Beyma CP25 questions

[dhsettim]

Hi Ya All,

further to Al's suggestion of the Beyma CP25. Is it a plug-in replacement for the T35 and compatible with the ALK, AA and A crossovers? Would it be ok to disconnect the T35 and place the new tweeter ontop of the Khorn cabinet? Does it need to be enclosed or would a simple baffle be OK?

Has anyone tried any of the Fostex tweeters?

Tim.

[ZAKO]

Yes it will work to place tweeter on top of K horn. You then can move it back & forth and check if you can detect time alignment.

[Shock-Late]

what about x-over compatibility? would this Beyma work with a modified (1uF bypass cap) AA x-over? What improvements should one expect compared to the stock T35?

thanks dudes!

[ssh]

The Beyma was played at the AR meeting. I think Jeff hooked it up with the ALK extreme slope xover on Dee's khorns. We didn't do any real comparison listening, & there were several variables changed, but several of us were, I think, considering the mod, as we listened. It certainly is a quality tweeter, & I would like to hear it alongside the JBL that some have posted about. For the cost, it will probably be a popular mod.

SSH

[Colin]

Ditto here on the Beyma quality, I heard them on Arkytypes superbly smooth system, and while I can isolate their sound from the 511B horns, they did seem to be silky with out hot sizzle

[Al Klappenberger]

Hi Guys,

I have posted this before, but here's a comparison I made between a K77 and a Beyma CP25. The Beyma is the clear winner!

It's is a drop-in replacement for the K77 performace-wise, but it is much larger and will require woodwork if you plan to make it look pretty.

The best thing about is that it only costs $60 direct from Beyma of America. Don't buy it through a dealer or you'll by $150 for it! For some dumb reason Beyma will bypass their onw dealers and sell direct. BTW: They are made in Madrid Spain.

Al K.

[Colin]

Al, my man, what range is that the the Beyma is hot and what range is the K77 hot; what is the low end of this graph?

[Deang]

Funny how I always see these graphs, and end up coming to completely different conclusions than others. To me, it looks as if the K77 is more sensitive, and shows a more uniform response from the crossover point (6Khz) to 12Khz -- the range I would think would be the most critical. From there, they are near identical out to 18Khz -- at which point the Beyma has better response out to 20Khz. Since most don't here squat between 15 and 20Khz anyways -- what's the big deal?

Also, was this graph generated with a reactive load with the crossover attached?

[Daddy Dee]

Al, was wondering if you still have your contact info on Beyma of America. I've looked around on the internet and have only found the home page in Spain and a dealer who sells them for $149 ea.

My take on the sound and the tracing is that the K77 is hotter than the Beyma and that the Beyma seems to disappear in the Khorn sound. I'd like to do some more listening. At times I wondered if the Beyma was bright enough. Often I'd like to turn down the sensitivity on the K77 just a touch.

One thing I'd like to do is have some familiarity with actual sounds at particular frequencies. For example I look at the K77 response and wonder, o.k. what am I hearing at those frequency peaks?

[Colin]

now that I met you, Im NOT afraid of you Dean, in fact I bet I could take you in fight if your back is turned, the big deal is the Klipsch tweeter continually slopes downward and that even though the Fletcher-Munson frequency response curve for humans proves that we middle-age males have no high frequency beyond 12kHz to speak of, scientific studies show that extended frequency response beyond 20kHz does drive cats from the room and enhance our impressions of imaging and smooth mid-range, which explains why so many loudspeaker manufacturers do extend their treble past the merely audible point and why Sony worked so hard to extend the upper frequency response on both SACD and DVD-A

nice graph!

it also shows that in the third and fourth quadrants, what frequency is that?, the K77 matches the sensitivity of classic Klipsch corner Khorns, otherwise some EQ might have to be applied for the Beyma tweeter to have the same sensitivity as the mid-range horn

[Deang]

You might be right. Bob Crites and me were talking about that on the patio, and wondering if the brain fills in some of the spaces the ears don't -- similiar to what the visual cortex does with people who have vision problems. For example, I have no central vision in my left eye, but with both eyes open -- my visual cortex lays my right eye image over my left one so I can see "normally". Of course, we don't know if the brain has a mechanism like that for hearing.

