• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Suggestions for three-way crossover filters?

Tangband

Major Contributor
Joined
Sep 3, 2019
Messages
2,994
Likes
2,789
Location
Sweden
Thanks for suggestions! I will unfortunately put in a restriction. Camilladsp isn't that very DIY hard coding? Unfortunately, data programming is definitely not my thing.

I understand that the system with several amplifiers must be synchronized and in balance with each other. I have three power amps and a preamp, but then I need to be able to plug all of these together in a sensible way.I don't really understand this. Trying to see how I can get it together but hm...

I understand that the system with several amplifiers must be synchronized and in balance with each other.I have three power amps and a preamp, but then I need to be able to plug all of these together in a sensible way...hm...

In any case I have these drivers go play with:

Bass:
Maybe if I buy two more so it's double 10 inches in each box.

Midrange:


Tweeter:

Edit:
Incidentally, the midrange and tweeter are used in this DIY::)




I have some advices to you:).

1. Buy a 3 way dsp crossover with a digital input . A minidsp with only analog input is better than passive crossovers, but not really good sounding. Minidsp HD is better sounding but only for 2 channels.

2. You need good measurement gear, a good mic and a soundcard and a good program . You need to read how to do this in parallel with measuring and listen and look at the result. This will take a lot of time to understand that the mic dont hear sounds the way your brain/ ears hear. This learning process will take 2-3 years If you measure one hour every day . This is very fun and timeconsuming.

3. All measurements tell also lies. You have to read them the right way. Thereś no 100% thruth in what the measurements tells you.

4. Do the crossover frequency at the needed baffle step correction frequency - between the midbass and subwoofer.
use the formula made by Troels Gravesen = 11600/20 cm ( the baffle width ) = 580 Hz .

”Any driver mounted on a baffle will have an f3 = 11,600/width of baffle in cm. A driver mounted on a baffle of 20 cm with will be down 3 dB at 11,600/20 = 580 Hz. Making the baffle 50 cm wide the f3 is reduced to 232 Hz. Enough for a midrange driver working from 300-400 Hz to release its full potential without baffle step compensation.”



5. Use a polyprop capacitor protection in series with the tweeter , 22 uf or more.

6. school books filtering in a dsp is never correct - you have to measure everything. You have to eq and peq every driver mounted in the loudspeaker box with nearfield measurements . This takes a lot of time with measuring individual drivers on the loudspeaker baffle. Dont waste your time doing LTAS measurements from listening position- the result will only tell you lies above 300 Hz.

7. Buy or loan a good reference loudspeaker to compare with. I used a Genelec 8330 . This is important !

8. Dont expect to do better than the best reference loudspeakers in the first couple of years. The value is in the learning process.

9. DIY is great fun but maybe a big waste of time and money. Do it for the fun and learning and dont expect miracles. You cant do better than Genelec or Revel. They have the skills and we dont.

10. Your second hand selfmade DIY will be almost wortheless when you try sell it - no matter how good it is. If you pay 1500 dollars for the whole project you gonna loose money , maybe more than half of it, If you will sell your speakers.

11. The best audio affair is probably to buy a good second hand active loudspeaker. You will not loose much If you sell it later and the result will be good sounding. Maybe this is a boring advice, I know…

12. Construct your active loudspeaker treated the way it would sound good also with a passive crossover - meaning dont cheat on internal volume and directivity. You cant fool physics.

13. Read : ”Measuring loudspeakers by John Atkinson ” and buy Dr Tooles book and read it .
 
Last edited:

MAB

Major Contributor
Joined
Nov 15, 2021
Messages
2,138
Likes
4,790
Location
Portland, OR, USA
1. Buy a 3 way dsp crossover with a digital input . A minidsp with only analog input is better than passive crossovers, but not really good sounding.
All of these MiniDSP discussed here are digital input. The SHD also has A/D, which actually sounds quite good. But, we are talking about DSP crossovers here.;)
 

Tangband

Major Contributor
Joined
Sep 3, 2019
Messages
2,994
Likes
2,789
Location
Sweden
All of these MiniDSP discussed here are digital input. The SHD also has A/D, which actually sounds quite good. But, we are talking about DSP crossovers here.;)
Not what I read . Daniel said he had the cheapest minidsp without a digital input, and with an A/D that will blur the sound somewhat. Ok for subwoofers but not fullrange If the sound quality demands are high.
 

