Hi y'all ,
Long time since I've been here 'cos I'm not really into the DIY side of audio but the bug is slowly biting 😀 . With a little bit of help I'm trying to turn a passive sub woofer into an active one. The passive in question is a Wharfedale PPS-1 and the driver is a Wharfedale Model 1780 - probably the date it was made 😀 .
The active amp bit is being taken care of by a friend but I was wondering if the speaker itself (Model 1780) could be bettered for not much money? The circular hole in the case in which it is housed is 15.5 cms diameter and, if required, my wood butchery skills might extend to opening it up to 18.5 cms max. (case limit).
So, anybody got any thoughts on the subject, or even got a better driver than the Model 1780 surplus to requirements or can suggest a better one that ain't going to cost me the proverbial arm and leg? 😀 . Or ain't it quite as simple as that 😕 .
Any response appreciated - TIA,
Dave.
Long time since I've been here 'cos I'm not really into the DIY side of audio but the bug is slowly biting 😀 . With a little bit of help I'm trying to turn a passive sub woofer into an active one. The passive in question is a Wharfedale PPS-1 and the driver is a Wharfedale Model 1780 - probably the date it was made 😀 .
The active amp bit is being taken care of by a friend but I was wondering if the speaker itself (Model 1780) could be bettered for not much money? The circular hole in the case in which it is housed is 15.5 cms diameter and, if required, my wood butchery skills might extend to opening it up to 18.5 cms max. (case limit).
So, anybody got any thoughts on the subject, or even got a better driver than the Model 1780 surplus to requirements or can suggest a better one that ain't going to cost me the proverbial arm and leg? 😀 . Or ain't it quite as simple as that 😕 .
Any response appreciated - TIA,
Dave.
Hi,
PE seems to always have sales on small powered subwoofers, this one is $79.00 for amp, driver and box:
Dayton Audio SUB-80 8" 80 Watt Powered Subwoofer 300-631
Regards,
PE seems to always have sales on small powered subwoofers, this one is $79.00 for amp, driver and box:
Dayton Audio SUB-80 8" 80 Watt Powered Subwoofer 300-631
Regards,
Hi Oliver,
Thanks for the pointer - very good prices and reviews - but I suspect shipping costs might be a problem as I'm located in UK .
Thanks again,
Dave.
Thanks for the pointer - very good prices and reviews - but I suspect shipping costs might be a problem as I'm located in UK .
Thanks again,
Dave.
The driver and the box make a system. If you know the T/S specs of the driver and the internal volume of the box along with the port opening size and length we could tell you if the box/driver system is optimized.
Hi Reverend Boden 😉 ,
Thanks for your very kind offer of help - much appreciated .
Sorry but I'm a newbie to these matters. I can readily give you the internal dimensions of the case but I haven't a clue what T/S spec refers to .
I assume the port is the hole with a plastic tube in it? - If so I can also readily give you those measurements - please confirm in idiot proof layman's language what is the information you require and I'll do my best.
Can I take this opportunity to ask about dampening/deadening material for the inside of the case please? The case as received from the manufacturer contained a folded sheet of 'kapok' type material at one end only, that looked as if it had been tossed in as an afterthought or to pay lip service to the concept.
TIA,
Dave.
Thanks for your very kind offer of help - much appreciated .
Sorry but I'm a newbie to these matters. I can readily give you the internal dimensions of the case but I haven't a clue what T/S spec refers to .
I assume the port is the hole with a plastic tube in it? - If so I can also readily give you those measurements - please confirm in idiot proof layman's language what is the information you require and I'll do my best.
Can I take this opportunity to ask about dampening/deadening material for the inside of the case please? The case as received from the manufacturer contained a folded sheet of 'kapok' type material at one end only, that looked as if it had been tossed in as an afterthought or to pay lip service to the concept.
TIA,
Dave.
"T/S spec" refers to Thiele Small Specifications. You can mesure them with minimal electronics. Measuring Loudspeaker Driver Parameters
These parameters are necessary to simulate a driver and box combination.
The port is the plastic tube.
The damping material is not necessary in a ported box unless the crossover point is very high for a subwoofer (above 120Hz).
These parameters are necessary to simulate a driver and box combination.
The port is the plastic tube.
The damping material is not necessary in a ported box unless the crossover point is very high for a subwoofer (above 120Hz).
Hi Rev,
Thanks for the link. I was looking forward to learning something by carrying out the checks and calculations unti I saw the actual article and the equipment needed . I think I'm going to 'pass' on that exercise and hope that the commercial guys who designed the sub W did it all right when they started .
To some extent this is by way of an experiment to see if adding a SW to my HiFi system brings anything to the party. If I feel it does, or might if implemented properly, I'll go for a 'proper' one. One thing I have going for me is that the guy building the 'active' bit (amp) and tweaking the existing crossovers does know his stuff and he has as much technical info on the passive SW that forms the base of the project as the manufacturer has published.
