FAST PPSL+TB W4-1320SIF design study sugestions

[jirm]

Hello everyone.

I'm an old rookie in the design and construction of audio gears. Old because for over 20 years I have been in the "scene" of the audio as passionate amateur builder trying achieve very good audio qualitty but my focus has been exclusively on the study and contruccion of electronic for audio so the "transducers " never have been in my "mint".
New because in the past I'm always have used and runspeaker cabinets from third parties and mainly bought from some comercial reputable manufacturers.

Now I've decided it's time for new challenges creating my own designs and constructions of the speaker cabinets, and to begin after thinking and thinking which could be a good project to start, and mainly what can fit my current skills (almost null) on design and make "physical" construction of the spakers, I believed I could be able to design and build with success something kind of FAST cab.

So I ask your expertise suggestions, tips, options, criticism (please but that not are so hard as to take away my dreams for ever), and any comment you can think.

My idea would be to create a FAST enclosure with a good enough (excel but cheap ) driver Full Range on top in a TL box that achieves with solvency 150Hz on low range and up to 20kHz with enugth flat frequency response on + - 1dB.

To complete the low band spectrum I think it likely would complement a true subwoofer (not just a woofer) that can actually reach 30Hz maintaining the maximum deviation of + -1 dB in the frequency spectrum.
After seeing some whens designs subwoofer I believed I could run a sub PPSL design, although once studied I have not seen any good information about this applied in home design, as teachers of the SLPP subs as DJK, Waltersys, etc .. mainly they have been made constructions for PA, and those who have made designs SLPP for domestic use like Less Hudson, and others diyers have not published results (measures) of their buildings.
But I think I should give it a try or at least make a good preliminary study for this case, until someone of you (or perhaps no one gets) make me change my opinion.

So here I put all the study that I have done so far so that you have to analyze and comment well all that ye believe on (and please repeat not are super bad guys).

There we go:

Some considerations that I have ben are:
- FR driver sensibility have to match PPSL (92db/1W/1m)
- XO cut arround 150 Hz , and maynly on natural roll off frecuency of FR response. To achieve this FS (75Hz) on FR driver need be enougth low to have 1 oct low rom xo frec.
- SAG Calulation for PPSL driver siteon horizontal plane

SAG= Cms*Mms*G 0,00058*0,0307*9,8 = 0,000175m = 0,175 mm

Cms = m/N
Mms = Kg
G=9,8 m/s

%SAG=(SAG mm/XMAX mm)x100 (0,175/9,5)*100= 1,85%

So seems SAG is low enougth from 5% min.

Thats all for now.
Keep wating your coments and recomendations.

Best for all !!

 

[badman]

Rotate that manifold 90 degrees to prevent woofer sag, is a start.

 

[jirm]

Thanks for your sugestion badman !.

I calculate SAG and seems not an issue.
You can see in the first post that numbers.

Drivers are small 8" and light 30 grams Mms.

Regards

 

[xrk971]

This was the basis of the woofer for my FAST setup at one point.

http://www.diyaudio.com/forums/full...arlson-6th-order-bandpass-26.html#post4226956

 

[jirm]

This was the basis of the woofer for my FAST setup at one point.

http://www.diyaudio.com/forums/full...arlson-6th-order-bandpass-26.html#post4226956

X so may thanks for your input.

Sure your woofer setup can match my design, but I belive PPSL can really "punch" feeling lower and mostly with clean bass like a true subwoofer not that a "simple" woofer setup, but I dont know enougth.
I like ear any other sugestion about PPSLor the FR purposse (what are the real cons) that you can give me will be for me a pleasure . Belive me you are here my first bulider that I always follow your adventures.
Last i think PPSL is a easy enougth build to make with no worries about enclosure construction.

Best regards X.

