Regarding improving soundstage via acoustic design (or by reducing cabinet diffraction effects)

[Decadent_Spectre]

Yes. I used JRIVER's DSP studio for implementing a DSP crossover + EQ. Attached pic-1 shows the filters I wanted to implement. Pic 2 shows a snapshot of JRiver's DSP studio in which I implemented it. It works well.

Regarding taking only horizontal, I was lazy to do more measurements with the prototype box shown in pic-3 . My goal was just to convice myself that Jriver can do this. In any real build I will take horizontal and vertical polars.

If one can's purpose gets fulfilled with IIRs, it is the way to go. Less processing power required and nice transfer functions can be obtained in magnitude response. However one has to live the phase response yielded by the magnitude response. WIth FIRs one can tune magnitude response and phase response independently of each other. To one's heart's content. Penalty is more processing power.

You should definitely try a proper outboard DSP rather than JRiver, I've found they sound better to me at least. Cheaper options would be the miniDSP or Behringer DCX2496.

If that is a DIY cab I can see what you mean by compact and looks. It looks good, I reckon purple would have looked even better.

I agree about phase/magnitude of IIR vs FIR.

 

[Vineethkumar01]

You should definitely try a proper outboard DSP rather than JRiver, I've found they sound better to me at least. Cheaper options would be the miniDSP or Behringer DCX2496.

If that is a DIY cab I can see what you mean by compact and looks. It looks good, I reckon purple would have looked even better.

I agree about phase/magnitude of IIR vs FIR.

Thank you. I will definitely buy a good DSP. At least for the convenience it offers if not for anything else.
On my shortlist as of now is the MiniDSP 4x10 HD. There are (seemingly) better open source DSPs like the freeDSP project, upon which I have been looking with a lot of enthusiasm.. But if it doesn't come up properly in the next year or so I will go the miniDSP route.
All this fiddling around with software DSPs was just for my own education.
Also the cabinet/baffle in the above pic, I carved out of 50mm insulation foam material. Hence the blue color.
The objective with it was to prototype the mid + tweeter enclosure, study the tweeter performance on that waveguide, study taking dual channel measurements and implement a DSP crossover. I think it has served its purpose well so far
I will make the final cabinet for that project hopefully in the coming months..

 

[Decadent_Spectre]

Thank you. I will definitely buy a good DSP. At least for the convenience it offers if not for anything else.
On my shortlist as of now is the MiniDSP 4x10 HD. There are (seemingly) better open source DSPs like the freeDSP project, upon which I have been looking with a lot of enthusiasm.. But if it doesn't come up properly in the next year or so I will go the miniDSP route.
All this fiddling around with software DSPs was just for my own education.
Also the cabinet/baffle in the above pic, I carved out of 50mm insulation foam material. Hence the blue color.
The objective with it was to prototype the mid + tweeter enclosure, study the tweeter performance on that waveguide, study taking dual channel measurements and implement a DSP crossover. I think it has served its purpose well so far
I will make the final cabinet for that project hopefully in the coming months..

I'm confident you will find it different, if not better.

The mini has never interested me, I've always used pro audio based DSPs. The mini is a stellar value though. With your interest in theem, I'd think you'd want to use PC based DSP for all the raw power and flexibility they offer.

Look forward to what you do. I still think a small (but deep) enclosure like the one linked with slanted 6.5"/8" mid/woofs and two slotted ports and a waveguide/horn with a CD could offer a compelling solution rather than a traditional bookshelf if your inclined to go with CDs. I remember years ago there was the SEOS project which I think you may have liked. They might still be available of diysoundgroup. Have a look!

 

[Vineethkumar01]

I'm confident you will find it different, if not better.

The mini has never interested me, I've always used pro audio based DSPs. The mini is a stellar value though. With your interest in theem, I'd think you'd want to use PC based DSP for all the raw power and flexibility they offer.

Look forward to what you do. I still think a small (but deep) enclosure like the one linked with slanted 6.5"/8" mid/woofs and two slotted ports and a waveguide/horn with a CD could offer a compelling solution rather than a traditional bookshelf if your inclined to go with CDs. I remember years ago there was the SEOS project which I think you may have liked. They might still be available of diysoundgroup. Have a look!

Thanks a lot. I have found this discussion very useful.
I am even more convinced now that I need to go the horn, CD route.
I have heard about the the SEOS project. Never looked it up seriously yet. I will do that now.
My current project as a 3way floor standing tower will go on and in parallel I will educate myself more about CD+horn configurations for the next one.

