New 3-way coming up.

[TacoD]

So what do you predict will be the winning combination Jim, 3-way with Aura or Scan Speak?

:B

Aura, the 25W Scanspeak you have is not on par with the newer 26W and Aura.

[Jed]

Jed, I believe you purchase both woofers? So, we should expect your evaluations on both?

Yes, I'll post objective and subjective evaluations.

[Jed]

Aura, the 25W Scanspeak you have is not on par with the newer 26W and Aura.

TacoD,

Could you summarize the distortion of the Aura NS10 513 at 85 or 90DB?

Regards,

Jed

[mazurek]

Here's an example of the test waves I'm talking about, distortion is fairly audible using this test wave. The picture is analysis on four of the test waves (ideal input, not output).

Image not available

I made a series of these test waves in separate files and uploaded them to my site. You don't have to use them, but I thought this might give you some level of audible distortion testing for the drivers you have that I am interested in.

Archive not available

It should sound like a clean pop, like popping the top off of a jar.

[Jed]

Thanks Maz-

I'm pretty sure I can create test tones in speakerworkshop too. I'll snag your files for practice.

Jed

[JonMarsh]

Aura NS10-513 came in today. Very impressive looking woofers and the magnet is larger than I expected.

Images not available

I think you're going to really like these drivers- the NS12-513A is pretty super, too.

Will be very interested to see your progress.

~Jon

[Jed]

Will be very interested to see your progress.

~Jon

Should have a system ready for measurement this weekend. I'm glad I made my baffles removeable on my last speaker design. I'm still waiting for the 25W so it looks like the Aura will be the first 10" I try.

[Jed]

C79 free air impedance

Image not available

Aurasound NS10 513 free air impedance

Image not available

Usher 8955a 60L closed box impedance

Image not available

Usher 8948a free air impedance

Image not available

Visaton MHT12 impedance

Image not available

[Dennis H]

Wow, no impedance hump at Fs for the C79?

[Jed]

Wow, no impedance hump at Fs for the C79?

Nope... I thought it was odd too, but I took several measurements that would indicate my results are accurate. We'll see what the impedance looks like in a sealed box this weekend.

[Dennis H]

Well that sure shows there's something 'special' about the Accutons aside from the obvious cone stuff.

[Jed]

Usher 8955a Nearfield Response In Box

Image not available


Visaton MHT12 1/2M On Axis In Box

Image not available

[TacoD]

Nope... I thought it was odd too, but I took several measurements that would indicate my results are accurate. We'll see what the impedance looks like in a sealed box this weekend.

IMHO this can only be accomplished if the motor is full of ferrofluid (according to the manufacturer it is). I had the same with a smaller accuton (c2-12).

[Jed]

update- drivers in box

Breaking in the drivers as I type. These drivers are in another league of the own. More to come.

Image not available

The Scan Speak 25W will be here Friday, so that will have to wait.

[Johnloudb]

aperiodic vents

So what do you predict will be the winning combination Jim, 3-way with Aura or Scan Speak?

:B

I'd bet on the Scan. Jed. I think it's better suited for a sealed enclosure and will dig deeper (lower f3).

Has anyone tried Scan Speaks' aperiodic vents. They are supposed to lower the box resonance, improve power handling, & tighten the bass.


I'm going to try'em in my speaker project. My help your 25W with power handling. You'd need two - ($9.00/ea.) Mandisound. If you go with the 25W.
John

[Johnloudb]

Jed, just missed your last post. Your speaker sounds impressive.

Images not available

If, anyone has experience with these aperiodic vents, I'd like to know.

I'm new, I hope these picts get posted!! 8O

[Jed]

Jed, just missed your last post. Your speaker sounds impressive.


If, anyone has experience with these aperiodic vents, I'd like to know.

I'm new, I hope these picts get posted!! 8O

Yeah, from what I'm hearing with the Aura so far I'm not sure the Scans will surpass them--- but I have a lot of work on measuring and optimizing the crossover network. The Aura will be ported, and the Scans either sealed or with the aperiodic vents as you suggested. Both in 60L.

By the way, welcome to the forum. You'll find the people here very knowledgable to say the least.