 

[xrk971]

Here is a slot loaded sub with XPS foam and two 5in drivers.

http://www.diyaudio.com/forums/subwoofers/258433-light-air-slot-loaded-band-pass-sub.html

 

[jirm]

Here is a slot loaded sub with XPS foam and two 5in drivers.

http://www.diyaudio.com/forums/subwoofers/258433-light-air-slot-loaded-band-pass-sub.html

X Thanks so much for your reply

I know very well your thread about that build SLOT loaded.
That and other threads have inspired me and confirmed the idea about a sub with SLOT are more than advisable to go for build of sub that can achieve high efficiency, low distortion, and a sound very very balanced, fast, dinamic and deep and although go with a vent design I think can mantain controlled frec delays (GD) kept in acceptable levels without so much adverse effects on listening.

I studied few designs with SLOT and I think specifically the SLPP design is perhaps the most advantages and benefits versus cons provided.

I would like you to comment me your opinon and advices about my general idea (about this type of FAST) and specifically about all the simulations I have attached, as well as the idea of trying to put the crossover as low as 150Hz cut.

Will be for me a pleasure read your analises about my humble aproach to the speaker cab buids.

My best wishes !

 

[jirm]

No one have any other sugestions or criticism or some analisys about my sure bad sims that I atach here???

I'm start thinking my idea it's really so bad than anyone have coments on that

I start thinking that I have not made a good start my career in this type of buids

 

[Mayuri]

Lets see...

For one, I wouldn't use a 4" FR driver as the top range. They beam A LOT at higher frequencies. It's probably a cliché at this point, but I'd recommend the Vifa TC9FD for that. I made a similar project with that as the FR driver, and was positively surprised by the sound quality. You can order a pair of them for about 40e to everywhere in EU from for example ebay. The top enclosure looks good for them, you could even consider closing the narrow end of FR TL with heavy damping. If it doesn't go against your plans, maybe move the FR driver off-center. Edge is a good program on simulation baffle diffractions, you can check a good place with that. You can also round the enclosure corners to minimize baffle step.

The bottom range also looks good, although I am not very fond of BR enclosures for subwoofers, and would rather do a closed sub if it was for myself. Also for aesthetic purposes I'd switch the top bass driver the other way around, so the cones are facing eachother

You probably have much more experience with electonics, but I'd recommend bi-amping with 1st order PLLXO. Had good results, will use again

 

[Godzilla]

I have both the 1320 and TC9 and think they are worthy competitors. Personally, I think they both are a bit recessed in the treble (more so the 1320) but they are both clear thru a very broad midrange. I choose to listen to both with a helper tweeter.

I'm interested to see what you decide to do with the bass.

https://speakerprojects.wordpress.com/2015/12/14/vifa-tc9-plus-helper-tweeter-on-open-baffle/

https://speakerprojects.wordpress.com/2015/04/27/tangband-1320-projects/

 

[hajj]

Jirm,
Super interesting project, especially for me since I was planning on doing the same thing
A couple of questions though:
1- Why don't you go with a sealed enclosure for the FR driver?
2- Will you be using an active or a passive XO?
In case you go active, there is no need to match driver sensitivity

Regards,

Nick

 

[jirm]

Lets see...

First of all thank you so much for your comments Mayuri.
Really thank you.


For one, I wouldn't use a 4" FR driver as the top range. They beam A LOT at higher frequencies. It's probably a cliché at this point, but I'd recommend the Vifa TC9FD for that. I made a similar project with that as the FR driver, and was positively surprised by the sound quality. You can order a pair of them for about 40e to everywhere in EU from for example ebay. The top enclosure looks good for them, you could even consider closing the narrow end of FR TL with heavy damping. If it doesn't go against your plans, maybe move the FR driver off-center. Edge is a good program on simulation baffle diffractions, you can check a good place with that. You can also round the enclosure corners to minimize baffle step.


