Hi everyone, i was just wondering if anyone could give me info on how to reduce the output of 2x bass units in a 3 way loudspeaker i have by 3dB. Currently they sound quite good but the bass is slightly too strong due to the fact the 2x 6.5" bass units that are in each cabinet are rated 90dB sensitivity while the midrange is 87dB. The tweeter is 90dB and seems to be operating ok, but it wouldnt be intrusive if it would become a little more apparent.
Thanks in advance!
Thanks in advance!
Hi,
Try wiring them in series with c/o mods, and knocking back the tweeter to the midrange.
rgds, sreten.
Your numbers are wrong. At 90dB each they would be 96dB in parallel albeit 4ohm presumably.
In series they will be 90dB 16 ohm presumably, which is fine, in reality around 3dB of BSC.
Try wiring them in series with c/o mods, and knocking back the tweeter to the midrange.
rgds, sreten.
Your numbers are wrong. At 90dB each they would be 96dB in parallel albeit 4ohm presumably.
In series they will be 90dB 16 ohm presumably, which is fine, in reality around 3dB of BSC.
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thanks for that, but i really should have provided more info. I meant to say that the rated sensitivity of the bass units is 90db and they are wired to the crossover in series, 4ohm each to make 16ohm at crossover. So im assuming that what you basically said is that in this config they end up producing around 87dB because of a -3dB BSC. In that case they do infact match up to the same as the midrange which is 87db. So are they ok wired as they are? It could be the small room im in that makes them sound a bit coloured tbh.
Yes, that's correct re: 4+4=8. If it's overpowering, try placement tweaking- pull them out further from the rear wall. If you still have too much bass you're in an enviable position- too much is better than too little, you can use line-level EQ to make a shelving filter, essentially a tuned capacitor and resistor in parallel, in series with the amp input. The capacitor sets the filter frequency, the resistor the level of the shelf.
The mid is a high midrange with crossover points set at 800htz - 5khz. It actually sounds very natural and reproduces voices and guitar notes spectaculaly well for its age. I know this because the speakers i have were old wharfedales - and the only thing ive kept original are the mids due to the other drivers/Xover needing serious repair work.
In other words, ive kept the cabinet the same, and used the same Mids, or im trying to anyway, the bass are scanspeaks 18w/4531G00's and the tweeter is D2905/950000 and the Xover has been upgraded with new better components to suit. Im thinking an alternative would be to try find some 3.5" mids with similar charactristics but at 90dB response to flatten out the overall freq response. Anyone got any view on this - or should i just do as badman said and use a line-level EQ?
Heres a crappy pic of one cabinet so you can see what it looks like and drivers/placement etc. - sorry for the quality.
In other words, ive kept the cabinet the same, and used the same Mids, or im trying to anyway, the bass are scanspeaks 18w/4531G00's and the tweeter is D2905/950000 and the Xover has been upgraded with new better components to suit. Im thinking an alternative would be to try find some 3.5" mids with similar charactristics but at 90dB response to flatten out the overall freq response. Anyone got any view on this - or should i just do as badman said and use a line-level EQ?
Heres a crappy pic of one cabinet so you can see what it looks like and drivers/placement etc. - sorry for the quality.
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Wow, looking at the bass drivers and tweeters you are using I would be sorely tempted to:
-1- Shell out for a midrange that is in the same league as the bass and tweeters,
-2- Invest the effort in a new cabinet (OK I am making a wild assumption here, but the odds of the alignment being ideal is pretty low).
-3- Spend the time to get the crossover optimised for the drivers. (This is unlikely to affect the bass end - but will make a massive difference to midrange and treble.)
Probably the most significant issue I see here is: If you have not tweaked the cabinet volume and tuning for the drivers, there is a very significant chance that the bass is indeed coloured. Have you modelled these drivers in your cabinet?
-1- Shell out for a midrange that is in the same league as the bass and tweeters,
-2- Invest the effort in a new cabinet (OK I am making a wild assumption here, but the odds of the alignment being ideal is pretty low).
-3- Spend the time to get the crossover optimised for the drivers. (This is unlikely to affect the bass end - but will make a massive difference to midrange and treble.)
