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Old 24th February 2016, 08:26 PM   #11
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Location: Manchester
Quote:
Originally Posted by jReave View Post
Now in order to select a woofer, it's best if you start by defining your needs. Such as:

- minimum sensitivity (how much power do you have available?)
- minimum impedance (what will your amp be happy with?)
- box volume (defined by your present cabs)
- F3 (music, movies or both?)
- and maybe max SPL levels desired too

Then you have to use a box modeling program to see how different drivers will fit those criteria. Just looking at the manufacturer's FR graphs doesn't tell you enough. Nor does just looking at a driver's resonance frequency, Fs. You have to plug in a driver's relevant specs into a modeling program to see how it will perform in the bottom end.

In terms of F3, the minus 3dB point, if the speakers are just for music, around 40Hz is usually good enough (bottom E string on bass guitar). Trying to get below that with a 6.5" driver does in fact get a little hard.

Figure those things out and then we can start to choose some drivers for you.
Ok, so I've done some homework now and will try and answer to the best of my current ability


Current amp:
Rated Output Power (1kHz, 1ch driven) 150W (4ohms, 0.9% THD); 125W (8ohms, 0.9% THD)
Rated Output Power (20Hz-20kHz, 2ch driven) 90W (8ohms, 0.09% THD)

Planned amp
Rated Output Power (1kHz, 1ch driven) 170 W (4ohms, 0.9% THD)
Rated Output Power (20Hz-20kHz, 2ch driven) 110 W (8ohms, 0.06% THD)

Box volume: 32 Litres

F3: Music and movies

I was thinking that 2 x woofers @ 4 Ohm in series might be a good starting point. I have enough box volume for this. The Silver Flute W17RC38-04 6.5" Woofer has good precision based on the graphs. However the graphs don't show any off axis, so not sure if I should be concerned about that?

WinISD says:
Volume of 11.5L
Tuning Freq: 63.79

What do you think?
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Old 24th February 2016, 11:14 PM   #12
jReave is offline jReave  Canada
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There's a nice +6dB in sensitivity advantage when you use 2 drivers in parallel vs in series and it looks like your planned amp can handle the 4ohm load. I think.

I would say your F3 isn't clearly defined yet. Will you be using a sub for movies? For music?

Again if without a sub for music, try to get an F3 closer to 40Hz. These Peerless HDS 6.5" would be a step up from the Silverflutes and 2 of them work vented in about 30L net with an F3 of about 42Hz. But I don't know if those are over your budget. With a 3-way, you've got to watch out for the expense of the xo too.

If you go with a sub, you can look for a sealed F3 as high as about 80Hz. Looks like the Silverflutes would work fine in this case.
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Old 25th February 2016, 09:09 AM   #13
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Hi spark,

Cool project albeit challenging

Just a reality check before you commit to the PR170M0; I looked up your speakers online and according to the specs the cabinet is only 165mm/6.5" wide (with a 130mm/4" midwoofer) whereas the Audax is 190mm. Better double-check
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Old 25th February 2016, 05:02 PM   #14
jReave is offline jReave  Canada
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Also is 32 L your total net internal volume or just for the woofers? Or in other words, what are the net volumes for the woofer and for the mid chambers? So you must exclude the volume taken up by the new mid enclosure you have to add and the volume of any bracing, new port, xo's etc.

Setting a budget for the drivers and xo will help focus recommendations as well as knowing how loud you want them to play - if you don't know exact SPL levels, think in terms of loud, very loud, or like THX reference levels?
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Old 25th February 2016, 06:07 PM   #15
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Location: Manchester
Quote:
Originally Posted by jReave View Post
I would say your F3 isn't clearly defined yet. Will you be using a sub for movies? For music?

Again if without a sub for music, try to get an F3 closer to 40Hz. These Peerless HDS 6.5" would be a step up from the Silverflutes and 2 of them work vented in about 30L net with an F3 of about 42Hz. But I don't know if those are over your budget. With a 3-way, you've got to watch out for the expense of the xo too.

If you go with a sub, you can look for a sealed F3 as high as about 80Hz. Looks like the Silverflutes would work fine in this case.
F3, id like to avoid a sub on this project. I'm a little short on floor space and don't fancy the estectics of a sub. So based on what you've said the Peerless look like a great option


Quote:
Originally Posted by InOtIn View Post
Hi spark,
Cool project albeit challenging
Just a reality check before you commit to the PR170M0; I looked up your speakers online and according to the specs the cabinet is only 165mm/6.5" wide (with a 130mm/4" midwoofer) whereas the Audax is 190mm. Better double-check
Good spot and thanks. I've looked at so many drivers and specs I hadn't noticed the diameter. Not sure where you got the specs from, the front panel of my cab is exactly 180mm.

