Faital Pro 15PR400 – Enclosure Options?

[Sub Sonic]

4 minutes ago, A9X said:

No it doesn't as the same signal will be going to the MB and SW drivers at the low end, say 20Hz to wherever the subs have their low pass set.

What if I only run the MB down to 40Hz or so, and EQ the subs to take up the slack in the bottom octave?

[A9X]

On 12/05/2019 at 9:32 PM, Wozza_Lee said:

Dave wants more siad that the dayton 6512 was a good option for horns

Yep, it's a JBL clone and has excellent directivity, but it's a waveguide, not a horn. This Celestion reportedly has excellent performance.

 

SS, do yourself a big favour in the design and mount the WG as close as possible to the Faital.

[A9X]

2 minutes ago, Sub Sonic said:

What if I only run the MB down to 40Hz or so, and EQ the subs to take up the slack in the bottom octave?

If you listen to rock, pop, jazz and most classical and run the MB down to 40Hz, then you won't need the sub. There is little below 40Hz in most of these genres.

If you mean run the SW up to a low pass of 80-100Hz then in my experience, running the SW and MB drivers overlapping usually sounds like ass.

[Sub Sonic]

51 minutes ago, A9X said:

If you listen to rock, pop, jazz and most classical and run the MB down to 40Hz, then you won't need the sub. There is little below 40Hz in most of these genres.

If you mean run the SW up to a low pass of 80-100Hz then in my experience, running the SW and MB drivers overlapping usually sounds like ass.

Thanks for the tips.

 

Re low end extension, I do like listening to pipe organ so the low end is important.

[A9X]

5 minutes ago, Sub Sonic said:

Re low end extension, I do like listening to pipe organ so the low end is important.

Then run the MB down to the natural 80Hz the sealed enclosure gives, then cross over to the subs.

 

My mains do 45Hz naturally outside and are better than that in room, but I still cross them to subs at 60Hz.

[Swarm]

Custom budget design from henry built by me. Always been pleased with these but my listening area is a dindgy shed with carpet on the floor and ply on the wall. still experiment with stuff but dont normally run subs

[A9X]

^^ My first car was that colour.

[Sub Sonic]

5 hours ago, Swarm said:

Custom budget design from henry built by me. Always been pleased with these but my listening area is a dindgy shed with carpet on the floor and ply on the wall. still experiment with stuff but dont normally run subs

Just read this thread, thanks for the link.

 

How have the speakers been, long term?

 

Cheers,

 

SS

[Sub Sonic]

So I spent part of yesterday modifying my enclosures to suit the 15” Faitals.

 

New smaller enclosures are planned, around 60 litres sealed but with extensive bracing - the current enclosures have minimal bracing. I added some yesterday but they really need more. The smaller enclosure will also help here.

 

Currently running sealed in 120 litres with twin Rythmik 12’ subs doing the bottom end, and Dayton D250P/H812 at the top. 1,000 Hz LR4 crossover (MiniDSP) between midbass and horn. I have a tune/EQ in place but will likely be modified. The beauty of DIY is that one can tune to the listening position instead of having to adopt a “one size has to fit all” approach.

 

A pair of SEOS 15 and B&C DE250’s are in the wind, so it will be interesting comparing them.

 

I’m using fibreglass flywire as grille cloth as I have several active kids... the bonus is I rather like the look. You can still see the drivers but they are protected, and it subdues the look somewhat. The tiny spots around the periphery of the bass driver are heat glue - stops the flywire slapping against the form ply baffle. Need to work on this one...

 

Edited May 18, 2019 by Sub Sonic

[Swarm]

3 hours ago, Sub Sonic said:

Just read this thread, thanks for the link.

 

How have the speakers been, long term?

 

Cheers,

 

SS

Built in 16 still going as normal. I bought a 3 way active crossover to bring in subs but have never got around to it.

[A9X]

3 hours ago, Sub Sonic said:

I’m using fibreglass flywire as grille cloth as I have several active kids.

Next time use the steel version ... and electrify it. Trust me they'll only touch it once. Just a suggestion.