Probably the most significant issue I see here is: If you have not tweaked the cabinet volume and tuning for the drivers, there is a very significant chance that the bass is indeed coloured. Have you modelled these drivers in your cabinet?
yes i modelled the drivers in this cabinet and it came out actually very well surprisingly. This is one reason why i bought them in the first place. Also the cabinets are 50litres on paper and according to my measurements they are 55 litres and the reccomended size on modelling came out at 53litres so its pretty much spont on size wise. The dimensions are optimal as well, the only thing is that the lower midrange possibly slightly resonates but i am not sure if that is due to my room which is quite small. Ive just played about with placement of the cabinets and i got a significant improvement already by pulling them away from the backwall. Also, ive been looking at every last piece of info on the midranges i still have and im not so sure if they actually are 87dB now. :S ive emailed an old tech guy that works for wharfedale to try get more info on them which i know will be correct. Failing that ill just have to find some new mids. Also i was thinking when i have more £££ and possibly a new midrange eyed up ill go and get the cabinets professionally tuned at wilmslowaudio because i just dont have any access to decent equipment.
OK all thanks for the advice, I have found success! I am still awaiting a reply to my email about the wharfedale midrange's from the tech man i emailed but i am starting to think their sensitivity might actually be 90dB after all.
All ive done to make them sound literally like different speakers all together is move them around a bit in the room and change some furnature about lol. I couldnt believe how much difference it made and now that additional bass has disappeared completely - while the detail in the music is much more defined. Also another major factor seemes to be the music im listening to ie. the source. I tried a test CD and to my ears it sounds very flat from 40-16khz; my ears dont do well beyond that. I also tested it with a cheap meter and within its capability they seem to produce a flat response also within 4db in my room.
A major factor also contributing to the added bass was modern CD recordings like pop music etc that my GF listens to. I tried playing some of my music which is mostly from 70s-90s like guns and roses, pink floyd, iron maiden original recordings and mark knopfler etc and it sounded much much better. They sound every bit as good as speakers ive heard at demos such as Pro Acs top end or the Naim Audio Allae's if not better. I'm only using a cambridge 640aV2 amp atm to power them so i think an upgrade there will be my next step. Overall though i am very happy with these speakers now and all problems solved, i really do love the midranges from these old wharfedales, they are the best mids they ever produced imo even if they do look a bit old fashioned now!
Thanks again everyone for suggestions and advice! Much appreciated as always! Thread closed!
All ive done to make them sound literally like different speakers all together is move them around a bit in the room and change some furnature about lol. I couldnt believe how much difference it made and now that additional bass has disappeared completely - while the detail in the music is much more defined. Also another major factor seemes to be the music im listening to ie. the source. I tried a test CD and to my ears it sounds very flat from 40-16khz; my ears dont do well beyond that. I also tested it with a cheap meter and within its capability they seem to produce a flat response also within 4db in my room.
A major factor also contributing to the added bass was modern CD recordings like pop music etc that my GF listens to. I tried playing some of my music which is mostly from 70s-90s like guns and roses, pink floyd, iron maiden original recordings and mark knopfler etc and it sounded much much better. They sound every bit as good as speakers ive heard at demos such as Pro Acs top end or the Naim Audio Allae's if not better. I'm only using a cambridge 640aV2 amp atm to power them so i think an upgrade there will be my next step. Overall though i am very happy with these speakers now and all problems solved, i really do love the midranges from these old wharfedales, they are the best mids they ever produced imo even if they do look a bit old fashioned now!
Thanks again everyone for suggestions and advice! Much appreciated as always! Thread closed!
Hi,
For an 87db midrange theoretically you need 93dB woofers for full 6dB BSC.
You are correct in that two 4ohm 90dB woofers will be 8ohm 90dB.
Basically what I'm saying is crossed over correctly, (none of the garbage
crossover calculator nonsense), the bass should / will not be too loud,
as the maximum BSC you will have given your numbers is 3dB.
FWIW you could used a tapped inductor/autotransformer on the midrange
unit to drop its effective impedance and up its sensitivity, do not mess
around with not driving the bass units directly, simply will not work well.
Given the standard of your bass/(mid) drivers I'm a little surprised,
they are overkill. This is the sort of thing do do with those drivers :
Zaph|Audio - ZRT - Revelator Tower
rgds, sreten.
Whilst I appreciate you have a fondness for that Wharfedale midrange unit,
I'd fully expect in the cold light of objective measurements a more modern
unit would absolutely cream it in terms of response / distortion / usability.
see : http://www.zaphaudio.com/smalltest/
http://sites.google.com/site/undefinition/diy (see FAQs)
http://www.zaphaudio.com
http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.rjbaudio.com/
http://speakerdesignworks.com/
http://www.htguide.com/forum/showthread.php4?t=28655
For an 87db midrange theoretically you need 93dB woofers for full 6dB BSC.
You are correct in that two 4ohm 90dB woofers will be 8ohm 90dB.
Basically what I'm saying is crossed over correctly, (none of the garbage
crossover calculator nonsense), the bass should / will not be too loud,
as the maximum BSC you will have given your numbers is 3dB.