Quote:
Originally Posted by jReave View Post
Also is 32 L your total net internal volume or just for the woofers? Or in other words, what are the net volumes for the woofer and for the mid chambers? So you must exclude the volume taken up by the new mid enclosure you have to add and the volume of any bracing, new port, xo's etc.

Setting a budget for the drivers and xo will help focus recommendations as well as knowing how loud you want them to play - if you don't know exact SPL levels, think in terms of loud, very loud, or like THX reference levels?
Yes 32L is the total volume, so after dampening and some internal bracing, i'd guess that's probably 28-30L.

Quote:
Originally Posted by jReave View Post
There's a nice +6dB in sensitivity advantage when you use 2 drivers in parallel vs in series and it looks like your planned amp can handle the 4ohm load. I think.
With the box volume limit above, do you think its too ambitious to have 2 woofers and a mid? Budget wise if it comes in under 500 all in i'd be happy Volume levels, definitely not reference levels. I'd say loud was top end for me.

Last edited by spark010; 25th February 2016 at 06:11 PM.
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Old 25th February 2016, 07:35 PM   #16
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Quote:
Originally Posted by spark010 View Post
Good spot and thanks. I've looked at so many drivers and specs I hadn't noticed the diameter. Not sure where you got the specs from, the front panel of my cab is exactly 180mm.
Everywhere: Google Search

If the official specs are off and you have measured the baffle to really be 180mm wide, you nevertheless have a problem with the PR170M0 being 190mm.

If you're not hell bent on a 3-way, that shape cabinet could lend itself to a 2-way MLTL or similar quarter-wave pipe.

If you want a 3-way and no subwoofer, you would perhaps fit a shallow 10-12" woofer made for small enclosures (e.g. car audio: JL Audio, Earthquake etc) on the side of the cabinet (340mm) and crossover at 80-100Hz to a 5-6.5" mid woofer on your front; at your budget, stick to Dayton or SB Acoustics. The latter has some nice tweeters that can be crossed relatively low for being domes.

I'm about to build a 3-way with a PR170M0. I think 2kHz is a good LP xo point for the PR170M0 but not the end of the world if taken to 2.5kHz. I was going to try it with a CDX-1 1745 on STH100. If you don't like horn, a high-sensitivity AMT could be a nice match, perhaps Dayton AMT3-4 or similar, at least if you can accept a bit of beaming. Similar, about 350Hz seems like a reasonable HP xo point. In that passband, consider this a 93-94dB driver.

If you've been hanging out here for years, you're way ahead already , but if you still feel like a "newbie', I would recommend you go with an active filter solution, at least for the W-T handover but preferably fully 3-way, like miniDSP, JRiver, Acourate, Audiolense or similar. Much much easier.

Why not sell those MS speakers and design something from scratch? If you're in the UK, these guys could build your enclosures for a very reasonable price:

speaker-cabinets.co.uk - Home

; especially if you go for their DIY flatpack option where you have to assemble yourself.
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Old 25th February 2016, 08:11 PM   #17
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Join Date: Feb 2016
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Quote:
Originally Posted by InOtIn View Post
Everywhere: Google Search

If the official specs are off and you have measured the baffle to really be 180mm wide, you nevertheless have a problem with the PR170M0 being 190mm.
I agree the PR170M0 is too large. Sorry I didn't acknowledge that in my last reply.

Quote:
Originally Posted by InOtIn View Post
If you're not hell bent on a 3-way, that shape cabinet could lend itself to a 2-way MLTL or similar quarter-wave pipe.
A 3-way is where i'd like to go with this project. I like the 3-way concept and want to see how it pans out.

Quote:
Originally Posted by InOtIn View Post
If you want a 3-way and no subwoofer, you would perhaps fit a shallow 10-12" woofer made for small enclosures (e.g. car audio: JL Audio, Earthquake etc) on the side of the cabinet (340mm) and crossover at 80-100Hz to a 5-6.5" mid woofer on your front; at your budget, stick to Dayton or SB Acoustics. The latter has some nice tweeters that can be crossed relatively low for being domes.
I've thought about a side firing sub (and its a good suggestion) but the area where my speaker sits isn't conducive to side firing subs and again i'd like to see where a more traditional 3-way design will work out

Quote:
Originally Posted by InOtIn View Post
I'm about to build a 3-way with a PR170M0. I think 2kHz is a good LP xo point for the PR170M0 but not the end of the world if taken to 2.5kHz. I was going to try it with a CDX-1 1745 on STH100. If you don't like horn, a high-sensitivity AMT could be a nice match, perhaps Dayton AMT3-4 or similar, at least if you can accept a bit of beaming. Similar, about 350Hz seems like a reasonable HP xo point. In that passband, consider this a 93-94dB driver.
Do you have a thread on the forum? I'd be interesting in reading you progress. I've used Dayton before and they seem to be great cost vs performance wise

Quote:
Originally Posted by InOtIn View Post
If you've been hanging out here for years, you're way ahead already , but if you still feel like a "newbie', I would recommend you go with an active filter solution, at least for the W-T handover but preferably fully 3-way, like miniDSP, JRiver, Acourate, Audiolense or similar. Much much easier.