Tangband

Major Contributor
Joined
Sep 3, 2019
Messages
2,994
Likes
2,789
Location
Sweden
Two advices more for Daniel :

1. Dont trust the drivers TS from the factory or even test-reviews of driver TS on internet. They are never correct. A loudspeaker program can give you some advices, but they are never 100 %correct.

2. Dont buy midbass driveunits that have horrible breakups outside the crossover band . The SB15NBAC may look really good on paper but the breakups higher up in frequency can probably be heard in longtherm listening - no matter how steep you make the crossover . I can be wrong on this but…. My experience is that the best sound will be had with well behaved drivers. The best and hardest combination to find is both well behaved such and with high sensitivity.
 
Last edited:

dualazmak

Major Contributor
Forum Donor
Joined
Feb 29, 2020
Messages
2,823
Likes
2,951
Location
Ichihara City, Chiba Prefecture, Japan
But I am not selling my Sela power amp. That is because it is part of Swedish PA history. I assume it is balanced with it, see picture below. But there is no documentation about that amp.
Yes, it looks XLR balanced input with balanced "through out" (I assume).

I would like to recommend, however, HiFi home audio "power amplifiers" or "integrated amplifiers" (I selected) in your possible home highly sensitive multichannel multi-amplifier system. I know and experienced that some of professional "PA" amplifiers would not be suitable for home HiFi audio system in terms of total sound quality...

I think sizing the amps appropriately is probably the best way to go.... there is no need for a 150 watt amp to be driving a tweeter.
I fully agree on this point. Please carefully review my amplifier exploration journey in my project thread.

There, in my summary post here, I wrote;
(Almost) all of the home-use Hi-Fi amplifiers, I mean integrated amps and power amps, are designed for full range operation, i.e. to cover ca. 20 Hz - 30 kHz. This means that we should be very much careful in evaluating and selecting each amplifier to directly and dedicatedly drive each of the SP drivers, in my case woofers (WO), Be-squawkers (Be-SQ), Be-tweeters (Be-TW) and horn super tweeters (ST). These BE-SQ, Be-TW and ST are highly efficient in response to amp's power input.

And, this specific my post shares: "Even Greg Timbers uses "reasonable and budget" Pioneer Elite A-20 for compression drivers (super tweeters) in his extraordinary expensive multichannel stereo system with JBL Everest DD67000 which he himself designed and developed."
 
Last edited:

MAB

Major Contributor
Joined
Nov 15, 2021
Messages
2,138
Likes
4,790
Location
Portland, OR, USA
Not what I read . Daniel said he had the cheapest minidsp without a digital input, and with an A/D that will blur the sound somewhat. Ok for subwoofers but not fullrange If the sound quality demands are high.
You should read this thread!
As I said, we are specifically discussing MiniDSP with digital inputs.
Yes, MiniDSP has one low cost 2-way analog only crossover (the 2x4), but that isn't being discussed here.
The MiniDSP Flex 8 that was just linked and discussed in this thread is digital input, as can be seen if you had clicked on the link!
1660248800694.png
 

dualazmak

Major Contributor
Forum Donor
Joined
Feb 29, 2020
Messages
2,823
Likes
2,951
Location
Ichihara City, Chiba Prefecture, Japan
The MiniDSP Flex 8 that was just linked and discussed in this thread is digital input, as can be seen if you had clicked on the link!
Interesting, but the analog outputs are all unbalanced RCA...
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight

For HiFi multichannel multi-amplifier setup, I would like to suggest "all in balanced analog outputs (TRS or more preferably XLR)" into XLR-capable amplifiers, just as I summarized my amplifier exploration in my post here.