Let us know what projects you have planned!

[Johnloudb]

Rd 50

Yeah, from what I'm hearing with the Aura so far I'm not sure the Scans will surpass them--- but I have a lot of work on measuring and optimizing the crossover network. The Aura will be ported, and the Scans either sealed or with the aperiodic vents as you suggested. Both in 60L.

By the way, welcome to the forum. You'll find the people here very knowledgable to say the least.

Let us know what projects you have planned!

Thanks, Jed. Well, here is what I'm working on. It's a 2 way B-G RD50 design. Front baffle is Maple.

Image not available

I had almost decided on the HiVi D8G (an 8" with 9mm of Xmax)
Then I saw the ScanSpeak Revelators on sale for $115. The box could be 2" to 3" shorter with same f3 of about 54Hz. I'm using an active crossover (300Hz).

Not Sure - what you think?

DG8:

Image not available

[ThomasW]

I had almost decided on the HiVi D8G (an 8" with 9mm of Xmax)
Then I saw the ScanSpeak Revelators on sale for $115. The box could be 2" to 3" shorter with same f3 of about 54Hz. I'm using an active crossover (300Hz).

Not Sure - what you think?

DG8:

The DG8's aren't known for having the best sound quality.

[Johnloudb]

7-8" woofers

Ok, I'll nix the D8G. 7" Scan Speak looks good. Any other favorite 7" to 8" woofers. I'm new to speaker building ... I've designed and built electronics, mostly.

[Jed]

Ok, I'll nix the D8G. 7" Scan Speak looks good. Any other favorite 7" to 8" woofers. I'm new to speaker building ... I've designed and built electronics, mostly.

Check out zaphaudio.com for driver tests. For a 7" up to 300hz, Usher is worth considering.

[Jed]

VERY bad news.

It appears my Accuton C79s are defective. The impedance is messed up/ doesn't match the manufacturers plots, and the FR drops off like a cliff below 1K with a 12db peak at 2k and it just gets worse from there. I cross referenced to other drives I had on hand like the tweeters and woofers, and I got perfectly acceptable results. I just emailed the vender where I got these so hopefully things will get straightened out. :M

[Johnloudb]

Seize the Day

It appears my Accuton C79s are defective. The impedance is messed up/ doesn't match the manufacturers plots, and the FR drops off like a cliff below 1K with a 12db peak at 2k and it just gets worse from there. I cross referenced to other drives I had on hand like the tweeters and woofers, and I got perfectly acceptable results. I just emailed the vender where I got these so hopefully things will get straightened out. :M

Adversity is the spice of life - savor these moments! :B

zaphaudio.com really helped. They liked the 7" Scan Speak Revelator the best and it will work great with my RD50s. So, I bought 4.

[Rick Craig]

It appears my Accuton C79s are defective. The impedance is messed up/ doesn't match the manufacturers plots, and the FR drops off like a cliff below 1K with a 12db peak at 2k and it just gets worse from there. I cross referenced to other drives I had on hand like the tweeters and woofers, and I got perfectly acceptable results. I just emailed the vender where I got these so hopefully things will get straightened out. :M

What size is your subenclosure?

[Jed]

Adversity is the spice of life - savor these moments! :B

True,

NOTHING is easy so you might as well try to enjoy the challenge.

Congrats on the Scan Speaks, you can't go wrong with those revelators.

Jed

[Jed]

What size is your subenclosure?

about 5L

Even in free air this driver should show an impedance FS hump and output below 1K.

[Jed]

Accuton's are going back for replacement tomorrow. Very odd that both would have such poor FR. There is no visable damage to the cone at all.

I keep thinking that it is something that I'm doing wrong, but every other driver specs out pretty close to the manufacturers specs.

Jed

[Johnloudb]

Gone

Accuton's are going back for replacement tomorrow. Very odd that both would have such poor FR. There is no visable damage to the cone at all.

I keep thinking that it is something that I'm doing wrong, but every other driver specs out pretty close to the manufacturers specs.

Jed

I'm glad that's getting resolved. People bought more revelators this weekend than avialable. The revelators gone :cry: .

"Hello John -

I regret to inform you we sold-out of the 18S sale drivers prior to your order.

