let the building begin: Small Audience A30 based nearfiel plus subwoofer

[erikb1971]

Background: about a month ago, I decided I was no longer happy with my small Genelec nearfield monitors 6010A. The sound of them is fine for what they are, but they lacked some finesse, and some low end. The latter could of course have been solved with a genelec subwoofer, but I am totally infected with the DIY virus, so the idea was quickly born: let's build something that is not a lot bigger, but sounds a lot better, and something that is passive. I have looked at a lot of options:
a two way system (these Xenums by a DIY audio member Wolfteeth were very tempting)
or radials (Seas has some very interesting drivers).
Eventually decided on a small 3" full range satellite with a subwoofer. At least the building of the satellites could be relatively straight forward, which is nice for newbees like us. We choose the Audience for their very flat frequency response and very enthusiastic reviews. We also got great feedback and response from them, so it felt like a safe and good choice.

A few days ago these (see attachment) beautiful drivers arrived. So the building can finally commence!

Since our almost totally beginner status, the first questions arise right away:
1. In WinISD, Z is asked. Would that be nominal or minimum or peak?
2. Again WinISD, re is asked, where can I find that value?

Audience adviced small enclosures (14cm x 14cm x 18cm, W x D x H) with a 3,5" passive radiator. Which raises the questions:
3. Is a passive radiator for a 2.1 design a good idea, and if not, will we have to enlarge the enclosures?
4. With this small enclosures, what would be the thickness of wood to use?

And questions on a more general level:
5. Should the enclosures be flat/square, or with rounded edges. And why?
6. Since the drivers are pretty ugly (sorry) can we hide them some way without interfering with the sound?
7. My home tv setup speakers are driven by an Audiosector premium chipamp kit. But these audience are 16 ohm. So what kind of amp should we build to drive them? For pretty low levels, since they will be about a meter form the ears...

As you can see.. quite a lot of questions... I am sure that with your help we can make this a success... so I am looking forward to your input! Thanks a lot in advance

Erik & Jorgen

[enigmaticEntity.]

2.) re is DC Resistance I think (DCR)

5.) Rounded edges (at least on the sides) are preferred due to reduction of diffraction effects, which usually create a ripple at ~1kHz depending on the width of the baffle. If you wish you can leave the top/bottom edges square if you wish for more aesthetic look, though there will be slightly more diffraction.

6.) Be creative with how you attach a grill cloth - if you make a frame that sticks out from the baffle surface you may have more diffraction effects, but you can try attaching it flush...make sure you leave enough room for the cone to move in and out without hitting the grill cloth! XD You could also try a rounded frame...

idk if you like silver drivers or not, but the Fountek fr88ex also has a very flat full range response and low distortion (on this page: Zaph|Audio). There are specs/graphs in the "comparison application". It only has 3mm of usable excursion, however since you are using a sub and nearfield it would be ok. Then again, I haven't seen an Audience A3 DIY build yet, should be interesting!

[erikb1971]

Originally Posted by enigmaticEntity.

2.) re is DC Resistance I think (DCR)

5.) Rounded edges (at least on the sides) are preferred due to reduction of diffraction effects, which usually create a ripple at ~1kHz depending on the width of the baffle. If you wish you can leave the top/bottom edges square if you wish for more aesthetic look, though there will be slightly more diffraction.

6.) Be creative with how you attach a grill cloth - if you make a frame that sticks out from the baffle surface you may have more diffraction effects, but you can try attaching it flush...make sure you leave enough room for the cone to move in and out without hitting the grill cloth! XD You could also try a rounded frame...

idk if you like silver drivers or not, but the Fountek fr88ex also has a very flat full range response and low distortion (on this page: Zaph|Audio). There are specs/graphs in the "comparison application". It only has 3mm of usable excursion, however since you are using a sub and nearfield it would be ok. Then again, I haven't seen an Audience A3 DIY build yet, should be interesting!

TNX!

We will keep you posted!