FWIW you could used a tapped inductor/autotransformer on the midrange
unit to drop its effective impedance and up its sensitivity, do not mess
around with not driving the bass units directly, simply will not work well.
Given the standard of your bass/(mid) drivers I'm a little surprised,
they are overkill. This is the sort of thing do do with those drivers :
Zaph|Audio - ZRT - Revelator Tower
rgds, sreten.
Whilst I appreciate you have a fondness for that Wharfedale midrange unit,
I'd fully expect in the cold light of objective measurements a more modern
unit would absolutely cream it in terms of response / distortion / usability.
see : http://www.zaphaudio.com/smalltest/
http://sites.google.com/site/undefinition/diy (see FAQs)
http://www.zaphaudio.com
http://www.rjbaudio.com/Audiofiles/FRDtools.html
http://www.rjbaudio.com/
http://speakerdesignworks.com/
http://www.htguide.com/forum/showthread.php4?t=28655
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ok ive had a look at those links, they are jst the sort of thing i need to better understand this topic. usually whenever i ask a question about something i get a reply which only half makes sense - which just leads to more confusion and more questions! You've helped me a great deal anyway Sreten and i think ill look into finding a pre done project which uses my drivers so i can just copy the design. As my speakers are atm, im quite happy but if you think that i am wasting the potential of the scanspeak units i may as well start from scratch!
one last question though - in your opinion do you think the tweeters i have are usable as a 2 or 2.5 way with my revelator drivers?
thanks again,
Andrew.
one last question though - in your opinion do you think the tweeters i have are usable as a 2 or 2.5 way with my revelator drivers?
thanks again,
Andrew.
http://www.scan-speak.dk/datasheet/pdf/d2905-950000.pdf
Hi,
I don't see why they cannot be used but you won't find a good complete
design for that combination of drivers, you might be looking at MMT 2.5ways.
If you go that route you'll end up with very low impedance speakers,
and they that would need a very juicy amplifier to drive them.
The other "better" option is probably to go for an 8 ohm MTM or BBMT.
DIY Loudspeaker Projects Troels Gravesen
FWIW if you've simply upgraded the components in the Dovedale crossovers,
it may be worth it to seek out some cheaper drivers to use instead.
checkout : stores.ebay.co.uk/willyshifiloudspeakerspares
rgds, sreten.
http://www.rjbaudio.com/Audiofiles/FRDtools.html
Hi,
I don't see why they cannot be used but you won't find a good complete
design for that combination of drivers, you might be looking at MMT 2.5ways.
If you go that route you'll end up with very low impedance speakers,
and they that would need a very juicy amplifier to drive them.
The other "better" option is probably to go for an 8 ohm MTM or BBMT.
DIY Loudspeaker Projects Troels Gravesen
FWIW if you've simply upgraded the components in the Dovedale crossovers,
it may be worth it to seek out some cheaper drivers to use instead.
checkout : stores.ebay.co.uk/willyshifiloudspeakerspares
rgds, sreten.
http://www.rjbaudio.com/Audiofiles/FRDtools.html
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Hi again, i just thought id ask a quick question regarding crossover design. I was wondering if the
3-Way Crossover Designer / Calculator
website with the crossover calculator was any good - at least as a starting point? I also thought, seeing as though ive modeled the revelator drivers through 2 pieces of software, one of which was done for me by wilmslowaudio showing that the optimum cabinet volume was 50-55 litres - could i continue to use the original cabinets? I do like the size/shape of them and im not fond of the modern long tall boxes about nower days. I am aware however, that the tweeter position in the baffle isnt ideal as they are not mirror images but tbh i dont notice any difference in the stereo image that people claim to be able to hear differently because of this (only imo of course).
I've been looking for the last couple of hours at different projects using scanspeak drivers but none of them use the 4ohm version of my drivers, instead they use the 8ohm version and most of them are either only bookshelf speakers or single bass/mid towers.
If i go down the road of self designing - it will all have to be done by theory and the practical side done by ear as i have no decent testing equipment like ive said before. As i have no real past experience here i dont know if this seems like a good idea, or if id be taking on more than i could handle. In the end, i need to do something with these drivers i have and i know they will work with each other if i can produce some sort of reasonable crossover design. I could also look into buying some new scanspeak mids to fill the gap and carry on with the 3 way idea - but first i need to settle on some kind of theoretical design.