Why not sell those MS speakers and design something from scratch? If you're in the UK, these guys could build your enclosures for a very reasonable price:

speaker-cabinets.co.uk - Home

; especially if you go for their DIY flatpack option where you have to assemble yourself.
I'd really like to re-used my existing cabs for a number of reasons. One of the most appealing parts of this project is improving upon the existing platform. Buying new cabs would take that away from me. I've already (4 years ago) upgraded the existing drivers to Dayton DS175-8 6-1/2", DC28FT-8 1-1/8" and a XO2W-3K. That was a great improvement over the stock Mordaunt Short drivers but still way off what i'd consider hi-fi That upgrade was done with research on my own and seeing where i'd get to without any external help. This time i'd like to learn more about the reasons why speaker are put together in a certain way and try and maximise the potential of my existing floor standers. This time around i'm learning those things (thanks to everyone who has helped) and i'm excited about where the project will go. I'd still class myself a newbie at the end of this project though One last reason why i'd like to keep my existing cabs is the aesthetics and size. They fit perfectly and the nice light cherry finish works very well in my home. Its important that the speakers look like a piece of furniture rather than something a little utilitarian

Last edited by spark010; 25th February 2016 at 08:17 PM.
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Old 25th February 2016, 08:59 PM   #18
jReave is offline jReave  Canada
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Quote:
Originally Posted by spark010 View Post
With the box volume limit above, do you think its too ambitious to have 2 woofers and a mid? Budget wise if it comes in under 500 all in i'd be happy Volume levels, definitely not reference levels. I'd say loud was top end for me.
Interesting dilemma.

Since you don't want to use a sub and you don't need anything too loud, I think 1 woofer may suffice. You could possibly add a hollow base to each speaker, removing the existing speaker bottoms and thereby increase the existing internal volume, and probably without affecting the aesthetics too much, but I estimate that would only gain you another 2 - 3L for 2 woofers. For a small mid, you can also use something like a 4" or 5" diameter plastic plumbing tube or concrete form tube for the enclosure which will take up the least internal volume as possible.

But with 1 of the Peerless woofers in about 21L tuned to 33Hz, you get an F3 of about 42Hz and an F6 of about 30Hz. Don't forget that the room will boost these lower frequencies as well (see Bagby's diffraction simulator for that as well). And it'll hit 100dB @ 1m with content above 30Hz without exceeding xmax. I think that will be good and loud for your purposes and getting that extra content down to 30Hz will make a difference for movies without a sub (that's what the larger internal volume will get you). It may also allow you to add extra bracing, maybe even double up some sidewalls, etc, etc.

With a 500 budget, I'd shoot for something like 300 - 350 for your drivers and the rest for the xo's and any miscellaneous.

Since you know how to do the box modeling now, have a look at how some of the other woofers in your budget from SB, ScanSpeak and Vifa NE look for Vb, F3 and max SPL.

Moving on to the mids, I would be looking at these (to go with a single woofer):
Peerless 830992 HDS 104 GFC MidWoofer Speaker
Audax HM100Z0 Aerogel 10cm 4" woofer
Scanspeak 10F/8424G00 Mid Range - Discovery Range

Each of the above are intended to cross high to a ribbon tweeter. Your tweeter selection from your 1st post may be just fine but I don't know anything about it. These I have seen used with high praise in other designs but there are still many more to choose from:
Fountek NeoCD1.0 Ribbon Tweeter
Fountek NeoCD3.0 Ribbon Tweeter Silver

See which of those drivers suit your tastes and then try adding different combinations together to see how they will meet your budget. I can pretty much guarantee that any of the above combinations are going to sound better than what you have now.

Cheers
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Old 27th February 2016, 07:50 AM   #19
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Location: Manchester
Quote:
Originally Posted by jReave View Post
Interesting dilemma.

Since you don't want to use a sub and you don't need anything too loud, I think 1 woofer may suffice. You could possibly add a hollow base to each speaker, removing the existing speaker bottoms and thereby increase the existing internal volume, and probably without affecting the aesthetics too much, but I estimate that would only gain you another 2 - 3L for 2 woofers. For a small mid, you can also use something like a 4" or 5" diameter plastic plumbing tube or concrete form tube for the enclosure which will take up the least internal volume as possible.