[erikb1971]

And the building began! To start with, we decided to build two beta test versions:

1. A 1.1 liter closed enclosure (12x10x14cm) with a QTC of about .7
2. A 2 liter passive radiator enclosure (14x18x14cm) as recommended by Audience

In the first picture you can see them side by side next to my laptop. The right pair is somewhat turned to see the passive radiator on the side (I was not sure if I had enough space to place it at the back, in retrospect, I did). The nice thing about building these small speakers is the cost of wood: the wood (mdf 12mm) for both sets set me back a respectable 4,35 euro, including sawing costs. Try to build a Vifa Basis for that! They are also pretty quick to assemble. We used these binding posts, and that was pretty stupid with 12mm wood. That's what beta versions are for. We used no bracing, and for now, no filling.

The interesting part occurred when I wanted to connect the driver to the posts. As you can partly see on the picture in my first post, there is a red wire connected to the plus pin running to the other side of the driver. There it is connected to the negative pin of a second pair of connectors. This connection is in place at both drivers from one box, but absent on both drivers from the second box... hmmm...
To confuse me even more, impedance over the connected pins was 12 Ohm, and logically, each set of not connected connectors of the other driver measured 6 Ohm. From a mathematical point of view fine, but in no way related to the 16 ohm from the specs. I emailed this to Audience and expect an answer by Monday. For comparing purposes, I wired the second pair the same way.

Then, the listening could begin. The smaller boxes were finished first and we decided to test them at Jorgens house. There we were faced with a horrible disappointment. Absolutely nothing sounded even remotely nice. Oh, that is not true. A cd fom Dead Moon, produced in mono sounded fairly ok. Apart from the fact that these guys can't play, sing, write, keep tempo or tune their instruments. But that was still more pleasurable to listen to than anything else we tried. One of my favourite tracks to listen to is Suzan Vega's Marlene on the wall. All of a sudden, the track seemed remixed by the acoustic guitar player, convinced that his performance was so great it should be twice as loud as the rest of the record. Suzan herself was hardly audible, and in the cases she was, she suddenly had a speaking disorder that could only have been caused by her drinking two liters of wodka (the kind my gf's father brews himself in his shed in Gromadka, Poland) an having had one of her front teeth broken. In general, everything sounded harsh, and unfriendly in what I would call MidHigh-High. And the lack of low end was not helping. The hopeful thing was that the level of detail in other frequencies and stereo imaging (except the notorious Dead Moon) were impressive.
When we connected my subwoofer (20 liters closed box, 10" Dayton RS 210 HF4), some things got a little bit better. The added low end seemed to soften up some of the hard edges. On other tracks, things got a lot worse with the sub woofer, with my favourite game from the cardigans as a miracle: the bass played a completely different song there. Seriously. It did not match in anyway the rest of the song. Spooky.

At home, after a good night sleep, I redid the test in my own environment. What a difference! The small speakers still do not produce a lot of low end, obviously. But Suzan is sober, had her teeth fixed and the guitar player knows his place. On more bass heavy tracks, you do not feel the bass, but you still hear the sub bass is there... What stayed is the detail, the stereo image. Wow... and those are only the small closed versions.
The bigger, passive radiator versions do not disappoint. Obviously a lot warmer, even better detail, beautiful stereo image. A bit more volume as well. And surprise: for the first time I am listening to speakers that make the Stone Roses sound as they should. Listening to, and judging speakers is a weird process, as I am noticing while writing this post. Opinions change when listening longer and getting deaf or getting used to sounds. Overall, as a first step, I am very positive.

So where does the difference in experience between the two places come from? Amp was the same. Cables the same. Songs the same. At Jorgen's, we used a cd player, at home I am using my Iphone with Spotify. So what remains is the room and the placement. Jorgen's room is large. And high. And one side completely glass. The left side of the room is about a meter higher than the right side. The speakers were placed on top of his high B&W speakers about 40cm from the wall. we were sitting at a few meters.
As you can see on the attached picture of the speakers, at my place they are on a table. About a meter apart. A meter behind me are books on shelves, floor to ceiling. Can this difference I heard be caused by those circumstances?

I am a bit unclear however about how to proceed from here. There is definitely still a few issues that need to be addressed. What Sub woofer, with what enclosure, with what filter? I also keep thinking that the speakers sound slightly harsh still in the high mid (or is that me projecting the visual spike at 9khz in the PDF file from post 1 to my ears?). Is the gainclone the right amp for speakers like this, it seems all a bit "in my face"?

