First impression of Bob's CT125's

[Rudy81]

Craig:

I just tested my center La Scala channel, which is stock, and have the same 10kHz + rolloff. At least the good news is that it is not a problem in the Khorn ALK networks or something in the setup there. Now I am down to the meter itself or the source material. Very interesting. If you have any suggestions, please pass them along. It cold always be a meter problem, or the way I am doing the test.

[Hardhead]

Hardhead: No, mine are the K55 M.

The reason I was forced to reserve the right to change my mind, is that some of the negative reviewers were originally impressed. So....don't want to seem like a flip flopper without fair warning.

Ah, I hadn't noticed that you were using the ALK crossover. Did you change the midrange/high setting when you were listening to the K-77-M and Bob's tweeter? If so, what were the changes? If not, what setting are you using?

Thanks.

[PrestonTom]

Craig:

I just tested my center La Scala channel, which is stock, and have the same 10kHz + rolloff. At least the good news is that it is not a problem in the Khorn ALK networks or something in the setup there. Now I am down to the meter itself or the source material. Very interesting. If you have any suggestions, please pass them along. It cold always be a meter problem, or the way I am doing the test.

Rudy,

Cheer up the problem is unlikely to be in the amp or pre-amp (it sounds like you are using solid state).

One red flag was when you mentioned the "source". What are you using as a source for your testing. Hopefully it is not music. That will have an inherent roll off. Another possibility is the microphone itself. It needs to aimed at the speaker (otherwise there will be a roll off). Also, how do you know if the mic is good? What mic is it?

Good luck,

-Tom

[Rudy81]

Hardhead:

I have always used the ALK universal in my Khorns and the mid range is attenuated 6dB for my taste. I decided on that years ago and am please with the sound. In this case, the only thing I changed were the tweeters, no other changes to the system were made.

Tom:

Thanks for the tips. No laughing and pointing fingers now...but I am using a Rat Shack meter just for some general idea of room response issues. I know this is not a good meter and not very scientific. But, those are the readings I am getting. Yes, I am using solid state, Parasound HALO processor and amps. They are very good. My guess right now is that the problem is with the mike and meter, not the system. However, I will look into the Denon settings and HALO settings to make sure I don't inadvertantly have the highs attenuated. The source disk is the Stereophile test CD 2 and 3.

[Rudy81]

Tom:

Thanks for the tip. You nailed the problem....operator error. I had been pointing the microphone at the ceiling, as suggested in something I read somewhere. Once I pointed the microphone at the tweeter, I did not register the steep rolloff at the highest frequencies. I only measured a 4dB loss at 16kHz and a 6dB loss at 20kHz vs the 10dB and 20dB loss I had registered before.

I greatly appreciate your tip, saved me a lot of fruitless troubleshooting.

Rudy

[NOSValves]

Rudy,

I knew something had to be screwy[]

Craig

[PrestonTom]

Tom:

Thanks for the tip. You nailed the problem....operator error. I had been pointing the microphone at the ceiling, as suggested in something I read somewhere. Once I pointed the microphone at the tweeter, I did not register the steep rolloff at the highest frequencies. I only measured a 4dB loss at 16kHz and a 6dB loss at 20kHz vs the 10dB and 20dB loss I had registered before.

I greatly appreciate your tip, saved me a lot of fruitless troubleshooting.

Rudy

Rudy, I am glad it was easily solved. Wouldn't it be nice if all problems were like that....

Good luck,

-Tom

[Rudy81]

Well, day two and I am still very impressed with these tweeters. Today was loud music day (wife was out) and no problems or annoyances noted. I find the CT125's and the ALK's a very nice match. At loud levels, just like at soft and moderate listening levels they perform extremely well. I did not find any harshness or piercing sounds. Rather, clean crisp highs, much more than I recall from the K77's. I still have to re-calibrate the mains and center for movie watching. Tonight could be the first movie with the new tweeters. More reports to follow.

[mark1101]

Rudy81,

Have you tried 1 K-77 and 1 CT-125 in mono mode? I would be curious as to your opinion on if the 2 tweeters play at the same volume with the ALK universals, or if one sounds louder to you.

Any info on that point would be helpful.

I noticed with AL-3s (1990 Las) the volume between the 2 tweeters is close, but the K-77 is just slightly louder. This issue became a tiny bit more pronounced in my system when I changed to the ALK Jrs. I'm talking a "slight" difference here, and I'm wondering if you are hearing it or not.

[Rudy81]

Rudy81,

Have you tried 1 K-77 and 1 CT-125 in mono mode? I would be curious as to your opinion on if the 2 tweeters play at the same volume with the ALK universals, or if one sounds louder to you.

Any info on that point would be helpful.

I noticed with AL-3s (1990 Las) the volume between the 2 tweeters is close, but the K-77 is just slightly louder. This issue became a tiny bit more pronounced in my system when I changed to the ALK Jrs. I'm talking a "slight" difference here, and I'm wondering if you are hearing it or not.

I am able to try somewhat of a comparrison by running my Khorns / ALK / CT125 in stereo and then switching to mono on my processor, which only calls up the center La Scala with the AL-3 and K77M. The K-77 is louder by both my measurements and by ear. The differance to me, is in the quality of the sound. The CT123 has a crisper, more defined sound when listening to symbols or high freq. instruments. I have been listening closely for two days now, at all levels and thus far prefer the CT 125's. They produce a sharper, more defined sound. I am really liking these vs. the K77's.

The funny thing, is that in stereo, the highs do not seem at all muted, they seem just perfect when compared to the rest of the music. I would think if they were louder, they would stand out too much and be rather bothersome. Please note, that I have my mid horns attenuated 6dB via my ALK network. I have always preferred that setting in my room, and that was not changed any time recently. I hope that helps.