""I will have into account what you says about baffle diffraction and I will use EDGE to see what happens. I would like if you can provide further clarification me a little more because you think the "beam" of 4 inches is much higher than the 3.5 Vifa "which is so similar in size, and also that aduible effects has that" beam ".
Of course I have considered the Vifa TC9FD and I think it was my first choice (after I put the simulation on it) ... but there are several reasons why I have not finally considered "the most appropriate".
- Vifa TF9 has a much lower sensitivity (arround 86dB/1w/m in my simulation) that make it very difficult either at the junction with the sub simulation that gives an efficiency of 92dB.
- Frequency response at the bottom seems to be much more critical (fs = 115Hz en Vifa versus fs=75Hz en w4-1320SIF TB) to cross to 150Hz with a margin of 1 octave below, to ensure the right response crossover.""

The bottom range also looks good, although I am not very fond of BR enclosures for subwoofers, and would rather do a closed sub if it was for myself. Also for aesthetic purposes I'd switch the top bass driver the other way around, so the cones are facing eachother

""Totally agree that the BR has serious limitations and many problems to not "dirty" the quality of the response, but I think PPSL is a different design where the SLOT and generally all your design achieves a radically different behavior to a BR " standard "minimizing many of their problems. In any case I want to comment that I have heard some of the best low bass boxes with ventilated designs. JBL, and others use historically (I remember the sound of JBL 43xx series, for me even insurmountable) and currently this design for your reference models.
So why not give it a try this design sub?""

The drivers that are placed oppositely (cone - magnet) is a prerogative of design PPSL. This is disposion of drives that can more efficiently get the profile manyfold get the best frequency response and get turn the cancellation of nonlinear distortion.
Here we talk extensively the topic:
http://www.diyaudio.com/forums/subwoofers/177905-thread-those-interested-ppsl-enclosures.html

You probably have much more experience with electonics, but I'd recommend bi-amping with 1st order PLLXO. Had good results, will use again

Totally agree with that PLLXO 1st order xo seems will be perfect but I'm go active on xover (and multi-amp for each driver and DSP) so I can try unlimited for best working xover and overall response.

Will see...

Best to you !

 

[jirm]

Jirm,
Super interesting project, especially for me since I was planning on doing the same thing
A couple of questions though:
1- Why don't you go with a sealed enclosure for the FR driver?
2- Will you be using an active or a passive XO?
In case you go active, there is no need to match driver sensitivity

Regards,

Nick

Many thanks for your comments Nick

Well...I´m happy to see someone that "think" some like me...Maybe I´m not totally mad at least

Maybe we can "walk" together...But I have to warn you that I am a lousy builder and very very very slow !!!!

1.- Sure sealed on FR can work maybe better, but I belive that 150Hz xover point determines a needed so low response from the little FR at least reach consistently near 80 Hz (at -3dB) for good xover profile matching.
So the option of a "mini" TL can greatly help lower the FR response enougth without impairing too mutch his frec response versus sealed option.

2.- Totally agree. Maybe it's not really a problem matching efficiency of the two systems drivers, but I think that matching also determines largely properly response of crossovers and totally affect "linearity" of the overall phase and frequency response according SPL changes.
So I think it's very very convenient to have that matching to avoid some weird problems and avoid disappointment.
But I agree that it is something that perhaps should not be considered too important, just something I wanted.

Best !!!

 

[jirm]

I have both the 1320 and TC9 and think they are worthy competitors. Personally, I think they both are a bit recessed in the treble (more so the 1320) but they are both clear thru a very broad midrange. I choose to listen to both with a helper tweeter.

I'm interested to see what you decide to do with the bass.

https://speakerprojects.wordpress.com/2015/12/14/vifa-tc9-plus-helper-tweeter-on-open-baffle/

https://speakerprojects.wordpress.com/2015/04/27/tangband-1320-projects/

Woow Godzilla. Thank you so much for your inputs !

I will review that projects that you provide me and will be perfect for see real performance about these small FR.

Very very interesting that perhaps remain somewhat "short" in response on highs. You think may we have look for other better alternatives in FR drivers ? or will you think it is near impossible avoid to complement with some kind of "super-twetter" for all woole system really "shine" as it should?

