A/D/S L910-II Reference Speakers

[beden1]

I have owned the A/D/S L910-II Reference Speakers since buying new in 1976. I have always enjoyed these speakers as IMO, they are still one of the finest speakers ever produced. Unfortunately, the A/D/S company looks like it has been bought/sold many times over, and I can't seem to be able to find anyone familiar with these speakers, or has access to parts/info.

I would like to either bi-amp or bi-wire these speakers with my new Pioneer Elite 82 receiver. The operating manual does not have instructions to bi-wire. The manual also said that in order to bi-amp, I need an electronic crossover unit (SAE 4000 or equivalent), and ADS part 601-0018 bi-amplification program card(s). They also offered an ADS BA-9 filter/amplifier module that converts the speakers to "powered loudspeakers". Unfortunately, I did not buy this option at the time and wish I did. But, in 1976, these speakers were over $1,000 each by themselves, and I didn't have the extra cash.

If anyone has knowledge of these speakers and can help me out, I would be eternally grateful.

[kirknelson]

Bi-wiring has no advantage over using a single run of wire. Yes, you reduce the resistance of the speaker wire but you also increase the capacitance. As short a run as most of us use the differences would be insignificant.

Bi-amping has some benefits though. It will allow you to "tune" the sound of your speakers by adjusting the power going to the tweeter versus the woofer. It will also allow more headroom by reducing the number of drivers each amp has to power. You could even use different types of amps for the different sections, e.g. tube for the tweets and SS for the woofers.

If you also use an active XO this gives even more benefits in that the amp will be able to couple directly with the driver which will yield better control and even more headroom. Of course this means ripping out the factory XO and doing a lot of tweeking to get the active XO set properly. From what I have heard it is almost impossible to set an active XO properly without test equipment. Of course if A/D/S is going to sell you an active XO one would think it came preset for the speakers.

That said, I don't have any info on your particular speakers. Usually speakers designed for Bi-amping have two sets of binding posts and you accomplish the Bi-amping by simply wiring one amp to the low posts and one to the high posts. It sounds like this may not be the case for these speakers and you have to get some additional parts.

Have you called A/D/S customer service?

[beden1]

That said, I don't have any info on your particular speakers. Usually speakers designed for Bi-amping have two sets of binding posts and you accomplish the Bi-amping by simply wiring one amp to the low posts and one to the high posts. It sounds like this may not be the case for these speakers and you have to get some additional parts.

Have you called A/D/S customer service?

I did call the company that now produces/markets a line of A/D/S, but they have no information on these speakers. I know the original company did not sell many of these in retail, due to the cost.

These speakers are able to be bi-amped, but the set-up is a bit different than just 2 sets of binding posts. This has me confused.

On the speaker panel, there are 5 positives (tweeter, mid, woofer, and 2 for full range). there are also 3 negatives (woofer, mid and tweeter). So, I'm not sure which to attach the wires. In most speakers utilizing 2 sets of binding posts, you don't need any additional equipment to accomplish bi-amping? So, if I am trying to bi-amp through the receiver (which offers this option) would I need to use another crossover, or bi-amp program card?

[bmurr]

You will need the card and the 910 can also be TRI amp but you will need the TRI amp card for each speaker.

[Alaric]

Bi-wiring has no advantage over using a single run of wire

Opinions are like , well , you know. I had a pair of ADS L1530s in the 80s and thought them fantastic. One of the best resources I know of for vintage ADS is http://www.audiokarma.org/
Quite a few knowledgeable folks . By now , you are looking at replacing the capacitors , and if the driver surrounds are foam , and original , replace them as well. Once the speakers are up to snuff you may not hear the need to do anything else. My $.02
One example http://www.audiokarma.org/forums/sea...archid=5147917

[Johnloudb]

In order to know if bi-amping will give any improvement at all, you need to know the speakers sensitivity, and the Distortion vs. Output power of your amp. Amps have an optimum power level for lowest distortion. Distortion of most amps tends to go up at low power, and when the amp is pushed near it's power rating.

I have some Nelson/Reed 804B loudspeakers (93dB sensitivity) that sound best driven by a high quality 75watt amp. I've tried these amps mono blocked (250 watts/ch) and the sound gets more irritating.

Actually, bi-amping is different since you're just splitting the frequency range which amp is driving. So there a definite benefits. And what I said above doesn't necessarily apply, at least as far as a change in distortion. Have I confused you enough yet? :B

If the crossover has seperate crossover boards/input connections for the Highs/Mids and Lows, you could just add a separate binding post for the High/Mid crossover. Do you know the sensitivity of the speakers?

Personally, if I'm happy with the sound I like to leave things alone. Unless I'm building my own gear, then I'm always messing with it.

[Turbo57]

Bi Amping the L910-II

does indeed require a card that ADS sold. I bought them for about $200 for the pair. the difference is breath taking. I have owned mine since 1980 and still think they are the best sounding speakers around. Note that the XO just needs to be at a 200hz / 12Db slope which means the high and bass are split at a certain frequency. i had my crossover built by DB systems in NH. Anyway, there are terminal connectore for biamping and triamping. If ever you get the chance, you will NOT be disappointed in the sound quality.

[beden1]

does indeed require a card that ADS sold. I bought them for about $200 for the pair. the difference is breath taking. I have owned mine since 1980 and still think they are the best sounding speakers around. Note that the XO just needs to be at a 200hz / 12Db slope which means the high and bass are split at a certain frequency. i had my crossover built by DB systems in NH. Anyway, there are terminal connectore for biamping and triamping. If ever you get the chance, you will NOT be disappointed in the sound quality.

I'm not sure what this means?

Did you get the bi-amping cards back in 1980, or were you able to find any recently? Thanks, and I agree that the ADS 910s sound spectacular.

[Turbo57]

To Beden1

I meant there on the crossover card inside the speaker, there are connector terminals for all configurations of the speaker. You can bi or tri amp them as well as normal single amp mode. Yes you do need the a/d/s cards that go into a slot in the internal crossover card inside the speaker. Also, yes, I purchased the biamp cards back in 1980 right after I purchased the speakers.