New system measuring tool

[User211]

Hocky - one of these and a measurement mic.

 

[JonFo]

Measuring technique is very important to recognize as a contributor to results.

One cannot measure in just one spot and correct for that. As Justin notes, the movement of the measurement point will have dramatic effects.

The best option is to measure multiple points and average them before making big decisions and / or changes.


Also, recognize that is no such thing as flat in-room response. The goal is to get the soundfield into as cohesive a balance as one can achieve.
People often screw-up by chasing one peak or null, and sacrifice overall system balance.

 

[RUR]

No actually, but I will do, and yes, I know - we all remember Ethan's contributions here I'd hope.

Reading them is educational. Acting upon them is beneficial.

 

[Hocky]

I have a 3gs and like I said, it has been inconsistent - in the same combo, same location, same day. Maybe the iphone 4 has a better mic? Or maybe my phone is just a piece of junk. lol

 

[JonFo]

That's the point I'm trying to make.

But assuming the headphone A/D input is linear, a decent mic will make it extremely good.

As long as the mic correction values are the right ones, it's actually pretty good. I've compared it with my main measurement rig and the old iPhone 3G is pretty wide-range. iPhone 4 not quite as good, but good enough for casual work.

They have a calibrated mic and external interface box that should be pretty cool, especially on iPads.
http://www.studiosixdigital.com/iphone_measurement_micropho.html

Note that the current hardware does not work on iPhone 4 / iPad or latest iPodtouch. they are revising the HW, but it's not ready yet.

But it makes a great way to re-purpose that old iPhone 3G or older iPodTouch ;-)

Nice review of it all in S+V mag: http://www.soundandvisionmag.com/ap...tal-does-serious-diy-audio-measurement-iphone

 

[User211]

Reading them is educational. Acting upon them is beneficial.

From the Duetta Signature manual: "Rear wall should have no damping material or very light damping material." It then goes on to say that basically you'll suck the life out of the mid/top if you use much more than very little or none.

 

[Rich]

The value of room treatments (with any speaker, but especially with dipole speakers) is crystal clear to me. In my room, with my system, they made a huge difference in the quality of the sound, particularly with imaging, instrument localization, and soundstaging. I did a lot of testing before, during and after I installed them, using the most accurate measurement tool I have at my disposal, my own ears.

Obviously, every room is different. And everyone's tastes are different. But I think a lot of people get used to what they call "ambiance" provided by dipole speakers, and then claim the sound is just "dead" without it. The truth is, if they listen to it long enough to get used to the sound without the added reflection, they will find that they can turn the system up louder and hear a lot better imaging and soundstaging from the lack of interrupting reflections. And after a few days listening to what is, in effect, the real signal they were supposed to hear, without the added noise of reflections, they will get used to the sound and not notice the "deadness" they thought they noticed in the beginning.

The rear wave off of dipole speakers is essentially just added noise to your system. Why work so hard to bring the noise floor down to nothing, but then ignore the greatest source of noise in your system? The effect we call Stereo was never designed to work with added late reflectivity. It was designed for direct radiation from two speakers a certain distance apart and a certain distance from the listener. If you have added reflections, they are smearing the soundstage and imaging created by the stereo effect. May as well just listen in mono.

 

[User211]

Why use a dipole with a curvilinear panel when you are going to have to work so hard to undo everything the speaker does by default i.e. throw sound not only at the rear wall but the side walls too?

 

[jtwrace]

I've ordered some GedLee Abbeys and two bandpass subs to go along with my Rythmik subs.

I recommend you read the white papers that Dr. Geddes has written. How do they sound?

http://gedlee.com/

 

[Rich]

Why use a dipole with a curvilinear panel when you are going to have to work so hard to undo everything the speaker does by default i.e. throw sound not only at the rear wall but the side walls too?

Because a dipole line source panel with a massless diaphragm has other sonic characteristics that make it a better alternative than point source cone speakers mounted in a box. But to try to take one of the engineering disadvantages of that design and pretend it is a necessary and desirable part of the sonic signature is pretty silly, in my opinion. That is like saying that the "boxy" sound of box speakers is desirable, and when you remove the box the sound lacks a certain something. Or, for instance, preferring the sound of a highly euphonic tube amp simply because the midrange sounds so good to your ears, even though the sound is a completely inaccurate reproduction of the original recording, being rolled off in the highs and mushy in the lows and with a lot of added harmonics in the midrange.

Ultimately, dampening of the rear wave of a dipole speaker is no different than putting absorption on the side wall first reflection points with a point source speaker. You are working to minimize distracting reflections that smear imaging and confuse soundstaging.

Most speaker designs have advantages and disadvantages. The key is finding the sonic signature you prefer and then working to minimize the disadvantages of that particular design. As for the curvilinear panel aspect of ML's panel design, I am not convinced that this is the best design for ESL's in general.

 

[User211]

That's exactly the answer I would have come up with posed with the same question, Rich. However, you have to confess there's a certain (large) amount of irony in it.

