ZAPH AUDIO ZRT UPGRADE

[Jamproject]

Hello,

I built zaph audio zrt about 10 years ago and now think of upgrading them, both from the aestetical (current painting is average) and performance point of view.
I would like to share and have your opinion about the upgrade.
What I'm planning to do is to make the column as two separates parts :
- The actual ZRT in a closed box of ~20L without further modifications (same passive filter) just eventually a slight increase of baffle width (something like 1cm shouldn't be very significant right?) and slight edges rounding.
- A subwoofer "stand"

For that subwoofer, I would like to go dual opposed side firing in a sealed configuration with DSP equalization. I would drive them in mono.
Something like above:

Depending on the depth, volume would be 22-28L which is not a lot for 2 drivers.
The depth of the drivers itself is also limited to ~12cm which eliminates a lot possible choices to.

I identify solutions while playing with WinISD:
- SB Acoustics SW26DBAC76-8: 250€ each, Qtc=0,669 in 22L. It's a shallow subwoofer and seems to perform well but don't know how it compare with similar prices non-shallow subs.
- PEERLESS XLS-P830452 (width increased to 25cm): 170€ each, Qtc = 0,593 in 22L. I don't know the performance but I read Peerless subwoofers was great in general? The problem with this is that it is a discontinued product. Don't know if it's a good idea to buy 4 of them..

If anybody have an opinion on which one is the best performer?
Is someone aware of an other solution?
Here is the max SPL (2m) simulation for 2 drivers - but the final objective is to have 4 - RED is SB ACOUSTICS

And frequency response:

Regardings the electronics I would replace my Wiim pro plus + amp with a Wiimp amp pro, which have a subwoofer output and dsp for equalization.
And to drive the 2 subs maybe a hypex NC502? Maybe it's overkill and cheaper options are OK? Diy is an option for this to if a cheap good performing amp module exists somewhere.

Thank you for sharing your thoughts
Have a good day,

 

[Gorgonzola]

As a Zaph ZRT owner myself, I'm interested to hear about the rework you considering. It seems sensible and well-considered to me, although I can't really make specific recommendations.

On the face of it, making a single mid-woofer version in a smaller, closed box seems perfectly viable. As far as I can recall, the Scan-Speak 18W/8531G 7” Revelators are good candidates for a closed box speaker. My own ZRT's are slightly modified from the basic vented Zaph design. I run them full range with a subwoofer working in at 50 Hz. For equalization I use the Math Audio Room EQ plug in for Foobar2000.

I currently driving my ZRT's with Purifi 1ET400A amplifiers that work extremely well IMO.

 

[jamescarter1982]

sb do another shallow subwoofer that's much cheaper had you considered that one ?

 

[JoshK]

For the sub amps, I'd probably look at the Fusion series from Hypex with the DSP built in, say the FA501. Slightly cheaper I think as well.

 

[Jamproject]

As a Zaph ZRT owner myself, I'm interested to hear about the rework you considering. It seems sensible and well-considered to me, although I can't really make specific recommendations.

On the face of it, making a single mid-woofer version in a smaller, closed box seems perfectly viable. As far as I can recall, the Scan-Speak 18W/8531G 7” Revelators are good candidates for a closed box speaker. My own ZRT's are slightly modified from the basic vented Zaph design. I run them full range with a subwoofer working in at 50 Hz. For equalization I use the Math Audio Room EQ plug in for Foobar2000.

I currently driving my ZRT's with Purifi 1ET400A amplifiers that work extremely well IMO.

I saw your zrt on different thread before, nice work
Yes I like them a lot to and bass performance is already awesome. I was thinking that liberate the driver from bass duty will increase general performance (definitely increase max spl).
On the zaph audio there is actually the plan for sealed version so I'm not worry it will work.
Here are mine:

 

[Jamproject]

sb do another shallow subwoofer that's much cheaper had you considered that one ?

I was aware of there existence but didn't simulate them (until now - they requires to much volume (55L for 2 of them)).

 

[Jamproject]

For the sub amps, I'd probably look at the Fusion series from Hypex with the DSP built in, say the FA501. Slightly cheaper I think as well.