[mark1101]

Rudy81,

Thanks for the info. We are hearing the same thing. I am running my squawkers at the same setting as you, just on ALK Jrs, not ALKs.

I am extremely impressed with the CT-125's performance. Everything everyone says I am hearing. They sound better than the K-77 to me almost all the time with one exception.

Now this is a critical comment with me being picky, but I notice this every once in a while and critical comments are what helps improve products. So I have to say again, most of the time the slightly lower output doesn't matter too much. But there are complex passages in familiar tunes where the tweeter seems to disappear in the music when it didn't used to with a K-77. Now I am being picky here, but that's the critical comment. Other than that, for me the CT-125 is a 100% improvement. The clarity and top end reproduction bests the K-77 hands down in my system.

In fact, I saw Al's comment above about his universal network. I will ask him a few more questions, and if I believe it to be a potential solution I'll get some ALK network's and find out. That's how much I want these tweeters to work for me. I will work with them.

But I just can't be 100% satisifed the way they sound in my system right now. I think I eventually will get by this, but I haven't yet.

I know everyone else must be hearing something similar. Your measurements and our ears don't lie. It must just not bother people the way it does me.

Just being honest. []

[Rudy81]

Mark:

I will make an effort to listen for what you are describing next time I sit for some critical listening. It's funny, but his evening I was listening to some jazz and remember thinking how clear the highs were, vs the K77's, throughout the recording. Can you give me some examples of these passages, I may have the music here and will play what you are playing.

[mark1101]

Rudy81,

Most of the music I listen to is live music. Last night it happened to be Grateful Dead dowload series Volume 5. Although this was recorded 3/27/88, it's decent enough for me to make the above comments.

As far as which songs, I don't even remember.

It occurs when the music gets loud with all the players contributing. Lots going on. This is where the lower volume on the tweeter becomes obvious. I remember having to listen very hard to pick up the cymbals at one point.

Tonight my system is off. I sent my Peach back to Mark for some upgrades. I'll be on the backup system for a couple of weeks. So, I'll quit complaining now. I'm waiting on some help from Al.

Thanks for taking the time on this.

[Rudy81]

I will try to check it out tomorrow and will get back to you.

[Deang]

Sounds like you just want elevated tweeter output. With either the ALK or ALK Jr. and the CTS 125 the output level is spot on where it's supposed to be. I can't believe Al would tell you that would hear a difference between those two tweeter filters.

[Wrench722]

Witch one is better Bob's CTS 125 or Beyma CP-25 ?

[Daddy Dee]

Witch one is better Bob's CTS 125 or Beyma CP-25 ?

Wrench,

Each of these has a different reference sound. Which is "better" is a matter of subjective preference.

I have done extensive listening to both of these and my take on the sound is that both of these are an outright improvement over the K77. Both walk all over the K77, IMO. It is a fairly commonly made observation that the CT-125 is a close complement to the signature sound of Heritage speakers.... that the Beyma is a departure from the Heritage sound. This may be due to the fact that the CT-125 has a phenolic diaphragm, like the K77 and k55 drivers. The Beyma has a titanium diaphragm.

The differences: To my ears, the CT-125 gives the sound of cybal strikes and other such percussion a startling realism that sounds live. My subjective preference here is that the CT-125 sounds better than the Beymas. I have BTW sold my two pairs of Beyma tweeters.

The Beymas are more efficient than the K77 or CT-125, so it is too hot without attenuation. That's not hard to accomplish, and the sound is good.

The CT-125 is a genuine drop in replacement for the K77. It will fit in the K77 motorboard opening. Also, it is equally efficient as the K77 so it requires no attenuation, though some users use it somewhat attenuated.

The price of the Beymas is $150 each from usspeaker.com. The CT-125 are $150 per PAIR from Bob Crites.

[Rudy81]

Rudy81,

Most of the music I listen to is live music. Last night it happened to be Grateful Dead dowload series Volume 5. Although this was recorded 3/27/88, it's decent enough for me to make the above comments.

As far as which songs, I don't even remember.

It occurs when the music gets loud with all the players contributing. Lots going on. This is where the lower volume on the tweeter becomes obvious. I remember having to listen very hard to pick up the cymbals at one point.

Tonight my system is off. I sent my Peach back to Mark for some upgrades. I'll be on the backup system for a couple of weeks. So, I'll quit complaining now. I'm waiting on some help from Al.

Thanks for taking the time on this.

Mark

I did quite a bit of listening looking for what you are experiencing. In all honesty, I did not find the type of problem you mention. In some pieces, sure, the cymbals are less prominent, but I think that is a mixing issue. On some others, they are very prominent, such as the "Foo Foo" track in Santana's Shaman album. I did quite a bit of switching back and forth between my Khorns and La Scala, just listening to the differance in HF. The differance is very obvious the more I get accustomed to the CT 125. They are so clear and refined when compared to my K77M. I don't think I will be going back to the K77, I really like the new tweeters.

[DRBILL]

"Needless to say, I reserve the right to change my mind at any time."

I'm sorry, but changing one's mind is neither tolerated nor permitted in the two-channel forum!

Erik

That is correct. And the punishment changing one's mind is swift and terrible!

:-)

As the Marx Brothers put it: "That's my story and I'm stuck with it!"

DRBILL

[Rudy81]

I liked the CT-125's so much, I just ordered three more to put in my center La Scala and side effects Cornwalls. This should get the timbre matching just about perfect in the HT room. That is, other than having 5 Khorns.