Sony buyout project

[philiparcario]

Re: Sony buyout project

photos


a world trade center progress report it is getting taller and the outer shell is being placed on it. every time I drive by this view it amazes me.

SECOND SHOT; the sony 's shot is from just behind the listening stage

THIRD SHOT; JEFF gives a sense of scale to the speakers which are 6 ft 2 inches tall.


Fourth shot : the listening seats. Jeff is 8 or 9 feet away from the sony's and his seat is a bit off center. I actually preferred to listen these speakers in the row of chairs behind Jeff. Maybe 10 or 11 feet away.

[Soundslike]

Re: Sony buyout project

Thanks for the comments and photos everybody -- and thanks Roman for being so open and accommodating. Wish I could have been there. But, I'll be building my own set and should get to hear them pretty soon.

That's some pretty classy seating there in the back row. Lee, you do get around.....

[philiparcario]

Re: Sony buyout project

Thanx for the update Phil. I suspected the nearfield image would be narrow with only one tweeter but once the line transfers to farfield......look out! Now the only remaining 'issue' i would expect would be the rapid decline in HF output the farther you move away vs the rest of the array......if Jim's white paper is accurate.

Roman.....i gotta get over there and give these a listen. Most remarkable for $60 worth of drivers........:D

each speaker has 60 in parts

the drivers 12 sonys and a tweeter and the crossover and the 2k filter to level excessive distortion for the sony at that freq.

[XtremeRevolution]

Re: Sony buyout project

Can't wait to be able to order the parts for all of these!

[r-carpenter]

Re: Sony buyout project

Thank you for kind reviews.
Let me explain the thought process behind the crossover and the outcome.
The Sony driver by itself is a dedicated boom box wander. The suspension has very little linear travel (I am guessing 2.5mm). Ones the travel limit is reached it will refuse to play any louder and if the amp is strong enough and you are curious enough, blue smoke will most likely come out of the voice coil. This is actually why I am interested to see Erin test them and look in to suspension nonlinearities.
There are issues in the passband around 2k and a horrible cone resonance between 5 and 6k.
So, how do we play around that?
In the line array with a centered tweeter if you filter out midrange from the mid woofer response too much, the line array effect of a large vertical image is also diminished. While listening and experimenting with the crossover, I realized that I need to bring the response of the Sony as close to 2k as possible to retain large image and yet soften the SPL at 2k so the speaker does not sound harsh. It sounds something like a healthy BBC deep but actually caused by nonlinear and linear trade offs directly related to the driver itself. And so at 2k, the tweeter kicks in full blast. I have to say that DX25 is surprisingly good at $25 a pop. Round about 1.5m loudspeaker reaches 95db spl without any sign of strain. Measured on axis it is fairly flat but a summed up signal arrives at you from the tweeter and the line, meaning that all these woofers will cut off at 2k and there's very little summed up reflected mid-range. This is where the “laid back” or “muted” mid-range is coming from. My solution was to have a slightly colored nonlinear speaker to a flatter but harsher sounding one.
The result of this solution to the problem is that harsher recordings will sound quite nice and nice recordings will sound “laid back” and “soft”. Experiment with the placement of the loudspeaker in relation to the back wall. This will adjust amount of direct mid-range and low end and reflected mid. Tweeter of cause is a monopole and the amount of high frequency radiation will remain the same.
This hopefully explains a general second order electrical crossover decision.

[r-carpenter]

Re: Sony buyout project

There are two notches implemented in the crossover.
Smaller LC a bottomless notch of L5 and C4 provides additional filtering at 5800hz. If the general second order filter is applied to the tweeter and the woofers, the effect of this notch is not immediately audible (visible on the FR plots). The effect is long term listening fatigue.
Phil summed it up in the conversation we had, very well. You start reaching for a CD remote control in 5minutes in to the song, without even realizing why. With the notch, I can listen to the music for a long time without fatigue.
Second LCR is to shelve raised response around 300hz.
I gave an option on this one because I have used this one

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=255-110

and I-core laminate inductors are not available as 2.7mH

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=266-556

So, want to save $10 per pair, use the 2.5mH version.
Audible differences in the response will be much more affected by placement in the room VS this notch option.

[r-carpenter]

Re: Sony buyout project

The impedance of the system.
It's fairly flat without too much of a swing in phase. I drove it loud with a 15watt Aleph clone (which is class A and hot all the time, so it's hard to say if it was over heating. ) and with 100wpch integrated Carver amp. Both amps did fine, no audible issues. Carver was barely warm. In my fairly large shop, speakers filled the room rather nicely but again, keep in mind, after the suspension travel of Sony is reached, you can pump more voltage in to the speaker without much of an SPL increase and at the risk of damaging the system and the amp. Under normal listening conditions it shouldn't matter but a few drinks and a Gogol Bordello may push in to the system limits testing area. So be aware.
Other then that, it's a solid 4ohm performance.
Additional crossover tweaks can be done but at the increased price for parts.
Mayhem,
Jim's paper is quite accurate. It's a white paper and he doesn't go in to the details as to what's audible and what's not or how important audibility of certain issues are. The decline in HF with increased distance is not that important IMO and your brains will fill in the void. On the other hand, lets say you are in the club listening to live performance. Because of absorption of the high frequencies in the interior, one may experience decrease in a high frequency SPL with an increase of the distance to the stage. So, not a clear cut case as well.
Give a tight budget for a an entry in the line array world, I don't see a line of tweeters for this particular project.
It just wouldn't make sense from the $ point of view.
Comb filtering is also greatly exaggerated in the DIY line array conversation and barely audible if at all. (IMO).
In conclusion:
Is this the "end all" line array? Surely not. Can it be made better? Sure. Better drivers or a line of tweeters will raise a bar. But the other question is, why? It's a budget build with very satisfying results. With so many Sony drivers sold I see this as a more "adventures" build. High sensitivity, high SPL capability, fairly low footprint.
Oh and one could paint it white and stretch white fabric over for a discrete look.