If anyone made it through this post, I am looking forward to hear your comments and input!

Cheers
Erik

[ultrakaz]

The A3 was designed to be used in multiples. Certainly all of the Audience designs are used in multiples. The rising treble is offset/cancelled to some degree by the corresponding driver(s). There has been a lot said of the detrimental effects of stacking the drivers (ie, comb filtering), but there has been credible testimonial feedback that combing is not that audible.

This does not mean you have to use more than one driver per cabinet, but you probably need some eq'ing to tame the rising top end. However, since you appear to have 2 pair of drivers you could run them together and see if the top end "softens." Or you could try and highpass the smaller pair of speakers at around 1kHz or so. Audience has a 2+2 design, which you might make a mini version of too, but you would probably need another pair of passive radiators.

Also, try run one pair 90 degrees to the other pair or one pair directly behind the other.

I would wait until you resolve the above prior to adding a subwoofer.

[talaerts]

How do you compare them now to your Genelecs? Genelec's typical monitor sound may not be for everyone yet their speakers are very well engineered in all details, so it can't be easy to surpass them in truthfulness with an FR speaker.

[erikb1971]

Originally Posted by ultrakaz

The A3 was designed to be used in multiples. Certainly all of the Audience designs are used in multiples. The rising treble is offset/cancelled to some degree by the corresponding driver(s). There has been a lot said of the detrimental effects of stacking the drivers (ie, comb filtering), but there has been credible testimonial feedback that combing is not that audible.

This does not mean you have to use more than one driver per cabinet, but you probably need some eq'ing to tame the rising top end. However, since you appear to have 2 pair of drivers you could run them together and see if the top end "softens." Or you could try and highpass the smaller pair of speakers at around 1kHz or so. Audience has a 2+2 design, which you might make a mini version of too, but you would probably need another pair of passive radiators.

Also, try run one pair 90 degrees to the other pair or one pair directly behind the other.

I would wait until you resolve the above prior to adding a subwoofer.

Interesting thoughts. I happen to know Audience might be working on a 1 driver with PR unit... so it should be doable. I will try to get a amp with two sets of speaker connections today to try some of your suggestions. Also, a friend of mine has more or less offered (I asked and he did not disagree) to help with the tuning. He works at a pretty big radio station, so he should have the ears, room and equipment to help us out! Could rounding of the edges of the enclosures and "sinking" the drivers into the wood help with those issues?

[erikb1971]

Originally Posted by talaerts

How do you compare them now to your Genelecs? Genelec's typical monitor sound may not be for everyone yet their speakers are very well engineered in all details, so it can't be easy to surpass them in truthfulness with an FR speaker.

That would be a sound idea if I still had them, but I needed the funds....
I can compare them however to my Anthony Gallo Nucleus speakers:
The difference is huge. The Gallos are of couse meant to be use with a subwoofer... so the low en of the A3 pr is unbelievably better. At first listen the Gallo's top end is a bit smoother. After a while however, it seems that is due to lack of mid high rather than a "better" high end. The stereo imaging of the A3 is also in a complete different class. For that I always use the song day is done by Johan. A lot of stereo panning of the instruments, but also a lot of "room" sound on drums... The Gallo's are fine, but when I close my eyes when listening to the A3s, I am actually IN the room.
It still feels that after I find the right tweaks the A3's will be awesome, their potential is already shining through!

[talaerts]

Those Nucleus speakers seem to be designer objects. Nothing wrong with that.
However a decent monitor like those that Genelec produces should offer a quite flat response. I can understand that a fr unit will give better imaging, but as a monitor they typically don't have the flat response you want for that usage.

[erikb1971]

Yes they are beauties, aren't they? :-) It is indeed not really a fair comparison. I think we could have a very long discussion on the use of dedicated brand monitors or more high end-ish speakers. So looking for where we agree is that monitors should be as flat and neutral as possible... that is why I chose the audience driver... one of these days I will compare them in a studio with some "real" nearfields. I will keep you posted!