Do I need a subwoofer ?

[Ian J]

This is a question often asked and my guess is that most people will answer yes because we aren't representative of the general public as we all lurk in the subwoofer area of an AV Forum.

Regulars may recall a thread a couple of months ago asking whether anyone had heard the Joss Stone album "Mind, Body & Soul, specifically track 9 "Snakes Find Ladders" which contained unusually deep and powerful bass notes for a music CD which was sorting the men from the boys in wooferland.

I took this CD to Bristol with me and on two occasions asked them to play it. The first time was after listening to the tiny Tannoy Prestige Autograph Mini speakers which seemed to be pumping out surprisingly huge volumes of bass considering their diminutive stature. When playing Joss the speakers still sounded marvellous, clear and dynamic but those bottom bass notes had completely vanished.

We had another go with a pair of huge and ugly Meadowlark speakers which were supposed to go very low and this time whilst the bass notes were audible it wasn't with the power or depth that I can get out of this track at home using Ohio's favourite son.

I suppose that the answer to the question has to be "It depends whether you want to hear everything recorded on the disc in the manner that the sound engineer intended."

For anyone intending to demo a 5.1 system or even just a stand alone subwoofer it is well worth investing a few pounds in this CD and using it as a reference point in the various shops.

 

[Cable Monkey]

I will add comment even though you seem to have answered your own question! In my case I would say yes, but primarily because of the sort of music I listen to. Some of my earliest memories are going to parties with my parents (weddings and suchlike) which were invariably West Indian. I used to stand in front of the speaker stacks and feel the bass from the music ripple through me. In most music of African origin, bass is a lead instrument and so vitally important to the experience. I still try to reproduce that feeling I experienced back then and when I get close it is fantastic. Obviously using domestic hi-fi, a sub is vital in trying to get low. I can't fit a PA stack in my lounge!

 

[HiFiRuss71]

As per usual, interesting comment. Maybe the question should be: How much do you have to spend before you don't need a subwoofer?

In my years of doing the Hi-fi shows (and I've worked a couple), I, like you, was astonished at the amount of poorly engineered "exotica" on display.

As AV Types, we often forget that that the box in the corner, has easily the largest driver in the room with the single biggest amplifier attached. Being active, more of that power reaches the driver, due to the lack of power sapping cross-overs. Unlike a front speaker, that single unit is shorn of responsibilty to reproduce anything above 80Hz, so it has a very focused remit.

If you take a speaker like an ATC SCM100AL which sports a 12" driver in a 100 litre cabinet (SVS-PB12/Monolith size), that same size of driver is asked to reach up to 380Hz and the free air -6db point is quoted as 35Hz which doesn't sound all that staggering. In reality, in room, it will reproduce the deepest organ notes and maintain a continuous 115db at 1 metre. It should also be pointed out, that when the bass unit hands over responsibility for higher frequencies, it does so to a 75mm dome unit with a 7Kg magnet and 1/2" of travel (yes half an inch for a midrange driver).

These are properly engineered speakers. They are the ones that the recording engineers use. £11k a pair. Sounds like a lot, but if you pro-rata a pair of DD12s x3 and consider that the grade of mid and treble amps required are far more exacting than those required by a sub it doesn't sound unrealistic. For instance Velodyne quote distortion of 1% or less. 1% You couldn't sell a £200 stand mount with a figuer like that.

By going the route of the separate sub we tread the line of a very skillfully designed compromise that provides astonishing performance for the money. But sit in front of a pair of any of the large ATCs and you'll imediately know where the money went. The one caveat is that the source and the material played on it had better be impeccable. They will let you know if it is otherwise.

Anyhoo, that's my two peneth.

Russell

 

[ttree sound]

I also was at the Bristol show armed with a selection of CDs including the Joss Stone CD. Using the same track as Ian,I asked to play it to test out a subwoofer. Yes, the sub did touch the lowest notes but with nowhere near the texture and power to what I am used to hearing, so its a good track to differentiate between subs as well as speakers.

Whilst listening to the PMCs strutting their stuff (FB1 and GB1) in the demo room which incedentally both sounded pretty good and fullsome, a person standing next to me commented "you wont need a sub with them", I replied, "I think you'll find that a sub would totally transform the listening experience". The person looked at me with almost total distain!

