What is ASP and how does it work?

[Pigmy Pony]

Been wondering about this.

Whether ASP (analogue signal processing) might help with a 'difficult' room, which mine is. I know less than nothing about this sort of thing. Is it something that can be used in a basic analogue set up (T/T, amp, speakers), and could it do something for room modes, and even help compensate for my ropey HF hearing? Or am I misunderstanding what such a thing is for?

[struth]

ive played with dsp in programs etc but not analogue bat the good old equalizer.

digitally it can work well. it can also be used with headphones

[walpurgis]

I assume ASP in an audio context relates to 'computer music' and involves equalisation. I'd think some kind of room acoustics analysis would be needed to get it right.

A graphic equaliser would possibly offer a similar end result.


(I have actually laid thousands of square meters of ASP 'artificial stone paving'. being one of the few qualified Mason Paviours in the country, but I don't think that's what you meant :))

[Pigmy Pony]

ive played with dsp in programs etc but not analogue bat the good old equalizer.

digitally it can work well. it can also be used with headphones

I have thought about equalizers (Macca has even kindly offered to loan me one) but I imagine it would need a lot of bands to be truly effective.

[Pigmy Pony]

I assume ASP in an audio context relates to 'computer music' and involves equalisation. I'd think some kind of room acoustics analysis would be needed to get it right.

A graphic equaliser would possibly offer a similar end result.


(I have actually laid thousands of square meters of ASP 'artificial stone paving'. being one of the few qualified Mason Paviours in the country, but I don't think that's what you meant :))

Yeah I imagine stone paving would do the acoustics no favours. Besides Mrs P prefers carpet.

[struth]

just get into digital and the world's your oyster steve

[Pigmy Pony]

just get into digital and the world's your oyster steve

Yes I have been giving it some thought, but it does make my brain hurt. And if I did I would be constantly pestering you over every little thing (which is everything!)

And I certainly wouldn't want to turn my back on my records.

[struth]

Yes I have been giving it some thought, but it does make my brain hurt. And if I did I would be constantly pestering you over every little thing (which is everything!)

And I certainly wouldn't want to turn my back on my records.

my phono stage can convert to digital on the fly and outs digi via usb or optical. you just have to think out of the old box a bit nowadays. When i was converting vinyl it would play analogue or digital at same time; no lag. i could alter things via pc too non distructively when copying. There is a whole new world to find tbh, and if i ever find a nice neat auto deck i could just play records digitally. lol:eyebrows:

[Pigmy Pony]

So could I go turntable>digitising phono stage>DSP>DAC>analogue amp? Or am I going all round the houses here and missing the point? I did warn you I'm not very clued up about this sort of thing :doh:

[struth]

So could I go turntable>digitising phono stage>DSP>DAC>analogue amp? Or am I going all round the houses here and missing the point? I did warn you I'm not very clued up about this sort of thing :doh:

you could i guess.

if youve a pc you could trial jriver and copy some cds to files and play them while playing with jrivers dsp settings and see if you find any improvements. if you do then it might be a viable idea

[Pigmy Pony]

Thanks for your suggestions Grant - no, I only have this crappy laptop which has no CD drive. I think I would only be interested in streaming music anyway, either from my phone, a cheap(ish) tablet or an actual streamer. But first off I was just thinking about how I could tweak things to sound better balanced in my less than ideal listening room.

I know there are certain room treatments that may help here, but I have to share this space with Anita and the telly. First World problems eh?

[sailor]

Hi Steve, experiencing problems with a difficult room? Well all rooms have modes :(
If you were to see a plot of your speakers in your room you would notice that from about 250Hz down to the lower limit of your system, the Schroeder frequency, a number of large peaks and nulls would be obvious. This is caused by bass energy bouncing around the room which combines constructively and destructively forming peaks and nulls respectively. Above the Schroeder frequency you are dealing with a reverberant field.

Unfortunately equalisation can only help a little. It can attenuate the peaks but can not fill in the nulls. A full null is no energy, that is, there is no sound, nada, zilch. It is MIA. No matter how much energy you pump into that missing information it will just cancel with the same energy. There are also partial nulls which may be 15dB. or more below the mean.

To increase sound by 3dB would require a doubling of power. To bring a null of -15dB up to the average level would require doubling 5 times. Scary stuff! Take a system operating with a 40W amplifier and double that 5 times means you will need to replace the 40W amp with one of 1.28KW. I don't know what speakers you are using but I doubt they will handle that power though they may be a good candidate for the 1812 Overture.

The long wavelengths causing this problem can be somewhat solved by introducing bass traps which must by necessity be rather large. If you find bass traps and absorbers unacceptable, all is not lost.

Introducing subwoofers can help this modal problem by randomising and increasing the number of modes. Instead of a few monster peaks/nulls you get lots more but significantly reduced to the point where equalisation is not needed. Imagine hearing for the first time all the detail from a double bass. There will be musical information heard which you were previously missing. The sound will take on something that will have you grinning while shaking your head in disbelief.

Now you may be thinking that you do not want to disturb your neighbours or be swamped by copious amounts of bass. In practice the neighbours will be less bothered. What the multi-sub does is just smooth out the bass. Though not essential, this whole setup can be viewed with an inexpensive mic. and a freeware program like REW.

The subs do not have to all match or be from the same brand and room setup is almost simple. Welti, Flloyd and Geddes are strong proponents and worth reading. Neither do the subs need to be huge.

