John Sayers' Recording Studio Design Forum Archive

oh alright...

Thing is a tank! Curse you and your obnoxiously large sub suggestion!!!

Think of it this way: It will knock your socks off! And thus it will keep your toes warm in winter, and massage your feet too, if you turn up the volume to 11!

But I do agree: It's a monster! However, it will really push the low end down to where I'd like to see it in that room. Your room deserves it, I think! It's looking so good already, that it really should have the low end extension that impresses the hell out of musicians and producers. I aim to get it as close to perfection as we can. ... You DID say you wanted this to be an amazing studio, right?

- Stuart -

hmmmm....feels more like this , but I trust you...It comes from hours of pushing these subs around the room and driving myself crazy.

In all honesty I don't expect much because the dynaudio is performing about the same. I'l do a measurement as proof of course.

Start with JUST the KH805... experiment with phase and cross-over, to get it reasonable. Keep the others off, and send me a REW test like that.
Then set up JUST the Tannoys on opposite walls, one phase-inverted (it doesn't matter which one), and send me a test like that (KH805 turned off).
That will give me enough to start on the digital tuning, while you play around with the exact placement, to see if you can improve things more..

Fun and games! Playing chess with subs is an entertaining occupation! (not)


- Stuart -

OK!! the Neumann wins damn you!!

Also,

I'd like to hang this picture above the CR window if we're not going to put anything up there...

Stadank0 wrote:OK!! the Neumann wins damn you!!

I just saw the new REW data for the sub tests you did... and I have to admit that you are right: The Neumann DOES win

(I really hate to say "I told you so, but, ....")

OK, but that latest REW data you sent only goes up to 600 Hz, so please do a full spectrum test now (without EQ!), and send me that. 3 tests: LS, RS, LRS. Then I'll post some images of REW data here, so you have some bragging rights.... (I reckon you've earned it!). And please check your calibration levels too: the last few tests seem to be about 5.5 dB higher than normal.

And sure, go ahead and hang the painting as well, if you want. That area above the window can stay bare. I don't think there's anything we need to do up there at this stage. (Hopefully the canvas doesn't decide to act as a resonant membrane...)

Next up: Do you feel like chasing down that 1ms refection that I mentioned? You'll need some string, a tape measure, and some masking tape....


- Stuart -

I'll get those tests up in just a bit.. Gotta get the dynaudio shipped back real quick. Guess that's not gonna work out!

Soundman2020 wrote:
And please check your calibration levels too: the last few tests seem to be about 5.5 dB higher than normal.

The calibration has been weird. I've had to re calibrate a couple times lately and it still seems to be off...hmmmm.

Soundman2020 wrote: Next up: Do you feel like chasing down that 1ms refection that I mentioned? You'll need some string, a tape measure, and some masking tape....

Sure, I'll need instructions..

Stadank0 wrote:I'll get those tests up in just a bit.. Gotta get the dynaudio shipped back real quick. Guess that's not gonna work out!

Unless you want to keep it for your rig in the Live Room? Or do you have another sub in there?

I'll get back to you with the instructions for the "string trick" in a few minutes.

- Stuart -

One more thing: You can start running your REW tests from 10 Hz upwards now, instead of starting at 18, as you have been doing up to now. That KH805 goes down really low, so I'd like to make it sing and roar, to check that there's nothing happening in the sub-sonic area. I'll roll that off in the digital tuning, of course, but we do need to know that the room isn't trying to sing whale-songs, now that you unleashed the 805 in all it's glory.

- Stuart -

No, I love Neumann in the LR so I'm going to swap it out... That sub is annoyingly large and amazingly awesome!!

Off to UPS..back in a flash!

OK, instructions for the "string trick"...

Carefully measure the distance from the very tip of your measurement mic to the acoustic center of your LEFT speaker (both speakers show the same reflection, but let's work with the left one, to identify the cause, as the peak is a bit better defined on the left). The location of the acoustic axis is shown in the SketchUp model. Now add 33cm to that measurement (or 13" if you live way back in a different century... ). Get a piece of string that is as long as that measurement, plus a few extra inches on each end, so you can attach it. Mark that exact length on the string with a Sharpie or some such. Tape one end to the front of the speaker so the mark is on the acoustic center, and tape the other end to the measurement mic, so the other mark is at the tip of the mic. The 33cm slack will hang down in the middle.

That loop of slack string represents the EXTRA flight time of the reflection: it is taking that much longer than the direct sound in time (and therefore distance) to bounce off "something" and arrive at your mic almost 1ms later than the direct sound. Now gently move the "slack" around the room to find the hard surface that it touches. There should be only one surface that you can reach perfectly with the loop of slack, but you might find that there are several points on that surface where the loop can reach: That's fine. Look for the spot where the angle that the string makes with the "surface" seems to be the same on both sides. In other words, "angle of reflection = angle of incidence". That's the center of the area that is causing the specular reflection.

My guess is somewhere in this area: Repeat for the RIGHT speaker, with the same string.

To double check that we have found the issue, put a dinner place-mat sized piece of insulation (the thin stuff that you used for inside the slot walls) over that area on both sides, and do a REW test like that. That won't be the treatment! It's just to confirm that we have found the right spot.

Then, if you feel like playing with string some more, you could go hunting for a couple more reflections...

On the left speaker, you'll need to mark bits of string at "direct mic-speaker distance plus 41cm", direct + 132cm, and direct+167 cm. For the right speaker: direct+41cm and direct+134 cm. The shorter distances might be other parts of the desk, but the longer distances are probably either floor bounce, side wall bounce, or maybe a bounce off the cloud. Those are all lower level than the 1ms issue, but still very worth treating if you can find them. They are all within the critical 20ms/-20db Haas window.... and they are also the very last major issues in your room! If we can subdue those, then we'll do the digital tuning... and move on to the live room tweaks!


- Stuart -

Yay!!! more tedium!!! oh well....

On the up side. I have a new beak through discovery! The Neumann stands on its own! I ended up losing the Tannoys and we have an easier situation. It Eq's with much fewer bands and has that awesome Neumann sound...Tweak, tweak, tweak!!!

file sent!!

Quick thought, We do have the option to tilt the top a smidge if your interested....

To elaborate on the Neumann... Not sure how I missed putting it more out in the room like I have it now....slightly under the desk instead of under the window..I'm Relieved to be out of the 3 sub situation. It sounds better all around. More clarity straight up...Well, largely because its the Neumann too.

Stadank0 wrote:Quick thought, We do have the option to tilt the top a smidge if your interested....

Sure! It's worth a try. With the short distances here it will need a fair angle on it, so try to tilt it as much as you feel comfortable with, and we'll see if that makes a worthwhile difference. Not so much that your coffee mug slides off!

- Stuart -