Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

[F-Train]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

Ty,
How do the 8-ohms sound compared to the 4-ohms? If they're nearly the same then they should sound amazing.
I built (partially) your 4-ohm version and even with the the baffles just clamped on they really sound incredible. I should have them finished pretty soon and post a build thread.
At first my wife didn't want anything this size in the office she decorated, but after hearing them she quickly changed her mind.
Thanks for your work on these-

[tyger23]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

I'm happy you like them. It's been more than a year since I heard the 4-ohm version. I shipped those off to my cousin as a graduation present, so I can't provide a direct comparison and my memory is very fuzzy. Too much alcohol ;).

On one hand, my initial impression is that the 8-ohms don't dig quite as hard as the 4-ohms. The mids and highs are just as nice as I remember, but I don't seem to be getting the lows out that I remember.

On the other hand, my measurements (with the microphone at 1M or further back) showed a whole lot of room cancellations in the bass frequencies. I'm in a different house now, and these are the first speakers I've tuned in this room. When I took the near-field measurements to remove the room cancellations, the bass actually measured as good as or better than the 4-ohm version. Also, when I walk around my room, I can hear the bass cutting in and out, which correlates with my microphone's measurements.

So - overall - I'm gonna state that they're just as good as the 4-ohms. Now I've got to get the "problem" woofer I had sent back for RMA and get the 2nd one built. Then I can really push it ;).

[sonex]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

out of curiosity what is the sensitivity of the 8 ohm version. your 4 ohm version sound incredible for their price point, I'm floored by the bass extension and clarity of your arias.

[tyger23]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

out of curiosity what is the sensitivity of the 8 ohm version. your 4 ohm version sound incredible for their price point, I'm floored by the bass extension and clarity of your arias.

I just measured it at around 83dB for the 8-ohm version at 2.83V and 1M.

I expect the 4-ohm version would be about 85dB in the same conditions, although I don't think I ever measured it. The 4-ohm woofer is more sensitive, but my use of an air core inductor in that crossover means that it would have more DCR and thus it won't get the full 3dB more sensitivity you'd expect.

I'd love to see pics of any completed builds and impressions. Thanks!

[Pete Basel]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

Nice work, just noticed your design here since it was referenced from another thread.
I have to ask, is the 3 dB depression from 1.5 to 3K deliberate?

[tyger23]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

Pete, I was not specifically targeting that response. I was targeting a good phase response with a deep reverse null, and the result was as pictured.

I'd love to get those speakers back someday and re-take some of those measurements. I've learned a lot since then and I wouldn't be surprised if the dip was actually measurement related.

[Pete Basel]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

That dip sounds quite good so, you might just be surprised if you were to remove it.

[saabracer23]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

I'm trying to source all of the crossover parts from PE. The 8R version uses an iron core 18ga 2.2mH coil. PE stocks an 18ga 2.5mH coil and the DCR Is close. Will that work? I can unwind a few turns to get it to 2.2.

Dan

[Wolf]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

I'm trying to source all of the crossover parts from PE. The 8R version uses an iron core 18ga 2.2mH coil. PE stocks an 18ga 2.5mH coil and the DCR Is close. Will that work? I can unwind a few turns to get it to 2.2.

Dan

Try a P-core...
Wolf

[tyger23]

Re: Introducing The Arias - my Black Box design. RS150-4 + XT25SC90-04

Just FYI - I always order all my parts from www.erseaudio.com. Even when their website shows "out of stock", I've never had an issue with that. I guess they always find one to send me or perhaps they wind one to spec. Unwinding the 2.5mH coil should work as well, but I don't know how many turns it would require....

[DinoRhinoDance]

I'm eager to build the 8-ohm version of these but I have two questions I'd like to sort out before committing to ordering parts.

What are the port dimensions?

Was this made with 3/4" MDF?

Thanks!

[a4eaudio]

I'm eager to build the 8-ohm version of these but I have two questions I'd like to sort out before committing to ordering parts.

What are the port dimensions?

Was this made with 3/4" MDF?

Thanks!

tyger23 doesn't post a lot of on the forum these days, so I'll take a guess...

I bet this is 3/4" MDF looking at the pics and that he mentioned using a 1/2" roundover instead of chamferring in post #5.

You can get the dimensions from the cut-list in post #1 for gross volume. Estimate displacement of driver, port and bracing for net volume. He says he used 2" PVC pipe in post #5 and tuned to 48Hz in post #30. Using WinISD you can get a good approx of what the length of the port would need to be. Box tuning is regardless of the driver, so if you have net volume, tuning and port diameter you'll get port length. If you have the ability to measure the TS parameters on actual woofers, you could modify the box volume if needed, as tyger mentioned he wasn't getting the bass response from the 8 ohm version that he remembered from the 4 ohm version. (Also, RS150 is a popular driver, you could use someone else's design for box volume and tuning and keep tyger's baffle layout and crossover.)

[DinoRhinoDance]

Thanks for the detective work a4audio. I don't fully trust my own work with WinISD and XSim so I'd like to follow in footsteps for a few more projects before I go solo!

I just ordered parts for the 4-ohm version after picking out an amp. I'll use the same port tuning from the C-Killa build by the late Lou.

Thanks for the help!

[Operandi]

I'm eager to build the 8-ohm version of these but I have two questions I'd like to sort out before committing to ordering parts.

What are the port dimensions?

Was this made with 3/4" MDF?

Thanks!

Just curious, did if you started building these yet?

Looking at building the 4ohm version myself and am getting close to buying the parts.

[tyger23]

All - yeah, I don't post much here anymore. Sorry for dredging this up many months later, but I thought I would answer the questions asked.

I think most of the information being asked was listed in post#2, which appears to have been a document that's now gone into the internet ether. I'll post that information below. DinoRhinoDance yes - this was 3/4MDF, and the cutlist was on post 1. The bracing and corner slices really don't factor into the calculations much at all. I believe the corner slices were about 1.5" on the 90-degree angle sides. The cross bracing pieces were about 2" or so wide. Something in that realm. The port was 2" PVC, and the total length from the back of the port to the front of the baffle is 6 ¾“.

I will say that I did prefer the 4-ohm version. They 8-ohm version was good, too. Just make sure your amp can handle 4-ohms if you build that.

[tyger23]

Here is the document that was missing from post #2. This was my full writeup on the project, and it contains most all my thoughts and information taken during the project.

https://docs.google.com/document/d/1D7eiRPi3m7Tg3xrAa44oAUSK_RfBaKgo/edit?usp=sharing&ouid=112998028120261674329&rtpof=true&sd=true