But with 1 of the Peerless woofers in about 21L tuned to 33Hz, you get an F3 of about 42Hz and an F6 of about 30Hz. Don't forget that the room will boost these lower frequencies as well (see Bagby's diffraction simulator for that as well). And it'll hit 100dB @ 1m with content above 30Hz without exceeding xmax. I think that will be good and loud for your purposes and getting that extra content down to 30Hz will make a difference for movies without a sub (that's what the larger internal volume will get you). It may also allow you to add extra bracing, maybe even double up some sidewalls, etc, etc.

With a 500 budget, I'd shoot for something like 300 - 350 for your drivers and the rest for the xo's and any miscellaneous.

Since you know how to do the box modeling now, have a look at how some of the other woofers in your budget from SB, ScanSpeak and Vifa NE look for Vb, F3 and max SPL.

Moving on to the mids, I would be looking at these (to go with a single woofer):
Peerless 830992 HDS 104 GFC MidWoofer Speaker
Audax HM100Z0 Aerogel 10cm 4" woofer
Scanspeak 10F/8424G00 Mid Range - Discovery Range

Each of the above are intended to cross high to a ribbon tweeter. Your tweeter selection from your 1st post may be just fine but I don't know anything about it. These I have seen used with high praise in other designs but there are still many more to choose from:
Fountek NeoCD1.0 Ribbon Tweeter
Fountek NeoCD3.0 Ribbon Tweeter Silver

See which of those drivers suit your tastes and then try adding different combinations together to see how they will meet your budget. I can pretty much guarantee that any of the above combinations are going to sound better than what you have now.

Cheers
Just been playing with ideas woofer ideas (I still like the Peerless 835025 HDS-164 recommendation) but wondered if I could squeeze a little more out of this woofer wise.. Not that i'm being obsessive If I drop to 4 Ohm the Peerless NE180W-04 has better sensitivity and seems a little better on the low end. It would just (only just) fit in the cab If that's looks like a good idea? The complication is finding a 4 Ohm mid range.. That seems a little trickery for some reason?

Tweeter wise. I've spent a couple of days looks at ribbon options and reading reviews. Zaph has mixed views on them and the Dayton didn't come out well on a tests, unless its in an array I'm thinking that going down the soft dom router might be safer and easier option

What do you think?

Edit: Thoughts on this as a possible midrange? Scan-Speak Discovery 15M/4624G
Edit 2: The NE180W-04 paired up is 15L, so I could put them in series and get 8ohms back. Not sure if going series might be a bad idea?

Last edited by spark010; 27th February 2016 at 08:15 AM.
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Old 27th February 2016, 06:05 PM   #20
jReave is offline jReave  Canada
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I would double check your sim for the Vifa NE180-4 because I don't get a lower F3 than with the Peerless. The NE180-8 however is comparable. My thoughts though are that if you are willing to pay for 2 of the NE's, you might as well take another step up in quality, albeit a small one, and go for just 1 of the ScanSpeak 18W Revelators or the Satori 16P-8.

Quality wise I would start at the Peerless, then the Vifa and then go up a little to the Satori and the Scan (just flip a coin I think between these 2). For bass and cabinet sizes, I've attached a comparison chart using Unibox. SPL levels are the limits @ 1m without exceeding xmax for content above 30Hz. The diagram looks a little blurry so,

Blue = Peerless 21L
Violet = Vifa Ne180-4 10L
Black = Vifa NE180-8 25L
Green = Scan 18W8531G 25L
Red = Satori 16P-8 25L

Just so you know, you don't have to match the impedance of drivers (4ohm with 8ohm is fine as long as SPL levels are compatible when you include baffle step loss and +6dB gain with 2 parallel drivers if applicable) and both parallel and series connections are valid.

Re ribbons: some people really like them. Some people not so much. If you use them, you have to implement them correctly which most importantly means crossing them high enough which means choosing a smaller mid. I plan to try one soon although I haven't yet at this point. My personal thoughts are that although the harmonic distortion may be a little higher at the lower frequencies, ribbons have extremely low diaphragm resonances which makes them sound 'fast' and clean. Really important at the higher frequencies I think.

Go with a dome if you feel so inclined but here are a couple of successful designs that use the Founteks:
https://sites.google.com/site/undefinition/speedster
Speaker Design Works
There are also some newish planars that are getting good reviews, the Airborne RT-5002 as just 1 example which maybe could work out for you given how crappy our Canadian dollar is right now, but there are others as well.

The Discovery 15W has a very good reputation, but with a ribbon one of the 10F or the 12W would be a better choice. I should have mentioned the Vifa NE123 before as well.
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