In this perspective, TOPPING DM7 (US$ 599!) with 8-Ch TRS balanced out (as well as OKTO DAC8PRO which I use) plus PC-based flexible GUI DSP software (like EKIO) would be nice choice, I believe.
 
Last edited:

MAB

Major Contributor
Joined
Nov 15, 2021
Messages
2,138
Likes
4,790
Location
Portland, OR, USA
Interesting, but the analog outputs are all unbalanced RCA...
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight

For HiFi multichannel multi-amplifier setup, I would like to suggest "all in balanced analog outputs (TRS or more preferably XLR)" into XLR-capable amplifiers, just as I summarized my amplifier exploration in my post here.

In this perspective, TOPPING DM7 (US$ 599!) with 8-Ch TRS balanced out (as well as OKTO DAC8PRO which I use) plus PC-based flexible GUI DSP software (like EKIO) would be nice choice, I believe.
They mention "Flexible I/O versions for unbalanced/balanced/digital connectivity Array".
I can only speculate... Are they planning on releasing a balanced version? I note that the 2-channel Flex offers three configs, Unbalanced, Balanced, and Digital:
1660252208630.png

Otherwise, agreed that there may be issues going with unbalanced.
I actually ran a 4x10 HD with the Unbalanced RCA to a 3-way system using a stack of Bryston amps. I also ran the same with balanced inputs, and had good success with both. I was a little surprised, I may be the exception, and agree with your caution. The Bryston amps have a ground lift provision for the inputs, but it didn't make a difference to my non-issue!;)

If the Flex Eight is going to offer a balanced output version, I personally would certainly go with that.
 

dualazmak

Major Contributor
Forum Donor
Joined
Feb 29, 2020
Messages
2,823
Likes
2,951
Location
Ichihara City, Chiba Prefecture, Japan
Yes, I have (had) some confusion on miniDSP series' output configurations; unbalanced, balanced, and combination of the two!

Therefore, I actually visited;
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight
to check and confirm, and found that in "miniDSP Flex Eight", all the 8-Ch analog out are "RCA unbalanced"...

If the Flex Eight is going to offer a balanced output version, I would certainly go with that.
Agree, but unfortunately not the case with present Flex Eight.
 
Last edited:

MAB

Major Contributor
Joined
Nov 15, 2021
Messages
2,138
Likes
4,790
Location
Portland, OR, USA
Yes, I have (had) some confusion on miniDSP series' output configurations; unbalanced, balanced, and combination of the two!

Therefore, I actually visited;
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight
to check and confirm, and found that in "miniDSP Flex Eight" all the 8-Ch analog out are "RCA unbalanced"...


Agree, but unfortunately not the case with Flex Eight.
If you look at the top of the Flex Eight Page that makes me think they are going to offer balanced version.
1660253657433.png

I sent a message to MiniDSP to clarify if they do indeed plan to offer balanced and digital versions.

Time for some humor. This is what they need to do;):
1660253844628.png
 

dualazmak

Major Contributor
Forum Donor
Joined
Feb 29, 2020
Messages
2,823
Likes
2,951
Location
Ichihara City, Chiba Prefecture, Japan
Agree, but I am afraid that some people would have possible misunderstanding and confusions that your "prepared/manipulated hope photo" above would be current real miniDSP Flex Eight;)

Yes, in;
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight
their description of "Flexible I/O versions for unbalanced/balanced/digital connectivity Array" at the top is really confusing and misleading, and it has inconsistency with their spec description of "Outputs: Unbalanced (RCA)"...
 

MAB

Major Contributor
Joined
Nov 15, 2021
Messages
2,138
Likes
4,790
Location
Portland, OR, USA
Agree, but I am afraid that some people would have possible misunderstanding and confusions that your "prepared/manipulated hope photo" above would be current real miniDSP Flex Eight;)

Yes, in;
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-flex-eight
their description of "Flexible I/O versions for unbalanced/balanced/digital connectivity Array" at the top is really confusing and misleading, and it has inconsistency with their spec description of "Outputs: Unbalanced (RCA)"...
The Flex Eight is a just released product. I did just ask their support if they plan on additional release of balanced I/O configs as they have on the Flex. I will report what they tell me. Like you say, a balanced version is the desired path for most who want to do an active system.