There is a small chance that some will become available, so I will contact you within the next couple days if that happens.

Best regards -

Adam"


Don't pay with PayPal when it matters. Credit card orders are filled first, at Madisound.

I found a new love, though. It's design for a sealed box with f3 of 48Hz in a 20 L enclosure. ($160.00)

The Scan-speak 18W/8535 7" woofer -

TECHNICAL DATA:
Sensitivity 2.83V/1M 86.5dB
Free air resonance Fs 26 Hz
DC resistance 5.8 ohm
V.C. inductance 0.3 mH
Power 70W
Effective cone area 145 cm2
V.C. diameter 38 mm
V.C. height 15 mm
Air gap height 5 mm

Lin. & max. excursion ±5 / ±10 mm
Force factor BL Product 5.7 Tm
Moving mass incl. air 15.5 g
Net weight 2.5 kg
Vas 72 liters
Qms 2.50
Qes 0.45
Qts 0.38

Outside diameter: 177mm
Cut out: 158mm
Depth: 70mm
25.4mm = 1" = 2.54cm


It has a very low resonance peak. Lower than the 18s/3531G Revelators. My question is - wouldn't this be a better driver for a sealed enclosure with crossover freq of 300Hz? The freq response is smooth, almost identical to Revelators.

[JonMarsh]

Accuton's are going back for replacement tomorrow. Very odd that both would have such poor FR. There is no visable damage to the cone at all.

I keep thinking that it is something that I'm doing wrong, but every other driver specs out pretty close to the manufacturers specs.

Jed

Are the VC's locked? That would account for the strange measurements, possibly.

What you get should look something vaguely similar to this, of course, with variation due to your baffle size and shape.



No one's going to confuse this with a subwoofer, but that's not the point-

Was your vendor an individual or one of the internet resellers?

I've never had issues with any Accuton's from Madisound, though I did get a bad pair of SS9800, they seemed to have been "fried" by someone. Previously.

~Jon

[Jed]

Are the VC's locked? That would account for the strange measurements, possibly.

What you get should look something vaguely similar to this, of course, with variation due to your baffle size and shape.



No one's going to confuse this with a subwoofer, but that's not the point-

Was your vendor an individual or one of the internet resellers?

I've never had issues with any Accuton's from Madisound, though I did get a bad pair of SS9800, they seemed to have been "fried" by someone. Previously.

~Jon

I bought them from an internet reseller (not madisound- they are all out of Accuton C79s and C90s). He will test my units to confirm that they are defective. I talked to him for awhile to prove I knew what I was doing etc. I'm not about to play around with the cones to see if the VCs are locked, but that seems like a possibility, especially if these were a return of some sort and sold as new. I doubt that but you never know. The drivers definitely had no signs of use before I got them. So hopefully I'll have some new C79s that work within the next 2 weeks.

[Jed]

It has a very low resonance peak. Lower than the 18s/3531G Revelators. My question is - wouldn't this be a better driver for a sealed enclosure with crossover freq of 300Hz? The freq response is smooth, almost identical to Revelators.

That's a nice driver, yes. But, as I start to work with larger diameter woofers I can't imagine ever going back to a tiny 7" driver for bass duties. :W

[Johnloudb]

Two Scan 21W/8555-00

That's a nice driver, yes. But, as I start to work with larger diameter woofers I can't imagine ever going back to a tiny 7" driver for bass duties. :W

I Hear Ya. My problem has been box size. Two Scan 21W/8555-00 might fit. What Qtc would you shoot for in a closed box? 0.7, 0.8 or higher?

(P.S. in fairness to Madisound they have my favorite drivers and provide excellent service.)

