Lowest frequencies...........infrabass.

Lowest frequencies...........infrabass.

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Crackie

Original Poster:

6,386 posts

241 months

Saturday 18th April 2015
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Putting aside cinema systems for now, I'm interested to hear PHers thoughts on what low frequency limit you think is needed for convincing 'full range' playback of most music.

Orchestral music with contrabass Bassoons, Clarinets, Harps, Pianos has low frequencies down to 30Hz or so. Big church organs extend into the mid teens but....... how low do you think systems need to go for more contemporary music ?

Is there any benefit in reproducing bass in the 10Hz to 25Hz region ??

Over to you...


Badvok

1,867 posts

166 months

Saturday 18th April 2015
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I thought the lower limit for the human ear was typically 20. Plus deterioration with age, I'm not sure pursuing bass into the teens in worth it

Crackie

Original Poster:

6,386 posts

241 months

Saturday 18th April 2015
quotequote all
Badvok said:
I thought the lower limit for the human ear was typically 20. Plus deterioration with age, I'm not sure pursuing bass into the teens in worth it
20Hz to 20Khz is usually published but some can hear single tones down to 18Hz and most perceive/feel frequencies lower than that. I'm getting old but deterioration with age tends not to effect low frequencies only high so I'm trying to gauge opinion on whether or not people think reproducing these frequencies is worthwhile before I spend too much money.

Very few commercial products have serious output below 20Hz so I'm interested to hear from any PHers who have experience of these extreme low frequencies.
Opinion is divided regarding how important the infrasonic region is.



Edited by Crackie on Sunday 19th April 16:31

OldSkoolRS

6,717 posts

178 months

Saturday 18th April 2015
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Crackie said:
Putting aside cinema systems for now, I'm interested to hear PHers thoughts on what low frequency limit you think is needed for convincing 'full range' playback of most music.

Orchestral music with contrabass Bassoons, Clarinets, Harps, Pianos has low frequencies down to 30Hz or so. Big church organs extend into the mid teens but....... how low do you think systems need to go for more contemporary music ?

Is there any benefit in reproducing bass in the 10Hz to 25Hz region ??

Over to you...

I've built a pair of sealed 15" subs powered by a 1500 watt (RMS) amp each. They can go flat down to 10Hz at 110dB and then tail off below that to about 100dB at 6Hz. They do sound very clean for music (since they are hardly moving even at high listening levels) as the bulk of music bass seems to be around 40Hz or above. Of course I built them for home cinema use, though I do listen to CDs and concert discs through them as well. IMHO the very deep bass is of more use in films as it can add tension even though you aren't necessarily aware of why.

There are occasional music tracks such as James Blake 'Limit to your love' which has some very deep infrasonic bass in, though whether it makes much difference to the song if you can play that infrasonic bass is another matter (JB isn't my thing to be honest).

I think there is a big thread on AVForus in the subwoofers section where people post about songs with good bass, though whether they particularly discuss infrasonics I'm not sure. My feeling is that for music it is more important to have clean, punchy bass rather than absolute depth. It is more a by product of my set up that I achieve this with the depth, but I would give up the depth rather than the clean, punchy side if it were a choice. I previously had a BK Monolith sub which is ported and a 12" driver/300 watts. It had less depth (though no bad for it's price), but was a bit 'soggy' in terms of music bass...initially impressive due to the level, but grating after a while.

Crackie

Original Poster:

6,386 posts

241 months

Saturday 18th April 2015
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Hi OldSkoolRS, pleased to hear your subs are working well for you........I remember posting / commenting in your thread about them. http://www.pistonheads.com/gassing/topic.asp?h=0&a... How much EQ do you need to apply to achieve flat to 10Hz ?

I agree that reflex bass can often sound soggy but in my experience this usually happens with poor underdamped alignments. Well engineered reflex designs like active ATCs, B&W 800 series, Wilson Audio, Focal Utopia all produce superb bass.

Before your Fi subs came along, did ever try to fix the soggy bass on the Monolith by adding time delay to the rest of the system ?



Edited by Crackie on Sunday 19th April 16:45

OldSkoolRS

6,717 posts

178 months

Saturday 18th April 2015
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Yes, I tried using an antimode and then later I bought an AVR with Audyssey XT32. However I didn't like the effect it had on my main speakers (MK MP150) as it made them sound too shrill.

I sold the AVR with Audyssey and bought a cheap processor to tied me over (old Arcam AV8) so I'm running with just manual eq on the Fi and they still sound way better than the old Monolith did.

As an aside I'm thinking of buying a miniDSP eq device (DDRC88A) which has Dirac live room eq, so I'll have much better control of target curves for the other speakers (and house curve for the sub too).

Crackie

Original Poster:

6,386 posts

241 months

Saturday 18th April 2015
quotequote all
OldSkoolRS said:
As an aside I'm thinking of buying a miniDSP eq device (DDRC88A) which has Dirac live room eq,
You mentioned Lyngdorf room correction in this thread last year http://www.pistonheads.com/gassing/topic.asp?h=0&a... I posted a link to the MiniDSP Dirac products because I was looking at room correction too; it looked ideal for you but they didn't do DDRC88a at the time.

