Oem brand 15" speaker, what to do with it...

[Vintage Audio Projec]

Ok, Some 16 years ago when I had the age of 16 and had no Idea about T/S specs of a speaker I got these 15" speakers for not to much money.
I used them in a BR enclosure I had build using online plans but tuning etc.....I didn't know.

It worked "OK" but wasn't perfect either.

So I still have these woofers lying around and was wondering what to do with them......

I recently got me a DATS measuring device so first thing I did was measure the T/S parameters.

This is what I got.

Re:7.691ohm
Fs:40.38Hz
Qts:0.8199
Qes:0.9743
Qms:5.174
Le:1.183mH
Mms:132.4g
Vas:135.8L
SPL:91.52

So looking at these they are a little strange. Qts is rather high.
Even for use in a closed box.
So what would you guys recommend when using this woofer?
Maybe I could do a little experimenting with MFB.....?
They are said to handle 400w but It's a little optimistic I think.

 

[GM]

I like these specs for TLs, so ~Fs/Qts = ~ 49 Hz tuning before stuffing and of course some prefer OB. The downside for both though is that they probably are low Xmax, so very limited peak SPL down low.

GM

 

[TBTL]

MFB will certainly help. You could put them in a small closed box if you go that way.

 

[bjorno]

Hi All,

FYI:

b🙂

 

[Vintage Audio Projec]

Thanks,

I'll have to look at it for some time to get everything.

Never tried a transmission line as a sub so this looks interesting.

 

[mashaffer]

I think they would make dandy OB helper woofers. With a decent size baffle (not huge) They should do nicely down to the low E on a bass guitar and a bit lower. Another possibility would be as part of an in-wall (i.e. infinite baffle) setup just don't expect true subwoofer output levels; Good for the mains though.

Some sealed sims...

Red line is about 10 ft^3 while grey line is about 14 1/2 ft^3.

A true infinite baffle (rear of driver exhausts into the next room)...

You could try an aperiodic vent too.

 

[hollowboy]

I recently got me a DATS measuring device so first thing I did was measure the T/S parameters.
[...]
So looking at these they are a little strange. Qts is rather high.
Even for use in a closed box.

At higher power levels, the effective value will be a bit lower.

I had a (prebuilt) ported sub with a similarly high Q driver. The FR plot was "M" shaped. Still sounded OK if used <80Hz.

So what would you guys recommend when using this woofer?

Bjorno's suggestion looks like a lot of bass / bang for the buck.

What other gear do you have? Other posts imply that you have a measuring mic & EQ, so you'd be able to tweak a complex build.

 

[Turbowatch2]

After such a long time, the suspension will stiffen up. Wobble it at it´s resonance frequency for at last 20 hours, with reasonable cone movement, I woud suggest +-5mm at last. Then let them cool down for about 2 hours (important!) and measure again. You will see much different TSP data, which represent the real, long therm values.
Most probably you can use them in quite different constructions/ simulations then.