Horn/Driver Comparisons

[Mr. Widget]

I believe that the level of distortion of the harmonics, 1,3,5, with step eloquence would expose new light of the differences of each driver...

WHAT think about it???

I agree that it would be useful, along with PWT measurements as has been suggested. However even this cursory look at these drivers was a fair amount of work and was only meant as a starting point. I do think that this information does shed some light on these drivers that was not available to the DIY community before we undertook the project. Anyone who would like to do some serious design work around these drivers will likely need to do additional testing.

If someone would like to continue the work and fully analyze these drivers that would be great.

Widget

[Zilch]

Rudimentary power testing/distortion plots are provided at posts 28, 29, and 30....

[B&KMan]

hi Mr. Widget,

to have made a very small part of this kind of work on my 4343, I then without hesitate to recognize the amount of work and I pick you
up my hat!




My remark wanted to be an extension of the questioning more the
performance of the HP... Indeed, an evaluation in power of the harmonics could undoubtedly expose good difference between the HP... in the same way the evaluation of the differences at the time of the change of the diaphragm or magnet by the harmonics would also more clearly expose the nature of the differences... and once again, I hello this large work and this generosity to divide this expensive and precious information.


Jean.



(currently I am seeing whether I then to make an evaluation of the
harmonics with my analyzers. The problem is that B&K has to develop a specific analyzer for that but costs only $ 50 000)
If I then to make this study, it would please to me to contribute to this analysis... I would send a p.m. in the positive case).

[B&KMan]

Rudimentary power testing/distortion plots are provided at posts 28, 29, and 30....

hello Zilch,

Oups!!! I believed that modifications had been made meanwhile on the HP and
that a new harmonics evaluation would have exposed these facts...

all my excuses...

In addition, It seems to to me odd that at the beginning of the curves; the harmonics is stronger than the fundamental ones...

is this normal really???

Jean.

[Mr. Widget]

The problem is that B&K has to develop a specific analyzer for that but costs only $ 50 000)

Clio is under $2K and is probably better suited to measuring loudspeakers anyway. Join the digital revolution!

http://www.e-speakers.com/products/cliowin.html

Widget

[Zilch]

I believed that modifications had been made meanwhile on the HP and that a new harmonics evaluation would have exposed these facts....

Well, you're right. The 2435HPL's were rehabbed by JBL.

I'll consult with Mr. Widget on the potential of LIMITED additional testing.

[I and others would likely appreciate knowing how 2430 distortion compares with the other drivers in the family, as well....]

[johnaec]

In addition, It seems to to me odd that at the beginning of the curves; the harmonics is stronger than the fundamental ones...

The distortion levels were raised 30db in those plots for clarity.

John

[B&KMan]

hello again,

In front of the enormous energy and effort which you provided to
clarify this forum...

I allow myself to give here my contribution to two pennies...

The evaluation of the HP must pass by the analyses of the harmonics. all the world gets along on that... The majority of the defects to the performance evaluation pass by an
analysis of the harmonics not of 2 or 3, who does not show anything, but of harmonics 5 to 11.

In effect, according to my documentation, the defects are clearly distinguishable in the distant secondary harmonics. ex: rub sound pushes the 7 and 9 harmonic of more than 20 dB: that passes from a normal driver of -70 to less -50 dB what becomes audible like distortion...

thus with all the fan of CLio and others, please do not hesitate to request your computers with the max power to perceive that...

thanks so much in advance...





Jean.

[B&KMan]

Well, you're right. The 2435HPL's were rehabbed by JBL.

I'll consult with Mr. Widget on the potential of LIMITED additional testing.

[I and others would likely appreciate knowing how 2430 distortion compares with the other drivers in the family, as well....]

YES YES YES


PLEASE PLEASE PLEASE

[Tom Loizeaux]

I would like to ask a question about horn / driver compatability:
Will a compression driver (JBL 2426H) perform correctly when mounted to an expoential fiberglass horn? The horn is similar to the Community Sound 800Hz horns with the extending "lips", so there's a soft roll at the edge of the flares. Also, I'm using this combination for high frequency only (3.5K and up). Will these horns let the 2426 drivers deliver this top end properly?
(These are for PA use, not audiophile listening)

Thanks,

Tom

[Mr. Widget]

There is certainly no harm in sticking it on the horn and giving it a whirl. The 2426 has essentially the same requirements as the LE85/2420 and most other 1" exit drivers. It should perform as well on that horn as any driver can.

Since it is an exponential horn it will have decent HF performance on axis, but will likely fall off at higher frequencies off axis.

Widget

[Zilch]

Thus far, I can attest that Mr. Widget has reliably detected buzzing/rubbing drivers without measuring 5+ order harmonics.

[Even with his fingers stuck in his ears.... ]

[Guido]

Here is a plot of Zilch's "better" 2435HPL. We are not sure what the specs are for distortion, but this unit has significantly more third harmonic distortion that the 435Be.

Widget and Zilch,

Was this measurement redone with the refurbished 2435? I was looking for this info but couldn't find it.

[Mr. Widget]

Widget and Zilch,

Was this measurement redone with the refurbished 2435? I was looking for this info but couldn't find it.

We did run measurements using the 2345s after they came back from rehab.... I have no idea which thread they are buried in. Zilch may have kept copies, I have not.


Widget

[Zilch]

We're pretty conscientious about keeping related material in the same thread here.

See post #68 et.seq.