In France, FA501 is 1000€ for 2, there are cheaper Hypex option (if no need for DSP). I also prefer to keep the amplifier outside the box.
But with plate amplifier I could do something like 2xFA502 so 500W for sub and 500W for ZRT or 2xFA253 in BTL mode so 500W for sub and 100W for ZRT.
That eliminate the need for wiim amp but price is higher overall.

 

[Jamproject]

In France, FA501 is 1000€ for 2, there are cheaper Hypex option (if no need for DSP). I also prefer to keep the amplifier outside the box.
But with plate amplifier I could do something like 2xFA502 so 500W for sub and 500W for ZRT or 2xFA253 in BTL mode so 500W for sub and 100W for ZRT.
That eliminate the need for wiim amp but price is higher overall.

Actually 2xFA253 option is invalid because the 100W hypex module is made for tweeter.

 

[JoshK]

In France, FA501 is 1000€ for 2, there are cheaper Hypex option (if no need for DSP). I also prefer to keep the amplifier outside the box.
But with plate amplifier I could do something like 2xFA502 so 500W for sub and 500W for ZRT or 2xFA253 in BTL mode so 500W for sub and 100W for ZRT.
That eliminate the need for wiim amp but price is higher overall.

Makes sense. I also prefer to keep my sub amps not in the sub enclosure for a few different reasons*. I just suggested in case it helped.

If you are in Europe, you may have different cost considerations that what is available here in North America.

* I have never loved the idea of having to run both a cable (line level or speaker cable) and a power cord to a speaker. I prefer only one and the power cords at the gear setup. Just less cables. Its an aesthetic consideration, but one I prefer. That being said, I currently have two Rythmik subs that have built-in amp. I would prefer passive plus one m channel amp in my gear rack and use a mini-dsp for all the xo and eq duties for the subs there. The other reason is subs generate massive vibrations which isn't great for electronics long term, so having them not in the same enclosure should ostensibly increase their longevity.

 

[JoshK]

One other thing to consider is generally multiple subs placed strategically around the room evens out bass in a room better than located at the mains. This is a very different solution but generally the rewards are higher.

I first came across this idea from Dr. Earl Geddes, whom I've met and visited his house. He isn't likely the first to suggest multiple subs, but his strategy was at least a bit novel and worked efficiently. Duke of Audio Kinesis was a student of his and released the Swarm back when his company was active. Look up the idea if you have flexibility on sub placement as this will achieve better results almost always.

For aesthetic reasons, you might pursue your proposal, and I would get it, but something to consider.

 

[Jamproject]

One other thing to consider is generally multiple subs placed strategically around the room evens out bass in a room better than located at the mains. This is a very different solution but generally the rewards are higher.

I first came across this idea from Dr. Earl Geddes, whom I've met and visited his house. He isn't likely the first to suggest multiple subs, but his strategy was at least a bit novel and worked efficiently. Duke of Audio Kinesis was a student of his and released the Swarm back when his company was active. Look up the idea if you have flexibility on sub placement as this will achieve better results almost always.

For aesthetic reasons, you might pursue your proposal, and I would get it, but something to consider.

Yes I'm aware of that and in fact that is why I want to make the two part separable. If performance is really better with different location, I build or buy stands for main and that's it.

 

[Jamproject]

I would like to share my latest reflexions.

For amplification, I will most likely go with the cheaper pro amp option with Yamaha PXXXXS or Crown XLS.

Regarding the drivers, I identified a third solution with 4x Dayton DCS205-4 per speaker. This is actually the cheaper option.
Does anybody as an opinion about the driver (an idea of distortion performance would be cool)?
Here is Max SPL comparaison between 4xDCS205 and 2xSW26DBAC76-8 (RED).

With same target curve, both hit exactly the same SPL (curve below).

The Dayton option requires a lot more power capabilities from amp but that shouldn't be a problem.
Average power consumption is probably lower considering frequency distribution of most music content?

I'm wondering what we could expects from distortion point of view.
At frequency higher than 45Hz and at same SPL, the Dayton is further from its maximum than the 10'. Does that mean that it will perform better or the inherent quality of driver is dominant?