Measuring Some Vintage Speakers

[Palladium]

I hope you didn't get any back pain from all that hauling.

 

[riker1384]

Getting into vintage territory, we have the JBL L100T 3-way with ported 12" and titanium dome tweeter. My uncle was the orignal owner of this pair from the mid 1980's.

View attachment 360217 View attachment 360218

Nice to see that graph. I've hear people say these speakers with the 035ti tweeter go bad and sound harsh because damping material in the tweeter disintegrates. But this measurement doesn't show any obvious problem in the treble.

 

[napilopez]

Thank you for doing all this and sharing! I'm always very curious about the performance of vintage speakers.

Because you have plenty of space around the speakers and measured at 1m, you should actually be able to get a decently high resolution gated (AKA quasi-anechoic) measurements for upper frequencies using the data you've already captured! How clean the data is depends on how much the cabinet the speakers are rested on affects things, but since you pushed the speakers most of the way toward the front, it should not be a big deal.

In any case, the measurements wouldn't change much since the speakers are already fairly far from the walls, but could be interesting to investigate.

If you are willing to share all the measurements in a REW file, I can go ahead and convert these into gated measurements (although it's not complicated).

Also, I don't at all intend for you to do any more work, but if there any specific speakers you want to measure the bass for quasi-anechoically I can help you out with that too. The measurements process is fairly simple to do, and basically just involves placing the microphone very close to the woofers and ports. You wouldn't have to position the speakers in any special type of way. I could do then do the processing.

Wouldn't be *pristine* without a bit more care, but should "close enough".

(I apologize if you already know how to do all this, just offering the few skills I have in this space )

 

[Juhazi]

bconline and napilopez, please show also distortion dB from REW! THD plus 2nd to 5th harmonics - and noise floor. Looks like your amp had same voltage/gain setting

Actually distortion dB and fundamental is enough, it uses variable gating I guess, and presents on-axis spl very well in same pic!

How did you mount small vs. towers, was mic height matched to tweeter height or what? Vertical response variation is guite bad, you know!

Notes:
- to record noise floor, it's box must be tagged before making the measurement!
- my collection of measurements are not standardized, and cover 15 years and several versions of REW

Pic of JBL LSR305

 

[DanielT]

I thought this group would be interested in how some vintage speakers compare to each other under the same measuring conditions. I have a collection of vintage speakers and simple measuring setup. No Klippel machine for me! I measured the frequency response of each speaker with:

• Laptop PC with Creative soundcard
• REW software
• Dayton UMM-6 microphone, with calibration loaded in REW
• Random Denon amplifier
• 1 meter distance, on the tweeter axis
• 20x24 garage with hard floor and 9.5' ceiling
• Small amount of damping on the floor

All of the measurement suffer from a floor bounce dip at ~80-90hz depending on the height of the woofer and mic. Sorry about that.

Here's the setup.
View attachment 360204

Here's the collection.
View attachment 360206

Here's all the graphs together. I'll post each frequency response curve separately.
View attachment 360208

A mighty undertaking, I must say. Good work!

Purely subjectively, which of all these speakers do you like best?

Which of the speakers do you listen to the most?

 

[Bob101]

Very interesting. I for one would be very interested in fr measurements of the speakers I grew up with, like the B&W dm560, B&W dm110i, JMLab Opal 19ti and B&W dm2a (still great IMO)

 

[hansik]

Thank you for doing all this and sharing! I'm always very curious about the performance of vintage speakers.

Because you have plenty of space around the speakers and measured at 1m, you should actually be able to get a decently high resolution gated (AKA quasi-anechoic) measurements for upper frequencies using the data you've already captured! How clean the data is depends on how much the cabinet the speakers are rested on affects things, but since you pushed the speakers most of the way toward the front, it should not be a big deal.

In any case, the measurements wouldn't change much since the speakers are already fairly far from the walls, but could be interesting to investigate.

If you are willing to share all the measurements in a REW file, I can go ahead and convert these into gated measurements (although it's not complicated).

Also, I don't at all intend for you to do any more work, but if there any specific speakers you want to measure the bass for quasi-anechoically I can help you out with that too. The measurements process is fairly simple to do, and basically just involves placing the microphone very close to the woofers and ports. You wouldn't have to position the speakers in any special type of way. I could do then do the processing.

