This is clearly wrong... The vast majority the Pro Audio / live sound industry choose "fast" bass and mid-range drivers (Fabric/linen surround with low Mms / high Bl large voice coil) and would simply laugh at the very thought of using an "Audiophile" "slow" driver (rubber surround / high /Mms low Bl). "Audiophiles" are quite happy to buy commercial "high end audiophile" speakers at £100,000 insane prices or DIY build speakers using these drivers at a fraction of the retail price... Either way the end products are equally flawed.
Lojzek, its sad that you believe applying DSP/Eq is so bad... Like you, the majority of "Audiophiles" and DIY community are quite happy to use the 100 year old "proven" design theory of passive crossovers with "Audiophile" drivers in a two or three way ported wooden box... Just check the posts in the speaker forum here.... An endless stream of "fresh meat" having just read the latest edition of the 100 year old "loudspeaker design Cookbook or similar scripture all seeking advice on the same subject ie "Help required for crossover design in two/three way Scan Spk/Seas/Accuton/ etc design" or " Advice on port dimensions for X,Y,Z, audiophile bass/mid" or "advice on cabinet volume for bass..."
For the last 10 years or so superb easy to use "Plug n' Play" DSP/crossovers/Eq and low cost power amplifiers are available at very affordable prices (Hypex / ICE Power, Mini DSP etc) and are now cheaper than "Audiophile" passive crossovers using unobtainium/snake oil capacitors/ inductors / resistors etc
Modern DSP/Eq solutions consistently give superb results with out any "black arts" or " legendary skills/experience" required, just follow the instructions and you get superb results.
I believe (YMMV) that for any given budget, the vast majority of DIY loudspeaker designers can achieve far better sound quality by using a "cookie cutter" two or three way sealed box with two or three Pro Audio "Fast" drivers Vs any combination of Audiophile "Slow" drivers with a passive crossover. In the case of a novice DIY, just the design and construction of a good passive crossover is a huge barrier to entry.
With DSP /active system you can simply pick almost any decent Pro 10 inch bass/mid and pair it with almost any AMT or dome tweeter / budget CD/horn and bolt them into a simple sealed box and you can almost guarantee great reults every time.
IE In one weekend you can build a great sounding pair of of loudspeakers:
Take almost any good" fast" Pro audio 8 or 10 inch bass mid from Beyma, B&C, Precision Devices,Ciare, RCF etc, (I love the Beyma 10 inch MMC 500) in approx 20 to 25 liters sealed box and a Beyma AMT TPL 75 or dome tweeter / budget CD/horn, in a small sealed box on top and you can easily build and Mini DSP / Eq your way to a great sound in a weekend.... No books or black magic required, just follow the online DSP video.
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Hi there,
i think we will not help Lehnok with some kind of philosophical debate about "slow" and "fast" drivers. From signal and system theory point of view the fast and slow thing can only apply to some kind of super full range chassis. A subwoofer driver with a low pass filter at 85 Hz do not need to be fast. One thing where for instance the Accuton driver excels is the complete abstinence of resonances in the working frequency range, look the CSD plot made here http://www.troelsgravesen.dk/SP44.htm
i think we will not help Lehnok with some kind of philosophical debate about "slow" and "fast" drivers. From signal and system theory point of view the fast and slow thing can only apply to some kind of super full range chassis. A subwoofer driver with a low pass filter at 85 Hz do not need to be fast. One thing where for instance the Accuton driver excels is the complete abstinence of resonances in the working frequency range, look the CSD plot made here http://www.troelsgravesen.dk/SP44.htm
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Hydrogen Alex, are you referring to high efficiency when you talk about ‘fast’? I hope so, otherwise you’re on the audiophiles track I’m afraid. My guess is Lojzek only meant in pro world it’s common to max out on requirements and then eq things reasonably flat (or as required). In pro audio efficiency, durability and light weight/small size are as important as sound quality. For most of us a not that needed mix of qualities.
About the CSD’s of Gravesen: are you kiddin? Look at the vertical scale… almost any metal cone does a better job.
About the CSD’s of Gravesen: are you kiddin? Look at the vertical scale… almost any metal cone does a better job.
