sony buyout

[Leroy R]

Re: sony buyout

How many drivers are there in a case?

[r-carpenter]

Re: sony buyout

how Many Drivers Are There In A Case?

24

[Charles Warwick]

Re: sony buyout

I've been mulling this thread over for a while and I see a few possibilities:

1. Using a line of woofers and one tweeter either in MTM or MMT style, probably crossing over about 3khz, and using however many woofers will fit in your design.

2. Doing a line array. As Sydney mentioned, you'd have to get some small tweeters (less than 1'') to get the integration even moderately decent at high hz , and there aren't any one clearance right now so that's not done cheaply. Plus the sensitivity of the woofers is so low just about any tweeter array would seriously outpace them.

3. Possibly some kind of cross-firing line array with tweeters in the middle or one on the top/middle. Forgive the crappy attempt, but I hope it gets across what I was imagining:


I was considering this because it brings the acoustic centers of the woofers close together, it allows the use of twice as many woofers increasing the sensitivity by 3db over the regular line array, and then you could put a some smallish tweeters in the gap between the two. Alternatively you could just put a good tweeter on the top or in the middle as well.

I really don't know exactly how this cross firing arrangement would affect the horizontal dispersion (likely increase) and comb filtering (also would probably increase), but if nothing else it'd be neat and unique looking and give some more output.

Any suggestions if this is even worth considering? My main concern is the effect of the cross-firing.

[Sydney]

Re: sony buyout

and comb filtering (also would probably increase),

The dispersion patterns are set to overlap and that is the result.
Bob McCarthy ( his books ) detailed the pattern interference created by this arrangement.

[forestroyse]

Re: sony buyout

Another long-time lurker here. I'm going to attempt a line array with these Sony buyouts. I've never built a line array before, and I'm currently digesting a paper called "Design Guidelines for Practical Near Field Line Arrays", found here: diy-audio.narod.ru/litr/nflawp.pdf

Do you guys have any other favorite online resources on line arrays? I suppose I could just search the forum.

I'm tempted to go with the Constant Directivity Horn tweeter mentioned previously, but I'm not decided yet. Would it be more difficult to integrate a single tweeter than a tweeter array? I do have a stash of about 20-some mylar car tweeters on posts that I could potentially press-fit very close together.

My cabinet design will be pretty unconventional. I plan to use laser-cut 1/2" MDF laminated with thin plywood in lieu of veneer. The cabinets will be well-braced to compensate for the relatively thin walls. I will make a separate cabinet for each group of parallel-wired drivers, and connect the cabinets in series. This modular design will allow me to use smaller material stock and make it much easier to transport the speakers. Any thoughts? I might start a new thread once I have a more detailed design.

[[email protected]]

Re: sony buyout

i excercised the driver and even played some music. ts are the same.

[Charles Warwick]

Re: sony buyout

I'm tempted to go with the Constant Directivity Horn tweeter mentioned previously, but I'm not decided yet. Would it be more difficult to integrate a single tweeter than a tweeter array? I do have a stash of about 20-some mylar car tweeters on posts that I could potentially press-fit very close together.

That horn is pretty nice, and would be able to crossover low enough to avoid problems with the woofers not integrating at higher (2.5khzish) frequencies. You may have to get an lpad to dampen it down depending on how many woofers you go with to balance the sensitivity difference. I am unsure as the best location for one tweeter, but I would think that you would want it close to the center of the woofer wavefront I think. Anyone please correct me if I'm wrong! This would either mean making it MMMMTMMMM or putting the tweeter off to the side of the middle, which would then make the array quite wide, which is also not great. Putting on the top of the woofer line would look good, and would also get the highs closer to ear level, so perhaps it's a compromise you could live with.

The mylar car tweeters would integrate well as they can be fitted close to the woofers (which is preferable), but they have to be crossed higher, which will lead to some amount of problems with the woofers not acting like a line array but as individual point sources from about 2.5khz to wherever the tweeters take over (probably around 5-6khz). There are always going to be compromises in this type of homebrew, and you just have to decide which are less preferable.

My cabinet design will be pretty unconventional. I plan to use laser-cut 1/2" MDF laminated with thin plywood in lieu of veneer. The cabinets will be well-braced to compensate for the relatively thin walls. I will make a separate cabinet for each group of parallel-wired drivers, and connect the cabinets in series. This modular design will allow me to use smaller material stock and make it much easier to transport the speakers. Any thoughts? I might start a new thread once I have a more detailed design.

So, something akin to the Bose L1s? If you want portability I'd go with 1/2'' ply (it's lighter), braced and painted. It's do-able but be sure to have a good way to keep the thing upright. I made a floorstanding array for HT use a while back but the base was only 12''X6'' for a 5 foot tall array. It's a little wobbly to say the least. :rolleyes:

Here's a good link for basic line array stuff that explains many of the compromises inherent in line array design: http://www.burton-manor.co.uk/Audio/LAthoughts.htm

[Sydney]

Re: sony buyout

... I am unsure as the best location for one tweeter, but I would think that you would want it close to the center of the woofer wavefront I think. Anyone please correct me if I'm wrong! This would either mean making it MMMMTMMMM or putting the tweeter off to the side of the middle,

In the center ( ear-line) or a tweeter line to the side is the usual approach.

