Hey, I am doing somthing similar to yours.
keep up your steam. You are on the right track. Playing with 3 way crossover active is not easy.
I am doing a similar project as yours right now. As I am in Hong Kong, I ordered my speaker cabinet from Shenzen and I am waiting for the cabinet to arrive.
I am planning to use the Scan revelator berillyum tweeter, Volt VM752 mid and a double bass using Scan 25w.
You can see my active crossover unit which is valve based.
https://www.facebook.com/#!/photo.p...435.1073741825.100007790467742&type=1&theater
You are welcome to search my update on the facebook - search 'akltam'.
How is your amp and electronic crossover unit going ? Keep us posted on your update.
keep up your steam. You are on the right track. Playing with 3 way crossover active is not easy.
I am doing a similar project as yours right now. As I am in Hong Kong, I ordered my speaker cabinet from Shenzen and I am waiting for the cabinet to arrive.
I am planning to use the Scan revelator berillyum tweeter, Volt VM752 mid and a double bass using Scan 25w.
You can see my active crossover unit which is valve based.
https://www.facebook.com/#!/photo.p...435.1073741825.100007790467742&type=1&theater
You are welcome to search my update on the facebook - search 'akltam'.
How is your amp and electronic crossover unit going ? Keep us posted on your update.
At long last the cabs are back from the finishers and looking great.
Anyone embarking on this sort of project, the finish is all important as these will be a major piece of furniture. With retrospect I would have bought pre-finished cabs. But hey, DIY is a learning curve.
Next job is to populate them.
Anyone embarking on this sort of project, the finish is all important as these will be a major piece of furniture. With retrospect I would have bought pre-finished cabs. But hey, DIY is a learning curve.
Next job is to populate them.
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Installing the Volt mid
I assume that you can reach the back of the Front baffle as they can only be installed from the back of the front baffle.
Are you going to add bracing to the internal of the cabinet. I guess that will make the cabinet stronger and hopefully tighter bass.
Unfortunately I am still waiting for my cabinet to arrive.
Alan
I assume that you can reach the back of the Front baffle as they can only be installed from the back of the front baffle.
Are you going to add bracing to the internal of the cabinet. I guess that will make the cabinet stronger and hopefully tighter bass.
Unfortunately I am still waiting for my cabinet to arrive.
Alan
Well the 2 x 150W doesn't work on one channel.
Next dilemma is whether to fault find on it or just use the salvage to build an F5 turbo.
Next dilemma is whether to fault find on it or just use the salvage to build an F5 turbo.
The Platinums are back on the drawing board. I'm wiring the cabs passively but using the crossovers externally for the time being.
The 2 x 150W was replaced with a Quad 909 clone. Again I've got problems, one channel works but the other one oscillates.
After a move of home - they're back
After a little sebatical the Platinums are finally being finished.
In order to remain flexible I'm just making the cabs entirely passive. I do have the bonafide crossovers which I'm going to mount in external boxes behind each speaker, that way I can play.
After a little sebatical the Platinums are finally being finished.
In order to remain flexible I'm just making the cabs entirely passive. I do have the bonafide crossovers which I'm going to mount in external boxes behind each speaker, that way I can play.
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Gor blimey, it's heavy, and that is with the mid range still not fitted. The mid on its own is a two arm lift. That's the first time I've moved the cab with any drivers fitted.
The existence of cavity standing waves can be seen in impedance
and FR plots. Once you have enough of stuffing or lining, those
signs of resonances would dissapear. I don't put any foam in boxes,
only polyester wadding from upholstery supplies because it's cheap
and working ok. This usually means making a role just enough in width
and height for proper dampening and checking with measurements when
it's enough. Space around port is free.
As speaker dave mensioned on more than one occasion, a very good quality
and efficient material for dampening standing waves would be mineral and
glass fibre wool. You can work with foam too, of course.
standing wave formula:
frequency=172/inner dimension; for 1 m of height you get: fr=172/1=172 Hz;
172= speed of sound divided by 2(m/s)
inner dimension(m)
All standing wave frequencies in woofer's passband should be taken care of.
and FR plots. Once you have enough of stuffing or lining, those
signs of resonances would dissapear. I don't put any foam in boxes,
only polyester wadding from upholstery supplies because it's cheap
and working ok. This usually means making a role just enough in width
and height for proper dampening and checking with measurements when
it's enough. Space around port is free.
As speaker dave mensioned on more than one occasion, a very good quality
and efficient material for dampening standing waves would be mineral and
glass fibre wool. You can work with foam too, of course.
standing wave formula:
frequency=172/inner dimension; for 1 m of height you get: fr=172/1=172 Hz;
172= speed of sound divided by 2(m/s)
inner dimension(m)
All standing wave frequencies in woofer's passband should be taken care of.
Well the first of the pair is finished. The external crossovers still need to be boxed.
First impression is that the mid range is not as bright as the DM683's.
I'll wait until both are finished and they're run in before I evaluate them.
Second impression is that are slightly less sensitive than the B&Ws which is a concern with a Class A amplifier.
First impression is that the mid range is not as bright as the DM683's.
I'll wait until both are finished and they're run in before I evaluate them.
Second impression is that are slightly less sensitive than the B&Ws which is a concern with a Class A amplifier.
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That's a bit worrying, these things should sing like crystal with that level of driver in them, would you mind sharing the schematic of the xo? or PM it to me if wilmslow have an issue with that... My experience of wilmslow xo design hasn't been great...
I'm at work at the moment but I'll post it later.
The aim was to go active with these eventually anyway.
The aim was to go active with these eventually anyway.
Yeah...not modelled it yet, but already spotting a lot of things that are making me raise my eyebrows. Try switching the polarity on BOTH the mid and tweeters and have another listen, wouldn't be surprised if that fixed the sound massively.. though looking at the kind of transfer functions you'd expect to see with those component values I'd never have gone for a schematic anything like that.... I'm guessing you're more interested in the final digital than the temporary passive xo's anyway?
I'm still having fun with the amps for tri-amping at the moment.
I've got the Pass Aleph 4 for the mids.
Poss. my Burmeister 933 Mk2 for the tweeter.
I did build a Quad 909 clone for the Bass but only one channel is working.
The crossover is a Linkwitz active crossover from Rod Elliot.
For the time being they will be on their passive crossovers.
I've got the Pass Aleph 4 for the mids.
Poss. my Burmeister 933 Mk2 for the tweeter.
I did build a Quad 909 clone for the Bass but only one channel is working.
The crossover is a Linkwitz active crossover from Rod Elliot.
For the time being they will be on their passive crossovers.
Volt dome is potentially a very low Qts driver and it may have something
to do with your first impression. Other than a few technical data about power,
sensitivity, frequency range, a weight of 9 kg ..., and a FR plot looking like
not being measured, I have no other objective data to use for making a sensible
suggestion.Without measuring we are in dark.
to do with your first impression. Other than a few technical data about power,
sensitivity, frequency range, a weight of 9 kg ..., and a FR plot looking like
not being measured, I have no other objective data to use for making a sensible
suggestion.Without measuring we are in dark.
I bought this as a kit as I have no means of measuring. I'm disappointed my B&Ws sound much better.
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