new metronomes

Dedicated to those large boxes at one end of the room
Cressy Snr
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#16 Re: new metronomes

Post by Cressy Snr »

Had a listen to these this week.
He's cracked it.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
Ant
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#17 Re: new metronomes

Post by Ant »

Quite enjoying these now, they seem to work well with everything ive played since I buggered about with them
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#18 Re: new metronomes

Post by Ant »

Following the little meet at Davids place yesterday, I realised I had made a cockup with the crossover in these.
When i worked out the cap size, i worked it out based on an 8r tweeter. It isnt, its 4r :oops:
Redone it with the correct value, bingo.
Much betterer
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Ant
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#19 Re: new metronomes

Post by Ant »

Another tweak to the speakers today.
There was still a honk from them that was partially sorted by changing the crossover cap from the wrong value (2.2uf) for a 4r twatter to the correct value of 10uf for a nominal 4k crossover with a 4r twatter.
The mid / bass is much better balanced, but it was still there.
So ive listened to the same bloody track about half a dozen times ( fast double bass) while pratting about.

First, stuffed the port so it was completely closed. Result, no honk, but not much in the way of low bass. As you would expect.
Second, took the felt off the base under the port so there was a reflective surface. A little better
Third, removed the plate id put in the gap between the port and base to reduce the outlet volume so it was back to being the same as the port diameter. Abit better again.

Then the old man says, wonder what'd happen if there was a cone under the port......

Well I just happen to have some cones, the ones richard Higgins turned donkeys ago that were underneath the lenco I got from him years ago. And then were used under the jbe when the courier broke its legs. And were only taken off last week.

There was an immediate removal of the honk, which i have always suspected was some sort of reflection in the cabinet. Didnt think to look outside the cabinet.

Its sat directly under the port and is directing the port output out of the slots in an annular fashion, rather like a phase plug on a lowther..

I think its abit small as it is, I think it needs to be fractionally wider than the port so that all the port output is hitting it and being directed. As it is, its smaller than the port so a proportion of the output is still being reflected back up as it hits the base.

I reckon It I turn a pair of new cones that are a little wider than the port at the base and poke up into the port by about a quater inch, that would be about right.
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IslandPink
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#20 Re: new metronomes

Post by IslandPink »

Speakers are lots of fun if you have a bit of spare time :D
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Ant
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#21 Re: new metronomes

Post by Ant »

Did abit of playing about with the speakers yesterday and today.
Yesterday I tried a set of spare faital 6pr110 drivers in place of the 6fe100s.
Nope. Just sounded odd. Dunno why, they sounded alright in these cabs when they were first bought...., might be the white tack that is around the dust cap.
Took them back out.

Today having nothing better to do because of being unable to do any order work due to the snow, i decided to try something else. The modded flatback speakers my old man took up to Steves have a directed port outlet, i.e on those the port output can go either out under the front or the back.
The metronomes let it out in all directions, so I decided to see what happened if i blocked the arches up.

Just a bit of cardboard box cut up and stuck on with tape, blocked the left and right arches and it didn't really do much at all. Blocking the back arch up aswell so the port output can only come out of the front arch made a nice difference, tightened them up quite abit in the midbass.

I dont think it's to do with an inherent issue with the speaker, its to do with some rather odd room acoustics I have here. The left hand corner of the room has a honk, which is worse the nearer the floor you are. always has. Directing the port output out into the room instead of letting it go into said corner via the rear and left arches seems to stop the speaker exciting the corner and making nasty noises.

The right hand corner has a wierd upper mid noise which comes from somewhere around head height, due to the alcove having an arch in the top of it about 6 feet up the wall. There is a built in cupboard in it a metre tall with a unit in the top with the ps4 and TV box in it. There is quite a big cavity behind this. Same again, blocking up the rear arch and side arches seems to stop the port output hitting the rear wall and exciting the strange acoustics in the alcove.

I dont seem to have lost any low bass or anything, untoward, just ended up with a more even balance.

Just abit of cardboard. Cost nowt. Happy with that
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Mike H
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#22 Re: new metronomes

Post by Mike H »

Rooms! Wha' can ya do with 'em eh... :D
 
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