Still not got round to buying one myself yet but I've been considering Room Perfect / DEQX / Dirac live for a long time. The miniDSP4x10 active crossover I use has been a revelation and will probably get a DDRC22D later in the year.





Edited by Crackie on Sunday 19th April 09:02

OldSkoolRS

6,717 posts

178 months

Sunday 19th April 2015
quotequote all
I'd forgotten about that thread, probably as I read on so many forums, especially AV. boxedin I have heard the Lyngdorf option, but only at the dealers, so I'm planing a home demo along with a pair of smaller, but supposedly more musical subs. However it is only a 2.2 eq solution, so I have a feeling that the DDRC88A will be more suitable for me since I want to eq the centre and surrounds too. I'm going to another dealer for an open day in a few weeks time to hear the '88 in action, so will see how I get on.

I've been thinking that next year I might build a baffle wall and put 4 x 12" subs in the front of my room and move both 15" to the rear in a similar baffle wall, so all speakers/subs will be hidden. That should give me a pretty decent response according to REW room sim (and plenty of headroom) leaving the eq with less work to do. Might take a bit of setting up, but I reckon it would be worth it. smile

Crackie

Original Poster:

6,386 posts

241 months

Sunday 19th April 2015
quotequote all
OldSkoolRS said:
I'm going to another dealer for an open day in a few weeks time to hear the '88 in action, so will see how I get on.
I'd be interested to hear what you think ??.

OldSkoolRS said:
I've been thinking that next year I might build a baffle wall and put 4 x 12" subs in the front of my room and move both 15" to the rear in a similar baffle wall, so all speakers/subs will be hidden. That should give me a pretty decent response according to REW room sim (and plenty of headroom) leaving the eq with less work to do. Might take a bit of setting up, but I reckon it would be worth it. smile
Sounds like an plan........... good luck.

Crackie

Original Poster:

6,386 posts

241 months

Tuesday 21st April 2015
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Hi OldskoolRS, just a thought. If you're contemplating building an AV wall you have the option of building a 1/4 wave sub. or transmission line, or tapped horn. They're all cousins but their bass power and quality is on a different level to most conventional ( sealed or reflex ) subs.

The reason you don't see them very often commercially is because they have to be very big ( long ) to work in the deep bass. PMC fold theirs and B&W coiled theirs in the Nautilus but it would be easy to build one into an AV wall.

If you want the best, and it looks like you're serious about getting it right, its they way to go.

You know the driver used for this sim, 12" Peerless XXLS 830845, which is the one BK use, there are 2 in parallel. Input at the terminals is only 20V / 100watts. The voice coils are hardly warmed up, excursion is in the linear region and half way to mechanical x-max. thumbup The harmonics are messy higher up because its a tapped horn but this design is optimised to be linear below 35Hz and everything above that is chopped by DSP. I have the amp and drivers ready at home; cabinets are coming along.........


Edited by Crackie on Thursday 23 April 06:30

OldSkoolRS

6,717 posts

178 months

Tuesday 21st April 2015
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Funny that I was looking at Peerless drivers last night on Partsexpress website. However, for a sealed sub (which is my current plan) they aren't so suitable. I won't have masses of space for a folded horn, because there is a big window in the middle of the front wall. Therefore I was just planing on building it out enough to cover my on wall MP150 speakers and fit a shallow, but maybe 3' tall sub box on the wall in each corner. Then fill the gaps with acoustic treatment and cover the front with AT cloth.

Since I plan to recycle my existing 15" FiQ pair at the back of the room (again in shallow, but tall boxes) then I think I'll have to stick with sealed. Perhaps the Monolith put me off ported due to blowing the driver twice, but I feel happier with sealed as I've not been able to kill my current ones. smile

EDIT: I'll let you know how I get on at the DDRC88A demo.

Crackie

Original Poster:

6,386 posts

241 months

Tuesday 21st April 2015
quotequote all
OldSkoolRS said:
Funny that I was looking at Peerless drivers last night on Partsexpress website.
Perhaps the Monolith put me off ported due to blowing the driver twice, but I feel happier with sealed as I've not been able to kill my current ones. smile
The Peerless driver used in the Monolith would be happier in a sealed box or an enormous 200+ liter reflex box; asking it to play loud and deep in a relatively small reflex box could easily exceed x-max and damage the driver unless a very steep high pass filter is used.

I bought some of the drivers from BK and went down the 200+ liter reflex route.

Edited by Crackie on Tuesday 21st April 14:06

OldSkoolRS

6,717 posts

178 months

Tuesday 21st April 2015
quotequote all
If I had space for 2 x 200 litre boxes then it would be worth following up on looking at your response for such a low input signal. By comparison I have to put 1500 watts (RMS) into each of my subs to hit 110dB (at the MLP) as they are in fairly small boxes and sealed, so ported (and a large box) is much more efficient. I'd love an infinite baffle sub, but that isn't' possible.

