What is the difference between the ADS L1290 series 1 and series 2?

[minibeardeath]

I have a pair of ADS L1290 towers that I want to use as the front L/R speakers for my home theater. I am planning to build a center speaker to match them, but I just realized today that I have the series 1 version, but most of the literature online is for series 2. I know that the crossover PCBs are different, but what about the XO frequencies? Also, how did the drivers change from series 1 to 2? Would it work to use series 2 tweeters and mid range drivers in my center channel, or would it sound noticably different?

Thanks.

[tysontom]

I have a pair of ADS L1290 towers that I want to use as the front L/R speakers for my home theater. I am planning to build a center speaker to match them, but I just realized today that I have the series 1 version, but most of the literature online is for series 2. I know that the crossover PCBs are different, but what about the XO frequencies? Also, how did the drivers change from series 1 to 2? Would it work to use series 2 tweeters and mid range drivers in my center channel, or would it sound noticably different?

Thanks.

There were some significant differences in the Series I and Series II ADS models, primarily the addition of Ferrofluid, changes in crossover component (improved quality components, etc.), slightly extended high-frequency extension, elimination of the slight 2-3 dB rise in the midrange response, greater overall power-handling capability and so on. The crossover frequencies remained unchanged, I believe, which in the case of the ADS L1290 Series I and Series II is 500 and 5000 Hz., 12 dB/octave slopes. The Series II high-frequency output, on-axis, was extended out to 27 kHz from 23 kHz, but of course this is just marketing talk mainly because of the extreme range involved. Who can hear out to 27 kHz? But the response was smoother out to the limits of audibility, and this could be heard. The Series II also used Kapton voice-coil formers for the midrange and tweeter (and the L1590-2 woofers) voice coils, and this enabled much greater power-handling capability. Fuses were eliminated in the Series II altogether in the midrange, and a solid-state protection system was embedded in the crossover to protect the tweeter against excessively large input levels or overload. You could probably mix and match for a center channel without causing too much difficulty, especially since it will be reproducing a lot of voice information and less deep bass and music, etc.

--Tom Tyson

[minibeardeath]

Thank you very much for that information. I do actually have some series 2 drivers that I got from ebay, and I will probably use some modern 6" woofers just so I can make the enclosure smaller.

Since you seem to know a lot about the ADS speakers, do you know where I might find Thiele/Small parameters for the ADS drivers? I want to change to a horizontal layout which requires me to design a new cabinet, and new crossover.

[tysontom]

Thank you very much for that information. I do actually have some series 2 drivers that I got from ebay, and I will probably use some modern 6" woofers just so I can make the enclosure smaller.

Since you seem to know a lot about the ADS speakers, do you know where I might find Thiele/Small parameters for the ADS drivers? I want to change to a horizontal layout which requires me to design a new cabinet, and new crossover.

I don't have those parameters, but you could get some internet-based measuring tools and measure the drivers that you do have if you want to try to match them. You could also simply reverse-engineer your existing ADS L1290s' crossover networks when constructing a new one, and then use basically the same drivers. If you are going to use non-ADS drivers, then you will probably need to start from scratch. It's probably not so much the impedance, sensitivity and so forth that are at stake, but the dispersion characteristics that would be different if you used something other than ADS drivers, but the latter are readily available on the internet. Changing the layout from vertical to horizontal will also affect the speaker's spectral balance, too. You are not likely to need the bass power of the standard configuration for your proposed center channel, so you could use smaller woofers or even a single woofer for the center. Good luck on your project.

[minibeardeath]

Thanks for the info Tom. I am currently getting my test equipment lined up, and I will probably start the design phase around christmas.

[Alkaloid]

On 11/12/2012 at 9:54 PM, minibeardeath said:

I have a pair of ADS L1290 towers that I want to use as the front L/R speakers for my home theater. I am planning to build a center speaker to match them, but I just realized today that I have the series 1 version, but most of the literature online is for series 2. I know that the crossover PCBs are different, but what about the XO frequencies? Also, how did the drivers change from series 1 to 2? Would it work to use series 2 tweeters and mid range drivers in my center channel, or would it sound noticably different?

Thanks.

https://www.adsspeakersservice.com/?lightbox=dataItem-jr3nhaum1

This is a link to Rich So's website, and it has a perfect center channel for any ADS L1290 or L1290/2 set up. Plans are there with the dimensions, and Rich has the parts. Crossovers, drivers. I built one for my system and all you need is a plunge router, and a jig. I will provide a few links to help someone achieve this since the company is no longer around.

https://jaspertools.com/

The jigs tell you what router to buy that will fit. The way I made the cut outs was to make stencils with my factory cabinets. I had sent out the drivers and the crossovers for a complete rebuild by Rich, so with the empty cabinet I was able to measure the woofer size, and I used stencils for the midrange, and tweeter, and crossover openings. They were first a square opening, and then inside the square opening the plate fit into was the opening for the driver magnets. Don't be intimidated, it can be done and is worth it for the sound and correct timbre matching.

 

 

 

 

 

 

 

 

 

[Alkaloid]