ErinsAudioCorner.com

erinh

Just thought I'd drop a line here and let you guys know that I am testing speakers/drivers and posting on my site.  I used to post to my old site but the server died and I had a lot of family stuff going on at the time so just never bothered to worry about it.  Decided to move everything over to a new spot and will hopefully start testing again soon once I see what the quote from Klippel is going to be.

I just ported over 3 reviews from the old site:
Scanspeak 12m Midrange
HAT L1-Pro R2 Ring Radiator Tweeter
Tectonics 2" BMR Speaker

Links below. Enjoy!

https://www.erinsaudiocorner.com/driveunits/scanspeak-revelator-12m-4631-g00_4.5_midrange/

https://www.erinsaudiocorner.com/driveunits/hybrid-audio-l1-pro-r2-ring-radiator-tweeters/

https://www.erinsaudiocorner.com/driveunits/tectonic-elements-tebm35c10-4-miniature-bmr-driver/

DanP

Do you have Klippel capability?

erinh

DanP said:

Do you have Klippel capability?

erinh said:

... will hopefully start testing again soon once I see what the quote from Klippel is going to be.

erinh

^ couldn't figure out how to add to my reply above.  But I guess you get the idea now.  The plan is to use Klippel again.  But that depends on what the cost is going to be.  I have been weighing starting a gofundme page to see if I can get some help with the costs.  

NavyGuy

erinh said:

^ couldn't figure out how to add to my reply above.  But I guess you get the idea now.  The plan is to use Klippel again.  But that depends on what the cost is going to be.  I have been weighing starting a gofundme page to see if I can get some help with the costs.  

What did you pay for the original one you had?

erinh

If I'm being honest I'd rather not put a number on it.  They helped me source a used one last time and hopefully that is something that can be done again.  I had well in to the thousands of hardware and software last time, though.  And that's without some of the other things I requested a quote for this time such as the laser (increased accuracy in T/S and linear Xmax) and the test stand.  Shipping is not going to be cheap, either.  I should know within the next couple weeks what the final verdict will be.

I've also asked about an automated turntable; I built one myself but if there's some way to automate turning the speaker that will interface with their software module(s) it then that improves not only time but also accuracy.  I'm trying to make as much of this as automated as possible because, no joke, it took me about 8 hours to do a review on a driver last time from the set-up (including cutting baffles which always was a drain), taking photos, capturing the data, posting and then finally tear-down and store away of the test rig.  I hate spending time away from my kiddo.  That's why I'm writing some post-processing scripts to help with some of the heavy lifting.  That's also why I'm planning on having her join me in some of my efforts.  I've told her I'd give her $5 for every intro she composes on her piano for my videos. 

erinh

For those who aren't part of the Facebook group or YouTube pages I've started in tandem with my website, I thought you might like to see this video.  It gives you some insight in to my background, why I'm testing and why 80's music is my love. 

Ed_Perkins

Erin –

Thanks for the informative video.  Back when you posted Klippel reviews over at diymobileaudio I felt you were a lone voice in the wilderness.   It seemed most members were only obsessed with buying the next, more expensive upgrade and price was always equated with quality.  When that website morphed into its current state I stopped visiting. 

I fully enjoyed your medleysmusings website, especially the KEF coaxial tests.  So I’m happy you have a new website.   I also wish you the best with your Youtube and FB sites.  I will have to admit that that I’m a dinosaur and prefer the forum and web based sites.  I have a lot of philosophical problems with the FB platform so I stay away from it.  But I guess that’s where a lot of people hang out.   Welcome back.

erinh

Thanks for the feedback. 

I understand that many are anti-FB.  And I'm not making content solely available there.  Actually, the FB group was created just as a quick way for me to inform a lot of people there is new data on my site.  It's the alternative to email blasting everyone.  

I think the YT format will be better in some ways to highlight products.  And other times a written review with photos is all I'll need.  But I know that I have gotten various questions about my test setup and I know I am a fan of multiple youtube reviewers because they do a good job of presenting an item I'm interested in.  So I'm just using the various methods at my disposal to yield the best quality review.  

squamishdroc

Sometimes it is nice to actually see something explained in a video format as opposed to a few pictures in a written article - I think that is one of the things that make the YT platform so popular in the DIY communities. I will keep watching

erinh

squamishdroc said:

Sometimes it is nice to actually see something explained in a video format as opposed to a few pictures in a written article - I think that is one of the things that make the YT platform so popular in the DIY communities. I will keep watching

I agree.  