Many people are missing out on the lowest of notes in music. Some would argue that music doesnt go much below 30hz, but it does, it really does. If only they had a sub capable of producing these frequencies would realise that most speakers this side of £5000 are simply not capable of producing the low notes with enough power to make it as enjoyable to listen to as a sub would.

Some of the subs I heard at the show were quite a dissapointment, partucularly with music. When I asked why were they so quiet I was told that they should be adjusted with a degree of subtlety, so I pose this question - How subtle do forum members like to adjust their subs?

Most of the manufacturers at the show were using their subs in multiples which is not really practical in a home environment I suppose, but the best sounding AV subs I heard were definately the M&k MX5100 in the basement which were part of a £100,000 setup.

 

[Ian J]

the best sounding AV subs I heard were definately the M&k MX5100 in the basement which were part of a £100,000 setup.

They were well integrated as was the big new REL sub underpinning the huge Vienna floorstanders but I agree many were not with the expensive PMC sub working with the wafer speakers being a good example, but that may have been room related.

The subtlest underpinning of the lot was in the Wilson Benesh room where the hugely expensive sub that isn't a sub was being used in conjunction with a pair of Arcs. It was so subtle that when they switched it off mid track I didn't notice any difference.

 

[Ilkka R]

This is a question often asked and my guess is that most people will answer yes because we aren't representative of the general public as we all lurk in the subwoofer area of an AV Forum.

Regulars may recall a thread a couple of months ago asking whether anyone had heard the Joss Stone album "Mind, Body & Soul, specifically track 9 "Snakes Find Ladders" which contained unusually deep and powerful bass notes for a music CD which was sorting the men from the boys in wooferland.

Here are a couple of spectrum graphs from that song. The bass line is around 28-36 Hz, with a single deepest tone at 26 Hz. Not really low for good subwoofers, but definitely a good test for speakers and lower quality subs.

 

[Etienne A]

Here are a couple of spectrum graphs from that song. The bass line is around 28-36 Hz, with a single deepest tone at 26 Hz. Not really low for good subwoofers, but definitely a good test for speakers and lower quality subs.

What software do you use for that? Can it be used to analize individually all the 6 (5.1) channels in a DD/DTS dvd?

 

[chrisgeary]

yes, I'd like to know what the software is that generates those analysis images.

 

[AngelEyes]

Yes, yes, then we can nerdily decide which are the best demo discs...

I'll let someone else spend their time doing that

 

[LostCause]

Not sure which one Ilkka is using but any resonable sound editor, cool, sound forge or wavelab with FFT (fast fourier transformation) will display a similar result. It is as I've long suspected that Miss Stone is not as low as some have been subjectively speculating. Listening to the sub will not tell how low something is. The better way is to rip the track to a WAV file or some other uncompressed format and run a fft analysis.

Re 5.1. It maybe the same software I've seen used on audioholics used on u571 and the haunting.

 

[paulst10]

yes, I'd like to know what the software is that generates those analysis images.

you can get it here ... http://people.freenet.de/dl4yhf/spectra1.html ...

i would also check this spectrum thread out as there are loads of graphs from films telling you low the bass is going .. http://www.avsforum.com/avs-vb/showthread.php?t=605496 ..

quote from the above thread .. Originally Posted by tkc
The charts are pictures of the sound spectrum in a movie over a certain time period. The person making the graph "records" the sound during playback of part of the movie. The numbers on the top indicate the frequency of the sound recorded, and the colours represent the level of the sound (in increasing order, blue, green, yellow, orange, red, pink, magenta. maroon, purple). The graphs are presented with the start of the recording period at the bottom of the graph, and the end of the recording at the top.

These are often used to show at what frequency the bass sounds in a soundtrack occur. For example, if a portion of a movie has a pink blob at 20 Hz on the graph, that indicates that there is a very loud 20 Hz component to the sound during that part of the movie, and that a reasonably good subwoofer is required to be able to play that back.

 

[AngelEyes]

Thanks Paul, glad to see someone has been to the trouble already