Eminence Gama 15A2 with PSD2002S need crossover help

I have to build a cross over for this setup.
Eminence Gama 15A2 and PDS2002S

The Gama runs from 40 to 3Khz.
The PDS 2002S from 1.5Khz to 20Khz.
PDF files for both attached.

Tools I have.
DATSv3 Can try to attach the dats files for both if it helps. Or the ZMA files.
Have entered up a basic first order crossover in XSim.
But keen to create a VituixCad project file also.
Any Pitfalls to avoid.
Any inputs from people who have built anything using these drivers.
The box is built using online plans. Only thing pending is the cross over.
Yes I know Im missing a calibrated Mic. Am trying to see if a regular mic and laptop sound card can be used.
These speakers and box were a gift from a friend.
Ps: I will upload the ZMA and FRD files in a bit. As well as my first attempt in winisd and Vituixcad.
The ZMA is from Dats. The FRD Ill extract from the company provided graph.

My benchmark is old Akai SW177.
Dont see the need for a mid range driver but if required I do have an 8 Inch full range.
Did spend a few days searching for people who have used these drivers but didn't find much.


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The pdf file you linked to for the gamma15a is a sales blurb from US Speakers, not from eminence. Usual Eminence datasheets include data like xmax, xlim, a frequency response curve and an impedance response curve. This is a discontinued product of Eminence. Considering your indicated country of residence, it is possible this product is counterfeit.
Eminence perhaps discontinued this product because the low FS, 33 hz, tempts people to use the driver below recommended lower frequency of 48 hz. Large excursion of those frequencies from stage floor bounce or magnetic phono floor bounce, can easily rip the spiral wires that connect the coil. Current eminence products have higher FS except the Lab12 Lab15 which have top response of 1000 hz. Eminence vented cabinet plans usually specify an 18 db/octave high pass roll off at something like 40 hz to prevent the wire ripping problem due to xmax violations. With a Qt of 0.3, this driver is specifically designed for vented cabinets. The 40 hz high pass rolloff is most economically achieved in an electronic crossover before the power amp, which also merges and filters bass from 2 channels for a sub.
I would suggest not using the gamma15a above 1800 hz, though 1200 hz would even be better. While on axis response can be flat, +-45 deg response from a 15 can be lacking above frequencies above. This is called beaming. Usually an eminence frequency response curve shows a resonance at somewhere between 1200 to 2500 hz. Lacking one you will have to test it yourself or make some assumptions.
The PSD2002-8 CD has Fs of 550 hz, Eminence says it is usable 1.2 khz to 20 khz. Eminence specifies a 12 db 1.2 khz high pass filter for this, Something like a 10 uf series capacitor and a 1.5 mh parallel inductor satisfies the David B. Weems charts for a butterworth low pass filter. For the woofer, putting that value capacitor parallel and that value inductor series achieves 12 db/octave also near 1200 hz. As the CD is 106 db 1w1m and the gamma15a is 98.6 db 1w1m, some series resistance of the tweeter is in order. I would suggest including a tungsten bulb series the tweeter to clamp down overvollage on the tweeter from clipping or mike drops on stage, or pops from a cable pulled loose. These are usually 1 ohm cold.
For the vented cab design, I suggest the David Weems book Designing Building and Testing your Own Speaker system, to calculate with a pen & paper or hand calculator, or if you have a windows computer, various speaker solftware packages. You want vented reflex box at the most primitive for a 0.3 QT speaker, although various people on here build more sophisticated designs for tuned columns. scoops or various other designs. I am no expert on these variants. Eminence has plans for various boxes for the somewhat similar product Kappa-15A on their website.
Verify your response with an omni mike, some sort of mike and speaker stands, and software like REW or ARTA. Off axis response is something I find key to my in-room listening experience. Others are not so convinced, and instead tune their rooms.
I'm quite happy with a 2 way 15"+CD (1.4") for my daily listening, restricted by the fact that my store purchase speakers tempt thieves to carry them off to the flea market for resale. I've replaced the stolen Peavey SP2-XT with SP2(2004), but they are on stands they are visible to all through my windows. I'm currently planning to build some ugly copies with eminence drivers , that perhaps would be not worth stealing.
Happy shopping, building, and listening.
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Pretty cool to hear about a Gamma.

Was extremely popular drivers.
Thousands of those things
Was Called 15A-8 before discontinued.

