What does the measurements on a common $152 pair of speaker look like?

HAL · « **Reply #120 on:** 22 Jul 2010, 11:47 pm »

Danny,
You are more then welcome!

My hope is that some folks will take on an A/B challenge with a redesigned XO and be able to switch between the two to hear any differences. Keeping the same cabinet and drivers with switching between the two XO's would be trick!

If it becomes a Cheap and Cheerful speaker then it would be fun. A possible gift for budding music lovers!

sts9fan · « **Reply #121 on:** 22 Jul 2010, 11:57 pm »

Going forward non technical posts in this thread will be trashed. So save your breath on +1ing what has already been said.

Danny Richie · « **Reply #122 on:** 23 Jul 2010, 01:44 am »

Dan,

Start yout time window at about 2.7ms or so and shut it down 6.7ms later. Be sure your speaker is at 39" away for that too or you'll miss it.

I also started a new thread in my circle about the posibility of doing a comparison in your area. We'll see if we can get you to see the light.

DanTheMan · « **Reply #123 on:** 23 Jul 2010, 02:11 am »

What demo is it that you want me to hear exactly?

Thanks for the test procedure for the CSD. It would be nice if we could get all AudioCircle members on the same wavelength as far as the measuring rig goes. It would help improve the usefulness of anything posted.

I bought some of the pink stuff(well actually yellow) and beefed up the cabinet lining. So I'll post the results of response and impulse changes. First will be prior to stuffing, the second will be after the stuffing.

OK, nothing to really get excited about there. My guess is that the slight improvement in the treble has something to do with cabinet vibration or something.

I was bummed by the results, but I also wanted to test my diffraction theory with the ports next to the tweeter. So I got some cotton balls from the wife's "stuff" drawer and filled the front of those ports with white cotton balls!

Well, the results are something to see:

No need for a side by side. This only makes me say that the Mackies should be great.

Dan

DanTheMan · « **Reply #124 on:** 23 Jul 2010, 02:19 am »

OK, let's also look at the cotton stuffed ports graph 1/3 oct smoothed vs. the added stuffing material's graph 1/3 octave smoothed:

Can you tell which is which?

Dan

DanTheMan · « **Reply #125 on:** 23 Jul 2010, 04:41 am »

Here's what happened on the low end. One line is with no fiberglass stuffing added, one is with additional fiberglass, and then the one that's about a dB higher is with the cotton added. Not that in all actuality it is not louder, it was just so the different lines wouldn't get confusing.

Dan

art · « **Reply #126 on:** 23 Jul 2010, 05:57 pm »

OK, this will be my only input on this food fight..........

Quote from: Danny on 22 Jul 2010, 12:06 am

I can already give you my opinion. They may be a good value for the money, but don't expect much more. The crossover parts quality ($4.00 worth maybe) is just what you'd expect for a speaker in that price range. Same goes for the box (unbraced MDF with a felt liner), binding posts, wire, etc.

It may have been well engineered but built to a price point. So there is likely a lot that can be done to take it to another level if somebody really wanted to.

Now, you have my opinion for whatever it's worth.

I see nothing to quibble about, in Danny's remarks. I'll be interested in seeing his measurements. So, until then..............ciao!

Pat

DanTheMan · « **Reply #127 on:** 23 Jul 2010, 07:12 pm »

Check out the differences in the spectrographs before and after the cotton in the ports. Not that they tell us anything new, but a new look at an old problem/solution. Sorry about the extra noise in the ones with cotton. As you can see from the impulse, the first reflection is a bit sooner.

The 90 degree 3k resonance is striking. I wish they had better borrowed from the Mackie sibling.

Dan

gprro · « **Reply #128 on:** 24 Jul 2010, 02:03 am »

Quote from: gprro on 21 Jul 2010, 10:48 pm

Haha!!! Danny posted right as I was posting this!

