Food For Thought About Subwoofers

[KirkJBL590]

Richard Hardesty was a well known and reputable writer for Widescreen Review and a huge bass head. His articles about bass and subwoofer reviews were phenomenal. At the time, he was who you followed and learned from pertaining to bass and subwoofers. He passed away in 2017 of cancer unfortunately.

In one of his articles for Widescreen, he introduced a phenomenon that most of us home theater enthusiasts hardly ever think about or discuss.
I'm paraphrasing so please don't beat me up for accuracy...

Have any of us actually heard a car explosion standing/sitting 10-20 feet away? An oil rig explosion? A car crash? A ship hitting a dock at full speed? The sound and feel of the earth moving while a Tyrannosaurus Rex walks acrosed your path? Most likely, the answer is no.

Now some of us have been in car wrecks, heard and felt thunder, the subsonic frequency of planes and vehicles with low resonate exhaust tones for example but in real life, most of us have never been close to a building while it exploded or on a ship that hits a dock at full speed then blows up.

If you have, did you measure it's frequency response and at what amplitude? How low of a frequency was it? 5hz,15hz, 20hz or 50hz? Were there any nulls, peaks, phase shift, cancellations?? Were there any bass traps around? Was it directional? Non directional? Subharmonics? Resonate frequency?

These are rhetorical questions for conversation. The fact is, we are all guessing trying to replicate these sounds in our own home theaters. Most subwoofers of today and regardless of price will reproduce a car crash, car and buildings blowing up. Its about reproducing that explosion to sound as real as possible TO YOU and how YOU perceive it to be. We all have our own opinions about what we think sounds realistic and we all use different ideas, take different paths and buy certain equipment to get us there in all price ranges. I thought this would be a great topic for discussion.

Bass music reproduction is an entirely different animal. We try to purchase subwoofers that do both well. Sometimes, that can be a difficult task. Balancing between the two can get very expensive. I look forward to reading your comments and opinions....

 

[bigkrazy155]

I think it's a fair point about enjoyment of low frequencies in a HT setting. But isn't the purpose of any speaker ONLY to reproduce sound as faithfully as possible. In that case, the argument being made is "you can live with some distortion in the lower frequency ranges."

 

[TheWarrior]

@KirkJBL590 Can you link any of his articles? The site seems to be mostly paid subscription access.

Sound Reproduction in Small Rooms:

The room is part of the playback system. Its parallel boundaries influence the sound being reproduced, and in doing so, effectively create two sound fields - related to wavelength and how they correspond to the dimensions of the room.

Any domestic home theater would be considered 'small' as its boundaries pertain to the wavelengths being reproduced - 20 Hz has a 56.5 ft wavelength for example.

Reproducing large sound waves between parallel boundaries induces standing waves. Through each cycle, there will be a high and low sound pressure area, that unless measured and balanced, will create inconsistencies in the play back, in the form of sounds differing, even across the seats of a couch!

There is no such thing as an 'ideal' room for reproducing sound. As such, any space, even open floor plan living rooms have parallel boundaries whose dimensions can be divided in to the speed of sound (1131fps @ sea level) and have its resonant 'modal frequencies' predicted so that the peaks and dips of a listening position acoustic measurement can be understood.

Yet despite that reproducible fact, we have marketing departments that have convinced people that a measurement recorded by an omni directional mic, in a room of unknown size, shape, or construction, provides sufficient information to apply signal processing that allows us to playback sounds exactly as the engineer intended.

All too often DSP is applied that modifies frequency at the expense of phase(time) to create smooth graphs that do not comprehensively or accurately describe the sound being produced.

But that is all related to sound Reproduction....

When it comes to sound Production, we have engineers listening on unknown loudspeakers in unknown rooms mastering the recording for distribution to both commercial cinema and your ear buds - with the same mastering/levels/etc.

Until we produce and enforce specific standards for Sound Production, how can we possibly know what type of car crash/boat crash/dinosaur stomp the engineer intended us to hear?

 

[shadyJ]

Most recordings are not purely natural acoustic recordings. There is a ton of processing and modification done on the sound by recording engineers. So the goal is to acoustically reproduce the source signal as close as possible as is intended by the artist/sound engineer- at least if you are interested in fidelity.

As for being close to an explosion, assuming you survive the overpressure wave, I don't imagine it sounds like much once your ear drums are blown in, which would happen right away.

 

[KirkJBL590]

As for being close to an explosion, assuming you survive the overpressure wave, I don't imagine it sounds like much once your ear drums are blown in, which would happen right away.

Good point...

 

[KirkJBL590]

What i try to do is emulate a good movie theater. Once i set up and test my system with test cd's, dvd's and eq, I get a good idea of where my systems limitations are, what it can do and not do. Then with some room tuning ideas, subtraction eq and bass tuning, i will tweak until i get it about right for me and the music i listen to.

With the pro audio equipment i have like the DBX 120A Subharmonic Synthesis, i will adjust the device to make powerful explosions and crashes sound rich, deep and full in my listening position. Just like a movie theater would do. I don't worry or obsess over what might be missing beyond the frequency response of my subwoofers. I know im at least receiving what my room will allow and that's a roll off below 30hz. I still FEEL it as well as hear it.

