Technical M&K speaker question?

[Techlord]

Hello members,

I have enjoyed my M&K LCR-750THX 5.1 system (bought 2001) for many years now and want to upgrade my Z11MKTV 4 ohm tweeters with an M&K tweeter that will have higher quality mids and high frequencies without loosing the matched system as far as both tweeters having the same roll-off characteristics with the same sensitivity, I'm just looking for a more smoother, warmer and better detailed M&K tweeter to replace what I have.

Thanks for any recommendations, Techlord.

 

[j_garcia]

I'm not quite sure what you are asking? What exactly is the problem with the current tweeters? You typically don't change a tweeter in a speaker without also having to take a look at the crossover design, so simply swapping different tweeters in there, even from the same manufacturer, is not quite as simple as it may seem. With M&K being out of business, it might be tough to track down new tweeters also.

 

[AcuDefTechGuy]

What exactly is the problem with the current tweeters?

They are not quite as smooth, chocolaty, sweet, and exquisite.

 

[Chicagorep]

M&K is back in business but I don't think they are producing the old models.

 

[Techlord]

I'm not quite sure what you are asking? What exactly is the problem with the current tweeters? You typically don't change a tweeter in a speaker without also having to take a look at the crossover design, so simply swapping different tweeters in there, even from the same manufacturer, is not quite as simple as it may seem. With M&K being out of business, it might be tough to track down new tweeters also.

M&K is now MK Sound and is pumping out products including the 750-THX, 950-THX and 150-THX speaker systems and all the other line of Pro Studio Monitors. I have 2 blown 750 LCR tweeters and thought why not use a high quality replacement Pro tweeters (5 of them) instead of the regular 750 tweeters. If it's not as simple as changing out the tweeter, I thought the tweeters are all the same with the crossover being the deciding factor.

MK Sound

Regards,
Techlord.

 

[j_garcia]

In that case, I'd contact them and see what they say about doing this. It may work, it may not.

 

[Techlord]

In that case, I'd contact them and see what they say about doing this. It may work, it may not.

I have tried emailing MK Sound without much success, their pretty much the distributor and get the feeling they may not have the answers. I tried emailing MK Sound in Demark, but only unanswered emails thus far. So I figure there must be people out there like me trying to tweek all I can out of my speakers as I plan on keeping them 10 more years!

Thanks for the reply,
Techlord.

 

[MidnightSensi]

I have a set of 750s in my closet somewhere, their tweeters are notorious for blowing. If I remember correctly M&K had THX and non-THX tweeters. The non-THX tweeters were often considered 'better sounding,' ironically, but the THX tweeters met THX specifications for output and so forth.

If you just want to replace the blown tweeter, I'd recommend looking on eBay. Lots of M&K whoring on there.

 

[Chicagorep]

I had 750 LCRs and I never cared for how the sounded when I was listening to music.

 

[ski2xblack]

http://www.deepsurplus.com/Speaker-Parts-Amplifier-Building-DIY-Audio/Tweeters-Vifa-Miller-Kreisel-M-K

Go with exact replacements for reasons others mention upthread. These are the vifa tweets that M&K had when they went belly up.

 

[Techlord]

Well I finely contacted MK Sound in Denmark or whereever they a located in the UK, the response was from a MK technician Victor Bromwell. I asked for more information regarding crossover differences and tweeter sensitivity and roll off characteristics, I'm still waiting for a second response from Victor. Are the crossovers responsible for directing the proper frequencies to the proper drivers?

Victor

You can put the Z16 in the 750, the 750 with the Z16 was never sent for THX certification but works & sounds fine.

Regards,
Techlord.

 

[TLS Guy]

Well I finely contacted MK Sound in Denmark or whereever they a located in the UK, the response was from a MK technician Victor Bromwell. I asked for more information regarding crossover differences and tweeter sensitivity and roll off characteristics, I'm still waiting for a second response from Victor. Are the crossovers responsible for directing the proper frequencies to the proper drivers?

Victor

Regards,
Techlord.

Yes the crossovers determine the crossover frequency, but changes in impedance and voice coil resistance between two different drivers will change the crossover point. Also all tweeters have different acoustic slopes, and the slope you get from the crossover and the slope of the driver are additive. In addition, if the sensitivities are different you have to change the crossover L-pad. So if you change drivers you have to change the crossover to take account of three variables essentially.

Those Vifa Classic tweeters have not been made for years, so you had better snap them up. I'm pretty certain they don't have ferro fluid. So with modern amps and digital material they will be easily blown, if you play them loud.

Not so sure why you seem to be emotionally attached to those speakers. I would move on.

 

[Techlord]

Yes the crossovers determine the crossover frequency, but changes in impedance and voice coil resistance between two different drivers will change the crossover point. Also all tweeters have different acoustic slopes, and the slope you get from the crossover and the slope of the driver are additive. In addition, if the sensitivities are different you have to change the crossover L-pad. So if you change drivers you have to change the crossover to take account of three variables essentially.

Those Vifa Classic tweeters have not been made for years, so you had better snap them up. I'm pretty certain they don't have ferro fluid. So with modern amps and digital material they will be easily blown, if you play them loud.

Not so sure why you seem to be emotionally attached to those speakers. I would move on.

What do you mean when you say Classic tweeters? So basicly if I buy the Pro tweeter then I need the matching crossover for it to work properly? Would you say the 5.25" mid-bass drivers are mostly the same? Also how do the new tweeters in the 750THX differ from the older Vifa Classic tweeters? Has anyone heard or have any info on how the new non-THX LCR 950 speakers sound compared to the 750's?

Thanks for the info,
Techlord.

