What can I do without drivers in hand? (1 Viewer)

[Ryan Leemhuis]

LOL. I consider 100 to be pretty dang loud. I doubt I listen over that. I calibrated to about 70 so I can't imagine I would ever make it to 100. Approx how loud would that be? I mean, movies get loud, but not I am hurting my ears loud

 

[Todd Shore]

I usually calibrate to 76dB for TV viewing and 80-82 for movies, though for some stuff I will bring it up a bit. Typically, I like to have at least 20dB head room for transients.

You would be surprised how loud you can have a good set of speakers turned up before you experience any discomfort. Speakers with a fairly flat in-room FR, good detail, and low distortion should not hurt your ears even at high SPL.

I am reminded of that every time the house is empty and I get a chance to turn it up to live levels. It isn't until I go to the other end of the house that I realize just how loud it really is. Dang, there really is a band playing downstairs!

Or, if my wife comes home wondering why it is so loud. Loud? Just lifelike, dear.

 

[Ryan Leemhuis]

hehe very nice. If the series design can go up to 100 DB how high can the MTM go just to see compare

 

[Todd Shore]

About 106dB with 65watts

 

[Todd Shore]

Are you looking at building just the front left and right channels or will you also be building a center and surrounds?

 

[Ryan Leemhuis]

For now, just a front left and right to provide some more balance bass output from the system. Right now, to me, it sounds a bit "bose-y" because I have to have my sub cover a large range because my dual 4" mains don't go down very deep. If my project is successful more speakers will follow. Any input on my chosen drivers or tips would be appreciated

 

[Todd Shore]

I don't like how the MG18s start to fall apart above 800Hz-1KHz. Most woofers of that size will have a dip around that point, but the off-axis response pretty much diverges there. Even if you went with 4th order slopes for the crossover, you wouldn't be crossing below 1.3KHz so off-axis response through the crossover range is going to be poor. I personally like a driver to stay coherent an octave past the Fc point, though that is often not possible.

 

[Ryan Leemhuis]

that is characteristic of pretty much all of vifa's drivers that are 6.5". The premium line reduces it a bit, but the trend is the same accross most of the series

 

[DorianBryant]

Ryan,

I have an HK 235 and have used it to power 3, 300 watt 4 way JBL towers. These are 4 ohm and have both a 10" and 8" woofer. They are rated at 95 DB sensitivity but I have had no problems with the HK powering these far louder than I can stand to listen.

Still does not guarantee you will have similar results. Also, I have an Onkyo 502 that also drives these speakers without problem. Both receivers are rated as being "high current" but neither specifically states they are 4 ohm stable...

 

[Kenneth Harden]

Hey, if you are going to engineering school - go to Home Depot, get some mylar film, a electric fence transformer, and build some electrostatic speakers.

 

[Ryan Leemhuis]

Well I decided on a MT design with a 7" Dayton RS180S and a Morel DMS-30 tweeter. What do you guys think?

 

[Seth_L]

What frequency do you plan on crossing the two at?

Also, how are you going to compensate for the 3dB difference in sensativity?

 

[Ryan Leemhuis]

I am going to cross at 1800 with a 4th order crossover on the woofer and use a 2nd order on the tweeter as the natural acoustic roll-up to 1800 should do the rest of the job. To compensate I plan on using a simple voltage divider circuit(people like calling them L-pads...)

 

[Ryan Leemhuis]

any input? I picked these drivers after analyzing 6 or so in excel. Just want to make sure I get good monitor or so quality

 

[Todd Shore]

I think that would be a good combo.

The next step is getting driver measurement capability and learning a crossover design program. Jon Marsh today posted on the PE board that the sensitivity of the RS180 was not quite as high as expected which might require a little more padding of the tweeter. I would highly recommend reading through his development notes on his MTM project.

 

[Ryan Leemhuis]

Todd shore I swear your stalking me

I have been posting as Sdiver2489 at PE website

 

[Todd Shore]

I noticed you on PE and believe I posted to one of your threads. I read 5 DIY speaker forums, pretty much on a daily basis so it is hard to escape.

 

[Patrick Sun]

Didn't JonMarsh also suggest crossing lower, around 1400Hz for that driver, the RS180?