With regards to curved panels, I'm not sure it is the best solution but they sure are entertaining to listen to, precisely because of the odd dispersion they produce. Attempt to kill it, or enjoy it, I say. The same goes for rear wall reflection. At the end of the day, it is just what you prefer to listen to - a highly damped room, an undamped one or somewhere in between.

The tube amp argument? Well, that just depends on the tube amp. Some really don't commit those sins. I've had amp after amp plugged into the Duettas (with still more lined up to try - Perreaux, Krell, Unison Research) and I still can't believe the res, speed, naturalness and yes - subjectively extremely uncoloured presentation afforded by the 211 monos I have.

 

[Rich]

That's exactly the answer I would have come up with posed with the same question, Rich. However, you have to confess there's a certain (large) amount of irony in it.

I do get the irony. But ultimately, it is not much different than anything else in this hobby. We spend tens of thousands of dollars on sources, preamps, amps, and speakers, and then drive ourselves crazy trying to find just the right cables to make them all sound good together.

At the end of the day, it is just what you prefer to listen to - a highly damped room, an undamped one or somewhere in between.

There's the rub. I prefer to listen to the source material, as it was supposed to sound. Isn't that the idea of a stereo system? To reproduce the source material in an accurate manner? If you are going to muddy it up with unintended reflections, why use Hi Fi equipment at all? Why worry about speaker placement at all? Either you are trying to create a proper stereo image and accurate frequency reproduction . . . or you are not. If not, I don't know why you would spend all the money on Hi Fi equipment in the first place.

Ever wonder why you don't see dipole speakers in most recording studio control rooms? Why their speakers are generally set up for near field listening? There is a reason. Sonic reflections kill the ability of the engineer to accurately master the recording. Just as they kill your ability to accurately hear the imaging and soundstaging of the instruments in the recording.

The tube amp argument? Well, that just depends on the tube amp. Some really don't commit those sins.

Absolutely, it depends on the amp. And I wasn't trying to disparage all tube amps. I prefer tube to solid state, in general. There are many highly accurate and fairly neutral tube amps. No, I was specifically referring to those particular tube amps that are highly euphonic, while also being highly inaccurate (some of the Jolida's come to mind). Those amps can sound awesome as far as liquid midrange. Just beautiful. And some people love them just for that reason. But in the end, it is a highly inaccurate portrayal of the original source material. The highs are rolled off, the bass is weak and mushy, and the midrange is way too lush. It's ok to prefer that kind of sound. You just have to give up on the idea that you are enjoying an accurate reproduction of the source. You are going to give up other things in return for that lushness through the midrange. You are not going to get a serious thump from that kick drum or a glittering shimmer from that cymbal.

Likewise, with reflections from the rear wave of a dipole. You may get some feeling of ambiance that you like, but you are giving up accuracy in imaging and soundstaging. Ultimately, it is all a tradeoff. I can enjoy the sound of a highly euphonic amp for a little while. But I could never have one permanently in my system, because I wouldn't enjoy it's inaccuracy over time with most material. Likewise, after having a well-treated room, I would have a hard time living with an untreated room for my electrostatic speakers. While the ambiance may sound nice, I would know what I was missing in imaging.

 

[User211]

Go on then Rich - recommend me 2 rear diffusers and I'll give them a try. I really have got a feeling they won't last but I'll give them a go.

 

[repman]

Go on then Rich - recommend me 2 rear diffusers and I'll give them a try. I really have got a feeling they won't last but I'll give them a go.

I think Rich was saying to use absorbtion on the rear wave and not a diffuser if I am reading him correctly.

 

[User211]

Yeah I dunno why I said diffuser... I did mean absorber!!!

 

[Rich]

Justin,

I don't know what might be available on your side of the pond for a more reasonable cost, but if you were ordering from the US, I would recommend the Real Traps HF Mini Trap. (Make sure you get the HF version, because you want even absorption of high frequencies. The regular version will actually reflect high frequencies.) Basically, you want a panel that will evenly absorb the entire frequency range that your speaker panel is radiating. For a hybrid ML, that is from about 250 hz. on up. I'm not sure about your Apogees, but would guess they are pretty close. If you wanted to save some money, I guess you could start off trying a two foot square panel instead of a two by four foot panel. It might not be quite as effective, but would probably get you most of the way there and save you $60 per panel plus maybe some shipping.

I mount my traps on the wall (about four inches off the wall, actually, which provides better absorption) directly behind each speaker. The difference in the quality of the sound between this and bare walls or diffusion was huge. The difference was much greater clarity, more pinpoint imaging, and more accurate soundstaging. I could also turn up the volume louder without feeling like the highs were grating on me.

I also have absorption at the first reflection point on the side walls, and I have bass traps in every three-way corner. But I suggest you just start with a panel behind each of your speakers and see how that goes. Make yourself live with it for a few weeks to get used to the sound change. Turn up the volume a little, since you don't have that excess ringing from reflected sound, you will be able to listen a little louder. I expect you will experience greater clarity and imaging. Then you will have to decide for yourself if that is worth what you lose in "ambiance."

Be careful, though. I recommended these to Jonathan, and look what happened . . . I think he spent a fortune re-treating his whole theater room.

