My MTM stand mount loudspeakers

[t.antony]

@Goldy
Yes it's a Peerless India driver,

@Neeraj
I was not very convinced with the impedance response of this driver - the high freq extension looked good, may be slightly better than the M-130, but there seemed like some major cone breakup issues exist around 1.8kHz. As I was not interested in making the crossover design complex, focused more on the paper cone drivers.

I think it is a usable driver, but can't say anything conclusive as I have not tested it.

 

[GeorgeO]

Antony

Do you have access to a source who can do CNC milled baffles for speakers?


Thanks

It's 19 mm MDF with a veneer design on one side . The external dimensions are H21" x W9" x D10.5". The front baffle is temporary and will be replaced with a CNC milled panel as I plan to flush mount the drivers.

 

[quad]

Antony

Do you have access to a source who can do CNC milled baffles for speakers?


Thanks

George, I am sure Irfan can help you. He is an excellent
DIYer himself, a qualified engineer and a CNC enthusiast. He
has a couple of DIY CNC machines.

Irfanulla. K. R.
No.80, old No.8, Appanna Block
R.T.Nagar,Behind HMT Layout
Bangalore-560032
Mobile:9845127159

E-Mail:
[email protected]
[email protected]

 

[GeorgeO]

Thanks Prasad

I will contact him.

George

 

[t.antony]

Antony

Do you have access to a source who can do CNC milled baffles for speakers?


Thanks

Here is the link - J K Skilled Arts

 

[GeorgeO]

I spoke to Irfan today he was helpful, but said he has sold off his CNC machines.However he suggested that I meet him sometime convenient, he may be able to guide me.

 

[t.antony]

The crossover design has taken more time than I anticipated, thanks to my creative audigy sound card! It gave erratic phase response data which made me believe that my tweeter has some cone breakup issues around 10kHz. I was struggling with the xover design and all the possible workarounds also made the high pass section a bit complex. It never occurred to me that the sound card could be at fault till I measured again with my old on-board card. This time there was no cone breakup at 10kHz and the impedance & phase data was justifying manufacturer's specs. The xover design also came out simple - 2nd order electrical with a level matching resistance for the tweeter.

Here is a pic of the xover. The components are populated on to a hardboard piece with cable ties. Wiring is yet to be completed. I will post the final results later.

 

[doors666]

i remember someone at PE forums mentioning that the inductors should be at 90 degrees to each other to avoid issues. thats the way most of the crossover pics look like there.

 

[GeorgeO]

Yes the coil orientation should be at 90 degrees, so this does look incorrect.

 

[GeorgeO]

Im building this system-look at the coils orientation on the crossover in the photo in the middle-each one is different, thats the right way to do it:

Bamberg Engineering Sound Lab

 

[t.antony]

i remember someone at PE forums mentioning that the inductors should be at 90 degrees to each other to avoid issues. thats the way most of the crossover pics look like there.

Yes, it's a good measure to take for reducing inductive coupling, I will be doing that once I finalize on the xover.

It's generally considered that if the distance between the inductors is more than 3 inches, then the loss in efficiency due to coupling is negligible, but again it's always better to take all possible measures to get most out of the design Thanks for your inputs.

 

[t.antony]

Im building this system-look at the coils orientation on the crossover in the photo in the middle-each one is different, thats the right way to do it:

Bamberg Engineering Sound Lab

The Bamberg way of putting different filter sections in longitudinal layout is good. I will consider this approach when I reassemble my filter sections.

 

[neeraj]

Hi Tantony,
Please update further progress

By the way what would be the RMS power handling of MTM System?

 

[t.antony]

Progress is slow... here are couple of pics after last weekend's work.

The boxes are getting readied for the fiberglass lamination.

Wondering which color will go well in the end. If not laminating, may be multiple layers of clear coat could turn out well.

@neeraj
Currently I am running these with my 120W RMS amp without issues. Haven't measured the sensitivity yet but expecting it to be around 89db.

 

[vivek.saikia]

Progress is slow... here are couple of pics after last weekend's work.

The boxes are getting readied for the fiberglass lamination.

Wondering which color will go well in the end. If not laminating, may be multiple layers of clear coat could turn out well.

@neeraj
Currently I am running these with my 120W RMS amp without issues. Haven't measured the sensitivity yet but expecting it to be around 89db.

These are some smart looking speakers. Why don't you use some flared port instead of that PVC pipe. It will increase the aesthetic value many-fold.

 

[iaudio]

t.antony, the cabinets are looking Wow!

 

[neeraj]

Hi Tantony,
Speakers Are looking Decent.

Waiting for complete Finished pictures.
Great job Dude.:clapping::clapping::clapping:

 

[grubyhalo]

That looks fantastic! If the sides too are veneered, multiple coats of clear would make it look gorgeous...

 

[kaushik]

oh..oh yeh!
the models making me go insane ...the curves the charm amazing.
I will soon spoil myself with such and adventure .

the port can be made to look flared sanding the sheet from front , and pushing pipe a lil inside.

 

[t.antony]

Thanks guys for the comments, my enthusiasm levels also high after this weekend

I am planning to do the flaring similar to Kaushik mentioned. Since the fiberglass coating is about 2mm thick, the little gap between the pvc and flared mdf will be filled up by fiberglass giving a seamless finish. Also planning to flare the other end of pvc like this method. Heat Moulded Port Flares. This site has some good information on construction, there is a flare calculator as well - Flare-it - Free Speaker Design Software