Outside the work frequency range ceramic is known for serious resonances
There are two plots one with 20 dB Y-scale one with 40db Y-scale both 300 - 20000 Hz log X-scale and 0 - 3.4 ms Z-scale
Note that most of the others use 25dB Y-scale (CLIO default) and 400 - 20000 X-scale. With CSD plots it is easy to compare oranges with apples. There must be BTW a reason why Accuton drivers are adopted from super pro's like the engineers of Gauder Akustik i believe
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Here another CSD plot for a decent 50 mm Morel dome midrange driver for a kind of comparison, X-scale 200 -20000 Hz log, Y-scale 25db Z-scale 0 - 3.58 ms
as i said, you need some kind of good imagination to compare CSD plots with different scaling values
As far as i remember the theory it doesn't make a lot of sense to show more than 25 dB because of this:
https://en.wikipedia.org/wiki/Auditory_masking
as i said, you need some kind of good imagination to compare CSD plots with different scaling values
As far as i remember the theory it doesn't make a lot of sense to show more than 25 dB because of this:
https://en.wikipedia.org/wiki/Auditory_masking
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Hey Lehnok,
Based on the driver set you bought, I'll guess, you expect to achieve high quality sound and that's important to you. Otherwise, there is no point in buying such expensive drivers. You have an excellent choice of speakers and the right concept.
Yes, 10-15 inch large-caliber speakers give excellent midbass, but in your case they are not very suitable as they are not able to play proper the midrange up to 800-1000 Hz. A light, fast 8 inch midbass, something like B&C 8NDL64-8, would fit perfectly into your concept.
Ideal split frequencies would be:
But in this case, accuton has a small sensitivity of 89 db. You can't give it a +6dB gain as it will spoil the sound quality.
You can put two Accuton mids and level the frequency response in the shelf at 95dB.
Another option is to reduce the gain by -6dB for the rest of the speakers.
But there is another "but" in this concept
The narrowest point is the use of DSP. Undoubtedly, it is the easiest and fastest way to build a crossover today. But the DSP will be the bottleneck of the whole system. The sound quality will be at the level of a good hi-fi system and nothing more. It is not a high-end level system and you will not be able to realise the full potential of the used drivers.
If it is really important for you to get maximum sound quality, the best option is to use a hybrid active-passive crossover. A 3-way active analogue crossover - sub, midbass
and top (mid - tweeter ) - passive crossover is quite suitable.
This is the hardest way to go, but the result is worth it. So You will get the ultimative high end speakers.
Based on the driver set you bought, I'll guess, you expect to achieve high quality sound and that's important to you. Otherwise, there is no point in buying such expensive drivers. You have an excellent choice of speakers and the right concept.
Yes, 10-15 inch large-caliber speakers give excellent midbass, but in your case they are not very suitable as they are not able to play proper the midrange up to 800-1000 Hz. A light, fast 8 inch midbass, something like B&C 8NDL64-8, would fit perfectly into your concept.
Ideal split frequencies would be:
- Sub 18” up to 60Hz
- Midbass 8” from 80 to 800-1000Hz (don't pay attention to the gap between sub and midbass - everything will fit perfectly).
- Mid accuton from 800-1000 Hz to 3-4-5 kHz.
- Tweeter above 3-4-5 kHz
But in this case, accuton has a small sensitivity of 89 db. You can't give it a +6dB gain as it will spoil the sound quality.
You can put two Accuton mids and level the frequency response in the shelf at 95dB.
Another option is to reduce the gain by -6dB for the rest of the speakers.
But there is another "but" in this concept
The narrowest point is the use of DSP. Undoubtedly, it is the easiest and fastest way to build a crossover today. But the DSP will be the bottleneck of the whole system. The sound quality will be at the level of a good hi-fi system and nothing more. It is not a high-end level system and you will not be able to realise the full potential of the used drivers.
If it is really important for you to get maximum sound quality, the best option is to use a hybrid active-passive crossover. A 3-way active analogue crossover - sub, midbass
and top (mid - tweeter ) - passive crossover is quite suitable.
This is the hardest way to go, but the result is worth it. So You will get the ultimative high end speakers.
