Speaker impedance equipment

[Maxp999]

Hello everyone, I’m very new DIY speakers, don’t have much equipment and have a lot of questions. I’m currently stuck on building a crossover properly. 
 

Basically, I’ve got some alto TS115a speakers I want to turn passive because the plate amps keep dying. I’ve got a measurement microphone to graph my frequency response but nothing to graph impedance. 
 

I’ve trolled through the internet to look for the driver specs, and I called alto to try to get them, but I still turned up with nothing.

 

I'm happy to measure everything my self but I’m just trying to find a way where I don’t have to purchase something like a DATS V3. I’ve looked into building a simple circuit and using my phone as a signal generator, but I believe I’m not technically savvy enough to do this.

 

So in short, is there any alternative to buying a DATS V3? I’m in Sydney and have been calling everywhere I can to borrow or loan one to no avail. I just need to use it once or twice and spending the money on it just seems pointless.

[almikel]

On 16/10/2024 at 6:37 AM, Maxp999 said:

Basically, I’ve got some alto TS115a speakers I want to turn passive because the plate amps keep dying.

I would investigate why the plate amps are dying rather than converting to passive.

 

The Alto TS115a is likely to have a Linkwitz Riley (LR4) active crossover with 24dB/octave slopes.

Easy to implement with op-amps/DSP - very rare to implement with passive crossovers.

 

If you implemented a shallower Xover in passive you're likely to:

• not achieve a smooth Xover between drivers
• allow more "out of band" signal to each driver - specifically your tweeter could overheat and fail

Designing/implementing passive Xovers isn't straight forward - Rod Elliot's article is useful information:

https://sound-au.com/lr-passive.htm

 

cheers,

Mike

[Allan]

For MACs;

if you don't want to spend money then look into REW, its free. It measures driver thiel small parameters. You will need to make a test jig ($10)

 

For Windows:

There's Speaker Workshop. Its free too and quite complex but an excellent program. Its a complete suite of acoustic tools to build speakers from concept through to final testing. It measures driver thiel small parameters, has an integral passive crossover design simulator plus it can measure a multitude of other acoustic related things. Again you'll need to make a test jig ($10).

 

Good luck, pity ya not in country Vic, I could have tested them for ya

 

Edited December 1, 2024 by Allan