[r-carpenter]

Re: Sony buyout project

Thanks for the comments and photos everybody -- and thanks Roman for being so open and accommodating. Wish I could have been there. But, I'll be building my own set and should get to hear them pretty soon.

That's some pretty classy seating there in the back row. Lee, you do get around.....

You are very welcome. My pleasure.
I can hang out and talk about audio reproduction for hours.
BTW, Jeff had a very interesting 4-way system in the end, that we ended up listening for a couple of hours. Lenium (linoleum ) tweeters side firing.
The Mahogany armchair and Club chair that Jeff is pictured seating on, were maid by me. Mahogany arm chair is a solid African Mahogany, Mahogany Crotch veneered back with maple inlay band. 6" coil spring upholstery with a 8-way spring tie, synthetic horse hair and cotton.
Lee's daughter was seating on it for over an hour I think pretty comfortably.
The arm chair was designed for an office meeting. It also has a coil spring seat. The upholstery is made less comfortable on purpose. You need to be comfortable but not fall asleep.
As a note: restaurant chairs are made uncomfortable (or I should say, less comfortable) so you don't seat there for more then an hour.
Also, Lee, welcome to our neck of the woods.

[Soundslike]

Re: Sony buyout project

Very impressive work and classic execution of the style..

[jeff_free69]

Re: Sony buyout project

Happy New Year guys!

Last Friday was a great way to kick off the holiday weekend, with a chance to do some extended listening at Roman's shop (quite a difference from a regular DIY jam session where you run through dozens of speakers, 6 minutes at a time!).

There are 2 intriguing things about this design, neither of which have I had much exposure to - dipoles and line arrays. They each contribute to a unique listening experience, and this design puts them together.

I didn't realize how tall the Sony's were until I stood next to them! That vertical height gives them a solid soundstage much more akin to a live club experience than you can get out of a conventional box.


The music on our listening plate was Phil's classic rock, our 2011 DIY disc and a Diana Krall album.

For a level set, round we first auditioned without a sub. Then we dialed in some sub to round out below 120 and it was clear this is pretty much required

We listened mainly at a distance of about 8 feet, switching chairs of different heights. Dead center was sweetest. Walking around a bit, it seemed that at 10-12 feet the directionality was minimized. At the closer distance, tweeter height was also a bit of a factor - it worked best at ear level. As is, it may have been just right for my own slouch/couch position at home. But when sitting in the taller chair, I was wondering if sliding the tweeter up one level would have helped improve the presence.

I also echo the sentiment that their presentation was on the laid back side. Not that your ears couldn't adjust; when listening through the Krall album, it became a warm, inviting experience. It's just that in side-by-side comparison they had a similar "height" but (no surprise) they couldn't touch the exquisite presence and detail of Roman's premium Jordan/Fountek arrays.

As noted, this compromise was necessitated due to the serious taming needed on the sony's midrange issues. I'm also feeling that Mayhem's suggestion (about the rapid decline in HF output the farther you move away vs the rest of the array) could be a factor. Especially with an array over 6 feet tall - what you measure 3 feet away is going to be very different from 10 feet. Plus at that distance, I suspect the dipole's open back allows more of the room to get in on the act. (note that the speakers were about 8 feet away from the nearest wall and the ceiling is 12+ )


It's pretty clear that Roman got everything you could ever hope for out of this woofer, while also giving a great way to experience some advanced topologies.

I could see an enterprising individual wanting to do some extra credit work and figure out a cost effective tweak on the high end to add some presence/ air etc. Unfortunately I can't think of any 69 cent tweeters. These came to mind - think I paid $4 for these a few years ago , but unfortunately it wouldn't be much help for a budget array now (victim of neo price rise) http://www.parts-express.com/pe/show...number=275-035

[r-carpenter]

Re: Sony buyout project

Thank you for the review Jeff.
Good times.

This is the updated crossover schematic. Note the value change on the woofer series inductor and reversed polarity of the tweeter.

[Leroy R]

Re: Sony buyout project

Roman it looks like you changed the value of L2. Was that the crossover I heard or did you make that change after I was there?

[r-carpenter]

Re: Sony buyout project

You heard the crossover with the final values and reversed polarity. On Axis response and impedance posted in #100 is with this updated crossover. I had incorrect file opened in Sound Easy previously. Sorry about it.
No changes were made after you, Jeff and Phil listened to to the speaker.
Roman.

[blaine]

Re: Sony buyout project

I have the attention span of a fruitfly and have never gotten into video games.

I have a similar attention span, which is the very reason I play video games...

[ErinH]

Re: Sony buyout project

FWIW, I believe I've got some on the way for testing.