[Sub Sonic]

22 minutes ago, A9X said:

Next time use the steel version ... and electrify it. Trust me they'll only touch it once. Just a suggestion.

I like the force field idea. V2 coming up...

[davewantsmoore]

On 17/05/2019 at 9:52 PM, A9X said:

Yep, it's a JBL clone and has excellent directivity, but it's a waveguide, not a horn. This Celestion reportedly has excellent performance.

I have a similar driver.  It is great.

 

Waveguide... horn...?  Semantics?

On 17/05/2019 at 9:56 PM, A9X said:

If you mean run the SW up to a low pass of 80-100Hz then in my experience, running the SW and MB drivers overlapping usually sounds like ass.

It's all about how they're "EQed".    If the SPL and phase are all matched ..... then it's just like having "4 subwoofers" .... just two of them die off at 40 (or whatever) instead of 20.

 

Certainly adding more drivers playing together, is more things to get wrong.

[Sub Sonic]

So I’d been noticing a slight imbalance between the compression drivers (Dayton D250P) since new, and after a bit of messing around (and finally getting around to it), some sweeps indicated significantly higher distortion between 1-5kHz on one of the drivers, as well as an accompanying dip in the FR. I had tried reseating the diaphragm a couple of times, but no go.

 

Fortunately I had bought a few spare diaphragms from PE as they were going out on special, and it would allow me to play around with low XO points without too much trepidation.

 

After replacing the diaphragm, all is good, and the distortion levels are where they should be.

 

The original diaphragm could still have been misaligned, but there was also a small dag of polyimide stuck to the inside face of the original dome that could well have been contacting the phase plug (?) assembly, as they are in very close proximity.

 

Anyway, all is good now, and the drivers are much better matched.

 

I’ve also eq’d the bottom end of the Faitals, and crossed over at around 40-50Hz. The sound is nice but the cabinets are still telling me they either need some serious bracing and internal treatment, or replacement. These will be fine for now, but the eventual plan is to build smaller, better braced and damped cabinets.

 

 

Edited May 19, 2019 by Sub Sonic

[davewantsmoore]

18 minutes ago, Sub Sonic said:

better braced and damped cabinets

For a low woofer cabinet, focus on bracing.

[Hifi Si]

Have you considered open baffle? I built the Troels Gravesen OBL-15. It uses these drivers and it has been a great result.

[davewantsmoore]

I'm a little sceptical of Troels result.

http://www.troelsgravesen.dk/OBL-15/BMT_c.gif

 

This chart is a near field measurement of the woofer in green.   Near field means that the true bass response will only be lower than the chart here .... and get lower and lower as the frequency decreases.    (ie. there is an extra "high pass" response which is not being shown)

 

The problem with that is that the chart already shows bass response which is decreasing below 50Hz....  it is already decreasing too much, and a truer measurement (not near field) would only show it decreasing more.

 

 

This is a nice driver.... but it's not really designed for the very high excursions you will need from an open baffle subwoofer...   although that does dramatically depend on the SPL (and bass extension) you really want.     I chose -6dB@20Hz and 105dB earlier ... which are pretty good defaults, but you might want something else.

 

[Sub Sonic]

20 hours ago, Hifi Si said:

Have you considered open baffle? I built the Troels Gravesen OBL-15. It uses these drivers and it has been a great result.

I hadn't really, thanks for the link though.

 

I did read through it and it sounds interesting, but one of the requirements for this set of speakers is that they sound good off axis and reasonable at other places in the room (family/lounge), which probably puts OB off the options.

[Sub Sonic]

So I've been looking at the link below:

 

http://libinst.com/SEOS/SEOS15/SEOS15%20TD1M%20redo/TD15+SEOS15%20design.pdf

 

The pair of speakers referenced here use the same compression driver and waveguide (DE250/SEOS 15), and a different but similar specced bass driver (AE TD15M) tot he 15PR400. I am running active with the current horns, but would love to do an external passive XO as well, and have the option to drive the entire speaker from a single low powered class A amp (8WPC) if & when desired, or to run fully active.