Hope my humor doesn't confuse too many people. I never know what to think!;) Or maybe I have a bad sense of humor...
 

Doodski

Grand Contributor
Forum Donor
Joined
Dec 9, 2019
Messages
20,753
Likes
20,785
Location
Canada
The Flex Eight is a just released product. I did just ask their support if they plan on additional release of balanced I/O configs as they have on the Flex. I will report what they tell me. Like you say, a balanced version is the desired path for most who want to do an active system.

Hope my humor doesn't confuse too many people. I never know what to think!;) Or maybe I have a bad sense of humor...
Looks to be a exceptional product. I'm not into surround sound and Dirac but it is offered with Dirac Live License (Full Range) as a option. How good is Dirac at what it does?
 

dualazmak

Major Contributor
Forum Donor
Joined
Feb 29, 2020
Messages
2,823
Likes
2,951
Location
Ichihara City, Chiba Prefecture, Japan
Hello again OP @DanieIT,

"Availabilities of repair, maintenance and overhaul services on SP drivers as well as amplifiers and DACs" is also the issue you need to seriously consider; please refer to my posts:
- Availabilities of repair, maintenance and overhaul services on my Yamaha SP drivers, Fostex SP drivers, as well as amplifiers I use in this multichannel multi-amplifier project: #584, #67(remote thread)
 
OP
DanielT

DanielT

Major Contributor
Joined
Oct 10, 2020
Messages
4,752
Likes
4,633
Location
Sweden - Слава Україні
The Flex Eight is a just released product. I did just ask their support if they plan on additional release of balanced I/O configs as they have on the Flex. I will report what they tell me. Like you say, a balanced version is the desired path for most who want to do an active system.

Hope my humor doesn't confuse too many people. I never know what to think!;) Or maybe I have a bad sense of humor...


Hello again OP @DanieIT,

"Availabilities of repair, maintenance and overhaul services on SP drivers as well as amplifiers and DACs" is also the issue you need to seriously consider; please refer to my posts:
- Availabilities of repair, maintenance and overhaul services on my Yamaha SP drivers, Fostex SP drivers, as well as amplifiers I use in this multichannel multi-amplifier project: #584, #67(remote thread)

Aha, new products, as well as old ones. This with reliability, durability, service, maintenance, warranty and so on.I follow my father's old advice he had about new car models. He said, never buy the first year model of a new car. It can have childhood diseases. In his time it may apply to cars, but I think it may also apply to HiFi electronics these days.

Old stuff that lasts. My Sela power amp that I mentioned earlier was built sometime in the 80s. Built to last, with quality components. Now with new electrolytic capacitors in the power supply part, it will last. I don't even know if they needed changing but my friend had new electrolytes at home and it was so easy to change them anyway. They fit well on the card.:)

Speaker. Well, refoaming a pair JPW P1. 8 inch bass element VIFA M21WG-09-08. After that was done, they work just fine. My parents got them and they have had them for over a year now. Playing music with them on a daily basis. Incidentally, they are powered by a receiver, Luxor 5082A. That receiver is from the late 70s. Works without any trouble.:)

So there are things that last.


 

Tangband

Major Contributor
Joined
Sep 3, 2019
Messages
2,994
Likes
2,789
Location
Sweden
Looks to be a exceptional product. I'm not into surround sound and Dirac but it is offered with Dirac Live License (Full Range) as a option. How good is Dirac at what it does?
Looks good.
 
Last edited:
OP
DanielT

DanielT

Major Contributor
Joined
Oct 10, 2020
Messages
4,752
Likes
4,633
Location
Sweden - Слава Україні
Yes, it looks XLR balanced input with balanced "through out" (I assume).

