DSP

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MartinC

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I started using room correction recently-  MiniDSP HD, originally I hoped to cut off woofers in my speakers fairly high - around 100-120Hz to relieve my amplifier from all hard work but I wasn’t very impressed with the changes it made to the sound . In the end I’ve tried running pre out into amp section through DSP with everything bypassed, conclusion was A/D and D/A conversion definitely does something to the sound which I wasn’t very keen on . In the end I decided to use another pre out going to DSP to correct and fill bottom end below 60Hz without cutting off woofer ,sounds much better but I’m still experimenting as SVS subwoofer has its own equalisation which I use to bump lows before applying DSP. Still long way to go but it’s early results are promising . 
Do bear in mind how cheap a 2x4 HD is in the context of the rest of your system - it is a very good value unit but higher performance options exist. 

Good to see you're making progress re. the sub  :) .

 
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tuga

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For the little that I think is wrong with my system, I’m not sure what the benefits would be, would be interested to know though. 
 

not sure what I would do about it in the physical sense, there would be no chance of room treatments.
@Blzebub is mistaken. If/when you can't correct the room then EQ is the alternative.

It doesn't have to be digital, but you will need to measure the response at the listening spot to find out the exact offending frequencies in order to design the Parametric EQ filters.

 

MartinC

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If you're using a single subwoofer then the crossover to the main speakers should be 80Hz or below, no wonder it didn't sound good.
I think it's more nuanced than this...

One key factor is the crossover filter used, with steeper crossover filters (both high and low-pass) allowing a higher crossover filter to be used. I crossover at 100 Hz but with 48 dB/Octave LR filters, which lets through far less higher frequency content than the 80 Hz crossover on my Blu-Ray player since the latter has a much slower roll-off filter.

The other key factor is the response at the listening position from each speaker and the subwoofer, which you may have been alluding to with your 'or below'. If for example the main speakers covered 80 Hz but the sub had a big dip in the response at this frequency at the MLP then a lower crossover would be more appropriate.

Time/phase matching in the crossover region is another consideration that may affect someone's choice of crossover frequency.

 
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tuga

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I think it's more nuanced than this...

One key factor is the crossover filter used, with steeper crossover filters (both high and low-pass) allowing a higher crossover filter to be used. I crossover at 100 Hz but with 48 dB/Octave LR filters, which lets through far less higher frequency content than the 80 Hz crossover on my Blu-Ray player since the latter has a much slower roll-off filter.

The other key factor is the response at the listening position from each speaker and the subwoofer, which you may have been alluding to with your 'or below'. If for example the main speakers covered 80 Hz but the sub had a big dip in the response at this frequency at the MLP then a lower crossover would be more appropriate.

Time/phase matching in the crossover region is another consideration that may affect someone's choice of crossover frequency.
I assumed that @mac72 knew how to set up a sub, but it's always a good idea to provide a primer.

My view is that 2 subs would be better (and a 4 to 6 sub array best for getting the flattest bass and sub-bass at the listening spot) but UK houses just aren't audiophile friendly...

 

mac72

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If you're using a single subwoofer then the crossover to the main speakers should be 80Hz or below, no wonder it didn't sound good.

According to Stereophile's measurements the port on your Ref201/2 is tuned at 50Hz but its operating band is on the wide side so at 60Hz you are still hearing the port.

I would try crossing at 75-80Hz with a high-pass on the Kefs, but perhaps you like the sound of the port. :dunno:
Crossing over bit higher with one subwoofer is not an option in my room as it reveals quite a dip above from 70Hz up so I need to cut it around 60-65Hz also I don’t use crossover on speakers as I wasn’t very taken on digital to analog conversion taking place in MiniDSP , probably as Martin mentioned I should try something more high end , maybe analog crossover . 

You’re right about 50Hz port tuning frequency which is quite pronounced, surprisingly subwoofer addition and DSP applied to subwoofer only smoothed that region a bit plus there is a gain in a lower bass , early days as I was away skiing over the Xmas and new year period and didn’t have a lot of time to play with.

 
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Blzebub

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For the little that I think is wrong with my system, I’m not sure what the benefits would be, would be interested to know though. 
 

not sure what I would do about it in the physical sense, there would be no chance of room treatments.
Have a look at this, from 43:38 for about 5 mins.

 
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Andrew_C

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No one serious  advises EQing above the low bass so 1kHz is fatuous, and it really straightforward to EQ for a second listening position.

 

eddie-baby

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1 hour ago, Blzebub said:

Have a look at this, from 43:38 for about 5 mins.

That is interesting, but people do often make up these things to please themselves or to suit their ideas a lot of the time. The AD DA thing aside with 'most' DSPs, lets just say equalizers then for arguments sake do the same thing as faffing with a room. Audio is made up of frequencies and these frequencies can be adjusted that bit doesn't have to be complicated. If you've a problematic room or even mismatched equipment just eq it, what's wrong with doing that.  