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Hi there, gaga_r makes some very good points. I have to mention although that the time alignment will be much more tough without DSP. You will have some misalignment between the mid-bass and the ceramic dome in a crossover range where time alignment gets crucial - 800 Hz is characteristic for the more or less nasal sound of a voice. Without DSP you need to correct the axis placement of the dome driver - like with a small waveguide. For the development of the speaker there is nothing faster than to go through the settings real quick with a DSP crossover. For instance with a decent measurement equipment and the DSP delay you can find out real quick with a first flat test baffle the value in mm for the time alignment between 8 inch cone mid bass and 2 inch dome driver
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All Right
I would decide to do separate enclosures. A la Wilson:
One for sub about 140L and midbass about 15L with a baffle. As a result, we'll get proper deep bass and a clear punch.
The other (narrow) is for the mid-tweeter.
Shift them along the z-axis
to get them perfectly phase-aligned.
And also play with baffle step compensation
Forgot to add, you can't get both deep bass and powerful punch at the same time in a 3-way as you can in a 4-way system.
Don't waste your time with experiments. 🙂
I would decide to do separate enclosures. A la Wilson:
One for sub about 140L and midbass about 15L with a baffle. As a result, we'll get proper deep bass and a clear punch.
The other (narrow) is for the mid-tweeter.
Shift them along the z-axis
to get them perfectly phase-aligned.
And also play with baffle step compensation
Forgot to add, you can't get both deep bass and powerful punch at the same time in a 3-way as you can in a 4-way system.
Don't waste your time with experiments. 🙂
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The Hypex DSP is used in a wide range of award winning high end studio monitors http://www.kiiaudio.com/ ... It is not a bottleneck in sound quality...
As per my simulation a few posts ago, I would run the 18 inch BMS sub woofer to 80Hz, then use a Beyma 12 inch P80 FE or Nd to cover 80Hz to 800Hz, then, if you must use the Accuton you will simply have to accept its low sensitivity as the "lowest common denominator" and just pull down all the other drivers to its level. But I would urge you to think hard... You could easily sell the Accutons and buy a superior performing pair of midrange drivers and then add on a high senisitivity AMT or similar tweeter.
The dedicated PHL midrange is used in this killer design by Tony Gee https://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Mezzo Galactica.pdf or this new variation which goes lower,
https://www.phlaudio.com/fileadmin/user_upload/phl_audio/1752NdU_SpecSheet.pdf or even this great driver from Celestion https://celestion.com/productpdf.php?id=995 would all be be way better in the 400Hz to 2KHz band.
As per my simulation a few posts ago, I would run the 18 inch BMS sub woofer to 80Hz, then use a Beyma 12 inch P80 FE or Nd to cover 80Hz to 800Hz, then, if you must use the Accuton you will simply have to accept its low sensitivity as the "lowest common denominator" and just pull down all the other drivers to its level. But I would urge you to think hard... You could easily sell the Accutons and buy a superior performing pair of midrange drivers and then add on a high senisitivity AMT or similar tweeter.
The dedicated PHL midrange is used in this killer design by Tony Gee https://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Mezzo Galactica.pdf or this new variation which goes lower,
https://www.phlaudio.com/fileadmin/user_upload/phl_audio/1752NdU_SpecSheet.pdf or even this great driver from Celestion https://celestion.com/productpdf.php?id=995 would all be be way better in the 400Hz to 2KHz band.
Hello,
I want to express my gratitude for all the responses and ideas provided.
Special thanks to gaga_r for sharing the information I was seeking!
Gaga_r, if I understand correctly, you are suggesting that passive components offer greater benefits to higher frequencies?
In the case of crossing over the tweeter and low treble passively, would it be appropriate to implement a bandpass filter for the mid treble and integrate it using an active crossover to the low-frequency drivers?
The Hypex DSP isn't bad, but for my deep regret it doesn't reach the sound quality of ess9038pro or ak4499 level dacs
Dear Alex,
I appreciate your input and insights.
I fully concur with your assessment that the Accuton driver may be the weak link in this setup. To optimize performance, it might be more sensible to utilize the Accuton driver in small monitors, accompanied by a high-quality hifi woofer like the Purifi.