Oops A little embarrassing looking

Just to clarify, I was reading this thread the day before, and when I came back to it, I failed to realize Danny had already posted in it. I thought he had made his first post, just as I was suggesting someone send a set to GR.
http://www.audiocircle.com/index.php?topic=83233.msg810538#msg810538

Cary on...the discussion has gotten interesting though. Can't wait to see how these speakers end up. Maybe with a few bucks in better crossover parts they'll be pretty good. Maybe they are already? Might make a really nice inexpensive theater set up. Looks like they have more dynamic capability than most small speakers in the price range.

Speedskater · « **Reply #129 on:** 24 Jul 2010, 05:26 pm »

What program did the Spectrogram charts?
And what does it all mean?

DanTheMan · « **Reply #130 on:** 24 Jul 2010, 06:46 pm »

The spectrogram came from REW Beta V5.

It's just another way of looking at the impulse response and frequency response. It's essentially FR over time. We want less delayed energy that's smooth with frequency.

Here's another look at the changes in bass response:

The line with the lower level is the one with the stuffed ports. Below 200-300Hz or so, bass really needs to be measured in room as it's the dominating factor there. My first graph is useless.

Dan

face · « **Reply #131 on:** 24 Jul 2010, 09:23 pm »

Quote from: Danny on 19 Jul 2010, 03:04 pm

Hey guys,

I would advise caution in trying to determine how something sounds only by its measurements.

An important rule of thumb is that if it measures good but sounds bad, then it's still bad.

You mean this?

Quote

"If it measures good and sounds bad, -- it is bad. If it sounds good and measures bad, -- you've measured the wrong thing." Daniel R. von Recklinghausen

DanTheMan · « **Reply #132 on:** 24 Jul 2010, 10:37 pm »

Yes indeed Face. That's where the whole study of psychoacoustics comes into play.

There are couple good books out on the subject that anyone serious about the hobby should read.

Floyd Toole's Sound Reproduction (Required IMO)

David Howard and Jamie Angus: Acoustics and Psychoacoustics
and
F. Alton Everest's Master Handbook of Acoustics

I personally have read through all of them yet--except Sound Reproduction, but it's clear they agree on a lot and from surprisingly different perspectives.

I know the Into to the Psychology of Hearing and Spacial Hearing have been recommended to me before.

FWIW,

Dan

planet10 · « **Reply #133 on:** 25 Jul 2010, 03:17 am »

This is your Brain on Music by Daniel Leviton

As important as the Toole.

dave

DanTheMan · « **Reply #134 on:** 25 Jul 2010, 04:28 am »

Thanks for adding to the list Dave. It's a subject probably worth its own thread.

Books on audio.....

Dan

tvyankee · « **Reply #135 on:** 2 Aug 2010, 01:25 am »

Hey,

So any new info info from GR on those monitor's he sent?

Was wondering what kind of measurements he got.

Thanks

sts9fan · « **Reply #136 on:** 2 Aug 2010, 01:34 am »

He says he has measured them but has not posted anything. He did not like keeping on topic so he started a new thread that he can control in his own circle. I imagine he will not post the measurements here although it would be nice.

Doublej · « **Reply #137 on:** 2 Aug 2010, 01:41 am »

Quote from: sts9fan on 2 Aug 2010, 01:34 am

He says he has measured them but has not posted anything. He did not like keeping on topic so he started a new thread that he can control in his own circle. I imagine he will not post the measurements here although it would be nice.

Are these the unposted measurements you are referring to?

http://www.audiocircle.com/index.php?topic=83841.msg815737#msg815737

Danny Richie · « **Reply #138 on:** 2 Aug 2010, 01:55 am »

Yeah, I posted the measurements yesterday.

Fell free to contribute to the thread if you like.

sts9fan · « **Reply #139 on:** 2 Aug 2010, 02:04 am »

Oops my bad. I recently put a bunch of circles
on my ignore list and forgot which ones.