 

tackleberry

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That is interesting, but people do often make up these things to please themselves or to suit their ideas a lot of the time. The AD DA thing aside with 'most' DSPs, lets just say equalizers then for arguments sake do the same thing as faffing with a room. Audio is made up of frequencies and these frequencies can be adjusted that bit doesn't have to be complicated. If you've a problematic room or even mismatched equipment just eq it, what's wrong with doing that.  



Does that mean he has made it up?

 

tackleberry

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I suppose I should have really said at the start of the feed and despite people bucking these trends as progress,  I feel bamboozeled by the reinvention of the hifi wheel, and wonder if it’s necessary.

Maybe if I had more time/inclination to appreciate the workings of streaming gear, dacs and eq’s I might see the benefit, but honestly I would just want someone to come and do it for me!

 
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AJSki2fly

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I suppose I should have really said at the start of the feed and despite people bucking these trends as progress,  I feel bamboozeled by the reinvention of the hifi wheel, and wonder if it’s necessary.

Maybe if I had more time/inclination to appreciate the workings of streaming gear, dacs and eq’s I might see the benefit, but honestly I would just want someone to come and do it for me!
If you want to get a view of what can be done with DSP then get a full blown demo of some Meridian gear.  Yes I know it is not everyones cup of tea and some hate it, and is quite costly, but they have been producing some rather high quality digital gear for many years now and are pretty respected for it.

I believe their current systems and those for at least the past 20 years or more have built in sophisticated DSP so that the ideal set up can be implemented for the room in which the system is put in. In theory achieving the best possible listening experience, I presume it also gives you the opportunity to play around endlessly with different soundscapes depending on your mood.

 

tackleberry

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If you want to get a view of what can be done with DSP then get a full blown demo of some Meridian gear.  Yes I know it is not everyones cup of tea and some hate it, and is quite costly, but they have been producing some rather high quality digital gear for many years now and are pretty respected for it.

I believe their current systems and those for at least the past 20 years or more have built in sophisticated DSP so that the ideal set up can be implemented for the room in which the system is put in. In theory achieving the best possible listening experience, I presume it also gives you the opportunity to play around endlessly with different soundscapes depending on your mood.
I’ve not looked at what you have yet but I’m sorry to say but one of the systems I heard that sounded pants was a rather expensive meridian setup. 
 

I thought it was all bass and fizzy tweeter.

 

Blzebub

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All I'm trying to say there is fashions with hifi, one minute its no tone controls, then its every tone control under the sun DSP. Then its room acoustics. A lot of it is just continually trying to sell the consumer something.



Tone controls and room acoustics aren't new, and DSP is just a posh tone control. There are downsides to altering the direct sound from the loudspeaker.

The OP hasn't posted his room dimensions, but from a photo it looks to be a good large room, with a sloped ceiling IIRC.

I would advise playing a pure-tone sweep at reasonable level from 20-400Hz. If there are no obvious anomalies with this, or with music, I wuld forget all about DSP. If there are anomalies, these can often be ironed out by careful repositioning of the speakers and listening position.

 

AJSki2fly

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I’ve not looked at what you have yet but I’m sorry to say but one of the systems I heard that sounded pants was a rather expensive meridian setup. 
 

I thought it was all bass and fizzy tweeter.
I had a Merdian 500 series system with non Meridian speakers some years ago and it sounded pretty good, but that was just prior to them getting into serious DSP. I have heard mixed reviews of their current offerings. My system is quite old school apart from it has a digital feed as well as Vinyl input.

 

uzzy

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I'm a little surprised at this observation. The vast majority of rooms I've been in at hifi shows over the years use neither DSP-based EQ to compensate for room effects, and the few that have some acoustic panels in them are a long way from having enough/the right type to be considered to have effective bass-trapping.
Probably very true - now one would think that someone trying to push their gear on the public would want to make it sound its best.  So as from observation very few use DSP (I have seen quite a few using bass traps) is it conceivable they don't like it? or know nothing about it? or just do not give a damn 🤣

 

MartinC

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I suppose I should have really said at the start of the feed and despite people bucking these trends as progress,  I feel bamboozeled by the reinvention of the hifi wheel, and wonder if it’s necessary.

Maybe if I had more time/inclination to appreciate the workings of streaming gear, dacs and eq’s I might see the benefit, but honestly I would just want someone to come and do it for me!
FWIW my gut feeling is that DSP isn't really something that you need to be worrying about exploring. Am I right that you're currently very happy with the sound of your system, and have a rather large room?

 

Andrew_C

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Probably very true - now one would think that someone trying to push their gear on the public would want to make it sound its best.  So as from observation very few use DSP (I have seen quite a few using bass traps) is it conceivable they don't like it? or know nothing about it? or just do not give a damn 🤣
Just ignorant of the importance of the speaker and room, countless rooms at shows ( when there was such a thing) with boomy bass which could be easily fixed, I guess there is more money and less hassle shifting boxes.