 

I'll use the crossover in the link above as a starting point - the bass drivers are very similar where it matters, although the impedance at the crossover point is a little different - I will need to adjust values to compensate for that. Sensitivity is almost the same for both bass drivers, both are nominally 8 ohms, and FR for both are very similar where it matters.

 

Any thoughts appreciated, as usual.

 

Here are some FR/Impedance plots, I found it hard to find manufacturer's plots for AE??

 

https://faitalpro.com/en/products/LF_Loudspeakers/product_details/index.php?id=101060100

 

 

 

And the AE TD15M, graphs are from third parties, not from AE:

 

http://aespeakers.com/shop/td/td15m/

 

[davewantsmoore]

1 hour ago, Sub Sonic said:

is that they sound good off axis and reasonable at other places in the room (family/lounge), which probably puts OB off the options.

An OB doesn't all disqualify that.

 

BUT... You'll be better off with a monopole, especially if you are trying to reach frequencies much below 40Hz.

 

42 minutes ago, Sub Sonic said:

The pair of speakers referenced here use the same compression driver and waveguide (DE250/SEOS 15), and a different but similar specced bass driver (AE TD15M) tot he 15PR400. I am running active with the current horns, but would love to do an external passive XO as well, and have the option to drive the entire speaker from a single low powered class A amp (8WPC) if & when desired, or to run fully active.

 

I'll use the crossover in the link above as a starting point - the bass drivers are very similar where it matters, although the impedance at the crossover point is a little different - I will need to adjust values to compensate for that. Sensitivity is almost the same for both bass drivers, both are nominally 8 ohms, and FR for both are very similar where it matters.

The W-T crossover should be an easy enough exercise.    You could try building the HPF for the horn exactly as specified .... and then design a LPF and baffle step circuit for your woofer to match in with the existing HPF.    If the woofer doesn't want to match it - you may need to redesign both filters.

 

The remaining issue with a passive filter approach is the bass.    Your driver will roll off substantially below ~100Hz  (just like the TD15M in the design).     Where will your bass come from?

 

A separate subwoofer(s)?

A ported box?

Active EQ, to lift the bass response to where it is correct?

[Sub Sonic]

10 minutes ago, davewantsmoore said:

An OB doesn't all disqualify that.

 

BUT... You'll be better off with a monopole, especially if you are trying to reach frequencies much below 40Hz.

 

The W-T crossover should be an easy enough exercise.    You could try building the HPF for the horn exactly as specified .... and then design a LPF and baffle step circuit for your woofer to match in with the existing HPF.    If the woofer doesn't want to match it - you may need to redesign both filters.

 

The remaining issue with a passive filter approach is the bass.    Your driver will roll off substantially below ~100Hz  (just like the TD15M in the design).     Where will your bass come from?

 

A separate subwoofer(s)?

A ported box?

Active EQ, to lift the bass response to where it is correct?

Thanks Dave.

 

Bass would be separate subwoofers or alternatively active EQ, but I'd like to be able to get a good FR (linear, except the low end) from the passive XO without active EQ required.

[davewantsmoore]

28 minutes ago, Sub Sonic said:

Thanks Dave.

 

Bass would be separate subwoofers or alternatively active EQ, but I'd like to be able to get a good FR (linear, except the low end) from the passive XO without active EQ required.

You'll be able to do that, although I'm unsure how much the existing woofer XO will help you

[Sub Sonic]

14 minutes ago, davewantsmoore said:

existing woofer XO

I’ll be able to have a play with that, that’s the beauty of DIY

[A9X]

1 hour ago, Sub Sonic said:

but similar specced bass driver (AE TD15M) tot he 15PR400

Significant Le difference between the two.

[Sub Sonic]

43 minutes ago, A9X said:

Significant Le difference between the two.

How is it likely to affect the XO in this application?

 

Edit: I know there’s an impedance difference particularly around the XO point which I will have to allow for, is that what you are referring to?

Edited May 21, 2019 by Sub Sonic