Taking measurements is time consuming and annoying to the family, but easy to do - interpreting those measurements and making appropriate changes that improve your room response (based on more measurements/woops woops) is the hard part...

 

...and mostly random people on the interweb (like me) don't know sh!t - treat internet content as opinion not fact etc etc...

 

On 05/01/2022 at 9:47 PM, OzJustin said:

Since my last post, I've actually shifted from positions 4 and 13 to position 9 and 14 as that is predicted to provide for a better house curve in the 50-80Hz range. 18-50Hz is also quite similar.

I would leave your subs in positions 9 and 14 - and have a crack at using MSO to optimise your bass across your listening couch.

MSO will recommend EQ and delay profiles for you to apply in miniDSP after running calcs based on your REW measurements across your listening couch.

I realise I don't have any cred in saying this (as I've never actually used MSO, or run multiple subs), but I'm confident in the science behind MSO.

 

On 05/01/2022 at 9:47 PM, OzJustin said:

From what I've read, adding any gain to the subs (if needed) should be done through the miniDSP rather than via the volume knob/SVS app on the sub itself?

Managing gain throughout the signal chain is a subject all on it's own - but yes - add gain via the miniDSP rather than the sub if required...

...In the simplest terms you want your signal to be as high as possible from source to amp without clipping to maximise the signal to noise ratio (S/N)...

 

...worst case is a signal that is attenuated through the chain then amplified again - which will reduce the signal to noise (S/N) ratio...

...IMO better to apply the gain earlier.

 

On 05/01/2022 at 9:47 PM, OzJustin said:

Re the cupboard at the back left of the room - that is a storage cupboard with board games, sports equipment etc. I have actually noticed a rattle in the back corner of the room that I haven't tracked down yet.  

Talk to your boss about making this a linen cupboard - filled with sheets/blankets/doonahs it makes a reasonable bass trap - filled with "rattly" stuff it will make your room sound awful.

 

On 05/01/2022 at 9:47 PM, OzJustin said:

Re a sub in the alcove - I hadn't considered that option. The traps wouldn't cancel out the bass energy before it gets into the main room?

No, the traps won't cancel the bass energy before it gets into the main room - from a bass perspective your room includes the alcove, and the room's bass energy is going through that alcove and any trap already.

Having a a sub in the alcove is just another option for room placement...not that you needed another placement option...but if it measures well...

 

Mike

[jamiebosco]

I've been having a look at Justin's REW measurements and I think he has some very good options to get a smooth response out of 2 subs, I do think he could improve it further using all 3,but 2 is looking promising right now (and put some $$$ back in his pocket) . 

Unfortunately, I had to ask him to remeasure all positions, as his initial measurements didn't include a Timing Reference (helps REW predict the response) 

Edited January 8, 2022 by jamiebosco

[jamiebosco]

Here's positions 14+9, you can see how they compliment each other's weaknesses,this was my initial recommendation

 

Looking briefly again today, I actually really like positions 1 + 14 (90deg phase on 14) with 10ms delay on position 1. I think this has more potential + I like to have 1 sub near the mains if possible

You can see how these also compliment each other's strengths and weaknesses very well

 

Here's a graph showing their combined response after some delay (Black Trace) Showing positive summation throughout 99% of the response

 

Here is REWs predicted response after EQ

 

 

 

 

 

Hope this helps @OzJustin 

did you end up getting Asio4All to work??

Edited January 8, 2022 by jamiebosco

[jamiebosco]

Now....... If Justin decides to add the 3rd sub into the mix, he will gain some more low end,more midbass, a much better response above 100hz and IMHO a smoother preEQ response all-round

 

This shows 3 sub positions (1 ,4 and 14 with 90 deg phase ) and the summed response . This is a VERY nice bass response with no EQ and no smoothing applied IMHO

 

 

This shows a comparison between the 2 subs summed response and the summed response with the 3rd PB2000 added into the mix

 

 

 

This shows a predicted EQ'd response of the 3 sub system using the 2x4HD

 

 

 

...ok..I'll stop now....

 

Edited January 8, 2022 by jamiebosco