HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

At the risk of getting laughed off the forum, why?

I mentioned to friend that i've modded some B&O's with doped drivers etc etc and he asked me to what advantage, and tbh i couldn't really explain.
Is it to tune the driver so no overly complicated crossover is needed? And if so, why aren't more doing it? There seems (apart from guitar amps) not much on the net.
Looking at Audiotalk & other forums it seems some design a crossover to make a bad driver sound good, which i can't really get my head around. I mean no disrespect to those who do it though.
My question will probably seem even more daft as i've bought some, but that was on the recommendation of people here that have done it.
As for my opinion on the modded drivers, i've only put a few hours through them so can't really compare at the moment.

Sod what other people say they are either idiots or just repeating things idiots have said, that is this industry sadly. You do what you want I couldn't give a toss. The point of Doc Mods is to remove all possible filters from the signal path, even the wadding is a filter. Doping is to take away the need for electronic component filters on the drivers. It is as though the driver had been designed and built properly in the first place, so needs no electronic crossover. An electronic crossover is bad because the components sit in the signal path and pollute the music. That loses information, things that are in the music you no longer hear. Worse they introduce timing errors into the music, and timing is the very essence of all music. Filters introduce phase lag and phase lead depending on the filter design, 1st order the least and worse as you go up through the orders, so more complex filter destroy the music timing and communication more. If people don't know or understand this then they are idiots, and it is up to you if you want to believe idiots.

The whole point is that it is empiric, it is your ears that decide and if YOU say it is better then it is better, if you think it is worse then it is worse. So far no one has said doped drivers are worse than crossovers, ALL have said it is better, so is that more valid than comment from idiots who haven't done it. Up to you who you believe, and do what you want.

I feel like I have wasted over two years of explanation since I went public on this.

Learn to use you ears, we can only advice, it is your project.

All you had to do was read the archive. That is what it is there for.

My understanding is that doping a pair of drivers means that any cone break-up and resonances at higher frequencies is dealt with meaning that you don't need to put a coil on the driver to roll it off. If you look at the frequency response curve of most bass/mid drivers, they spike quite considerably beyond a certain point. Very few drivers seem to be designed to have a natural fall-off. An exception is the SEAS A26 which falls away gracefully from around the 1khz mark all on its own. Its predecessor was used in the Dynaco A25 and in that speaker, the tweeter just had a cap and a few resistors to tweak the output. The bass driver ran 'full range'.

The Doc's mods allow you to deal with with those cone break-up issues and get rid of the coils etc. And of course, it's really cheap with so many suitable donor speakers around.

BTW I already gave you advice you decided to ignore. The midrange unit needs doping and may also need padding resistor. You need to tell us what you are hearing.

All I can say Jonty is that my Doc modded bass/mid drivers plus a SEAS tweeter with just a 3.3uF cap and 12 ohm resistor sound very good to my ears with my system in my listening room. For me there's no going back to commercial mainstream speakers with a component cost of perhaps 10% of the selling price (or less). I may drop the resistor down a tad after exposing the system to a wider variety of music, but it's an empirical process that needs listening time, especially with music you know well.

Apart from the uncalled for aggression, that was the answer i was looking for, and i did have a snout through the archives but theres a lot of threads to digest.
I'm not ignoring your advice otherwise i wouldn't have bought the drivers (or anything else for that matter) in the first place. I'll get mids when i can afford them and report back.

A good test track for me is Catherine Wheel's Thunderbird. With the wrong setup, the bottom end sounds awful with a boomy bloated bass. With my Doc modded standmounters (full monty with steel etc.) the bass is more defined than I've ever heard it. With Eric Bibb's Diamond Days, if there was anything nasty going on with cone breakup, you'd hear it in the vocals. There isn't.

Jonty2547 wrote:Apart from the uncalled for aggression, that was the answer i was looking for, and i did have a snout through the archives but theres a lot of threads to digest.
I'm not ignoring your advice otherwise i wouldn't have bought the drivers (or anything else for that matter) in the first place. I'll get mids when i can afford them and report back.

What the feck do you expect, do you think I am at your beck and call, what do you think we have an archive for. Do I make money from Doc Mods NO, do I get grief and lack of respect for my knowledge YES so do expect it here NO. Look at the wording in your OP if you want to see why I am angry. Basically you say you would prefer to believe others, fine send the drivers back for refund. You don't need to get MY bass drivers, yours need more dope, if you wish to start believing me again you can send them and I will do them for you if you feel unable. THEN you need to tell us what you are hearing not the eeediots US and we will talk you through the tuning process.

What are you going on about?
I asked a question because i don't fully understand and would like to. The question wasn't directed at you personally.
The reason i said "laughed off the forum" is because i thought it was a daft question as i don't have the knowledge and probably everyone else knew the answer.
FFS, i'm looking to learn, not looking for a fight

Looking at Audiotalk & other forums it seems some design a crossover to make a bad driver sound good, which i can't really get my head around. I mean no disrespect to those who do it though

Read again