Would it be more difficult to integrate a single tweeter than a tweeter array?

Not necessarily - often it is the converse; as a fundamental issue with using multiple HF elements is they have to be small.

[forestroyse]

Re: sony buyout

So, something akin to the Bose L1s? If you want portability I'd go with 1/2'' ply (it's lighter), braced and painted. It's do-able but be sure to have a good way to keep the thing upright. I made a floorstanding array for HT use a while back but the base was only 12''X6'' for a 5 foot tall array. It's a little wobbly to say the least.

Here's a good link for basic line array stuff that explains many of the compromises inherent in line array design: http://www.burton-manor.co.uk/Audio/LAthoughts.htm

Not really like the Bose L1s. Those are smaller and even more portable than what I have in mind, and they have a crazy baffle. I just ordered 50 buyout woofers and 2 of the constant directivity horn tweets. I'll make a new project thread once I finish the cab design in SketchUp. I agree that 1/2" ply would be a better choice than MDF for my project, thanks. And thanks for the link. The closer I get to a design, the more I realize I need to read more and go back to the drawing board.

[tagaiz]

Re: sony buyout

I've whipped up this.


3/4" mdf is what I'd be using because I have just enough to complete them. They're 49" x 10.5" x 7". 8 woofers apiece using these unless anyone can think of a better option. I have no idea what I'd do for a crossover so someone else would have to help me. I'd probably have to front mount the woofers because of the thickness of the mdf although I don't really think it'd affect the sq on these but someone else is going to have to chime in on that.

[Charles Warwick]

Re: sony buyout

Front mounting will have little to no effect on the sound quality compared to rear mounting.

You could rearmount like what was done here:

http://techtalk.parts-express.com/showthread.php?t=226211

Another option is to perhaps put a round-over on the outside.

You may consider looking at some of the 1'' dome tweeters PE has like this one http://www.parts-express.com/pe/show...number=299-944. They would probably be sufficient for 2-3khz crossover.

These were also suggested earlier in the thread http://www.parts-express.com/pe/show...number=270-049. They are more expensive (and likely overkill), but if you were running this array loud you wouldn't have to worry about them like a small dome.

Here's a start to finding crossover values:

http://www.diyaudioandvideo.com/Calculator/XOver/

While it takes some tweaking, generally it'll get you close enough. Off the top of my head, I'd suggest something along the lines of a 3rd order butterworth 3000hz crossover, depending on what tweeter you choose. Just a start, I'm sure others will chime in with more thought out suggestions.

[r-carpenter]

Re: sony buyout

So I got my 3 cases today.
Pulled out random driver and tested it cold and warm after 4 hours of music through it. No significant TS changes noted.


Completed: Tue Aug 09 16:51:17 2011
Drive level 100.000 % [ 3.620 mA]
Sine,LoZP(LV/LA)->Q/Fs,82 pts
;------------------------------------------------------------------
Re 8.017 ohms
Fs 79.148 Hz
Zmax 64.645 ohms
Ro 22.569 ohms
F0 68.416 Hz
F1 93.823 Hz
Fmin 218.517 Hz
Qes 1.2523
Qms 8.8461
Qts 1.0970
Le 1.068 mH @1k
XLe 12.312 ohms @1k
PLe 33.015 Degrees @1kHz
;------------------------------------------------;
; Approximate Impedance Fitting Constants ;
; (Improved with Completion of Vas Test) ;
;------------------------------------------------;
Krm 121.330E-06 ohms Freq dependent resistance
Erm 1.067E+00 Rem=Krm*(2*pi*f)^Erm
Kxm 11.904E-03 Henries Freq dependent reactance
Exm 701.013E-03 Xem=Kxm*(2*pi*f)^Exm, Lem=Kxm*(2*pi*f)^(Exm-1)

S&L woofer tester also has suspension linearity test where it'll excite the driver with different voltage and measure TS. Nothing terible showed up there.
This driver definitely will need a tweeter and some EQing. Will be testing on the baffle soon.

[hasekisgod]

Re: sony buyout

Did anyone say how the cone is? is it thick enough where if u push yur finger on the back side does it flex the cone? I didnt put my order in yet and was wondering if they would be like some buyouts I bought a few years ago that the paper cone is so thin. I know im being picky but I have tons of buyouts now I can make for a array but if the cones are pretty stiff what the heck I will buy more :-)

[XtremeRevolution]

Re: sony buyout

About to pull the trigger on too many of these for a line array. Would the Pyle super tweeter sound better than the horn loaded one?

Also looking at these tweeters. Seem to be able to be crossed low enough.

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=272-120

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=270-125

[nottaway]

Re: sony buyout

Since this is ultra budget..... How would this work? MMMMMMTMMMMMM with one of these:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=280-062

Isn't this the tweet on the Cabrini? Where is the Cabrini crossed over? Any chance to re-use the tweet circuit on it and run the woofs full range?