Sony buyout project

[r-carpenter]

Re: Sony buyout project

I'll take you up on that offer next time in Brooklyn!

thought this might interest you

http://fredt300b.smugmug.com/Hobbies/Speakers/132721_kcDVmw#1512196823_37hRx64

http://audioroundtable.com/forum/ind...sg&goto=69696&

Yep, i looked at it. Would be interesting to compare head to head because my FR is very similar. The solution is entirely different tho.

ARG! I'm so jealous! My XLR preamp arrived yesterday, but I'm headed out of town to visit the family today through Monday. I wanna measure stuff!

Just wait till you start. It usually results in a hair pulling for a first few weeks.:D

I don't have one at this time, but if you can provide another crossover based on that tweeter, I will be more than happy to build one, if not two pairs of these for my home theater. I can easily pick up a 6' plank of 3/4" southern yellow pine for $32 and not have to do any cutting at all; just routing. It would be a surprisingly simple project for me.

The changes would be very small if any. In all probability I'll get a few stock DX25 tweeters and correct the crossover, but that'll be after the new years.

Good news is......................drum roll...............the crossover is done.
Even better news, the speaker sounds awesome. I rarely compliment myself but this $0.69c wanders are singing now. And I mean it, they are sweeeeeet.
Frequency response is leveled within 4db, which is fine considering it's a dipole. Ops, I've changed a 6k notch slightly. Also added another shelving notch to tame raised response below 500hz. Impedance is amp friendly and doesn't drop below 4ohms (mostly about 6-7ohms, 4ohm in the tweeter range).
I am using 100wpch Carver amp. At 90db SPL on the music, the dials are around 3watt. The amp is barely warm. I'll be trying Nelson Pass 15watt class A clone next.

The next step is to take the drivers out, finish the speakers.
I will verify the performance and fine tune things in a next couple of weeks. Of cause squiggles will be posted.
Speaker works fairly flat to 120hz with distortions 40-50db below 200hz to 20khz at 94db spl.

[ROTECH]

Re: Sony buyout project

hooorah!!!

Thank you for my new game room speakers!!!!! Great writeup too, very informative.

[johnnyrichards]

Re: Sony buyout project

As I said, best project going right now. Good job, and I hope to see many copies of this design!

Now, you need to come up with a focused line array subwoofer for them

[nottaway]

Re: Sony buyout project

Yep, i looked at it. Would be interesting to compare head to head because my FR is very similar. The solution is entirely different tho.



Just wait till you start. It usually results in a hair pulling for a first few weeks.:D



The changes would be very small if any. In all probability I'll get a few stock DX25 tweeters and correct the crossover, but that'll be after the new years.

Good news is......................drum roll...............the crossover is done.
Even better news, the speaker sounds awesome. I rarely compliment myself but this $0.69c wanders are singing now. And I mean it, they are sweeeeeet.
Frequency response is leveled within 4db, which is fine considering it's a dipole. Ops, I've changed a 6k notch slightly. Also added another shelving notch to tame raised response below 500hz. Impedance is amp friendly and doesn't drop below 4ohms (mostly about 6-7ohms, 4ohm in the tweeter range).
I am using 100wpch Carver amp. At 90db SPL on the music, the dials are around 3watt. The amp is barely warm. I'll be trying Nelson Pass 15watt class A clone next.

The next step is to take the drivers out, finish the speakers.
I will verify the performance and fine tune things in a next couple of weeks. Of cause squiggles will be posted.
Speaker works fairly flat to 120hz with distortions 40-50db below 200hz to 20khz at 94db spl.

Nice! Thanks for posting for those of us holding a few of these.

Any advice for someone wishing to adapt your measurements/design to a sealed alignment?

Is this adaptation possible without direct measurements and/or crossover rework to attain reasonable results?

[r-carpenter]

Re: Sony buyout project

hooorah!!!

Thank you for my new game room speakers!!!!! Great writeup too, very informative.

Thanks. For the gaming you'll need a pair of subs or just a nice size inexpensive woofers (or 4 if you are doing surround sound gaming with 3d) .
After I post the measurements, it'll be clear how to roll off the bottom end.

Now, you need to come up with a focused line array subwoofer for them

That's allot of work Johnny. I'd see a price/value relationship issue with that. First of, most of the guys can pop 26 holes with the router and screw the drivers in. Not everyone is going to laminate, make curved templates and spend like 40 hours on that. Because of how low the main array goes, you don't need a pricy woofer with clean extension in to upper bass, lower mid range. Anything will do. Small plate amps cut off at a 100hz and a pair of sealed cabinets, that would be my way to extending in to 40-50hz.

Any advice for someone wishing to adapt your measurements/design to a sealed alignment?
Is this adaptation possible without direct measurements and/or crossover rework to attain reasonable results?

Unfortunately, no. I can make some suggestions but the design will be different and without verification, who knows what it'll sound like.
In a sealed alignment (which I don't think is the best for 1. QTc driver), the response from a 100hz to 500hz will change significantly. Because it's not a dipole any more, mid range SPL will change as well. You could probably keep the tweeter section if the high pass of the woofer section is the same acoustically.