I would like to recommend, however, HiFi home audio "power amplifiers" or "integrated amplifiers" (I selected) in your possible home highly sensitive multichannel multi-amplifier system. I know and experienced that some of professional "PA" amplifiers would not be suitable for home HiFi audio system in terms of total sound quality...


I fully agree on this point. Please carefully review my amplifier exploration journey in my project thread.

There, in my summary post here, I wrote;
(Almost) all of the home-use Hi-Fi amplifiers, I mean integrated amps and power amps, are designed for full range operation, i.e. to cover ca. 20 Hz - 30 kHz. This means that we should be very much careful in evaluating and selecting each amplifier to directly and dedicatedly drive each of the SP drivers, in my case woofers (WO), Be-squawkers (Be-SQ), Be-tweeters (Be-TW) and horn super tweeters (ST). These BE-SQ, Be-TW and ST are highly efficient in response to amp's power input.

And, this specific my post shares: "Even Greg Timbers uses "reasonable and budget" Pioneer Elite A-20 for compression drivers (super tweeters) in his extraordinary expensive multichannel stereo system with JBL Everest DD67000 which he himself designed and developed."
My guess. Home HiFi with few components, short lengths of signal cables, speaker cables. Take a simple setup: Speakers, amplifier and let's say a CD player. Only that. Balanced is probably not needed then.

But within PA. They have the stuff they have because they need to have that stuff. They need balanced. That's because, contrary to the example with the home hifi above, they plug in more stuff, more cables, longer ones and so on.

So with increased numbers of various gadgets in home HiFi, several different amplifiers, DACs, miniDSPs and so on then the more need for balanced, I suspect.:)
 

Tangband

Major Contributor
Joined
Sep 3, 2019
Messages
2,994
Likes
2,789
Location
Sweden
Simulate the tweeter to mid with software + DSP and make a passive filter, IMO. Save the DSP/active for the bass filter. Passive bass filters tend to require large and more expensive components.

This also gives protection for the tweeter and may lower distortion and compression a tiny bit if you drive the tweeter with a higher resistance.
This suggestion is suboptimal for sound quality . I have tried it and you loose transparancy in the treble, no matter how good the passive crossover is, compared to a 3 way dsp crossover like dbx pa2.
You can add a resistor to the tweeter when you go active to get theoretical lower dynamic compression, but my listening test shows the opposite-you get a more dynamic sound with low impedance coupling in most cases.

Dont waste your time with passive crossovers, as Linkwitz used to say.:)



”Crossovers may be implemented either as passive RLC networks, as active filters with operational amplifier circuits or with DSP engines and software. The only excuse for passive crossovers is their low cost. Their behavior changes with the signal level dependent dynamics of the drivers. They block the power amplifier from taking maximum control over the voice coil motion. They are a waste of time, if accuracy of reproduction is the goal.”
 
Last edited:
OP
DanielT

DanielT

Major Contributor
Joined
Oct 10, 2020
Messages
4,752
Likes
4,633
Location
Sweden - Слава Україні
I have some advices to you:).

1. Buy a 3 way dsp crossover with a digital input . A minidsp with only analog input is better than passive crossovers, but not really good sounding. Minidsp HD is better sounding but only for 2 channels.

2. You need good measurement gear, a good mic and a soundcard and a good program . You need to read how to do this in parallel with measuring and listen and look at the result. This will take a lot of time to understand that the mic dont hear sounds the way your brain/ ears hear. This learning process will take 2-3 years If you measure one hour every day . This is very fun and timeconsuming.

3. All measurements tell also lies. You have to read them the right way. Thereś no 100% thruth in what the measurements tells you.

4. Do the crossover frequency at the needed baffle step correction frequency - between the midbass and subwoofer.
use the formula made by Troels Gravesen = 11600/20 cm ( the baffle width ) = 580 Hz .