If something explodes or blows up in real life, are we gonna worry about or be concerned about feeling 16hz?? Are we gonna go run home to mommy and go get our radio shack spl meters, wait for the next explosion to measure SPL?? Hook up REW??

Do you realize that if a building blows up around other buildings, those other buildings act as bass traps? How do we know what frequency we are hearing or feeling when a building blows up in real life? The sound engineer has decided that for us and subwoofer designers have produced a few subwoofers that can play that low. The debate is, at what low frequencies are most action movies recorded? My research says between 25--35hz.

I think with this hobby, its important to bring ourselves back down to reality and not get so hung up on numbers pertaining to subwoofers. You are only going to receive what your listening room allows. If some people would take the time and pay more attention to how subwoofers should sound and feel versus the numbers and graph game, it would cause less concern and lower the headache a bit. Measurements are great and needed. But don't forget it also needs to sound and feel as close to what you're trying to emulate and to what the director intended. There lies the challenge...

 

[KirkJBL590]

By the way, try this....play tracks wether it be from cd's or dvd's that have deep bass down to at least 15hz. I have the BASS MEKANIK, QUAD MAXIMUS cd that contains test tones from 10-100hz. It contains powerful bass music in the 30-50hz range. You'll find that bass between 30-35hz is very pleasant and enjoyable. Especially if your room has a resonanant frequency between 30-35hz.

30hz bass to me is favorable and low enough and i love it! The only thing im missing is a little impact that you feel in an action movie below 30hz. Gunfire in a war movie will hit you below 30 but i don't find myself missing it or wishing that i had it.

 

[William Lemmerhirt]

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[William Lemmerhirt]

Reading this thread makes me feel like I’m receiving driving advice from my 16 year old.



Btw, you don’t want a conversation, YOU WANT VALIDATION. So here. You love your 30hz and how you achieved that. Yay!

Really, run to mommy for my spl meter and graphs? Grow up.

 

[KirkJBL590]

Reading this thread makes me feel like I’m receiving driving advice from my 16 year old.



Btw, you don’t want a conversation, YOU WANT VALIDATION. So here. You love your 30hz and how you achieved that. Yay!

Really, run to mommy for my spl meter and graphs? Grow up.

Well, since I was banned for a day because of my reply back to you, i guess i received the punishment you think i deserved. I think this has more to do with the butthurt political posts directed towards you versus my sarcasm in my remarks in this thread. Offended much?? I lean more towards the sceptical within this hobby of ours in many subjects so get used to it. Many of my comments will reflect a bit of sarcasm as we move forward. Too many of you focus on graphics and numbers instead of sitting down, tuning and listening like it used to be. Graphs and numbers should be a guide to success not an end all be all. Subwoofers are easy to set up if you stick to the basics and keep your goals realistic. Like everything else with life, technology advances however, the foundation of this hobby in which it has been founded gets lost. If you don't like my posts, move on. Do you really care what i have to say?? It appears so...

 

[Trell]

Well, since I was banned for a day because of my reply back to you, i guess i received the punishment you think i deserved. I think this has more to do with the butthurt political posts directed towards you versus my sarcasm in my remarks in this thread. Offended much?? I lean more towards the sceptical within this hobby of ours in many subjects so get used to it. Many of my comments will reflect a bit of sarcasm as we move forward. Too many of you focus on graphics and numbers instead of sitting down, tuning and listening like it used to be. Graphs and numbers should be a guide to success not an end all be all. Subwoofers are easy to set up if you stick to the basics and keep your goals realistic. Like everything else with life, technology advances however, the foundation of this hobby in which it has been founded gets lost. If you don't like my posts, move on. Do you really care what i have to say?? It appears so...

I don't know what transpired here but the moderators have much more tolerance in The Steam Vent forum than in other forums, just saying.

 

[KirkJBL590]

I don't know what transpired here but the moderators have much more tolerance in The Steam Vent forum than in other forums, just saying.

Im sure they do however, he was able to post a provocative statement towards me accusing me of wanting attention?? He's a big liberal and i made a mockery out of him in a thread in that forum and he's butthurt over it.

Im a realist pertaining to subwoofers and home theater. Depending on your room and seating position, ONE 10 inch subwoofer with peaks parametrically eq'd, placed in a corner will produce awesome and satisfying bass and reproduce car crashes and explosions. A 12 inch, bigger bass. An 18 inch, Huge bass! If you want it to be rocket science, it can be rocket science.

 

[AcuDefTechGuy]

We all have different preferences for everything, including the kind of bass we want.

I consider myself a "bass-head" because I love a lot of bass that I can HEAR and FEEL (chest thumping and all that) that is most likely "unnatural".

But this doesn't require the bass to go below 20Hz, maybe not even below 25Hz.

In my system, I use the Yamaha PEQ to boost the Bass frequencies from about 30-100Hz by 2dB.

So it's fine if people want bass to go down to 5Hz and it's fine if people want bass to go down only to 20Hz, 25Hz, 30Hz. Whatever sounds great to you is great.