[WayneO]

Hi Jed, looks like a nice project you have going here. A couple of years ago I purchased a pair of C79s from an online vendor for a project that did not work out. When I got them I gave them a close visual inspection and they looked fine. I dusted them off on the weekend to get ready for your project and found a small hole in the spider close to the voicecoil. It's the same on both drivers. Looks to be a stain around the edge of the hole darkish brown in color. From sitting so long (I turned them upside down every so often), could the ferrofluid have leaked on to the sider and "burned" a hole?
Cheers, Wayne

[Jed]

Hi Jed, looks like a nice project you have going here. A couple of years ago I purchased a pair of C79s from an online vendor for a project that did not work out. When I got them I gave them a close visual inspection and they looked fine. I dusted them off on the weekend to get ready for your project and found a small hole in the spider close to the voicecoil. It's the same on both drivers. Looks to be a stain around the edge of the hole darkish brown in color. From sitting so long (I turned them upside down every so often), could the ferrofluid have leaked on to the sider and "burned" a hole?
Cheers, Wayne

See if you can snap a shot of your drivers so I can understand a bit better. Are you able to take measurements to see if they are working properly? A quick impedance measurement should give you a clue, then if you notice something out of the ordinary continue with FR measurements. Mine clearly didn't have an FS hump in the impedance curve, and they definitely should.

Jed

[Jed]

I Hear Ya. My problem has been box size. Two Scan 21W/8555-00 might fit. What Qtc would you shoot for in a closed box? 0.7, 0.8 or higher?

(P.S. in fairness to Madisound they have my favorite drivers and provide excellent service.)

I wouldn't go over .6-.7 Qtc to tell you the truth. Take a look at Usher 8955a over at partsexpress if you are considering the Scanspeak. You'll save a lot of money and equal performance. The Kevlar 8" Usher looks interesting as well. 2 of those per side would be interesting. I've used the Usher 8955a sealed and thought it was excellent.

[Johnloudb]

Usher

I wouldn't go over .6-.7 Qtc to tell you the truth. Take a look at Usher 8955a over at partsexpress if you are considering the Scanspeak. You'll save a lot of money and equal performance. The Kevlar 8" Usher looks interesting as well. 2 of those per side would be interesting. I've used the Usher 8955a sealed and thought it was excellent.

For a Qtc = 0.7 only the kevlar/carbon, Usher 81374 will work, with f3 of 60Hz. I'm really liking it though, so is my wallet.

[Jed]

For a Qtc = 0.7 only the kevlar/carbon, Usher 81374 will work, with f3 of 60Hz. I'm really liking it though, so is my wallet.

Should offer you some nice tight bass. Check out the low distortion specs too.


As for more developments with my 3-ways, I've decided to go ahead and buy SoundEasy. By the time I have working drivers, I might as well try to learn some new software. Plus I want to take distortion measurements of my own.

Edit: Soundeasy is backordered

[SQdude]

Jed,

What software do you currently use to measure your drivers / system?

[Johnloudb]

TrueRTA

Should offer you some nice tight bass. Check out the low distortion specs too.


As for more developments with my 3-ways, I've decided to go ahead and buy SoundEasy. By the time I have working drivers, I might as well try to learn some new software. Plus I want to take distortion measurements of my own.

Edit: Soundeasy is backordered

Jed, You might check out this software also. TrueRTA - very powerful/flexible, $99.00.

http://www.trueaudio.com/

[augerpro]

Jed did you check if e-speakers has SE in stock?

[Jed]

Jed,

What software do you currently use to measure your drivers / system?

SpeakerWorkshop

[Jed]

Jed did you check if e-speakers has SE in stock?

Yes- both partsexpress and e-speakers are backordered. If you know another vender let me know.

[Jed]

LSPcad is on its way to me as I type! Looking forward to learning a new speaker design software.

Jed

[Johnloudb]

8 inch woofers

Should offer you some nice tight bass. Check out the low distortion specs too.

I just purchased four 8137A Usher woofers. I feel like they are a perfect match for my B-G RD50s. Thanks for the Tip!! :T

I'm a novice, but the distorion numbers look great. Lower than many preamps I've read about!

Let me know when you get those 25W Scans.

[JonMarsh]

LSPcad is on its way to me as I type! Looking forward to learning a new speaker design software.

Jed

I bet you'll like it- I'm still discovering extra things it can do, and exploring the less common features. The Std version is very good, but the Pro version can be worth it, too, if you spend a lot of time with it. I started out wtih the std version but upgraded.

The only way right now I can imagine LSPCAD being better would be if "the EDGE" were built in and usuable in the design flow. That, and a tracing utility like FRD tools.

~Jon