So far in the "zone" sub I keep my idea of going to a PPSL, but still think I have to mature a lot more the idea, and I would love to have the opinion of some expert (reach bat-radar call DJK ?? ) that can validate my simulation BassBox attempt I've done with that little 8" Gradient drivers. My sims outputs seems too much good to be true.

Security here I will put all my progress ... when achieved.

My best wishes !

 

[badman]

Thanks for your sugestion badman !.

I calculate SAG and seems not an issue.
You can see in the first post that numbers.

Drivers are small 8" and light 30 grams Mms.

Regards

They'll sag over time, which is more the issue than the immediate loss of a tiny amount of Xmax. No reason to have it configured in a way where that's an issue.

 

[jirm]

They'll sag over time, which is more the issue than the immediate loss of a tiny amount of Xmax. No reason to have it configured in a way where that's an issue.

Indeed that is possible that over the time the sag can be a problem but the reasons why I chose this orientation was given because with this amount of SAG should not be a "major" problem (as calculated) and for me seems much more easy to build the woodworking and for some aesthetic reasons too.
Any way I seriously considers now change to a vertical manyfold to better fit the drivers and avoid any sag problem.

Regards

 

[jirm]

Woow Godzilla. Thank you so much for your inputs !

I will review that projects that you provide me and will be perfect for see real performance about these small FR.

Very very interesting that perhaps remain somewhat "short" in response on highs. You think may we have look for other better alternatives in FR drivers ? or will you think it is near impossible avoid to complement with some kind of "super-twetter" for all woole system really "shine" as it should?

So far in the "zone" sub I keep my idea of going to a PPSL, but still think I have to mature a lot more the idea, and I would love to have the opinion of some expert (reach bat-radar call DJK ?? ) that can validate my simulation BassBox attempt I've done with that little 8" Gradient drivers. My sims outputs seems too much good to be true.

Security here I will put all my progress ... when achieved.

My best wishes !

From the beginning I have thought about TB W4-2142 and TB W3-2141 as one of the best candidates, but finally I believe that these drivers in my simulations were too low efficiency to well accommodate their responses of the sub section.
Maybe I'm wrong, in my considerations regarding the importance of the matching efficience, if finally the response at highs is considerably better with other drivers.

The FR Foundtek like FE85, FE88ex, FE89ex... also I have considered but although its efficiency is suitable I not see too well his frequency graphs responses (on their manufacturer papers) although I know it is not a reliable way rule "to out" a driver, I do not know their actual real sonic print, behavior and performance.

Any other suggestions on this?

 

[badman]

Don't worry about matching efficiency/sensitivity, you're going active, it doesn't matter!

 

[jirm]

Don't worry about matching efficiency/sensitivity, you're going active, it doesn't matter!

I am thinking of the matching efficiency sacrifice (more correct will talk about sensitivity, but efficiency is the common parameter that can be found easily at any manufacturer paper) but I'm still resistant to the idea that efficiency does not only affect the perceived acoustic power but also is directly related to the dynamics, better sound compression and therefore the cone travel required for a given spl and more and better result directivity control all factors that also must be taken into account.
Therefore it explained why horns are so appropriate and even necessary to play in the best way possible the upper-middle range of freq. As we all know the main direct effect of the horns is the dramatic increase in speaker sensitivity (efficiency) and therefore improve all the factors commented before.
Besides the above, the increased efficiency is also perceived as greater easy amplifier to control the load and since the impedance is not linear across all the frequency spectrum that variability can put in serious trouble to the amplifier preventing it to react properly in certain load situations when "in theory" it should be able to handle the load perfectly well.

All this is only my opinions that are probably somewhat erroneous, but today this is I consider more true.

Badman thank you very much for your comment

 

[jirm]

Posting same sim TL enclosure but with Vifa TC9 and Faital 4FE32 FR.
We can see the 6db decrement in sensitivty for the vifa and the 2 db decrement for Faital compared with TB W4-1320SIF