Frankensoundsystem Bodge - Is it worth it?!

[bob4]

Ok final design is ready, building next week. Very exciting.

I know that I delayed your buid by two days with my final remarks, but damn the suspense is KILLING me!

 

[dokkodo]

Ha! Believe me, it's killing us both, I just got a couple of weeks of work which is probably turning into three! It's good work but I definitely wish I was playing with my speakers. Don't worry I'll keep you posted once work begins!

 

[bob4]

ah thanks that's good to know, I'd been keeping an eye on this thread for any updates

 

[bob4]

Any progress?

 

[dokkodo]

Just in case you thought i'd given up...

progress has been slow as all the time i thought I had seemed to dissappear...

coming along well though finally! should have one finished tomorrow for an initial test. ive left one original box together so I can compare them by ear at first... I havent got round to buying a test mic yet but i will do, or see if I can borrow one...

I also now cant decide on a finish for them. Speaker paint is expensive but looks ok, also i have a roll of thin carpet i could use...

 

[dokkodo]

sorry for the sideways picture!

 

[conanski]

Nice work but there is 1 problem I see there.. you have 2 drivers you will never be able to get out once the box is finished. Or have you thought of that already and planned for it?

 

[dokkodo]

That did strike me during the design... its going to be fiddley either way, but i was thinking to build in a removable panel on the back with the terminals panel on it also. as long long as its well sealed and with plenty of threaded insert nuts to hold it in, should be ok no?

 

[dokkodo]

Any progress?

only just saw this, been meaning to post for a few days. Should have a pic of final product soon!

 

[dokkodo]

also im nearly at wiring stage.

the Xover has only one + and - for the four 12s. Should I wire in series, or series-parallel, and then swap polarity for a pair?

 

[conanski]

That did strike me during the design... its going to be fiddley either way, but i was thinking to build in a removable panel on the back

The usual way to do this is to surface mount those 2 drivers so they can all be installed through the front slot, that makes use of that gasket that all drivers have.

 

[conanski]

the Xover has only one + and - for the four 12s. Should I wire in series, or series-parallel, and then swap polarity for a pair?

What impedance is the crossover designed for? And are all the drivers 8 ohm?

If so then you don't have a lot of choice, wire the L and R pairs in series and connect those together in parallel with 1 pair reversed polarity.

 

[bob4]

wow, nice!!!

 

[bob4]

I also now cant decide on a finish for them. Speaker paint is expensive but looks ok, also i have a roll of thin carpet i could use...

Get Warnex, it's a water-based paint for loudspeakers. You can apply it with a roller or with a spray gun. It can be easiy thinned with water, and is non-toxic. Shouldn't break the bank either. You will probably have some trouble with the exposed MDF cuts. Afaik the open mdf fiber structure will soak up more paint than the sealed surfaces. I built my last MDF boxes a long time ago, but I think I already used Warnex on them.

Avoid carpet at all cost....... it belongs to the 80ies.....

 

[bob4]

Hi,
I started my own ppsl inspired midtop build, pictures can be found in my thread on speakerplans:


2x8" PPSL midtops made from junk - Speakerplans.com Forums - Page 1

 

[dokkodo]

They look great, have they gone well? are you pleased with the result? youve been a lot quicker than me... ive had quite a lot on my proverbial plate, as usual.

so i got my first box all sealed up and put some signal through it. bass seems clean, but the comp driver is very over powering and the tweeters dont work at all! I cant figure out why as they are wired in right, maybe i should open them up and check inside, they might just be done. the other thing it might be is a break around the crossover, which is a bit fiddley to check out but ill use the other tweeters to check first.

im using a cheap second hand 600w power amp, which seems to cut out if i push the volume too much, another complication. could/should I just use a better quality 400w hifi amp for testing?

so my next objective is to haul the other original box out and do a comparison by ear, and maybe steal the tweeters off it and start looking for some second hand replacements for the other box.

i havent got a reference mic yet, but one of the guys in the units near me is an audio engineer so i might see if he has one i can borrow.

also im wondering how to solve the balance between low and mid drivers. could I convert them bi-amping somehow? either with an active crossover or some other way...

questions again!

 

[bob4]

Hi,
how are you doing with your project?

I more or less finished my pair of midtops, the speakerplans thread I linked in my previous post is now 7 pages long with pictures, there is also a link to a public album on facebook with some more pics in case you are interested.

 

[dokkodo]

Hi again Bob

Glad to hear yours went well, will take a look at the thread. But importantly, how do they sound?

My build went well but I only made the first cabinet in the end, when I started experimenting with signal it turns out both the crossovers have died. I dont know whether it was the damp storage or me manhandling them or maybe they never worked (i was told they did but didnt check)

So its on hold for now until I figure out what to do next. Maybe an active crossover is a good way to go?

Thanks for your continued interest!

 

[dokkodo]

In the latest news, I have bought a Behringer DCX2496 as i found a second hand one going for ok money. I look forward to experimenting with it and finally maybe finishing the project now I have some time over christmas and a bit of money again.

Any advice on how i should set it up would be greatly appreciated!

 

[bob4]

Godspeed!