Not everyone needs to have the same kind of bass or subwoofers.

 

[AcuDefTechGuy]

ONE 10 inch subwoofer with peaks parametrically eq'd, placed in a corner will produce awesome and satisfying bass and reproduce car crashes and explosions.

For a long time I used a 10" NHT SW2 passive subwoofer with 80 Watts external amp. In a 18' x 20' x 10' room sitting 15 ft away, it produces awesome shaking bass. It actually rattles every wall in the room and the other rooms next to the room.

These days everything is about overkill, which is fine. I have 10 subwoofers in my HT room. But it's not necessary if you don't want overkill.

Just like not everyone needs an external amp, but most guys have at least one external amp anyway.

 

[KirkJBL590]

We all have different preferences for everything, including the kind of bass we want.

I consider myself a "bass-head" because I love a lot of bass that I can HEAR and FEEL (chest thumping and all that) that is most likely "unnatural".

But this doesn't require the bass to go below 20Hz, maybe not even below 25Hz.

In my system, I use the Yamaha PEQ to boost the Bass frequencies from about 30-100Hz by 2dB.

So it's fine if people want bass to go down to 5Hz and it's fine if people want bass to go down only to 20Hz, 25Hz, 30Hz. Whatever sounds great to you is great.

Not everyone needs to have the same kind of bass or subwoofers.

Absolutely and i completely agree hence the point in my posts. In my recent years of doing research on different forums and other forms of internet and social media, i feel we have veered off the path of many things pertaining to this hobby. Im all about bringing things back down to reality. Many Audio enthusiasts get lost in a whirlwind of rabbit holes instead of just having fun with our investment. You mentioned eq. You do realize boosting your bass by 2db is "ILLEGAL' in this hobby?? If you do and people find out about it, you'll end up in a concentration camp for audiophile rejects lol

I boost my JBL's 2db at 30hz when i run them in "large"... we're crazy and out of ar minds, aren't we??

 

[KirkJBL590]

For a long time I used a 10" NHT SW2 passive subwoofer with 80 Watts external amp. In a 18' x 20' x 10' room sitting 15 ft away, it produces awesome shaking bass. It actually rattles every wall in the room and the other rooms next to the room.

These days everything is about overkill, which is fine. I have 10 subwoofers in my HT room. But it's not necessary if you don't want overkill.

Just like not everyone needs an external amp, but most guys have at least one external amp anyway.

There's some 10 inchers that play pretty low. My Cerwin Vega SL- Series subs played as low as 28hz in my room and loved em before i bought an 18 incher. You're exactly right, overkill is an understatement. Overkill is fine as long as you understand reality. Im guilty of overkill. I have three Yamaha 350 watt per channel amps for all channels. Do i need it? No...but love the thought of having the overhead and dynamics. Especially with the JBL 590's....

 

[AcuDefTechGuy]

You do realize boosting your bass by 2db is "ILLEGAL' in this hobby?? If you do and people find out about it, you'll end up in a concentration camp for audiophile rejects lol.

If it doesn't sound great, then it is illegal.

There are different types of EQ. For one thing, Parametric EQ is much better than Graphic EQ, as Gene points out.

Another thing is which frequencies to EQ. Most audiophiles feel that EQ for frequencies below 200Hz is perfectly legal, but above 200Hz might be considered "illegal".

 

[AcuDefTechGuy]

There's some 10 inchers that play pretty low. My Cerwin Vega SL- Series subs played as low as 28hz in my room and loved em before i bought an 18 incher. You're exactly right, overkill is an understatement. Overkill is fine as long as you understand reality. Im guilty of overkill. I have three Yamaha 350 watt per channel amps for all channels. Do i need it? No...but love the thought of having the overhead and dynamics. Especially with the JBL 590's....

Then there's also the WIFE factor. Most wives would have issues with their dishes, cups, and windows rattling.

So not everyone needs a giant subwoofer. If your subwoofer sounds great, there is no need to replace it unless you just feel like it replacing it or adding nine more.

 

[panteragstk]

Then there's also the WIFE factor. Most wives would have issues with their dishes, cups, and windows rattling.

So not everyone needs a giant subwoofer. If your subwoofer sounds great, there is no need to replace it unless you just feel like it replacing it or adding nine more.

Did you ever measure your room to see what your subs are actually producing? I'm curious just because of the sheer number of them as well as the quality. Would be interesting for the REW thread.

 

[KirkJBL590]

If it doesn't sound great, then it is illegal.

There are different types of EQ. For one thing, Parametric EQ is much better than Graphic EQ, as Gene points out.

Another thing is which frequencies to EQ. Most audiophiles feel that EQ for frequencies below 200Hz is perfectly legal, but above 200Hz might be considered "illegal".

Gene as always would be correct...I have my sub at a subtractive EQ centered at 50hz down at 4-5db with a Q factor of 2.4 through a built in PEQ in the Outlaw 976. This brought down the levels between 40-60hz closer to flat so they weren't dominant in the bass and sounds much better where i can turn up the volume and fill the room more evenly. In my opinion, you need EQ for bass. You're always going to have peaks to deal with and especially around or at 50hz.