Thanks again sreten btw, ive looked at all the links youve sent me and had a good read on the undefinition link especially.
sorry that ended up not such a quick question by hey ho - thats the way it goes
3-Way Crossover Designer / Calculator
website with the crossover calculator was any good - at least as a starting point? I also thought, seeing as though ive modeled the revelator drivers through 2 pieces of software, one of which was done for me by wilmslowaudio showing that the optimum cabinet volume was 50-55 litres - could i continue to use the original cabinets? I do like the size/shape of them and im not fond of the modern long tall boxes about nower days. I am aware however, that the tweeter position in the baffle isnt ideal as they are not mirror images but tbh i dont notice any difference in the stereo image that people claim to be able to hear differently because of this (only imo of course).
I've been looking for the last couple of hours at different projects using scanspeak drivers but none of them use the 4ohm version of my drivers, instead they use the 8ohm version and most of them are either only bookshelf speakers or single bass/mid towers.
If i go down the road of self designing - it will all have to be done by theory and the practical side done by ear as i have no decent testing equipment like ive said before. As i have no real past experience here i dont know if this seems like a good idea, or if id be taking on more than i could handle. In the end, i need to do something with these drivers i have and i know they will work with each other if i can produce some sort of reasonable crossover design. I could also look into buying some new scanspeak mids to fill the gap and carry on with the 3 way idea - but first i need to settle on some kind of theoretical design.
Thanks again sreten btw, ive looked at all the links youve sent me and had a good read on the undefinition link especially.
sorry that ended up not such a quick question by hey ho - thats the way it goes
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ok im pretty much decided on what to do now, I understand ill need to either make or buy a quality mic b4 attempting this so i can adjust the Xover according to the results i get. Im going to reuse the same cabinets and just make sure the Xover can cancel out any underlying peaks or dips which may occure.
All im really asking here is if that website i quoted is any good, and if the 3way Xover design calculator can be used as a good starting point. Once i know this i may as well get on with it - no better way to learn than to give it a go!
All im really asking here is if that website i quoted is any good, and if the 3way Xover design calculator can be used as a good starting point. Once i know this i may as well get on with it - no better way to learn than to give it a go!
Hi,
That crossover "calculator" site is absolutely the worst place to start.
Start here and only here : FRD Consortium tools guide
Peruse the details on Zaphs site for his designs regarding c/o choices and points.
Following the above strictly speaking you don't need a microphone.
Using your ears and a test CD with the above as guidance to show you
(e.g. AUDIO TEST TONE CD FOR HOME, STUDIO OR IN-CAR USE on eBay (end time 19-Feb-11 14:31:56 GMT)
Actually not that good for aural testing, warble tones or pink noise bands would be better.)
what would be happening if you fiddle with the crossover can work well.
Get familiar with Unibox, WinISD and WinISDpro and work out yourself
how well your drivers are matched to the cabinet. Personally I like
taking the Butterworth vented alignment and detuning the port
70-80%, possibly making the cabinet a little bigger in the process.
Also checkout Humble Homemade Hifi for building techniques.
With those drivers + Scanspeak mid I'd be tempted to build a variation of :
http://www.humblehomemadehifi.com/Diary.html
Possibly wider and less deep, with the twin bass drivers front and back for force cancelling.
The baffle would be less tall and wider, allowing some smoothing offsets for the drivers.
Take your time and theoretically prototype with the tools available.
TinaTi circuit emulator is good for playing around with simple circuits, nice impedance meter.
Only commit to the actual building when you are sure that is what you want.
rgds, sreten.
That crossover "calculator" site is absolutely the worst place to start.
Start here and only here : FRD Consortium tools guide
Peruse the details on Zaphs site for his designs regarding c/o choices and points.
Following the above strictly speaking you don't need a microphone.
Using your ears and a test CD with the above as guidance to show you
(e.g. AUDIO TEST TONE CD FOR HOME, STUDIO OR IN-CAR USE on eBay (end time 19-Feb-11 14:31:56 GMT)
Actually not that good for aural testing, warble tones or pink noise bands would be better.)
what would be happening if you fiddle with the crossover can work well.
Get familiar with Unibox, WinISD and WinISDpro and work out yourself
how well your drivers are matched to the cabinet. Personally I like
taking the Butterworth vented alignment and detuning the port
70-80%, possibly making the cabinet a little bigger in the process.
Also checkout Humble Homemade Hifi for building techniques.
With those drivers + Scanspeak mid I'd be tempted to build a variation of :
http://www.humblehomemadehifi.com/Diary.html
Possibly wider and less deep, with the twin bass drivers front and back for force cancelling.
The baffle would be less tall and wider, allowing some smoothing offsets for the drivers.
Take your time and theoretically prototype with the tools available.
TinaTi circuit emulator is good for playing around with simple circuits, nice impedance meter.
Only commit to the actual building when you are sure that is what you want.
rgds, sreten.
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