Thanks for your interest .
Dave.
Thanks for the link. I was looking forward to learning something by carrying out the checks and calculations unti I saw the actual article and the equipment needed . I think I'm going to 'pass' on that exercise and hope that the commercial guys who designed the sub W did it all right when they started .
To some extent this is by way of an experiment to see if adding a SW to my HiFi system brings anything to the party. If I feel it does, or might if implemented properly, I'll go for a 'proper' one. One thing I have going for me is that the guy building the 'active' bit (amp) and tweaking the existing crossovers does know his stuff and he has as much technical info on the passive SW that forms the base of the project as the manufacturer has published.
Thanks for your interest .
Dave.
Dave, where are you based? I can measure the TS spec of the driver, I live in Brum if you're near by. You could always post me the driver if further afield.
You can work out the rough tuning freq of the enclosure from the port length and diameter-your friend dealing with the amp will need to know this to prevent the driver over excurting below tuning freq. Post box internal dimesions and port dimensions (internal diameter and length) and I'll give you a ball park "subsonic" HPF frequency to go with.
PE will ship to the UK, I've used them for some bits and bobs, prices aren't too bad-provided the tax man doesn't add his bounty to them on entry!
You can work out the rough tuning freq of the enclosure from the port length and diameter-your friend dealing with the amp will need to know this to prevent the driver over excurting below tuning freq. Post box internal dimesions and port dimensions (internal diameter and length) and I'll give you a ball park "subsonic" HPF frequency to go with.
PE will ship to the UK, I've used them for some bits and bobs, prices aren't too bad-provided the tax man doesn't add his bounty to them on entry!
Try playing around with a program like WinISD to get a understanding of the various parameters involved and what they do. It's free and there are loads of pre programmed drivers available so you don't have to put in the T/S parameters.
LinearTeam
LinearTeam
Baron,
Thanks (M'lud 😉 ) for your generous offer. I'm based in Sheffield and visit Wolverhampton fairly regularly to visit my daughter, so maybe something could be arranged. But at the moment I think I'll go along with the current trial as work on the amp and crossover are well under way. Based on what I think I hear I may come back to you on this if I may?
The way forward may be to work backwards, starting with the amp and crossover, deciding whether the speaker itself will ever give me what I want and proceed or replace accordingly, and then put together a case and horn to suit.
The port diameter is 5 cms and length is 13 cms and the internal dims of the case are 42.5 x 20.5 x 17 cms - the case material is 1.5 cms chip board.
Importing the finished item from across the pond is a bit of a gamble, duty wise, and knowing my luck .....
Mark, thanks for your pointer - I'll take a look at WinISD and see if I can learn anything.
Thanks again both 🙂 ,
Dave.
Thanks (M'lud 😉 ) for your generous offer. I'm based in Sheffield and visit Wolverhampton fairly regularly to visit my daughter, so maybe something could be arranged. But at the moment I think I'll go along with the current trial as work on the amp and crossover are well under way. Based on what I think I hear I may come back to you on this if I may?
The way forward may be to work backwards, starting with the amp and crossover, deciding whether the speaker itself will ever give me what I want and proceed or replace accordingly, and then put together a case and horn to suit.
The port diameter is 5 cms and length is 13 cms and the internal dims of the case are 42.5 x 20.5 x 17 cms - the case material is 1.5 cms chip board.
Importing the finished item from across the pond is a bit of a gamble, duty wise, and knowing my luck .....
Mark, thanks for your pointer - I'll take a look at WinISD and see if I can learn anything.
Thanks again both 🙂 ,
Dave.
lol, let me know if you're down and I'll happily pull the specs off it.
According to BBpro your current enclosure is tuned to around 50Hz, so your friend with the amp needs to set the subsonic around there too.
You can download WinISD from the LinearTeam link in Mark.Clappers' post above-I just did and will play with that too now-looks to be a useful tool-I've only used Eminence Designer (lesser version of BBpro) BBpro and hornresponse-so good to have another resource🙂
According to BBpro your current enclosure is tuned to around 50Hz, so your friend with the amp needs to set the subsonic around there too.
You can download WinISD from the LinearTeam link in Mark.Clappers' post above-I just did and will play with that too now-looks to be a useful tool-I've only used Eminence Designer (lesser version of BBpro) BBpro and hornresponse-so good to have another resource🙂
You're very welcome 🙂
If you start using winISD remember that it simulates everything for half space, ie no baffle step!
Also if you go active take a look at making the enclosure "sealed" and using a linkwitz transform. This would allow you to extent the frequency range below the driver Fs at the expense of amplifier power and cone excursion.
If you start using winISD remember that it simulates everything for half space, ie no baffle step!
Also if you go active take a look at making the enclosure "sealed" and using a linkwitz transform. This would allow you to extent the frequency range below the driver Fs at the expense of amplifier power and cone excursion.