 

[TLS Guy]

What do you mean when you say Classic tweeters? So basicly if I buy the Pro tweeter then I need the matching crossover for it to work properly? Would you say the 5.25" mid-bass drivers are mostly the same? Also how do the new tweeters in the 750THX differ from the older Vifa Classic tweeters? Has anyone heard or have any info on how the new non-THX LCR 950 speakers sound compared to the 750's?

Thanks for the info,
Techlord.

Vifa used to have an extensive line of useful drivers at budget prices, known as the Vifa classic line. Sadly these were discontinued some time ago. Your tweeters are a member of that classic Vifa line of drivers.

All drivers have huge differences. No two drivers are alike. They all have unique Thiel Small parameters, and unique acoustic responses.

Basically if you substitute a bass driver, then you are usually in for a new design form the ground up including box and crossovers. A tweeter substitution involves a crossover redesign.

 

[Techlord]

Vifa used to have an extensive line of useful drivers at budget prices, known as the Vifa classic line. Sadly these were discontinued some time ago. Your tweeters are a member of that classic Vifa line of drivers.

All drivers have huge differences. No two drivers are alike. They all have unique Thiel Small parameters, and unique acoustic responses.

Basically if you substitute a bass driver, then you are usually in for a new design form the ground up including box and crossovers. A tweeter substitution involves a crossover redesign.

Was there something special about the VIFA Classic Line other than the low prices? I here you about the newer tweeters needing a crossover redesign, the 950 Series tweeters do have a lot of improvements that would change the characteristics. What if I bought just two 950 series tweeters for my L/R speakers to see how things match up, what would you expect would happen during playback?

Regards,
Techlord.

 

[Techlord]

Update

I just received an email from M&K and another source, it was a shocker but in a good way!

P815040 - 4ohms (Z16)
P813836 - 8ohms (Z16)
206-08290000 - 8ohm (Z16)

Typically, all surround speakers are 8ohm in the 750 and 950 systems. We do carry the tweeters and woofers for the LCR-750 in stock. However, the Z11 tweeters are no longer made and they have been substituted with the P815040, which is actually the same tweeter used in the LCR-950. The woofer is 206-08290000. Both the tweeters and woofers are $70 each.

The SUR55T is compatible with both the P813836 and P815040 tweeters. The woofers in the SUR55T are the same woofers as in the LCR-750. Both the tweeters and woofers for the SUR55T are also $70 each.

Thank you.

Jeremy Holmberg
The Dolphin Group
service@thedolphingroup.org
1-866-290-2673

the newer tweeter will not be louder but may be slightly clearer for the
higher frequencies
the tweeters will work fine in the 750 as this was made as the 850, I
haven't put any in the 550 & have never been asked to, in theory it should
improve it.
The Z16 is slightly better than the Z11 it all really depends how good your
hearing is.

Regards,
Techlord.

 

[Jack Hammer]

They mentioned the 850's, I've got some. The 850's used an upgraded tweeter from one of the 'professional" series speakers. I'd have to dig around to find out which model it was from. I'm not sure if the crossovers were the same or not. They used to bill the 850's as being similar to the 750's but with the better tweeter. IIRC, the 850's were bigger and heavier than the 750 series speakers.

 

[Techlord]

They mentioned the 850's, I've got some. The 850's used an upgraded tweeter from one of the 'professional" series speakers. I'd have to dig around to find out which model it was from. I'm not sure if the crossovers were the same or not. They used to bill the 850's as being similar to the 750's but with the better tweeter. IIRC, the 850's were bigger and heavier than the 750 series speakers.

Could you take a picture of the crossover and tweeter then write down the numbers on you 850 tweeter and crossover? The more confirmation I have the easlier it will be to spend $350 dollars for the new tweeters! My 750 front speakers are exactly the same dimensions as the 950 speakers, my 550's surrounds are also the same dimensions as the Surr 95T's. I just purchased some really sweat piano gloss black surr 95T Tripole cabinets from Deep Surplus for $30 dollars!

Thank you,
Techlord.

 

[Jack Hammer]

Here's the numbers:

Tweeter - Z16 MK TV 4 OHM
021215 MADE IN DENMARK

Woofer - Qc: 040303 Cat.no: 17012 8ohm
there is a barcode on it with the following #: 5 702548 306433

The board on the crossover is marked "THX 750"

The dimensions are 16" x 6-7/8" x 7-3/8" not including the grill. Not sure about the weight.

 

[Techlord]

Here's the numbers:

Tweeter - Z16 MK TV 4 OHM
021215 MADE IN DENMARK

Woofer - Qc: 040303 Cat.no: 17012 8ohm
there is a barcode on it with the following #: 5 702548 306433

The board on the crossover is marked "THX 750"

The dimensions are 16" x 6-7/8" x 7-3/8" not including the grill. Not sure about the weight.

Wow, I can't say I'm surprised one bit! So to go from the 750 system to the 850 system only the tweeter is changed from Z11 to Z16 and from the 850 to the 950 is yet another tweeter swap! I'll bet my bank account that the 950 system uses the 750 THX crossover, I mean why pay for another THX certification fee when M&K already has one? I'm 100% sure the new Professional tweeters will do just fine with the one and only THX crossover that the 750, 850 and probably 950 all use!

It seems like a pretty ballsy statement, but with all the evidence collected it's most likely true! I'm not implying that M&K is doing anything wrong, M&K is simply improving on the original line of speaker systems by tweaking the drivers used. Now all we need is for someone with the 950's to remove the crossovers to see if it is indeed a 750 THX crossover! Well I guess I'll be buying a set of five pro tweeters next month for only $350 dollars, I will report back when I do and tell you how they sound!

I would like to thank you Jack and everyone else for contributing in this thread!

Regards,
Techlord.