Project M2 DIY Thread

[sguttag]

There is a gasket (rubbery) but that only seals between the driver and the adapter plate. It does NOT mate to the waveguide.

[Fischer]

Hi!

I finished my M2 build during the spring but have barely tested them. But when I did the first listening test it certainly was a lot of punch in the bass but I had higher expectations on the tweeter and these D2or.
I come from the jbl's 3732 cinema series and there I experienced a significantly larger and airier sound, so could I have done something wrong?
What I'm a bit pensive about is whether the filters we loaded into my BSS soundwebb 160 was done right (got help with it), and that's why I'm experiencing the sound a little stuffy and hard, do you have any ideas on what it can be?

[sguttag]

I could see the impression of the 3732 being a larger sound but they are anything but natural. The mids are, typically, nasally. The HF section has a capable driver in the 2432 but again, while a decent driver, it is nowhere in the class of the D2 (that I've personally heard). The 2432 sounds like "reproduced sound" whereas the D2 sound natural. I've listened to a lot of speakers and the D2/M2 has an incredible amount of detail to them and the stereo imaging is spooky good. I'm hearing details in recording that I've heard for decades that I never heard before.

Sound is subjective so you are going to have your likes/dislikes that are neither right nor wrong.

Another thing I've noted in my experiments with my M2 clones is that you can "push" the D2 and it doesn't break up or get that metallicy sound that most compression drivers seem to get. If you like that extra sparkle, then you can push it and get it without it fussing.

So, moving over to the DSP side of things. In this thread, there are quite a few places where the DSP response is posted and whereas most/all people are trying to reproduce the BSS response, I suggest comparing your response to that.

There is a "Google Docs" on the M2 crossover that not only lists various "generic" crossover parameters as well as what the results should look like: http://goo.gl/GdfQ7N

Note, there is another thread "JBL Master Reference Monitor" that has a lot, if not most, of the DSP and frequency response discussions but I've found that one really needs to follow both this and the other thread if you want to get the collective information presented in Lansing Heritage on the M2. Here is a link to what should be the desired response, if settings were put in correctly. http://www.audioheritage.org/vbullet...Monitor/page10

-Steve

[Fischer]

Thats why I think I have done something wrong, since I experience the sound on my M2 just the opposite to what you`re telling!

[sguttag]

Don't forget that you may have merely grown accustomed to the 3732 sound. I, personally, think we "imprint" on speakers. I've found that I've always liked the Altec sound, for instance. I attribute that to having grown up with them as THE speaker company. Before 1980, you probably had a 90% chance of hearing Altec in every movie theatre as well as a high probability of hearing them in other venues. To this day, I like the Altec sound (particularly the A4, A5, 604). That said, I dislike the multi-cells and much prefer the Mantarays.

I've also lived through the era of Dolby Noise reduction and having people tell me that Dolby kills the high-frequencies (it doesn't). They associate that sparkle, even if exaggerated, with better HF. However, if you have a 3-head deck and switch between NR on and off, all that goes away is the noise, not the music/sound. Yet, to this day, there are people that record with NR on and playback with NR off because Dolby kills the HF response (it still doesn't). Maybe in a particularly cheaply made, poorly calibrated deck it can; but if they at least get their calibration levels right, Dolby just makes the hiss/noise go away, not the audio but people will stick to their guns on that one.

I'm wondering if, perhaps, you have conditioned yourself to the 3732 sound, which is bound to be a bit on the harsh side on the HF as compared to the M2. The 3732 was designed to play behind a movie screen (sheet of vinyl with perforations in it) that naturally tends to attenuate above 9KHz to take some of its edge off. The M2 is definitely a smoother speaker. I don't detect any "bite" in it that I have with the 3732.

Probably the first thing to do is measure the output of the BSS and see what your responses are there as compared to the published responses linked to earlier. Then measure the two speakers and see what you are hearing.

[Fischer]

You are probably right to some extent that I have become used to a certain sound character, but when I read that the sound on these M2 should be so much smoother in the higherfrequencies

and when I also have talked to others who had almoast the same speakers as I that say that their M2 is significantly better at the higher frequency

, and I experience them much harder, almost so I get sore ears, so I have probably done something wrong, the question is just where ;-)!

And a good start is just as you propose measuring the speakers, have never done it before so I have to do some research on how to do it!

Best Regards Per

[baldrick]

My pair no 2 is more or less finished without paint. Will be useing Crown DCI4/600N but not sure ID thats a great idea since I was planning to use 2452Sl instead of D2

[baldrick]

Now with paint

[srm51555]

Looks good, thanks for sharing. I look forward to hearing your impressions of the crown dci. What network will you be using with the 2452sl?

[baldrick]

I will start with org M2 settings in the DCI but it will probably need some adjustments for the 2452.there are raw measurements of both so it should be quite easy to guess aprox needed adjustments

[pos]

Very nice build!
What plans did you use?

[lesliew]

These are my new and improved recently finished pair


Attachment 82233[ATTACH]8

[baldrick]

lesliew: they look more org than DIY, very Nice!!

Very nice build!
What plans did you use?

Thanx! No plans used, only dimensions from org M2 and done the best out of it A bit concerned how the finish/paint will keep over time, especially in front With the curve, but hopefully it will stay OK.

What are you guys useing as feet/spikes under the speakers??

[lesliew]

And to finish it off, I present the stunted half child of the M2.

Using the M2 waveguide, D2 & crossover, this will be sitting on top of a fire mantle as the center channel, mid range and bass will be directed to a Sub 18.

[lesliew]

A bit concerned how the finish/paint will keep over time, especially in front With the curve, but hopefully it will stay OK.

What are you guys useing as feet/spikes under the speakers??

What paint did you use, looks a bit like Duratex Smooth - Spray Grade. You did a very good job with the cabinets.