What does this actually mean? Been in car audio for years-but the home stuff I'm just getting into!
There is a relation between the width of the enclosure and the frequency at which it starts radiating from half space to "full space". Think of it like this, for low frequencies the speaker emits sounds waves in every direction at the same strength. when the frequency goes up it starts emitting the sound wave only to the front not to the back. The difference in strenght is in theory 6dB but in practise in a room usually somewhere between 4 and 6dB.
Baffle Step Compensation
Baffle Step Compensation
Half space is exactly what it sounds like - infinite baffle.
Full space is effectively cabinet on a really long stick.
Quarter space is on the boundry between floor and wall.
Eigth is in the corner of a room.
Corner loading gives the most boost, with the least being in full space.
As you're relatively new to this stuff, here's some reading for you.
DIY Audio Articles
For speakers and other parts, my usual supplier is
http://cpc.farnell.com/
Cross reference with
MCM Electronics: Home and Pro Audio/Video, Security and Test Equipment
for details on some of the speakers on sale at CPC.
Have fun,
Chris
Ha, I actually "knew" this in a round about way-car audio is problematic due to the many reflective boundaries-my tweeters are mounted in spheres in my install for this very reason!
Cheers Chris, will have a read up, the quick explanation does a good job in getting me started🙂
Thanks for the tips on UK stockists, got any more? Bits I haven't found in the UK I've found Parts Express and Madisound to be very good in the US, Madisound actually refunded me shipping I'd agreed on and paid for after they found a cheaper route for my Variovents🙂
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Not a problem. The site linked is where I've learnt much of what I know.
Some other suppliers...
Europe Audio - Home page - shipping (and prices) can be expensive, but there's a wide range of stuff there. Check out the crossovers (coils and caps) section - massive range there.
BluePlanetAcoustic seems to be down at the moment, but they stock lots of Tang Band stuff, including the new Ferrite range. No personal experience with them, but I'm told they're good.
Blue Aran - Professional Sound and Lighting - stocks the 24" PD woofer 😀 . Again, no personal experience, but they're UK based etc, with a decent range of stuff. Prices seem reasonable.
For woodworking, try here
Peter Benson Plywood Ltd
Decent prices, and they have a big CNC machine (extra cost, but if its a complicated shape, worth paying)
Chris
Mornin' Baron,
Yep, job done!! 🙂 . I extracted the crossovers from the passive sub and sent them on to my builder friend. He swapped a couple of items on each and then added a self built little amp with a volume control and a PSU (+ some of his fairy dust 😉 ) and I put them all back in the case. I use my HA10 headphone amp (HA10 Headphone Amplifier - Custom HiFi Cables Ltd.) as the source (never going to need a sub woofer and the headphones at the same time) and I must say I'm happy with the result. Perhaps not as taut as it might be but just needed to get the right amount of bass with the volume control and everything is OK to my ears. Will probably never qualify for 'hi-fi' but my old ears are probably not capable of appreciating it if it did 😀 .
Next little job for my builder is to add these (eBay - The UK's Online Marketplace) to my Mission 774 speakers and I reckon I shall be set up 🙂 . Another forum friend is putting together some old Noble L-Pads and chokes (?) for me.
The super tweeters have arrived and, judging by the weight, finish quality and professional packing/protection that came with them I'm tempted to believe that they are actually genuine, but time will tell 🙂 .
Having spent much of my working life in the steel foundry industry and reached my present age my hearing is officially suffering from age related damage at both ends of the spectrum so maybe these addittions will go some way to compensating??
Thanks for your interest.
Dave.
Yep, job done!! 🙂 . I extracted the crossovers from the passive sub and sent them on to my builder friend. He swapped a couple of items on each and then added a self built little amp with a volume control and a PSU (+ some of his fairy dust 😉 ) and I put them all back in the case. I use my HA10 headphone amp (HA10 Headphone Amplifier - Custom HiFi Cables Ltd.) as the source (never going to need a sub woofer and the headphones at the same time) and I must say I'm happy with the result. Perhaps not as taut as it might be but just needed to get the right amount of bass with the volume control and everything is OK to my ears. Will probably never qualify for 'hi-fi' but my old ears are probably not capable of appreciating it if it did 😀 .
Next little job for my builder is to add these (eBay - The UK's Online Marketplace) to my Mission 774 speakers and I reckon I shall be set up 🙂 . Another forum friend is putting together some old Noble L-Pads and chokes (?) for me.
The super tweeters have arrived and, judging by the weight, finish quality and professional packing/protection that came with them I'm tempted to believe that they are actually genuine, but time will tell 🙂 .
Having spent much of my working life in the steel foundry industry and reached my present age my hearing is officially suffering from age related damage at both ends of the spectrum so maybe these addittions will go some way to compensating??
Thanks for your interest.
Dave.
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