B & W Tweeter Replacement - Metal Dome to Fabric?

[kinetic]

Hello,

I'm finding my B&W DM603's with metal dome tweeters quite harsh. I am looking for a way to tame them a bit or even completely replace the driver with a smoother fabric style speaker.

Does anyone know of any drop in replacements that could yield good results with this speaker?

The speaker features one metal dome tweeter, one kevlar mid and one passive radiator.

Thanks,

-Mike

[Telecine]

I wouldn't replace the tweeter if I were you. What amplification are you using?

[henry218]

it is inherent for b&w to be bright sounding. its evident in almost every measurement that stereophile did.

i think there will be 2 ways to do this

1. add subwoofer, so you'll get warmer sound to compensate the highs

2. add resistor to the tweeter to attenuate

are you sure its passive radiator? i checked on the web its bass drivers.

[Paul Spencer]

Mike,

A different tweeter requires crossover modification, the level of equipment and skill involved is close to that involved to designing it from scratch.

Henry is on the money. The first thing I would do is add an Lpad, and try 3 dB of attenuation, two resistors, any online calculator with the correct nominal impedance is fine. That's a fairly aggressive change, but if it's MUCH too bright, that's probably a good first guess. If you find you've gone too far, then try 2 db.

I did this with some Vifa metal dome tweeters I thought were a bit bright. I padded until it was just right. In the end I became quite attached to the metal tweeter, and managed to get it to sound sweeter than most domes. I also stopped listening to Celine Dion!

[LogicprObe]

Or.........get a preamp with tone controls!

[kinetic]

Or.........get a preamp with tone controls!

Hurrah! The amp is a Marantz PM6010OSE KI Signature. Sounds quite good but can be fatiguing. No tone controls though!

I have plenty of resistors laying about. What exactly is an LPAD?

[Paul Spencer]

An Lpad is two resistors, of the 5 or 10w variety, added to the crossover as the last component from amp to tweeter. Place one in series with the + to the tweeter and the other in parallel, connecting + and - terminals. You need the right values so that the overall effect is attenuation of the desired amount, but they also avoid changing the impedance load seen by the amp in the tweeter range.

[henry218]

try mh-audio.nl for calculation. what paul meant is put the resistor after the crossover board to the tweeter

[hochopeper]

You can get service manuals for the older B&W models from here - http://www.bwgroupsupport.com - I can't link directly to the document as you must agree to their terms and conditions first. I believe the site is USA based but the speakers should be the same as sold in Aus.

It shows a schematic and the parts for the crossover in the DM603. It will also give some good diagrams for disassembly of the speaker to add an L-pad if that is an option you want to pursue.

[L J T]

Something from left field - Add a tube buffer between your source and amplification. I had the 602s3's and the sound from them was a little bright with some metal recordings.

Yaqin or Grant Fidelity can be had fairly cheaply online and you can sell them off of you find you don't like the sound of them.

[kinetic]

I do have a Delphonica valve amp. I'm waiting on some new valves as the stock Chinese ones seem to accentuate the harshness.

These most definitely do have the passive radiators. They are S1 series.

[henry218]

interesting design. have u tried to open the terminal cup? usually the crossover is there. since the speakers are relatively old, it may be a good idea to check the components.

[Telecine]

A couple of things to consider before performing surgery on your speakers:

1. Have a look at the room accoustics and consider some room treatments.

2. It may be that your amp is clipping trying to drive these largish floorstanders (the amp is 50 WRMS into 8 ohms)

3. Try some damping in the bass port. It may help balance the sound and allow you to run the amp at lower volumes.

4. Try a different source, that may be the cause of your problem, rather than the speakers.

[henry218]

for kinetic's case, its basic imbalance of design to perceive greater detail on short listening session, which you may or may not find it too bright on longer listening session.

ive noticed that to almost any b&w speakers, but of course if you are not sensitive to high freqs this would not be a problem at all.

telecine's suggestion no. 1-3 is valid for bass isssues, for no. 4, i agree, some amps do put emphasis on the highs.

regards

henry

[olderas]

kinetic, just an idea that may be of some use. Firstly I would not mess with a well designed speaker, the problem is probably not with the speaker, but rather the ancillary equipment. You know that it is a well designed speaker that has been well "balanced" in the factory. What I have found is cables can fine tune a system, but most people recommend buying a new box of some sort. Before spending megabucks on new equipment try changing cables, I use them as "tone controls"! The excess treble, may be a lack of midrange and/or bass, rather than an excess of treble, or it may be distorted treble. I have found the following to be true of the few cables I have owned or auditioned for protracted periods first in a valve amp/electrostatic panel system, and then in a ss amp/cone speaker system. So while system synergy is the buzz word, and I agree with that, I believe these cables to have the following characteristics, and so each would suite a different type of system.

1. Transparent Ultra - warm emphasized bass and mids, a bit lacking in detail

2. Kimber KTAG - lacking in bass/mids with emphasized/?distorted treble initially wow what detail and air, then fatigue and realise missing the important bits

3. Audiquest Black Diamonds - pretty good, but a little edgy

4. Vanden Hull The First Ultimate - overall well balanced all the detail great mids and bass, no edge or harshness

5. Stealth Indra - as for Van den Hull, brilliant sound (for a metal cable )

So I would suggest you find someone to lend you some Vanden hull The Firsts or The Second, and give them a try, you may just find the problem solved. I obviously can't comment on the millions of cables available, but without breaking the bank, these are exceptional interconnects (in my experience).

Don't laugh at me, I have heard many very expensive systems, each component has had rave reviews, but set up badly they sound awful. So as others have said room placement and furnishings (treatments), and interconnects are critical in getting the best sound out of your gear. I often think taking the trouble to set up your kit properly is more important than getting more expensive components.

[svenr]

Try a semi-decent solid state amp first. There's a 50% chance that what you hear are just the inadequacies of the valve amp design.

[henry218]

superes resistor

http://speakerbug.com.au/shop/index.php?main_page=index&cPath=16_31

$3.30 each, prob u will need 6-8 for diff combination for the l-pad.

adding resistor will not change the transfer function, it will be seen as reducing gain on tweeter itself.

[kinetic]

I do have the Marantz PM6010KI but someone alluded that may be underpowered. Will be interesting to try something a little more powerful.

[svenr]

Got you, I understood you as saying the Delphonica drives the speakers. I'd start from basics and take measurements at the listening position. They are most likely to reveal the nature of your problem.

[kinetic]

To be honest, the measure right now is mainly the way my ears feel after listening to a couple of albums.

It feels like I've been listening to hiss.