If I remember it had a huge magnet maybe 56 ounce.
Way better than the wimpy Deltas and Betas.
Very affordable
Common factory driver for MI instruments in 80's / 90's

Did great in the usual 3 cubic feet / 40 Hz reflex


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I have to build a cross over for this setup.
Eminence Gama 15A2 and PDS2002S

Any Pitfalls to avoid.
How do you plan to use these speakers, is this a home listening system or a party system? If it' the latter then you have the wrong driver for a scoop... it needs to be much more robust, the PSD won't really like a 1.5khz crossover.. it will sound harsh at anything but just ticking over spls, and a 15" should not be allowed to go above about 750hz-1khz, so you need something else to go in between the scoop and the CD to carry mid-bass frequencies. I'd suggest you make 12+1 tops in separate boxes and build passive crossovers for those, and then power the tops and scoops with separate amplifiers and an active crossover. This 3 way system would have crossovers of 100-150hz and 2.5-3khz.
If this is a home listening that will only see 5-10w or less and you only care about 1 listening position, then use what you have, but you're going to need lots of EQ to flatten the rising response of the Gamma.
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Thank you for your inputs. Im open to building a new box. Because to be honest the existing box is way to big for a small flat.
But right now I want to focus on the cross over and at least hear them working.
Have measured the drivers with Dats, have extracted the FRD values This is as far as I have got.
There is some confusion about the woofers The label says Gama-15A-2.
The results I got with Dats. Looks identical to the graph shown. So I have confirmed that much. These drivers were made in the USA and were imported from the USA to India. The fake ones are way lighter. And the results on Dats do not match what Eminence has put on their website.
Here is the file where I have collected all the data I could.

Here is a pic of the woofer. (The confusion is some people say 15A some 15A-2).
I did buy these 10 inch sweton speakers but for some reasons thought that a FS off 42 would be crappy. And was lusting after a lower FS and less XMax. They are amazingly well made speakers for the price. And their TS specs are pretty close.
Also have their 8 inch full range.
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Many of us do not download files not on diyaudio.com
The 1200 hz crossover parts are in post #2.
The 100 w large cabinet design is at the end of the eminence file white dragon uploaded in post #3. Be sure to pre-filter the signal to the amp to prevent signals below 45 hz that cause xlim violation damage.
As Conanski indicated in post #4, the gamma15a has a rising response above 1000 hz, where it also beams (narrow response). I handle this on eminence 15" by crossing over at 1200 hz or 1000 hz.
If you don't like the results from the PSD2002 down to 1200 hz, you could purchase a 1.4" N314T-8. I did. The econowave builders seem impressed by the PSD2002-8. Pi speakers FourPI uses PSD2002-8 or a B&C DE250 as the tweeter. https://www.pispeakers.com/Products.html
You could ask Wayne at Pi Speakers for suggestions as he has a lot of experience with Eminence drivers. https://www.pispeakers.com/contents.html

IIRC Eminence's stock 1k6 network highpass came in a bit low for a PSD2002 and its lowpass too high for some woofers -here's the values I remember.

Gamma 15 sure made good use of a 59 oz magnet slug and 2" coil to get its specs. Have you modeled it in that scoop?Is the scoop already built? - just wondering what this speaker has to do work-wise.

btw, Eminence's networks had one good thing on their highpass - a light bulb limiter consisting of two 211 incandescent lamps wired in parallel with each other and in series with the driver/ L-pad