Wouldn't be *pristine* without a bit more care, but should "close enough".

(I apologize if you already know how to do all this, just offering the few skills I have in this space )

Would be nice if you could explain how you measure the bass (incl processing)

 

[martijn86]

Nice work, I assume that the common 55Hz peak is a room mode? That may color the low end extension. I think that with dispersion patterns, these vintage speakers are going to show most of their age. Especially the ones with odd and distant driver placement. You can correct the on-axis frequency response and possibly even use an active crossover but you can't fix the comb effect, diffraction and off axis response. Fun post!

 

[Rja4000]

Thanks for publishign this.
Quite some work...

Here's all the graphs together. I'll post each frequency response curve separately.

Looking at this one is interesting, IMO, since it shows immediately common "incidents" which are more likely due to room/position.
Like the peaks at 55Hz, 70Hz and 95Hz and the consequent dip around 85Hz.

This could be even more obvious if the plot levels were aligned on an average on, say, 1kHz-2kHz, as an example.

 

[F1308]

Thanks for publishign this.
Quite some work...



Looking at this one is interesting, IMO, since it shows immediately common "incidents" which are more likely due to room/position.
Like the peaks at 55Hz, 70Hz and 95Hz and the consequent dip around 85Hz.

This could be even more obvious if the plot levels were aligned on an average on, say, 1kHz-2kHz, as an example.

I don't quite understand...
Those measurements are not being corrected by
the analizer?
If so, are we seeing loudspeaker performance or
room responsiveness?

Thank you.

 

[Toni Mas]

These are in a room responses at 1m on axis at tweeter height.... How do these curves correlate with listening experience, in this or other setups? Are these measurement really useful at all?

 

[Toni Mas]

I don't quite understand...
Those measurements are not being corrected by
the analizer?
If so, are we seeing loudspeaker performance or
room responsiveness?

Thank you.

Yes basically these are in a given room with the speaker placed at a given location responses with the mic placed at 1m, on axis, at tweeter height, etc, etc...

 

[F1308]

Yes basically these are a given room responses at 1m, on axis, at tweeter height, etc, etc...

Sorry, did not realize the way work was done.
I thought it worked the system we usually see here when Amir shows results.
I understand now.

Sorry...Thank you.

 

[Toni Mas]

Sorry, did not realize the way work was done.
I thought it worked the usual system we usually see here when Amir shows results.
I understand now.

Sorry...Thank you.

Yes i have spent hundreds of hours doing similar job, and so have learnt that are totally useless...

 

[Toni Mas]

Thanks for all the great measurements.

I can't be alone in thinking that there's not as much as improvement from old to new as you might anticipate.

Question is if what you see is what you hear?

 

[F1308]

Then why do measurements at all?

Well, I think we can see the performance each offers when placed there.

Then you grab the best.

But I think I could do it by just listening, as
I did when looking for my first system.
Of course I would not have the peace of
mind measurement might offer to reasure
my decision, but if I am happy, I am happy.

By the way, I remember I was offered a pair reaching 10000€ and I said the sound was
so bad I couldn't even withstand them.
The man said I was obviously not accustomed to high performance, insisted and then we discovered they were not sounding at all due to wrong wiring, resulting in another pair, costing some 15€, to be the ones being herd !!!!

Can you believe that?

 

[Toni Mas]

Then why do measurements at all?

You need measurements to get an insight. The picture in itself is irrelevant if there is no way to understand what can be learnt from It. Or the cues It gives are misleading.

 

[DanielT]

Are these measurement really useful at all?

Then why do measurements at all?

Perfect as an educational example to show how room acoustics work regardless of which speaker is used. I am thinking specifically of the area around 80-90 Hz.

 

[Toni Mas]

Perfect as an educational example to show how room acoustics work regardless of which speaker is used. I am thinking specifically of the area around 80-90 Hz.

Yes but what is true at 1m is no longer the same at 2m, on axis and 30° off, etc...

 

[F1308]

Yes but what is true at 1m is no longer the same at 2m, on axis and 30° off, etc...

And if you move the coach or add a jar with
flowers the sound will also change...

A never ending story.

We talk about temperature and humidity later...