RSS315HF-4 as the anchor of a 3-way???

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???

Hey Pete, here's a measurement of the 15W/4831g00 ... is that smooth enough for ya ;)

Wow . . .

That's the nicest behavior I've ever seen from a midrange of any flavor.

Believe me, I'm having fun auditioning them. :D

Got any off axis data?

And what size baffle is that on?

[DoubleTap]

Re: RSS315HF-4 as the anchor of a 3-way???

Hey Pete, here's a measurement of the 15W/4831g00 ... is that smooth enough for ya ;)

[Wolf]

Re: RSS315HF-4 as the anchor of a 3-way???

Dan's HOSS and BassLines have that awesome low end, but he's done both actively, with separate amps. It's really neat to find out how the subs do in a passive XO, and they really do shine.

Pete- the BassLines had TD12H in them, and they were passive.

The 'Blades' had an active RSS265 in the bottom.

Later,
Wolf

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???

There's becoming no doubt in my mind about the musical quality of the RSS subs. They really are woofers, and can be considered such, remaining articulate to well beyond sub range. Dan's HOSS and BassLines have that awesome low end, but he's done both actively, with separate amps. It's really neat to find out how the subs do in a passive XO, and they really do shine.

Right now, they're crossed at 200Hz using 8mH iron core and 100uF film capacitor. I sure do like what I hear so far. I took care of some leaks around the PR this morning and bass sure tightened up afterward.

I decided that the XO will be outboard. There's some left over veneer which an be used to cover the XO enclosures. So the drivers all have their own 5-way binding posts on the rear bottom, just below the PR. That sure will make playing with various XO implementations an easy proposition.

One thing I want to try is using an impedance compensation circuit for the tweeter. Modeling suggests that better phase tracking is possible using it. It does add 3 more components however. But since it's easy enough to try, why not?

And for the next few hours, I'm just going to run a 40W sine wave at 12Hz through them. Both the PR and RSS are moving near Xmax, and there's nary a sound from them. I do hear just a touch of the 2nd harmonic at 24Hz but at 2" p-p excursion on both the PR and woofer, I'm not surprised. It is barely audible.

[Jeff B.]

Re: RSS315HF-4 as the anchor of a 3-way???

Well I got some listening done with one of the cabinets, just to get an impression of the capabilities. I pulled out the old Sansui G8000, a very generous 130W capability with power meters to give me an idea where the output is to keep it clean. Nothing fancy for the source, just headphone output from the laptop into the Sansui, running WAV format for the music in Media Player. Far from optimal.

I adjusted the output so that the meter was hovering around 10W.

The cabinet will need some cross bracing for the side panels. The baffle doesn't need anything to stiffen it up. Solid as a rock. Even as large as the side panels are, the nature of the build has created really stiff walls that don't move very much. But from a simple touch test, I could tell that a brace or two would improve things.

That said, after I spent an hour listening to some cuts, I got around to playing Allison Krauss, "Deeper than Crying" and was just mesmerized. I think the mid and tweet are so close to right that I don't know that any more tweaking will improve anything. And without the stereo pair in their final places in the listening room, it's tough to tell if the overall bass levels are right. But during Hotel California - Live/Acoustic, the big drum and bass seemed to be all there, with a real visceral quality to the lows. I can't wait to get the second one up for final voicing.

....and I can't wait to hear the pair at some future gathering. The raw cabinets sure were impressive when I saw them in April.

Jeff

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???

Well I got some listening done with one of the cabinets, just to get an impression of the capabilities. I pulled out the old Sansui G8000, a very generous 130W capability with power meters to give me an idea where the output is to keep it clean. Nothing fancy for the source, just headphone output from the laptop into the Sansui, running WAV format for the music in Media Player. Far from optimal.

I adjusted the output so that the meter was hovering around 10W.

The cabinet will need some cross bracing for the side panels. The baffle doesn't need anything to stiffen it up. Solid as a rock. Even as large as the side panels are, the nature of the build has created really stiff walls that don't move very much. But from a simple touch test, I could tell that a brace or two would improve things.

That said, after I spent an hour listening to some cuts, I got around to playing Allison Krauss, "Deeper than Crying" and was just mesmerized. I think the mid and tweet are so close to right that I don't know that any more tweaking will improve anything. And without the stereo pair in their final places in the listening room, it's tough to tell if the overall bass levels are right. But during Hotel California - Live/Acoustic, the big drum and bass seemed to be all there, with a real visceral quality to the lows. I can't wait to get the second one up for final voicing.

[superspeeder]

Re: RSS315HF-4 as the anchor of a 3-way???

Subscribing - I want to see these once they're finished, beautiful cabinets!

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???

Well, I slapped together a crossover, LR2, for the TM section and started playing a bit of music through it to get an idea for the overall sound.

Mmmmmm . . . those Scanspeaks are so, so tasty. And that laid back RS28A is really a special tweeter, and compliments the 15W very well.

Took an impedance sweep of the "system" and it matches the PCD simulation spot on.

The TM section is definitely light on bass of course, but the balance between mid and tweeter seems about right. A measurement sweep will confirm what the ears hear, but that will have to wait for the weekend.

I think I'll be taking DoubleTap's advice and add some serious damping to both the mid chamber walls and the main enclosure, with roofing felt/caulk. The "touch test" during music revealed some vibration in the cabinet, even as stiff and thick as the walls are. It's not much, barely noticeable really. I'd like to see it reduced just a bit more.

Hopefully the XOs will finalized by the end of next week. Then it's on to final finish for the cabs before everything gets stuffed inside and sealed up and friends/family invited over to experience them.

It's been a long time coming, but I can see the light at the end of the tunnel!!!

:D

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???

The drivers and the shape of that cab are begging for LR2 ... but you'll need to measure very accurately acoustic offsets.

You've got a good point. The slope on the front is quite significant, and may actually put the tweeter acoustic center just a tad behind the mid, giving a slight upward tilt to the forward axis, which wouldn't be at all unwelcome since the tweeter height is on the low side.

What are the subtle audible differences between LR2 and LR4? The modeled responses are literally on top of each other, with less than 0.2dB separating the two traces.

[DoubleTap]

Re: RSS315HF-4 as the anchor of a 3-way???

The drivers and the shape of that cab are begging for LR2 ... but you'll need to measure very accurately acoustic offsets.

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???

OK, I've got the cabinets ready to accept drivers. I'm starting with the TM section and will add the RSS315 later on. The Scanspeaks will be run wide open with no padding other than the series resistance of the LP filter inductor. High pass frequency is 200Hz.

The question I have for you guys is what type of topology to use.

The combination of Scan and RS28 will allow for LR2 at ~2600Hz with pretty good phase tracking on axis, but a limited vertical window. LR4 at 2400 has a better vertical window, and both are very similar in terms of response.

Modeled power response looks very good with either one as well.

I can build both XOs and try them out, but was hoping to get some input on what you guys think. Thanks for any suggestions.

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???

Further progress . . . :eek: :D

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???

Isn't that something . . . Nice find!

Correction to the driver compliment . . . The Scanspeak Revelator is back for mid duties.

[nordhaven]

Re: RSS315HF-4 as the anchor of a 3-way???

[Pete Schumacher]

Re: RSS315HF-4 as the anchor of a 3-way???