I've been thinking that maybe I should just buy another pair of Fi Q15s, another iNuke6000DSP and then get four new boxes built. Same 60 litres volume, but as shallow as is possible to fit the speaker depth in. Put them in the 4 corners of the room, hidden 'inside' the front and rear false walls. Setting up 4 identical subs would be easier with only the delays to tweak (then the '88 would eq them as 'one').

It's all just at the ideas stage at the moment though. I like the results I get now, but no harm in trying to further improve things (I'm sure the '88 will help in this regard), but I also have an aversion to AV gear being visible, so I'm making things hard for myself by trying to hide all those subwoofer drivers, plus the 9/11 speakers once I go the full Atmos/DTS:X. I think I'm going to need a lot of AT fabric...

GT2CS

657 posts

168 months

Tuesday 21st April 2015
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My Stax Lambda Nova Signature earspeakers have a frequency response of 7Hz to 41KHz. A 10Hz tone can be 'heard' as a series of fast beats - 10 por second!
Bach toccata and fugue in d minor does sound really impressive.

Crackie

Original Poster:

6,386 posts

241 months

Wednesday 22nd April 2015
quotequote all
OldSkoolRS said:
If I had space for 2 x 200 litre boxes then it would be worth following up on looking at your response for such a low input signal. By comparison I have to put 1500 watts (RMS) into each of my subs to hit 110dB (at the MLP) as they are in fairly small boxes and sealed, so ported (and a large box) is much more efficient. I'd love an infinite baffle sub, but that isn't' possible.

I've been thinking that maybe I should just buy another pair of Fi Q15s, another iNuke6000DSP and then get four new boxes built. Same 60 litres volume, but as shallow as is possible to fit the speaker depth in. Put them in the 4 corners of the room, hidden 'inside' the front and rear false walls. Setting up 4 identical subs would be easier with only the delays to tweak (then the '88 would eq them as 'one').

It's all just at the ideas stage at the moment though. I like the results I get now, but no harm in trying to further improve things (I'm sure the '88 will help in this regard), but I also have an aversion to AV gear being visible, so I'm making things hard for myself by trying to hide all those subwoofer drivers, plus the 9/11 speakers once I go the full Atmos/DTS:X. I think I'm going to need a lot of AT fabric...
Just to clarify, the very efficient simulation above isn't ported it is a tapped horn; it also uses 2 drivers in parallel. The sim was made using Hornresponse software and is what I'm working on at the moment.

The 240L reflex loaded version only uses a single Peerless 830845 and is much less sensitive. Both subs will only be used below 30Hz; four, quarter wave loaded, Celestion Kevlar 12" drivers take care of 30Hz to 80Hz.

Here's the 240L ported simulation


Here are individual nearfield measurements of the port and the driver.


Unsmoothed Farfield in-room response with wide measurement window. The room modes make it look lumpy but the impedance measurement shows the 17.5Hz tuning and 'room averaged' measurements are extremely close to the simulation.


Finished speaker.


Edited by Crackie on Friday 1st May 16:26

OldSkoolRS

6,717 posts

178 months

Wednesday 22nd April 2015
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Nice work Crackie. smile

I did some measuring up last night and I reckon that the largest volume I can fit in each corner would be around 80 litres, partly limited by the positions of the (on wall) LCR speakers. I could go bigger at back of the room, but then the subs wouldn't all match. The current 19" cubes with bracing work out around 68 litres so I would have a slightly reduced Q with the new boxes.

This is the response I get from two of them measured at the MLP:


David A

3,602 posts

250 months

Wednesday 22nd April 2015
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Not much to add other than I have one of these fairly rare hobbies SVS PB12 ultra/2

http://www.hometheatersound.com/equipment/svs_pb12...
With these dimensions it's a wee bit excessive

Dimensions: 26"H x 19"W x 29"D
Weight: 190 pounds

Must get a much much bigger house.

OldSkoolRS

6,717 posts

178 months

Wednesday 22nd April 2015
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I like it David; I nearly bought a used one a few years back to replace my Monolith (which it would have swallowed whole I reckon in terms of bass output, let alone the smaller BK stuff...). You really need to be in a detached house (or have very deaf neighbours) once you get to that sort of bass output. smile

Crackie

Original Poster:

6,386 posts

241 months

Thursday 23rd April 2015
quotequote all
David A said:
Not much to add other than I have one of these fairly rare hobbies SVS PB12 ultra/2

http://www.hometheatersound.com/equipment/svs_pb12...
With these dimensions it's a wee bit excessive

Dimensions: 26"H x 19"W x 29"D
Weight: 190 pounds

Must get a much much bigger house.

David, that big SVS has impressive performance; I did consider their big 13-Ultra cylinder a while ago but carried away with building my own in the end.

The ported sub above is a wee bit excessive too
Dimensions: 48"H x 24"W x 16"D
Weight: 102 Kg / 224 pounds on scales at work.

Bigger house already sorted.thumbup current one went on the market yesterday.

telecat

8,528 posts

240 months

Thursday 23rd April 2015
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The Japanese Hifi Nuts have Horns built into their houses. Most just Like Horn Speakers.