DL8 modding

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Dave the bass
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#1 DL8 modding

Post by Dave the bass »

I'm interested in what Richard's mods can do to a pair of speakers like this.

Image

Image

As stock they sound 'ok' IMO. Nothing special but 'ok' all the same. I've spent a couple of nights listening to them to remind myself of what they're like before performing the Doc-Mods.

So, copying the list from Richard's thread we have to -

Stages (in this case for two way)
1 remove all wadding and damping panels from the speaker, block and seal any ports.
2 line the inside of the cabinet with steel plate
3 remove the crossover and replace with just a protecting capacitor and padding resistor on the tweeter
4 dope existing bass driver to control the response mechanically or buy the already doped drivers from HFS

Find music at last.
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Dr Bunsen Honeydew
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#2 Re: DL8 modding

Post by Dr Bunsen Honeydew »

That's the ticket, remove the wadding and listen and tell us what you hear.
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#3 Re: DL8 modding

Post by Dave the bass »

Yup, 'On it' already matey.
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#4 Re: DL8 modding

Post by Dave the bass »

4 screws and out comes the mid/bass unit...
Image

....inside, a lot of wadding ....
Image

A LOT OF WADDING! This from just one speaker...
Image

Crossover filter network mounted on rear speaker terminal plate (these were riddled with dry joints when I was given the speakers as a freebie)...
Image
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#5 Re: DL8 modding

Post by Smeege »

Off to a great start Dave! :D

Just follow what the Doc advises and you'll be fine.

Just one word of warning re doping - if you are going to trial it with BluTac. Do not apply Plasti-dip before you use the Blu -Tac or you'll struggle to get it off the cone, but this of course is only if you don't like the Doc mods (highly unlikely).

Plasti dip spray on, or brush on coating will be for fine tuning after you find you are almost getting there with the attenuation of the bass cone. It's surprising how much you'll need to apply.


Enjoy the journey!

JR
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#6 Re: DL8 modding

Post by Dave the bass »

Dr Bunsen Honeydew wrote:...... listen and tell us what you hear.
OK, I'm hearing a louder overall SPL, no controls were altered between 'with' and 'without' wadding. I seem to be hearing the low mid/upper region is more dynamic and bouncy without the damping but there's a some peaking going on in the that area too, its a bit ruff 'n' ready compared to what I heard before. I don't know why but the whole tweeter output seems louder too. In summary so far, Interesting, a change rather than "good lordy, we've found a cure for the common cold" type statement.

EDIT. Ta for the advice Smeege, just seen your post.
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#7 Re: DL8 modding

Post by Dr Bunsen Honeydew »

You will find the balance has changed, you can now push the speaker further back to the wall for balance. For some people that change is a revelation, it is swopping accuracy for musical information at this stage. Is it enough change for you to continue the process. If so local metal dealers and see if they have off cuts. This will kill some of the rough and ready and deliver more music, then crossover then doping. But if it is not enough for you to carry on just bung the foam back in, and you will be a first.
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#8 Re: DL8 modding

Post by Daniel Quinn »

I am correct in assuming , that the only change so far is you have removed the wadding ?
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#9 Re: DL8 modding

Post by Dave the bass »

Daniel Quinn wrote:I am correct in assuming , that the only change so far is you have removed the wadding ?
Yeah Daniel, just the wadding so far, nothing else. I'm going further with Richard's mods, see below.
Dr Bunsen Honeydew wrote:You will find the balance has changed, you can now push the speaker further back to the wall for balance. For some people that change is a revelation, it is swopping accuracy for musical information at this stage. Is it enough change for you to continue the process. If so local metal dealers and see if they have off cuts. This will kill some of the rough and ready and deliver more music, then crossover then doping. But if it is not enough for you to carry on just bung the foam back in, and you will be a first.
OK, will do, I'll get them set further back on some stands and listen again. I've built 6 pairs of speakers over the years but this is the 1st time I've ever fettled ready-mades as it were. To answer your question, its not so much a case of if there's enough change to warrant continuing the process so don't worry about that, its more a case of' "what happens if...", I'm an inquisitive little (veggie) Sausage :) and was interested very much in what others have heard by following your mods list, thats the real driver, experimenting aka 'sperrymenting' as its called here. Good stuff.

Got any recommends for local metal dealers Richard, I'm down the road from you in Dartford, who do you use?

I read on the Doc Mod thread you use 3.3uF and 12R as a starting point on the crossover fettling yes? And IIRC on a HFS thread trying to avoid Electrolytic caps yeah?
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#10 Re: DL8 modding

Post by Dr Bunsen Honeydew »

Well I have only done one pair myself recently it is bought by the modders. I used ebay, just watch for what becomes available, or check your local stockists and fabricators, they always have off cuts.

Yes to both questions.
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#11 Re: DL8 modding

Post by Dave the bass »

Noted, ta for the answers Richard. I popped into B+Q today on the off chance to find some plate and could only find Aluminium sheets, not steel plate. Meh, I'll scan eBay, 3-4mm ish thick is what I'm looking for I believe.

Next question, I've got the speakers apart again and looking at the filter network the tweeter appears to be running in anti-phase to the mid/bass unit. It's not a mistake, both cabs are the same. I'm going to strip out the network and fit just the simple 12R + 3u3F tweeter protection components, so the question is... tweeter in or out of phase? Or even possibly 'adjust to taste'?!

I've no experience with speaker filter networks, all my other projects have been single driver horns and such like (except a pair of kit based LS3/5a's) hence the newbie question.
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#12 Re: DL8 modding

Post by Dr Bunsen Honeydew »

In phase for me, normally out of phase is to counter some of the bad effects of the crossover.

A few local to you here https://www.yell.com/s/steel+stockholders-kent.html
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#13 Re: DL8 modding

Post by Daniel Quinn »

delete
Last edited by Daniel Quinn on Sat Jan 07, 2017 4:31 pm, edited 1 time in total.
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#14 Re: DL8 modding

Post by Daniel Quinn »

with the removal of the crossover from the bass drivers you will negate the need for inversion on the tweeter.
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#15 Re: DL8 modding

Post by Mudshark »

Come again......... :!:
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