Acoustics for Clubs and Lounges – 2

Great. Now that we’ve largely taken care of soundproofing in the previous post, let’s look at what happens in the interiors.

All Glass 

Glass is something we can’t avoid these days, and the challenge is to ensure that the sound field in a room is sufficiently diffuse, despite perfect planar reflections from large panes of glass all around you. This poses trouble even for the mids and highs, let alone the LF.  How do you introduce time and phase shifts? How do you reduce the spot intensity of standing waves forming peaks and nulls at the same spots ALL the time? Well, clever options are possible if you lay down the fundamentals of the concept/solution to the architect, and let them play with it. They ARE the creative of the species. In Mumbai, a lot of old industrial sheds have been successfully converted into music lounges – despite the theoretical odds.

Mixed Usage

Here’s a very generic scheme of what sound should sound like, for various usages:

Frequency	Movies	Live Music	Gaming
Bass	Loud, but not boomy	Tight	Loud and Boomy
Mids	Short	Long, resonant	Short
Highs	Dead	Long,	Short

Now lounges have another category    – DJ music. The kind of absorption you need for these scenarios is really different, but we always have to strike a balance. There is always a mixed usage. The kind of bass you need for DJ music is thumping, compared to the kind of tight bass you need for say, smooth jazz. Actually, for those who know their music, within EDM ( Electronic Dance Music), there are so many sub-genres each of which have a typical characteristic feel – all contributed to by the balance of highs, mids and lows.

Now while it’s great to experience this variety, at the design level it is not really possible to alter a room’s response to suit different scenarios. So broad generalizations are made, keeping in mind the primary use, the secondary use, etc. Sometimes the extremes are too far away to bridge – such as one project I’m pitching for where I will need to design for typical lounge music, DJ music, and the space also doubles up as an exhibition area, or ( hold your breath) – a conference room!  The ambience for an exhibition area must be a quiet one  – low noise, piped music, etc, and for speech – deadly quiet. HVAC hum, etc are factors to monitor here. Now for the volume of the space, speech is going to sound terrible if music is to sound awesome. Variable acoustics is the key here. There will have to be additional absorption brought in when there is a speech event going on. The design must be modular, easy to assemble and move, and sturdy.

Such a situation also requires variable sound systems. You can’t be playing piped music through a line array meant for live music. Sound system engineering is also critical for soundproofing. Choice must be made between having a distributed system or a line array-like system. Distributed systems must be chosen to ensure their coverage isn’t much more than needed – to avoid excess sound pressure at the walls. Compared to distributed systems, for the same power configuration, a line array system will beam all energy along the main axis – while keeping smaller amounts of energy in the side lobes. This makes it suitable for long halls, marginally/significantly reducing soundproofing needs for side walls, but surely increasing the soundproofing requirement for the opposite wall. However, low frequency response is nearly similar to that of a distributed system. So soundproofing requirements for LF stays the same.

Mixed usade presents another issue in that seating plays a very important role in acoustics, and we are unable to take that into account for such cases. Seating accounts for a significant absorption, and so does the crowd – we design for 2/3rds occupancy typically. If furniture is going to be modular, to be shifted in and out for various scenarios, our calculations have to buffer for that. Also, the place could have 150 people for a DJ session, and only 25 for an exhibition. The challenge lies in making intelligent estimates, and in knowing the broad ranges of parameters within which these estimates are true.

Concluding each such article leaves me excited about the variety of cases we get to solve in the ever-evolving melting pots that our cities have become.

 

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Acoustics for Lounges and Clubs – 1

I’ve recently had a chance to look at a few of these projects not six months into my freelancing, and there’s plenty to be said here. Pubs and lounges have integrated themselves into the lifestyles of Bangaloreans for over 10 years now, and plenty of people spend the best part of their weekends catching up with friends and family at such places. This post is for a broad spectrum of audience – aimed at giving general information to people to go to such places, people who design/sell audio, people who own such spaces, and people who live near such spaces.

This post is the first of two, and looks exclusively at operational aspects of such spaces. The second part will go into the technical aspects of soundproofing, interior soundscaping, and sound system engineering.

Why Soundproofing

This is by far the biggest problem required to be addressed for such places, for more reasons than one. For obvious reasons, these places  almost always in the heart of the commercial pockets in various areas in the city, rarely ever on the outskirts. This is usually good news for everyone, because it makes sure they’re not too close to the residences for the most part. Occasionally, when residences have given way to commercial spaces, and some residences are still hanging around on what is now a commercial hub, soundproofing becomes a more critical issue. Like I just said, for more reasons than one:

• Residents face noise issues. Right , easy to guess that. Only thing, they don’t put up with it these days. There are plenty of groups out there lobbying for noise laws to be stringently implemented, and complaints can lead to spot confiscation of music equipment, and repeat offenders can get their license revoked. This is more serious than it appears – places can get shut down in 3 months of taking off. Full Stop. Anyone who doesn’t believe this can call me on my phone, and I will be happy to put you in touch with people who’re facing this issue.
• False Threats: There is another aspect to this : It takes all kinds to make a world, and so there are people who can really live with the noise, but choose to make complaints and harass and extort money from owners. Again, there are some famous people who are known troublemakers in Bangalore  –  who give the rest of the genuine anti-noise lobbyists/activists a bad name.
• Genuine Threats: Residents really do face noise issues : I know this microbrewery that has a reputation for playing extremely loud music. It’s not just residents who face this  (Eg. A glass vendor I was talking to lives about 9 buildings away, and took 15 mins to vent his frustration on how he is completely sleep deprived on weekends because of the loud noise coming all the way from that microbrewery – he said he doesn’t get sleep till they turn off the bloody thing, and has been talking to the welfare association of that layout to press complaints.) Customers also face the same issue – a close friend of mine advised me never to go there with my toddler – her hearing will end up being permanently damaged. She said she their gang of friends couldn’t bear to sit there for even half an hour. Add to it, the place is a metal and glass jungle, the interior acoustics have not been taken care of, and so the music they play sounds bad anyway. I am obviously going to wait for one positive review from trusted sources before I think of going there.

Now, getting an acoustical consultant in early will help owners to relax and run their place happily for years. I’m doing this project where I was roped in rather at the last minute, with tons of changes not possible because many things had already been done. It’s been quite a challenge to work on it, and I cannot assure them that they will comply with the written word of law .That requires measures they’re not willing to implement. So we’ve taken measurements late night, and we’re going to meet ambient noise levels ( which in that space are higher than those stipulated by the law). So we’re really just blending in. However, all measurements are averages, and it is not possible to design for peak noise levels to be contained in. Not the best of things, but with residences right behind them, not doing anything would be far worse.

Why Interior Acoustics

This is the other aspect which is increasingly being paid importance to. With something like 4 restaurants/lounges/pubs opening in Bangalore every month, there’s plenty of competition, and people rely on designer aesthetics, michelin-rated chefs, and plenty of live music and DJ-ing to attract clientele. Now celebrity chefs are fine, but designer aesthetics sometimes don’t allow for even the minimal essential acoustical treatment. The second part of this post will go into detail on what issues we typically see in such spaces.

Why Sound System Engineering 

Now we’ll all just go by our own ears. Fair enough an argument. However, there are also technical factors that go into the design of speaker systems, and while you don’t need to know them in detail, you should still spend time understanding and experiencing the USP of the systems you demo.  My reason for mentioning sound system engineering is that providing the right kind of speakers based on the needs and the type of space will significantly influence the amount of soundproofing and acoustical treatment you will need to spend on. 

Accurate sound system engineering and critical acoustical treatment can make any kind of place sound warm and intimate. Owners of these spaces should take the effort to do plenty of research, because most vendors will usually only try to make the biggest sale they can – that’s their job.  The mid and high end ranges have lots of options, and ideally the sound system should be finalized after the venue has been decided, not the other way round. It seems to be a trend these days to have a DJ space and live area in the same club. The acoustics required are different, but we try to strike a balance between the clear, tight bass needed for smooth music, and the boomy, thumping bass required for EDM.

The next post will discuss the acoustical requirements of such a space.

Types of Noise (Part 3): Noise in Office Spaces

This is part 3 of a multi-part article dealing with common sources of noise in the urban environment.  Part 1 talks about Community Noise, and Part 2 talks about Road Traffic Noise. 

Now this may raise eyebrows, because a lot of us go to quiet, plush offices that don’t sound sharp or reverberant. The carpets provide absorption for both, footfalls and some amount of reverberation. Offices are supposed to be quiet anyways – if you’re talking, your boss won’t like it too much.  But there are enough scenarios in Bangalore alone, listed below. Again, each of these are what I have personally experienced.

• Fancy glass exteriors, with inaccurate glazing specification, let in road noise and vibrations.
• Whirring printers and coffee machines.
• Irritating hum of the air conditioning system.  I know of an office space where the ventilation duct above the false ceiling turned into a resonator of sorts, and sitting below that was like sitting below a jet engine.
• Porous meeting rooms.  Privacy issues are huge. I know of a time when improper glazing made someone’s appraisal discussion public.
• Some job profiles revolve around phone calls. The others nearby could do with some quietness for 8 long hours.
• Creaky revolving doors.
• Typing noise
• Machine hum. I once sat next to the only server test bed in our office, and experienced crazy amounts of heat and noise.
• Lift noise. This is a problem in hospitals too. My little one was constantly jolted out of her sleep each time the lift was called up.
• Highly reverberant meeting rooms. Speech intelligibility issues, especially during conference calls where you can’t lip read.
• Last but not the least, aircraft noise that makes boardroom windows rattle. This is a case at hand. In business hotels, this can be a big factor affecting business – corporates don’t want to rent boardrooms that have deafening noise coming  through the window, muffling speech during conferences.

All said and done, offices are among the quieter spaces we experience, and only specific issues like the ones listed above are what we acousticians constantly address.  Speech privacy and speech intelligibility are the main aspects here. All these issues are easily solvable, even in retrofit cases.