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Yes I was up most of last night devouring all the articles he has on pispeakers.com. Its a treasure trove of useful info.
Yes the drivers are installed in the scoop. And the scoop is built. I took the drivers out to measure them and to transport them safely to my penthouse. If you look at my Dats files the FS is not 33 its 36. The rest of the parameters are pretty close. Maybe the FS goes up with age. Maybe its the whole confusion between the A and the A-2 modell.
I will add the dats files with scoop enclosure and without scoop enclosure. Just like I did for the CD i.e. with horn and without horn. The use is just something to listen to when I work or have friends over. My penthouse is a 3 bedroom flat with a nice open sitout area. Its basically my workshop. I have one room for engine work. One room for Electronics. The 3rd room is just used to store stuff. The plan is give each driver its own individual channel. Right now Im driving them from a PA3 type amp.
Also have a STK AMP, and a TDA7294 amp. And a few other transistor amps. All are 100 watt amps. Except for the TDA that is a 70 watt amp. Also have a 40 watt transistor amp. All home built or junk yard rescued and repaired. My objective is to recreate that 70s sound. So was advised to avoid anything class D. And to stick to trying class A / AB / STK based amps.
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Spent hours trying all kinds of complex designs. From 6Db to 24 DB Nothing works as well as a simple 10Uf cap and one resistor. Tomorrow I hope to start to read up on phase and how that impacts sound.
Adding inductors to the woofer just mudies the sound have tried all inductor values. The woofer sounds fine without an inductor.
Only one issue remains the drop off that happens from 15K to 20K.
Then again at my age I can't hear those frequencies anyway. So should I really bother trying to pick up or flatten that area of the curve ?. Is there even a passive component solution. That is the only problem area left.
And adding 12v 20 watt bulbs to protect the CD. I have a feeling with the bulbs I wouldn't even need the 15 ohm resistor.
Will measure the res of the bulbs and add them as resistors to the modell.
I agree 15k to 20 khz doesn't matter. I can't hear that either. Reason I use a 1.4" N314T-8 CD instead of a 1" PSD2002-8. Or live Peavey RX22 CD instead of either, because I have screw on horns, and can get used ones on ebay for cheap.
While leaving the gamma-15a with no roll off inductor is not physically dangerous, Rolling off PSD2002-8 at 6 db/ octave with one 10 uf cap can be dangerous. They really don't like pumping out sound below the resonance point. Most everybody suggests 12 db octave rolloff for compression drivers. 10 uf series, 1.28 mh*2.0 likwitzriley correction = 2.56 mh parallel to the CD. That is not cheap from janzen but David Weems Page 177 says ~133 feet #18 wire on a 1 1/2 " core (wood or plastic) is approximately 2.56 mh. If I coulld find an L meter not made in ***** for <$620 I would buy a roll of 150 ' #18 wire from a surplus house I know then unroll wire until the inductance was right. Surplus sales make much nicer rolls than I do, and the core comes free. ****, I was saving up to buy a CH500 LCR-ESR meter from Japan, for $140 when the listings totally disappeared from ebay +amazon. No, I don't trust the wizards on the mainland to produce anything but random numbers with their $6 LCR meters.
Yes treating the cold resistance of incandescent bulbs as part of the CD volume reduction resistor is normal practice. Just make sure your listening practice doesn't run the tungsten bulb somewhat hotter. Like party systems run pretty loud could significantly heat up the bulb in normal service. you want the tungsten to do the 10 to 1 resistance trick when something dangerous like a mike drop or 1/4 phone plug pull-out happens, (POP!) not all the time. Or some idiot turns volume up to 11 and clips everthing to square waves with massive high freq content, which both shatters CD's and melts woofer voice coils (read story of Hartley Peavey's development of "DDT" high freq reduction after replacing a lot of voice coils & diaphragms under warranty.)
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I have been buying 18 or 19 gauge copper wire for about 180 bucks or 2$ for 100 grams. Which give me two 1uh inductors. I have plastic round bobbins. And I use my bat powered drill gun on slow speed to wind them.
When it comes to measuring them. I find DatsV3 does a decent job. With Inductors, caps and resistors.
I don't own a mic. Have no plans to own one.
My kids are all adults and moved out. My friends dont mess with my amps. They wouldn't know which knob to turn my tables has 5 different amps on it. Most times it takes me time to figure out which one is playing and which knob is for volume.
For now I'm going to just add the bulbs to the CD to protect them. Considering Im using piddly little PA3 type or 100 watt amps. I dont see them as being able to do much damage This CD is designed to handle 80 watts RMS.
Based on the hours of youtube videos I have been watching on CDs. Most guys look at that drop off from 15k to 20k which is pretty common for CDs and say there is no passive solution to this drop off meaning they are saying you need an active solution to fix it. Which Im not going to bother with. I have a 10 Band EQ that I may use if I really need to bump it up.
Yes the numbers on the cheap china meters do not match with DatsV3.
I need to somehow figure out a solution to use REW without blowing 100$+ for a umic mic.
RTA for Android is one option Im looking at. It works with the 22$ dayton calibrated mic. And allows you to save frd files.
So based on more readings it would seem that I need to protect the woofers from low freq esp when the volume is high. I can use the s/w to see at what point this causes my Xmax to become a problem. By slowly ramping up the watts to the speaker. In the software.
Also looked into rumble filters. It would seem it should work. But rumble filters are a. Complex and One more PCB to add.
I have this speaker protection circuit already which I plan to use to protect the speakers.
Can this circuit be tweaked to act like a protection from my understanding it switches off the relays if it detects d/c on the line. Can it be tweaked to open the relay for say anything under 30 Hz.
I have no plans to drive this thing hard. Should somebody by mistake crank up the volume can this circuit protect it.