It's all very interesting stuff, but I've come to the point that "better" is really quite subjective. I appreciate the somewhat rolled off response of the K77 since I tend to listen louder than most. I can tell it's rolling off, but it doesn't bother me. I guess I'm just still enjoying the sound the way it is. Maybe someday I'll get bored with the sound -- and instead of swapping speakers I'll just change out drivers and horns.

I find John Warren's mod more interesting than this one.

[Daddy Dee]

Dean,

I think you are right about hearing filling in like vision. Ran across an article somewhere on the net about that. In terms of "audiophiles" it works to "fill in" sounds, but it doesn't work of the speakers "add" something that shouldn't be there. Not the best article, but food for thought.

I don't recall John Warren's mods. Would you mind posting a link to that?

[IB Slammin]

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On 5/12/2004 4:20:45 PM Colin wrote:

now that I met you, Im NOT afraid of you Dean, in fact I bet I could take you in fight if your back is turned, the big deal is the Klipsch tweeter continually slopes downward and that even though the Fletcher-Munson frequency response curve for humans proves that we middle-age males have no high frequency beyond 12kHz to speak of, scientific studies show that extended frequency response beyond 20kHz does drive cats from the room and enhance our impressions of imaging and smooth mid-range, which explains why so many loudspeaker manufacturers do extend their treble past the merely audible point and why Sony worked so hard to extend the upper frequency response on both SACD and DVD-A

nice graph!

it also shows that in the third and fourth quadrants, what frequency is that?, the K77 matches the sensitivity of classic Klipsch corner Khorns, otherwise some EQ might have to be applied for the Beyma tweeter to have the same sensitivity as the mid-range horn

----------------

But will it get a cat from under the bed?

Terry

[WMcD]

I think there is more to it than the on axis sound curves.

This is a bit repetitous on my part. I've posted the polar response of the T-35 months ago. It is keeping the high end by narrowing the beam.

To digress, there is a bit of a debate on whether a speaker frequency response is best characterized by on axis reponse (alone) or overall acoustic response. The latter included on axis response and the sum of all power at off axis.

I read that McIntosh would put a driver and the microphone in a large box lined with bathroom tile. Hence all off axis energy was reflected to the mike.

The Beyea looks more like a JBL baby cheeks and, to a lesser extent, the EV ST-350. These are more or less constant directivity tweeters. There is some directivity, but it is constant with frequency, and does not narrow. Some equalization is used in the ST-350. I don't know about the JBL.

The result of the above is that anyone in a room, listening to the Beyma or ST-350, may well perceive more treble than the EV-35 - K-77. Some of it, despite constant directivity, is coming from reflections off the walls.

I tell myself, I can't hear above 12 kHz (and only youths can hear 15 kHz) and hence there is nothing wrong with the T-35. None the less, the issue may be in how much total energy is pumped out without narrowing.

Further to this, I like the tweeters in the Forte II and Quartets. They are not quite like the K-77 in structure (more exponential) and may occupy a nitch (regarding directivity) between the very wide field constant directivity models mentioned above and the K-77.

The bottom line for me is that tweeter horn design may well play a part in perception starting 15 kHz and going down to 4 kHz, even if you can't hear quite to that upper limit.

Gil

[Deang]

Thanks Gil, pretty interesting.

Here you go Dee.

http://home.comcast.net/~wooferboy/The_Audio_Engineering_League.html

[John Warren]

/

[Al Klappenberger]

Guys,

Yes, the K77 is hotter in the area just above the 6000 Hz crossover. This is the reason PWK chose it. He liked high efficiency!

I have also done off axis response curves. The Beyma has a baby-butt looking horn somewhat like the big JBL tweeters. It has a much nicer dispersion than the K77. This is even more important then the on-axis response.

Al k.

[Al Klappenberger]

Guys,

Here is the plot I did of the CP25 versus the K77 off-axis. The plot was done with an older setup, so it looks a lot different.

Here's how to get up with Beyma:

Beyma USA

1333 2nd Ave

New Hyde Park, NY 11040

Phone: 516 616-9414

fax: 516 616-9415

Al k.

[Daddy Dee]

Dean,

Thanks for the link to JW's mod.

Al,

Thanks for the BA contact info.

[Daddy Dee]

Dean,

Thanks for the link to JW's mod.

Al,

Thanks for the BA contact info.