Can Tannoy 609MK I be converted easily to MK II?

[TannoyFan]

Hi all,

I'm a newbie at this, so please be patient with me. I've got a pair of Tannoy 609 MK I's, and although I like them very much, I find them very sibilant. I have heard the MK II's and I really like the way they sound, and would love to convert my speakers. My question is, does anybody know if it is just a matter of replacing/altering the crossovers, or do I also require a new set of drivers?

Thanks in advance for any help you can give.

 

[Sonusthree]

Hmmmm.... there are differences between the sixes Mk1 and 11 for sure. I have owned 611's Mk1 for years now and auditioned the MK1 and 2 versions side by side in my home for a few days.

I find the 611 Mk1's sibilant as you do but I found the 611 MK11's are perhaps a little muffled as if something was missing. I guess that's the trade-off. I believe that Tannoy were criticised for the forwardness of the Mk1's and the MK2 was their answer.

According to the manual, the crossover point remains the same for Mk1 and 2 at 2.5KHz.

I know that the Tannoy Sixes Mk1 and Mk2 were supposed to have different mid/bass drivers but I know that this is not always the case. This leads me to believe that all of the differences are likely in the tweeter and crossover. From memory, the crossover caps were the same but I couldn't verify the inductor because it wasn't marked. I may be able to check some old pics of the crossovers if you need this to be verified.

Here are my experiences of tackling the sibilance in the 611 Mk1. :

I tried reducing the tweeter's crossover capacitor a little from 3.2uF to 3.0uF. Not much discernable difference really! Reducing more may help .... maybe??

One easy thing to try is a little acoustic foam or fibre behind the mid-bass driver. To me, that seemed to prevent some reflections back 'through' the speaker cone. It's a very cheap and reversable experiment. Helped a little I think.

More Bass can help. If there's a way of positioning the speakers to produce a bit more bass then that would certainly help to provide a little more balance. Perhaps against or nearer a wall? Are your ports unblocked? (609 have ports at the rear and 611 do not.)
I even went as far as using active equalization to add more bass. Overall the sound was well balanced but adding something else into the signal chain lost me the detail and imaging that I love so much. Is there any way that you could try a sub in your setup?

Bi-amping. At the moment, as a temporary solution, I am using one amp for the tweeters and another amp for the rest. I have set the tweeter's amp to a lower volume and that helps quite a bit. Again, probably an easy experiment because the tweeter amp doesn't need to be very powerful. The results are quite good but not perfect.

Other possibilities I haven't tried:
An L-pad attenuator on the tweeter.

A 'notch filter' to rduce the sibilant frequencies.

New Mk2 drivers and crossover!

All the best,
Martin.

 

[TannoyFan]

Thanks for that Martin,

I think I will start with your acoustic foam/fibre suggestion, and see how that works. This would indeed be the easiest option.

I have heard from Tannoy themselves that the drivers are the same both for the MK I and MK II 609's, but from a company in the UK that provides spares for these, I have heard that there may be a difference in the tweeters indeed. The guys there are going to check it out for me and I will let you know what they say.

I really don't want to buy new drivers. If it comes that far, and I really find that I can't live with the sound, then I think it'll be time for new speakers.

Thanks again, and I'll let you know how I get on.