And maybe something like this for the CD (Wonder what's inside this).


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Well, 600 hz protection as the PE link really cuts off a lot of the sound we like to listen to. Useable for tweeters perhaps.
It is a real issue, I tore the leads to a 10" woofer in a KLH23 by walking across a wood floor with the turntable playing an LP. My PAS2 preamp bass filter affected all frequencies below 2000 hz so I left the knob at center. In tube amp days the power amp would not reproduce those low frequencies due to output transformer cost.
You could put a 12 db/octave high pass series the speaker, but C=159000/(Z*f) for 4 ohm speaker gives 1325 microfarad for 30 hz. That's $24.50 per speaker for parallel 3 400 uf and 1 125 uf 100 VNP capacitors from parts-express.
Paralllel inductor to driver of 12 db/octave filter would be 21 millihenries or $50 for two series 10 mh air coil inductors. $33 for two series 10 mh iron core inductors. Parts-express prices.
It is really much cheaper to do this filtering between the sound source (DAC?) and amplifier input. I picked up a used NADY CX-22SW sub crossover for $50 which has a knob adjustable frequency 18 db/octave low pass filter on both pass through channels and a summed channel for a subwoofer with both lower and upper filters knob adjustable. Similar products are available from Peavey and if you like use once & throw away products, behringer.
My analog graphic equalizers also have this function built in with a fixed frequency enabled by a switch. My PV8 mixer also has a fixed high pass frequency built in and switch selectable. Most bar stages are wooden and a microphone can pick up footsteps if it does not self filter low frequencies like the SM58.
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if it was up to me i would just route everything thru my laptop with Peace EQ . Which allows you to setup any filter you can think off for any freq.
But I hang with some pretty snooty audiophiles. They will walk out if they hear a class D amp. Or a software EQ paying anything lol. It has to be all transistors and large bulky crossovers or its not worth listening to.
Dont tell them but thats what I listen to when Im alone. lol. If you have not played with Peace EQ your missing something I feel. The best part its free. And it runs on any old laptop.
So I tried to impress one of my audio gurus with all the new softwares I have learned to use.
And explained how I was trying to get a flat response curve.
He asked me a question which kinda stumped me.
Who says a flat response curve sounds the best.
Did some reading the best I could find was a mention of smiley face as sounding good.
Anyway long story short.
This is the simplest cross over I could come up with. Only one problem there is a bump at 8500 hz that I need to tame.
Any ideas. Maybe a notch filter at 8500 to drop the output.
Any other ideas ?. Or maybe this bump will just sound good.
Other simple solutions is just a simple L pad with a -6Db slope on the CD.
Vituixcad seems to be much better than Xsim.
And explained how I was trying to get a flat response curve.
He asked me a question which kinda stumped me.
Who says a flat response curve sounds the best.
It can be calculated mathmatically that a bump in a driver response curve causes frequencies in the result that are not there in the original signal. This is called "distortion".
If tuning for rooms, yes a response curve the opposite of what the room does to your signal can make for accurate sound. I have a 10 db room resonance bump at 200 hz. I tune for that with a $60 used graphic equalizer between mixer & amp. (I have LP, CD, FM radio, inputs to the mixer, no computer).
The 8500 hz bump is in the original PSD2002-8 response data. Personally I handle that by buying a Eminence N314T-8 myself. People with no Kentucky bias may prefer to buy something like a B&C DE111-8, although I haven't checked its suitability below 1000 hz.
Yes, individual bumps in the response curve can be filtered off in the speaker by a RLC trap parallel to the driver. It is a lot cheaper to buy a used graphic equalizer which can also be used to filter off room resonance modes. Other people that are addicted to cell phones prefer a DSP, although I find the constant update of software of digital equipment leads to obsolesence of digital accessories faster than I am willing to tolerate. I downloaded my REW software last year and it already is obsolete. My graphic equalizer is 15 years old and will be obsolete only when vendors quit using 1/4 phone plugs and twisted pair to hook up devices that produce and use 1 to 2 vac signals. .