 

[Kannan]

Some of the finest DSPs you will find are 12 volt ones made for car. Very advanced with floating point processing and very good quality DACs.
I place these leagues ahead of miniDSP.

Some options:
Helix:
https://www.audiotec-fischer.de/en/helix/processors/
https://www.audiotec-fischer.de/en/brax/processors/

Audison:
https://www.audison.eu/product_lines/bit/

Mosconi:
https://mosconi-system.it/1549-2/

Dayton Audio DSP: Comes with 12 volt adapter for powering at home.
https://www.daytonaudio.com/product...gital-signal-processor-for-home-and-car-audio

Some of the audiophile grade car audio active head units if you are lucky to find are
Clarion HXD2 (4-way active), Pioneer P99RS (4 way active), Eclipse CD7200 mkii (3-way active)
Pioneer P80RS (3-way active)

Kenwood has 3-way active head units in their current line-up which you check on their website,

 

[Decadent_Spectre]

Thanks a lot. I have found this discussion very useful.
I am even more convinced now that I need to go the horn, CD route.
I have heard about the the SEOS project. Never looked it up seriously yet. I will do that now.
My current project as a 3way floor standing tower will go on and in parallel I will educate myself more about CD+horn configurations for the next one.

Most welcome.

If going CDs please make sure to investigate. I'd recommend BMS,TAD,Faital,Beyma. Stay away from B&C IMO.

What drivers are you using for this 3 way?

Kannan, are those car audio DSPs? They don't seem pro to me.

 

[Kannan]

Kannan, are those car audio DSPs? They don't seem pro to me.

Yes.

 

[Vineethkumar01]

@Kannan : Thanks for these links for Car audio DSPs.. I will look them up..
@Decadent_Spectre : In my curren project, the drivers are:
1) Satori WO24P-8: Woofer
2) SB acoustics SB15CAC30-8: Mid
3) SB acoustics SB26CDC004 on an elliptical waveguide: tweeter
Crossover to be implemented in DSP.
I will look up these proaduio brands. I am familiar with BMS and faitalpro, and beyma. I had searched around for BMS 5s117 sometime back. But long waiting times etc in India. So didn't eventually choose it.
Anyway I have a lot of time to do some research.. I will study about the theroy behind horns first. Really a lot of activity happening around this on diyaudio with mabat's ATH4 software for making one's own horns etc since last 2 years..

 

[Decadent_Spectre]

Just remembered, have you looked at AE drivers for midrange and woofers?

 

[Vineethkumar01]

Just remembered, have you looked at AE drivers for midrange and woofers?

No. I haven't. In fact when I started planning this project, I only had some good home audio drivers in mind. Mostly because of my lack of knowledge/exposure to what all were available at pro audio level and because I started planning everything with "compactness" ( and the mild SPL levels that I would allowed at home) in mind.
Recently when I started looking at pro audio offerings, i find very interesting drivers and designs. Just now I looked at AE website and I find beautiful looking (without knowing anything about sound quality of those) projects like these:

Doug's DIY TD12M - SEOS12 / DNA-360 LCR

These beautiful 3way DIY speakers are finished in crotch mahogany veneer with automotive 2k metallic paint baffles. They use the TD12M along with the SEOS12/DNA-360 compression driver combo and CSS SDX15's for low end reproduction.

aespeakers.com

UB151's with Dipole15's and AH300's - Alain Ciarraighe's pursuit of Audio Perfection

B&C DCM50 modified field coil compression drivers and Dipole15's in UB151 U-Baffles make up this system processed by Larry Owens modified DEQX processors and powered by Bob Smith modified Nuforce amplifiers.

aespeakers.com

 

[Decadent_Spectre]

The AEs claim to fame is low inductance, while I am no driver expert, John at AE has explained this allows the driver to put the voice coil where it needs to be, offering more detail and control, properly tracking the signal. They are a bit frail for what they are, but if you aren't out and out hammering them, they are a good option for "SQ" drivers. They also have very good top end extension.

AFAIK they have no Indian distributor so you'd need to import them.

 

[Vineethkumar01]

The AEs claim to fame is low inductance, while I am no driver expert, John at AE has explained this allows the driver to put the voice coil where it needs to be, offering more detail and control, properly tracking the signal. They are a bit frail for what they are, but if you aren't out and out hammering them, they are a good option for "SQ" drivers. They also have very good top end extension.

AFAIK they have no Indian distributor so you'd need to import them.

Thanks. I am no driver expert either. From what I have heard, the Satori woofers I have are amongst very well regarded low inductance woofers at home audio level. But probably nothing compared to pro audio drivers and nothing compared to low frequency extension of optimized pro audio drivers, Anyway, good knowing about these..