[Sidi]

Re: Sony buyout project

I'd see a price/value relationship issue with that. First of, most of the guys can pop 26 holes with the router and screw the drivers in. Not everyone is going to laminate, make curved templates and spend like 40 hours on that. Because of how low the main array goes, you don't need a pricy woofer with clean extension in to upper bass, lower mid range. Anything will do. Small plate amps cut off at a 100hz and a pair of sealed cabinets, that would be my way to extending in to 40-50hz.

While I still haven't measured them, I have 16 of those $5 10" that, by my sims, will work beautifully below the sony's. Two 8x10" are my plan, if they work out.

[Soundslike]

Re: Sony buyout project

Roman,
I see you used 1" material for the baffle. I presume you used the thick baffle for the additional strength. bit since the drivers are rear-mounted, will a 3/4" baffle affect the performance acoustically? In theory I would guess the 1/4" closer position (to the baffle surface) could make a difference, but is it likely to be audible, or have any effect on your crossover design? As for the strength of the baffle, I'd think the "wings" you have planned would take care of that? 1" material will be harder to come by, and the cost will likely be pricey, considering it would have to be special ordered, or purchased from a wholesale supplier who doesn't really want to mess with low-volume customers. I could glue up two pieces of material (3/4" and 1/2") but then I'll end up with a thicker baffle, and if the recess distance is of any significance, I'd have to cut rebates on the back side for each driver. For these reasons I'd rather go with 3/4" material, supported as necessary.

Ron

[XtremeRevolution]

Re: Sony buyout project

As soon as you have the crossover ready for the DX25, I'm ordering the tweeters and the crossover parts for 2 pairs of these. Can't wait.

[ROTECH]

Re: Sony buyout project

Thanks. For the gaming you'll need a pair of subs or just a nice size inexpensive woofers (or 4 if you are doing surround sound gaming with 3d) .
After I post the measurements, it'll be clear how to roll off the bottom end.

Sorry, I should have clarified better, not that kind of gaming- I have the attention span of a fruitfly and have never gotten into video games.
The "gameroom" is the easy name for my space that has a bar, living room, seating areas, and drinking game space!!!

Though yes it is a large space and subwoofers will surely be implemented with these arrays if I get to them.

[r-carpenter]

Re: Sony buyout project

Roman,
I see you used 1" material for the baffle. I presume you used the thick baffle for the additional strength. bit since the drivers are rear-mounted, will a 3/4" baffle affect the performance acoustically? In theory I would guess the 1/4" closer position (to the baffle surface) could make a difference, but is it likely to be audible, or have any effect on your crossover design? As for the strength of the baffle, I'd think the "wings" you have planned would take care of that? 1" material will be harder to come by, and the cost will likely be pricey, considering it would have to be special ordered, or purchased from a wholesale supplier who doesn't really want to mess with low-volume customers. I could glue up two pieces of material (3/4" and 1/2") but then I'll end up with a thicker baffle, and if the recess distance is of any significance, I'd have to cut rebates on the back side for each driver. For these reasons I'd rather go with 3/4" material, supported as necessary.

Ron

You can use 3/4". It's not that important. I just happened to have 1" panel in the shop and decided to use it. At the time, I wasn't sure if I was turn it in to U-pole, so 1" sounded like a more rigid solution.
Stay tuned for an update on the tweeter mounting. If you change 3/4" from 1", the radius will not change enough to cause any audible changes.

While I still haven't measured them, I have 16 of those $5 10" that, by my sims, will work beautifully below the sony's. Two 8x10" are my plan, if they work out.

You'd be using your woofers 100hz down and that's where you can design based on TS.

[r-carpenter]

Re: Sony buyout project

The baffle is 10" wide and now I am ready to take the drivers out but have to router the tweeter in. It just happened so that DX25 has a large front plate. It'll be very close to the edge. So, two possible solutions to make it look better and bring the tweeter closer to the woofers (not as important as in conventional system)
1) Machine the front plate so it drops in closer in towards center
2) remove the front plate and cut the tweeter from behind.
3 bolts hold the plate to the tweeter. A proper Allen wrench is 2mm but if you are careful 5/64th can work. The screws look like M3 0.5. I'll have to check that tomorrow.

[bkeane1259]

Re: Sony buyout project

Toss faceplate, recess from behind with a roundover = mini waveguide??

[bkeane1259]

Re: Sony buyout project

The "gameroom" is the easy name for my space that has a bar, living room, seating areas, and drinking game space!!!

That's the BEST kind of gameroom. :D

[r-carpenter]

Re: Sony buyout project

Toss faceplate, recess from behind with a roundover = mini waveguide??

that's what I am thinking. ;)

[XtremeRevolution]

Re: Sony buyout project

that's what I am thinking. ;)

So its going to look something like this?

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-1028