help with driver specs

[threegee]

I inherited two 15" subs from my son's car system and wanted to try to use them in my DIY home theater. I plan on building my own box(s) but haven't been able to use any design software because I don't know any of the driver specs.
What I do know:
4 ohm, 310 watt max, 15" 30 ounce (magnet)
They are called Y2K Titan and have a sphinx logo on the driver.
Any help locating the info or, at least, some insight on how to proceed sans the info would be greatly appreciated.

 

[Cal Weldon]

Hi,
I couldn't find anything on google but that seems like a very small magnet for a sub. That likely means a high Q. That means a big box. You might want to consider building them into the walls or ceiling.

 

[simon5]

If you have basic tools, you can measure the specs.

http://www.diysubwoofers.org/measure.htm

 

[threegee]

Thanks, I tried that too. I have plenty of room for a big box though.

 

[threegee]

Cal,
Sorry about that short reply.
I have heard about the wall or ceiling option before and was wondering how (or if) that is any more effective than just taking a wild guess and building a box. Other than the time and materials of course.

Simon5
I have the multimeter. are you aware of anything for the pc that would work as a sig gen?

 

[Cal Weldon]

I would find the specs first, then we can work on a design.

 

[owdi]

Cal,
Sorry about that short reply.
I have heard about the wall or ceiling option before and was wondering how (or if) that is any more effective than just taking a wild guess and building a box. Other than the time and materials of course.

Simon5
I have the multimeter. are you aware of anything for the pc that would work as a sig gen?

For a quick and easy signal gen I use WinISD. Jost open a project, then set the signal generator to get the frequency from cursor. Now click and drag with the mouse. This method lets you quickly dial in the resonance frequency by measuring current.

Dan

 

[simon5]

This tool is great for a tone generator :
http://www.david-taylor.pwp.blueyonder.co.uk/software/audio.html#SweepGen

 

[threegee]

This tool is great for a tone generator :
http://www.david-taylor.pwp.blueyonder.co.uk/software/audio.html#SweepGen

Thanks,
Looks like it will be perfect! I'll let you know how it turns out.

 

[michaelpage26]

This tool is great for a tone generator :
http://www.david-taylor.pwp.blueyon...o.html#SweepGen

Thank you Simon5 and the others for the helpful links and software !!!
I am an absolute beginner with the urge to learn more and more (I wish I had more time...though)

A little bit off-topic maybe:
The tone generator that you recommend is simply great tool, but I have a question: Every tool that I use for tone generation makes a buzzy sound when I put values from 19700-21000 Hz, through my Audigy 2 6.1 ? Is this a fault of my soundcard or all the soundcards that are available? It would be easy to come up with the opinion that this HF included in cds is making the sound playback dirtier...Is that true? What should I do?

Thanks in advance guys...😀

 

[simon5]

If your tweeter is an aluminium or titanium diaphragm, you could be hearing tweeter resonance.

What speakers are you using?

Also, the Audigy 2 is also a very poor performer that high in frequency. I don't know if SweepGen output in 44.1 kHz or 48 kHz. 48 kHz causes less problems that high in frequency with an Audigy 2.

The Creative X-Fi line corrected the problem with a beefy hardware resampling algorithm.

M-Audio Revolution line doesn't have this problem.

 

[michaelpage26]

Hi,
My tweeters are silk domes, Audio Pro Avantek Six Floorstanders...
But Audigy 2 was measured in some beanchmarks nearly flat till 19.5khz...Being -6db in 20khz doesn't mean it can buzz, right?
Anyway, I will try different cards and see...

 

[simon5]

Silk domes are supposed to be very "smooth" that high usually...

Yeah at -6 dB it should be less loud... trying another soundcard is probably the best idea. Try an X-Fi or a M-Audio Revolution...

Most soundcards have problems that high, except high-end soundcards.

 

[michaelpage26]

I found what will I do!
I will make a wav file with 20Hz and burn a cd. Then I will play it through Audigy 2/PC and then through my separate sony cs-player, to find out what is going on!
Thanks for the help though

 

[simon5]

Then try the same 20 kHz wav file, but record it at 48 kHz if you can and play it on your Audigy 2.

Audigy 2 is way better at 48 kHz than 44.1 kHz.

Good luck!

 

[michaelpage26]

Thanks for the advice!

I also have another question about Fs. Experienced people say that it is the point where driver impendance is maximum

I have noticed that its true with most drives, but I found out that it's not the case with this Excel woofer: http://www.seas.no/excel_line/excel/E0017.PDF

The impedance peak is at 60hz while the Free air resonance at 31Hz

What is wrong?

 

[richie00boy]

From the seas datasheet at top of graph:

The loudspeaker is mounted in a closed box of 12 l net. volume

So obviously resonance will be shifted up somewhat.

 

[michaelpage26]

Hm! 😀
Well, Seas seems to be a little different compared to other companies that measure their drivers in free air, isn't it?
Does these measurements help a loudspeaker designer? I mean which one is preferable? (cabinet measuring or free air)

Regards,

Mike

 

[threegee]

Sorry owdi for not acknowledging your suggestion about WinISD.
It works great also.
Thanks!

 

[simon5]

Hm! 😀
Well, Seas seems to be a little different compared to other companies that measure their drivers in free air, isn't it?
Does these measurements help a loudspeaker designer? I mean which one is preferable? (cabinet measuring or free air)

Regards,

Mike

Well, you get the best of both worlds. Some people want to have free air resonance and some people want a typical impedance curve. Usually you use speakers in a box, so the impedance curve in a box is usually more useful.

They give both, free air and in box measurements. Good stuff.