I have some ideas for videos in the future.  Just patiently waiting for the folks at Klippel to get back to me regarding costs of what I've asked about.  After that then I can decide how I want/need to move forward.  

Thanks for watching!

- Erin

Kornbread

High school buddy had a dog with that same problem.  Guess how it woke us up in the morning ...

Yea, I like the video idea backed up with hard data and your background lends plenty of credibility to the findings.      

4thtry

Whoops.  I should have put my question in this thread, sorry about that, copy & pasted here:

"Hi Erin,

I was reading the "Test Methods" section on your website and was wondering if you are using the same IEC test baffle as listed in the Legacy Review section?    I am currently building a DIY IEC test baffle for my own use at home and was wondering what your thoughts are on the baffle size needed to get good measurements.  Thanks.   Bill"

erinh

4thtry said:

Whoops.  I should have put my question in this thread, sorry about that, copy & pasted here:

"Hi Erin,

I was reading the "Test Methods" section on your website and was wondering if you are using the same IEC test baffle as listed in the Legacy Review section?    I am currently building a DIY IEC test baffle for my own use at home and was wondering what your thoughts are on the baffle size needed to get good measurements.  Thanks.   Bill"

Well, just to be clear, I haven't started testing again just yet.  I'm still waiting to get a final quote.  Klippel told me to give them a few weeks  (they are going to have to wait to get everything together in order to give the final shipping quote).

As far as the size, that depends on a few things.  How low you can (plan to) measure in terms of a reflection free window (i.e., how high you can gate) and if you plan on doing nearfield/farfield merging.  My scaled down baffle was adequate for testing by combining the NF and FF measurements without having any issues show up.  Between that and modeling with Edge or VirtuixCAD to determine the impacts of the baffle, I would say a true IEC baffle is unnecessary.  I had that at one point very early on and see no need to do that again.


That said, one of my hair-brained ideas is to actually build a room in my attic for testing and in doing so, I will dedicate an entire wall for being the test baffle. 

4thtry

 Thanks for the info.  The size I am building is 1350 x 1650mm, which is roughly the scaled down size recommended for 8 inch woofers.   I do not plan to build speakers using anything bigger than an 8 inch woofer.   I will be raising the test baffle up on a stand which sits on top of my home brew horizontal polar table.  This will place the mic and speaker at a height of roughly 55 inches above the floor.   This will be in the middle of my living room or "great room" which has a sloped ceiling leading to a loft area.   The nearest reflection will be about 6.5 feet from the mic tip and speaker in all directions, except the floor, which will be closer (55" ).  I generally set my gate at 5ms.  

I will not be merging NF and FF data.   When I build and test a speaker cabinet, I will be doing all my design work using FF data only.  I want to include the floor boundary reinforcement effect in my measurements, which varies quite a bit with woofer height.   If I  apply smoothing to the bouncing data curve below 400Hz and then merge this back onto the FF curve, I can get the amount of BSC to apply fairly close in XSim.   I do not use Edge or VirtuixCAD to model the baffle, as the baffles I have been building lately are generally too complex in shape to fit the models.

I think your "hair-brained" idea is a good one.  Go for it. 

JasonP

This is great Erin. I love to see the data from medlymusings returning. I hope you get it all figured out and back into action, that would be amazing!

JasonP

Also something to note: If you look at the bottom of the page here on this site, https://www.erinsaudiocorner.com/driveunits/kef-q100-drive-unit/ you can see the effect of a woofer cone position on the output of a coaxial mounted tweeter. It is the only place I have seen this examined, and I've always felt it was audible (though minimally) in these designs.

erinh

Thank you, Jason.  I'm working hard on bringing back all the old reviews.  And still waiting for Klippel to get a final quote for me.  I hope to hear back this week.  Then I can move forward.  


Also, thanks for the note about the Q100 testing I did.  I actually had a few industry guys contact me privately and tell me they thought it was insightful and would likely implement similar testing on their own coaxial drivers.  Pretty sweet!

4thtry

+1 on the KefQ100 9 volt battery test.  Very informative.  The ear is probably very sensitive to that 7.5kHz glitch.

erinh

Good news!  I got a quote from them this morning. As expected, however, it’s not cheap. Regardless, I’m moving forward and will be sending payment shortly. But I would really appreciate any donations from the community that I can get to help me offset those costs and, namely, to help fund some of the other things I would like to purchase to help me make my testing more efficient and accurate.