”Any driver mounted on a baffle will have an f3 = 11,600/width of baffle in cm. A driver mounted on a baffle of 20 cm with will be down 3 dB at 11,600/20 = 580 Hz. Making the baffle 50 cm wide the f3 is reduced to 232 Hz. Enough for a midrange driver working from 300-400 Hz to release its full potential without baffle step compensation.”



5. Use a polyprop capacitor protection in series with the tweeter , 22 uf or more.

6. school books filtering in a dsp is never correct - you have to measure everything. You have to eq and peq every driver mounted in the loudspeaker box with nearfield measurements . This takes a lot of time with measuring individual drivers on the loudspeaker baffle. Dont waste your time doing LTAS measurements from listening position- the result will only tell you lies above 300 Hz.

7. Buy or loan a good reference loudspeaker to compare with. I used a Genelec 8330 . This is important !

8. Dont expect to do better than the best reference loudspeakers in the first couple of years. The value is in the learning process.

9. DIY is great fun but maybe a big waste of time and money. Do it for the fun and learning and dont expect miracles. You cant do better than Genelec or Revel. They have the skills and we dont.

10. Your second hand selfmade DIY will be almost wortheless when you try sell it - no matter how good it is. If you pay 1500 dollars for the whole project you gonna loose money , maybe more than half of it, If you will sell your speakers.

11. The best audio affair is probably to buy a good second hand active loudspeaker. You will not loose much If you sell it later and the result will be good sounding. Maybe this is a boring advice, I know…

12. Construct your active loudspeaker treated the way it would sound good also with a passive crossover - meaning dont cheat on internal volume and directivity. You cant fool physics.

13. Read : ”Measuring loudspeakers by John Atkinson ” and buy Dr Tooles book and read it .
Thank you Tangband! Good tips. The fact that it can take time and that you need to learn is nothing that deters me. On the contrary, that's the fun. Then I have something to do in my spare time.

I have bought the UMIK-1 measuring microphone. Thought of doing some different measurements outdoors with the elements placed on a baffle.:)

Calculation programs for the construction of loudspeakers are, luckily, easy to come by these days.

General about used HiFi. Anyone who is interested can find out roughly what the prices of used hifi are. Approximately. You can buy and sell for roughly the same price. But DIY I know that you don't get that money back when you sell your stuff. But DIY for me because it's fun. It doesn't matter if I can't sell the stuff then. You should have fun for the money you earn.:D

Used active speakers a little more difficult to predict the price on the used market from what I think I see.

Measuring loudspeakers by John Atkinson ” and buy Dr Toole's book and read it. Sounds like a very sensible tip.

2. Dont buy midbass driveunits that have horrible breakups outside the crossover band . The SB15NBAC may look really good on paper but the breakups higher up in frequency can probably be heard in longtherm listening - no matter how steep you make the crossover . I can be wrong on this but…. My experience is that the best sound will be had with well behaved drivers. The best and hardest combination to find is both well behaved such and with high sensitivity.
Regarding SB15NBAC. What you are saying is exactly what I was thinking about. Is a steep filter enough? Maybe maybe not?

Revel seems to have done well in and of itself. Although it's Revel and not me. He he.:D

 

MAB

Major Contributor
Joined
Nov 15, 2021
Messages
2,138
Likes
4,790
Location
Portland, OR, USA
Looks to be a exceptional product. I'm not into surround sound and Dirac but it is offered with Dirac Live License (Full Range) as a option. How good is Dirac at what it does?
I've used Dirac with 2-channel but not with with multi-channel. I like it. I imagine it would be even more useful for surround, but I have never tried a surround sound implementation with Dirac. Some of the features are questionable to me like the tight vs. wide image focus feature, perhaps I haven't given that one a chance...
I allows you to apply most any 'preference' curve you wish for instance.
It can only address certain problems. If you have a strong room mode, it will fail to correct and even do harm. If you have other reflection issues, it will not correct. If you have a speaker with a fundamental problem, it will not correct.
It is somewhat useful to measure your room and speaker/subwoofer placement. If you didn't have REW, you could use Dirac to do some basic room and speaker evaluation.
 
Top Bottom