 

[User211]

Basically, you want a panel that will evenly absorb the entire frequency range that your speaker panel is radiating. For a hybrid ML, that is from about 250 hz. on up. I'm not sure about your Apogees, but would guess they are pretty close.

Hm... the whole speaker is a panel The bass panel is 500Hz downwards, the mid/treble ribbon everything above 500, obviously.

I'm not sure about this - if it ain't broke don't fix it? The fact is, at least to my ears with the latest ribbons and x-over tweaks, everything at the moment just sounds amazing - super high resolution across the entire frequency range, no harshness issues whatsoever, excellent imaging, great scale, fantastic speed etc etc.

I think GIK UK is probably the best bet here. The MBL chappie in Gordon's meet thread had some GIK panels. But he passed them on I think. He's heard my Apogees a couple of times and he didn't mention that he thought they'd be worthwhile. I'll have a chat with him about it first. If he reckons not, I will take his advice. But if he thinks it's worth a stab, I will go for it.

 

[Rich]

Hm... the whole speaker is a panel The bass panel is 500Hz downwards, the mid/treble ribbon everything above 500, obviously.

Then perhaps the 244 bass panels would be more appropriate for your speakers. They absorb well down below 80 hz. and supposedly don't suck the life out of the highs, which is one of your concerns, I know. And by using these, if they don't work well behind your speakers, you could try placing them in a couple of corners for some bass trapping, which should help your overall bass response. In other words, if they don't work for one purpose, they will definitely work for the other. And I haven't found a room yet that couldn't benefit from some bass trapping in the corners.

I'm not sure about this - if it ain't broke don't fix it? The fact is, at least to my ears with the latest ribbons and x-over tweaks, everything at the moment just sounds amazing - super high resolution across the entire frequency range, no harshness issues whatsoever, excellent imaging, great scale, fantastic speed etc etc.

I understand the "if it ain't broke, don't fix it mentality." The question is, are you absolutely sure it ain't broke? And if you don't experiment with some room treatments, how can you be so sure? It is easy to get used to a sound and think it is perfect, then you change something out only to find out it can get even better. Room treatments were a very eye-opening experience for me. I had no idea the sound could get that much better.

It is pretty common knowledge that room issues contribute a great deal to the sound of any system. That is one of the reasons it is so tough to get great sound at a show. If you don't have any room treatments in your room at all, I would say that your sound quality is not likely to be nearly as good as you think it is. In other words, it can still get a lot better from here. But, of course, it will require the proper amount of treatments in the right places. And what works well for my system in my room may or may not work for you in your room. But I think taming the rear wave and adding some bass trapping would help you out a lot.

Either way, no skin off my nose if you don't wish to mess with it. If you are happy with your sound, that is ultimately all that matters. But you did say earlier in this thread:

There is a remarkable lack of proof of concept on this forum with regards to this. But much verbosity advocating there use. It'd be nice to see someone actually proving that they have made room treatments work well - at least in the field of straight forward frequency response.

Ultimately, the proof is in the pudding. I know how much better my system sounds now than before I treated it. I specifically A/B'd the treatments behind the speakers and compared them directly with bare wall and with quadratic diffusers. The difference was painfully obvious and immediate. The rear wave needed to be absorbed. That is why I advocate their use. JonFo experienced the same thing. Only he actually did do the measurements that I was too lazy to do that help confirm and explain why this works so well. But ultimately, it was his ears that made the final decision. Of course, our experience is with ML's, not Apogees. But I would expect the physics to be more similar than not.

 

[tsv_1]

I dunno Rich... I mean I hear your argument and you make solid points... but with the CLXs now setup and singing in my room (with no front-wall absorption) the soundstage - the pin-point accuracy of vocal and instrumental placement in 3 dimensions, and most of all the clarity of the sound is unlike anything I've ever heard from a music reproduction system (and yes, I've been to audio shows and heard some very high-end systems). I am completely blown away. Could it be better with some front-wall panels? Maybe, but I understand Justin's position wrt it sounding so good now it's hard to even want think about mucking with it.

This is not to say that experimentation is off the table... only that it's a relatively low priority for a while.

 

[Rich]

I dunno Rich... I mean I hear your argument and you make solid points... but with the CLXs now setup and singing in my room (with no front-wall absorption) the soundstage - the pin-point accuracy of vocal and instrumental placement in 3 dimensions, and most of all the clarity of the sound is unlike anything I've ever heard from a music reproduction system (and yes, I've been to audio shows and heard some very high-end systems). I am completely blown away. Could it be better with some front-wall panels? Maybe, but I understand Justin's position wrt it sounding so good now it's hard to even want think about mucking with it.

I'm sure you thought that about the Summit X's before, too. But the CLX's bring the performance to a whole new level, do they not? Why wouldn't you think that proper room treatment will squeeze even more performance out of those speakers? Besides, your speakers aren't even burned in yet. So don't give me that crap about how good it sounds now. You know it will continue to improve until you get them run in. And I fully expect you would experience another huge improvement with proper room treatment. You really have no idea just how good your system is capable of sounding . . . until you actually hear it.