I helped a mate with a very stubborn wife. I rounded up some 8" drivers, one of which was from and old pair of Bostons. We settled on a square footprint but tall enough to blend in. One sub was painted exactly the same colour as his wife's bookcase and made to be the same height. One was made to be a coffee table and the last to support a pot plant. This all took up very little extra space and was hardly noticed. The boxes were all sealed with woofer firing downwards. The tallest one next to the bookcase was larger than necessary, so to get the Q back to about 0.7 we simply placed some bricks inside.

The sub that measured the lowest was 3dB down at about 45Hz. This is not great as far as a sub goes but that is not the true reason for using them. What Andy got was an impressively flat response from about 50Hz upwards. No thunderous bass, just glorious music. There is of course still the problem of overly long decay across the full spectrum but that can only be addressed by introducing absorption.

If you can also install a few absorbers to tame overly long decay then you have optimised your room to the full. It is truly transformative. Paradoxically improving the bass improves the entire range.

[Macca]

Good post by Charles which is spot on - the only problem being that for either analogue or digital EQ to be effective you still need to start with loudspeakers that have a reasonably flat on axis and off axis response.

Sell the Zu speakers and move on from there.

[walpurgis]

I wouldn't worry about accuracy or what is 'right'. Aim for a sound you like (anybody who does otherwise is likely to end up dissatisfied).

Borrow Martin's graphic equaliser to play with, it'll be fun to use and may give you an idea of what direction to head in.

[dave2010]

Thanks for your suggestions Grant - no, I only have this crappy laptop which has no CD drive. I think I would only be interested in streaming music anyway, either from my phone, a cheap(ish) tablet or an actual streamer. But first off I was just thinking about how I could tweak things to sound better balanced in my less than ideal listening room.

I know there are certain room treatments that may help here, but I have to share this space with Anita and the telly. First World problems eh?I don't know enough about JRiver to know whether Grant's suggestions are going to work for you, but maybe not having a CD drive on your laptop isn't a huge barrier - though you would need to get one or two downloaded good quality download files to experiment with. There are even sites which have demo files which might be very good to try.

If you have other kit you can rip CDs there, and use USB sticks to transfer to your laptop. It certainly is possible to shape sound using software on a computer - add reverb, alter frequency response etc - using DAW (digital audio workstation) software - and to do it pretty much in real time. However how well it works may also depend on the processors in your computer. Laptops don't always have the best/fastest processors. Then another factor is what output to use from the laptop - the audio output from a laptop probably isn't great, but a USB output can be fed into a DAC. Note also, that if you were using the laptop to feed additional speakers, you could use your regular amp and speakers, but take a feed off to provide modified audio for other speakers around your room. For example, you might simply want to modify the bass, so use a sub woofer with its own amp, and tap off the audio routed via the computer

However, familiarising yourself with all that and testing is going to take time. As I've already said I don't know JRiver - but maybe it does some of what you might need without having to spend too much time tweaking parameters in a general purpose DAW. If you were to go multi-channel you could do even more - but with more software hardware required, and even more tweaking. I have a friend who has a room with around 15 speakers and is spending a modest fortune on amps and other kit for use with films. Apart from the kit and the costs of all that, his efforts also seem to involve "structural" work on his listening/viewing room - cutting holes in walls and ceiling for speakers and wires etc. Not to be undertaken lightly, I feel.

I liked sailor's suggestions - but again I think there'll be some considerable amount of work involved.

[Pigmy Pony]

Thank you guys for all your suggestions - to be honest, I know I would struggle badly then fail with any attempt at digital correction, no matter how simple that route may seem.

It looks like Barry's, Charles' and Martin's suggestions - graphic equalizers, subs, maybe even a change of speakers - they're all things i feel better qualified to have a go at. Maybe even another set of ears could be useful, although as Barry points out (and I totally agree) the aim shouldn't necessarily be accuracy, but rather a sound that works for me.

Martin - if you feel you could stand a few hours in sunny Chorley sometime in the New Year, I'd be more than happy to pick up and drop you off - I trust your judgement and experience in these things :) - and you can see for yourself what a total arse my listening room is.

[Macca]

Yes, we can do that anytime you want. I'll bring a 16 band Klark Teknik and we can try some analogue EQ and see how that goes for starters.

[Pigmy Pony]

Cheers Martin, I may even get some biscuits. Not sure which ones sound best though.

[AJSki2fly]

Thanks for your suggestions Grant - no, I only have this crappy laptop which has no CD drive. I think I would only be interested in streaming music anyway, either from my phone, a cheap(ish) tablet or an actual streamer. But first off I was just thinking about how I could tweak things to sound better balanced in my less than ideal listening room.

I know there are certain room treatments that may help here, but I have to share this space with Anita and the telly. First World problems eh?

I think that out of the box thinking is required. One suggestion would be to have a house re-design/extension, knock some walls out and do a new layout resulting in a better lounge/listening room. Another would be to consider another property that meets your needs for both of you. I am sure that Anita might be persuaded with either if she thought the end result would be an improvement overall. :D

[Pigmy Pony]

I think that out of the box thinking is required. One suggestion would be to have a house re-design/extension, knock some walls out and do a new layout resulting in a better lounge/listening room. Another would be to consider another property that meets your needs for both of you. I am sure that Anita might be persuaded with either if she thought the end result would be an improvement overall. :D

Both sound suggestions Adrian, but a couple of small points stand in the way: Firstly, it isn't our house. Secondly, Anita loves this place and would buy it tomorrow if we had a lottery win :) in which case I'd build a big ass listening room onto it. Who needs a garden anyway ;)

You are the only person on AoS who has seen what my room looks like (well in a photo anyway), but it's even odder in real life...