Project: Improve old DM602S3

[DiyEverything]

Hello everybody,
I am new here and am taking on a little project that I might need help with.

I have a pair of B&W DM602 S3 that I have had for 10 years now and they just don't do it for me. The upper-mid harshness, lack of fine detail and sometimes boomy bass is driving me crazy. The only speakers I would really feel are worth the upgrade are well out of my price range at $8,000 per pair.

I would like to first redesign the first order crossover, there is only a coil for the woofer and it is (from my understanding) at 4khz for a 7" woofer.

The cabinet needs bracing - or complete reconstruction.

I do understand that I possibly will gain 0 improvement, but it's worth a shot knowing I fixed the weaknesses.

Does anybody have any advice to offer or is anybody willing to help me design a crossover if I provide proper measurements of each speaker?

Thanks!

[kipman725]

The first step is to measure everything! get hold of an ECM8000 measurement mic and mic preamp with phantom power and find out what the problem is quantifiably.

Secondly cost, the best solution would be a DSP based crossover/equalisation solution which can be done quite cheaply if you use something like the mini-dsp and only buy one additional amplifier.

The problems may not be fixable though, for example the midrange harshness may be cone breakup and although notch filters can help with this they don't remove it totally, the bass alignment may also have to be changed to get rid of the boominess.

[DiyEverything]

Thank you for the informative reply.

I have the mic, I have the extra amp(s) - what I don't have is measurement software.

I am almost certain it is cone break up if this 7" woofer really is crossoved over at 4khz @ 3db/octave, but I will measure out the xover and see what they did there.

As for boomy bass, I have decided I will definitely be redesigning the enclosure as a sealed rather than ported. The speakers do sound much improved with the provided foam port plug. I think the enclosure is just too large.

What measurement software do you recommend (if you even recommend using software...)

I will pull them apart after work and measure the drivers themselves with my woofer tester 3 as well and post graphs up.

Thanks again!

[kipman725]

Room Eq Wizard is pretty good for getting a frequency response as you can do a spatial average and as such optimize for the room.

If you look through this it will show you how to use a mini-DSP to create a two way system, but the advice is applicable no matter which way you do it:
Prototyping a Dipole Bass System | Hifi Zine