If you don’t mind helping out, you can use the link below to contribute to via PayPal (they take 3%, I’m OK with that):

https://www.erinsaudiocorner.com/contribute/

If you don’t care about the rest of the details then there’s no need to read any further. However, if you’re interested in what your donations would be going toward, keep on reading…

I want to provide as much accurate information as I can about drive units, speakers and whatever miscellaneous ‘tasks’ I take on. IMHO, Klippel products will provide far more depth of knowledge than anything else and that’s why I’ve chosen their product(s). But I also want to keep my hobby/family balance. Testing takes up a good deal of time; but it's not so much the "test" as it is the setup/takedown time: cutting baffles, setting up the measurement rigs, getting the cabling out and running all the wires, fixing the driver/speaker to the test stand, and then writing up the report. In the time it takes to get prepped for a test I can complete another test cycle.

To help with accuracy and efficiency, I also hope to build a dedicated "test" space in my attic. I have about 11x17 feet that I'll need to floor, wall, and insulate to make it a test room. The reasons this is important to me are:

1) Scientifically speaking, the space would be large enough to push the first reflection out another 1 or 2 milliseconds which may not sound like much but is another 200hz or so of accuracy in my measurements. 200hz is a lot when you're expanding that over multiple octaves.

2) It gives me a fully repeatable environment to work within whereas my garage is a state of constant flux with temperature, humidity and ... stuff. Having a dedicated area means that the ambient conditions are within reason throughout the year but also it means that I won't have to spend hours setting up gear and taking it down to complete a couple tests which would help me complete more tests over time.

3) If I were to go this route I could also build an ‘infinite’ baffle to help with drive-unit testing.

Another thing that would help immensely is a small, tabletop, CNC. For raw driver testing I use a large baffle which has a cut-out for inserting smaller baffles. These smaller baffles are the pieces that the raw drivers are attached to. In my previous years of testing I didn't have the ability to surface mount complex drivers or oversized flange drivers. This was a detriment to my results (I always noted when that was the case). Surface mounting is the proper way to test drivers. I do own a router but the time it takes to cut flush-mount surfaces for some drivers … well, it adds up over time. Therefore, I would also like to purchase a small, table-top CNC router so I can cut my baffles to the exact dimensions needed for a driver cut-out. I've got my eye on an item that is just large enough to cut the baffle templates I need.

The third thing is having an automated turntable for polar measurements (on/off-axis frequency response). Now, I can build one from wood … I’ve done it before. But it’s a manual turning system which consists of: measure speaker, go turn speaker, measure speaker, go turn speaker… doing that in 5 to 10 degree increments over 90 to 180 degrees takes time. So, it would be really nice to use one that’s automated and works with the Klippel where I could click the run button and let it measure and rotate automatically. Again, this helps with repeatability and accuracy. But these are not cheap, either. I’ve gotten a couple quotes back > $3k. So, this is probably more of a pipedream at this point.

Obviously I wouldn’t be doing this if I didn’t enjoy it and feel like I’m learning from it as well so I’m not about to cry “woe, is me” here. But presenting data to the masses requires an extra level of accuracy and robustness that throwing together a simple test setup in my spare bedroom and caveating to the nth degree cannot provide; I know this from experience.  So anything you can donate to help me with that would really and truly be appreciated.

Thanks again,

- Erin

erinh

FWIW, this is a list of everything I got:

1 DA2 - Distortion Analyzer 2

Item No.: 2000-002 processor unit for all modules (incl. cable set) Refurbished unit Revision 2.1

2 LPM - Linear Parameter Measurement 

Item No.: 1000-400 identification of linear electrical and mechanical parameters

3 LSI Woofer + Box - Large Signal Identification Woofer + Box for DA2 

Item No.: 1000-230 identification of linear, nonlinear and thermal parameters of woofer drivers in free air, sealed and vented enclosures

4 LSI Tweeter - Large Signal Identification Tweeter for DA2 

Item No.: 1000-220 identification of linear, nonlinear and thermal parameters of tweeters, micro speakers, compression drivers in free air

5 TRF Pro - Transfer Function Measurement Professional 

Item No.: 1000-910 measurement of transfer function, harmonic distortion and rub & buzz

6 DIS Pro - 3D Distortion Measurement Professional 

Item No.: 1000-810 DIS features + measurement of HI2 and amplitude intermodulation distortion

7 TBM - Tone Burst Measurement 

Item No.: 1001-109 peak SPL measurements using tone burst signals (CEA2010)

8 PWT Pro - Power Test Professional 

Item No.: 1000-700 power testing with temperature measurement and transducer identification