Best regards, Konrad
Yes
You can use standard 3-way active analog cross like Bryston etc in the configuration:
Sub - up to 60Hz
Midbass - 80-800Hz
Mid tweeter - over 800Hz
Correspondingly 3 separate amplifiers
Mid - tweeter split passive.
It looks old-fashioned, but in this way you achieve the best possible sound quality.
Of course, you need phase alignments
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The Accuton is a great speaker and low sensitivity does not mean it "is a weak link."
You just have to get the right integration into your system.
If you decide to sell the acсuton, keep your concept.
The optimal split will be slightly different:
Sub 18" to 60Hz
Midbass 8" from 80 to 300-400Hz
Mid from 300-400Hz to 3-4-5 kHz.
Tweeter above 3-4-5 kHz
So look for a mid that plays well at 400-4000 Hz.
But this is not an easy quest either. 🙂
You just have to get the right integration into your system.
If you decide to sell the acсuton, keep your concept.
The optimal split will be slightly different:
Sub 18" to 60Hz
Midbass 8" from 80 to 300-400Hz
Mid from 300-400Hz to 3-4-5 kHz.
Tweeter above 3-4-5 kHz
So look for a mid that plays well at 400-4000 Hz.
But this is not an easy quest either. 🙂
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Then you could use a larger 10-12" midbass.
By using my concept and the above-mentioned highest quality DACs you will have no weak links in your system. Everything will fit together as harmoniously as possible.
Even if you have the best DACs in your system and you use The Hypex DSP or any other DSP, firstly there is double conversion, secondly the internal DACs in the DSP will not be as good as the external DACs.
also employing two separate enclosures and correctly calculating the baffle width and gain of each band you can fully compensate bafflestep
By using my concept and the above-mentioned highest quality DACs you will have no weak links in your system. Everything will fit together as harmoniously as possible.
Even if you have the best DACs in your system and you use The Hypex DSP or any other DSP, firstly there is double conversion, secondly the internal DACs in the DSP will not be as good as the external DACs.
also employing two separate enclosures and correctly calculating the baffle width and gain of each band you can fully compensate bafflestep
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Just for comparison... Check out the CSD of a nice Pro audio midrange...And this is with a 30dB impulse... Under 1 ms across the board!
https://audioxpress.com/article/test-bench-celestion-cf0617m-prosound-midrange-driver
https://audioxpress.com/article/test-bench-celestion-cf0617m-prosound-midrange-driver
Didn't someone say try the Beyma 12P80?😉
Didn't the OP say he was looking to build a 4 way DSP / active system in his first post?😉
As all digital sources can be directly connected and processed in the Hypex (or similar, there are several good options) there is no double conversion, and the internal DAC's are very good. Also this is a superb DSP digital in and digital out so you can use your DAC's... https://linea-research.co.uk/asc48/
The wide baffle / shallow cabinet greatly reduces any baffle step isssue... BS is just about the least important and easy to compensate for side issue, ie using good birch ply and internal damping materials is will benefit the sound more than small tweaks on BS wiggles in frequency response.
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You are right, for 95% of people it is good enough. But if we are talking about high end, then any existing DSP reaches the level of top external DACs like ess9038pro or ak4499. The question is what level of sound quality do you want to get. DSP has one undoubted advantage - simplicity and ease of use. But it is not the pinnacle of sound.
The 118dB dynamic range from your example can't compare to top DACs 126dB. Also 96kHz via 384 /768kHz sample rate. Also can't play DSD, etc.
The 118dB dynamic range from your example can't compare to top DACs 126dB. Also 96kHz via 384 /768kHz sample rate. Also can't play DSD, etc.
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Gaga, You do know that all digital music (including "classic" master tape and vinyl DSD releases) are all processed in digital studios?...
Now your point about dynamic range... No listening room and loudspeaker combination can ever even approach 118 dB or 126 dB range...? For example if you have a recording studio grade ultra quiet room the ambient sound level will be around 30dB ( https://www.lighthouseacoustics.co.uk/acceptable-sound-levels-explained/) so if you add on 118 dB SPL peaks from a massive pair of in wall full range monitors you would hit 148 dB.... Instant and permanent hearing loss, unconciousness and probable brain damage....
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