 

[Decadent_Spectre]

I don't know about home audio drivers so much, brief look seems to say it looks fine, proof is in the pudding of course. I'm sure it will sound good once adjusted to taste.

I doubt you'd find anything with lower inductance than the AE drivers. Pro audio drivers are not actually designed for max extension, the car/home stuff is more optimized for that.

Maybe you could use the AE in the possible future CD/Horn build?

 

[Vineethkumar01]

I don't know about home audio drivers so much, brief look seems to say it looks fine, proof is in the pudding of course. I'm sure it will sound good once adjusted to taste.

I doubt you'd find anything with lower inductance than the AE drivers. Pro audio drivers are not actually designed for max extension, the car/home stuff is more optimized for that.

Maybe you could use the AE in the possible future CD/Horn build?

Thanks. I will definitely consider AE if it is available at justifiable prices (after import) once I try a CD/Horn project in future.
But since now I don't know much and I am just in the studying/long "literature survey" part of this entire domain of CD/horn related stuff, I don't know where I will end up.
One thing I like for sure is the idea of directivity/pattern control to the lowest octave (simply to satisfy my curiosity around this and nothing related to sounding better). CD/Horn seems like a natural route to take at least as of now. I am also toying with ideas around cardiod/super cardiod radiation patterns down to reasonably low frequencies where there will definitely be an efficiency vs directivity trade off I have to handle. So good quality woofers are a must in that aspect.
Hopefully I will end up somewhere good with this.

 

[Decadent_Spectre]

The duty is about 30% CIF value so you can roughly calculate your landed cost.

Your probably aware of this but to get low frequency directivity/pattern control you need a large cabinet, large horn and a large mouth. These types of enclosures are rarely found in pro audio as the size,weight and expense becomes prohibitive for a market where these issues are important. You do find some large cabinets but after a point it seems to taper off where they favor running multiples in a "stackable" approach. I personally think in general all things equal low frequency pattern control can sound better but preferences vary of course. You must have also seen djks (I think this was his handle?) posts about the PPSL if you are on diyaudio.

Please remember that CDs in general can sound a bit metallic compared to domes, IME.

 

[Vineethkumar01]

The duty is about 30% CIF value so you can roughly calculate your landed cost.

Your probably aware of this but to get low frequency directivity/pattern control you need a large cabinet, large horn and a large mouth. These types of enclosures are rarely found in pro audio as the size,weight and expense becomes prohibitive for a market where these issues are important. You do find some large cabinets but after a point it seems to taper off where they favor running multiples in a "stackable" approach. I personally think in general all things equal low frequency pattern control can sound better but preferences vary of course. You must have also seen djks (I think this was his handle?) posts about the PPSL if you are on diyaudio.

Please remember that CDs in general can sound a bit metallic compared to domes, IME.

Ok..
I have not followed djks but now I will search for djks on diyaudio and his projects.
At least as of now, my cardiod bass ideas revolve around resistance enclosures like in Kimmo Saunisto's experiments here (ideas similar to the Dutch & Dutch 8C):

Cardioid bass

and/or DSP-assisted multi-driver cardioid pattern generation like the one used in Kii audio speakers. Kimmo is well known for his cardiod constructions I think. Horn takes over at higher frequencies.
Still early days for me to comment about all this. So I many not stick around with these ideas later.. But I will explore..

 

[Decadent_Spectre]

Not too familiar with cardioid, IIRC it aims to gain directivity by using phase cancellation? Requires more drivers and power for given output level. Often used in pro audio to keep the sound where they want it. About right?

Good luck!

 

[Vineethkumar01]

Not too familiar with cardioid, IIRC it aims to gain directivity by using phase cancellation? Requires more drivers and power for given output level. Often used in pro audio to keep the sound where they want it. About right?

Good luck!

Yes you are right. That is a good summary of the idea..
Thanks.

 

[Vineethkumar01]

@Decadent_Spectre: Seems like B&C had released a design with driver configuration similar you were mentioning earlier.. I found it interesting. Hence sharing here
Pic attached.
Link to design here (215-DCX) : https://www.bcspeakers.com/en/resources/suggested-designs
Video here:

 

[Decadent_Spectre]

Yes, they used to be pretty popular because they are effective. The depth limits their use for some applications, a regular WTW is also similar but without the angling the efficiency of the woofers in the midbass suffers as well as cohesion. There may be some loss of directivity too in the midrange/midbass.

Edit: The models I had seen earlier were more angled/deeper and hence provided more efficiency in the midbass, if depth isn't an issue it's certainly preferable IMO.