9 Pro Driver Stand

Item No.: 2211-002 transducer fixture with laser and microphone positioning (incl. laser calibration spacer), Rev. 1.5

10 Laser Set ANR 1282 

Item No.: 2102-010 +/- 20mm, for woofer + midrange (incl. Controller ANR 5132)

11 Mic 17 IEPE 1/4" 

Item No.: 2400-103

12 Cable; BNC - BNC, 2m 

Item No.: 2300-106 Microphone cable, BNC male to BNC male, 2m, low capacitance coaxial cable type, blue

13 Mic Holder; MK10, for 1/2" Mics, fixed 

Item No.: 2400-206 fixed Mic Holder for 1/2" mics, made of plastic, 1/4" mounting thread

14 Manufacturer Calibration DA, PA, PM8 

Item No.: 6000-001 DA, PM8 or PA calibration with formal certificate, recommended every 2 years

erinh

The one thing I'm excited to have is the Pro Test Stand.  It has connection points for the mic and laser and will fit various size drive units. 

Edit:  This is used for getting T/S parameters and namely linear xmax.  Not for Frequency Response related measurements.   A baffle will be used for FR measurements of drive-units like I've always done.

erinh

And since I know I'll be asked at some point what this stuff costs, here's the price list.

https://www.klippel.de/fileadmin/klippel/Bilder/Our_Products/R-D_System/PDF/KLIPPEL_Analyzer_System_Price-List.pdf

Some of the things I purchased aren't on the price list as they have since been updated so you would have to get a quote.  My contact at Klippel was able to locate me a couple used parts to help me pad my costs a little. I won't get in to my exact costs because, frankly, that's not information I want out on the internet.  But, if you look at the sheet you can see the list price for some of the things above and that'll give you an idea of what I've invested.

erinh

I won't bump this again until I get some of the actual products in but figured I'd share this.

One of my car audio buddies also set up this GoFundMe page here which I thought was wicked cool of him to do so if you'd rather support that way than through PayPal here's the link: 

https://www.gofundme.com/f/help-hardison-erin-hardison-that-is?utm_source=customer&utm_medium=copy_link-tip&utm_campaign=p_cp+share-sheet

squamishdroc

Thanks for your commitment to the hobby!

erinh

Glad to help.  This stuff is fun for me and I figure I might as well share what I can along the way.  Sharing helps us all; it gives you guys access to info you may not otherwise have access to and it helps me by process of peer review and learning from those wiser than myself (which is a lot of folks).

erinh

Baffle wall construction for drive unit testing has begun. In lieu of using a portable test rig like before, I decided to do something different.  I have a 3-car garage with a 2-side and a 1-side.  When we built the home, I asked the contractors to build a wall between the two sides so I could have a "workshop" area and hang pegboard.  Plus, it makes it easier to heat/cool when I work on projects on either side.  I made a 14.5”x13” cutout between my garage partition. Like others do, I’ll use swappable inserts for each new driver tested. Driver hole cut out on insert, attach insert to wall, test, remove insert. Done. And when not in use a painted blank will be placed back over the wall so I don’t have to have a window between sides. This will be large enough for 12 inch drive units to be tested.  I figure anything larger than that and I'm not really worried about frequency response since it's more than likely a subwoofer and frequency response in to the mid 100's won't really matter at all.

The wall itself is about 17ft x 10ft. The center of the DUTs (devices under test) will be placed about 5 ft off the floor and about midway on the wall. With the garage door down, this puts the first path length of reflection at about 5 ft. Which is good enough to keep the first null above about 225hz. For testing this is actually quite good. Most people’s test setups are closer to 3 ft; 330hz. The further the distance the better. And thanks to the very large baffle there will be no diffraction effects to remedy once I’ve merged nearfield and farfield responses.

Blah, blah, blah... what this all means is I’ll have highly repeatable and accurate testing on as good a setup a dude testing drive units at his house could hope for.

PS: If you don’t hear from me again after this post, tell the cops my wife is responsible.

erinh

THE KLIPPEL STUFF HAS ARRIVED! 

Thanks again for those able to help donate a few bucks.  The support means a lot.  I'll post an 'unboxing' video soon... because, apparently that's what you're supposed to do with these kind of things now.  lol

Ed_Perkins

All right!  Xmas time for us speaker nerds (my wife's phrase).

erinh

Ed_Perkins said:

All right!  Xmas time for us speaker nerds (my wife's phrase).

Exactly! 

squamishdroc

Fun!