Jump to content


Photo
- - - - -

Driving AR-303a speakers


  • Please log in to reply
17 replies to this topic

#1 Speakersound

Speakersound

    Newbie

  • Members
  • Pip
  • 2 posts

Posted 26 January 2011 - 10:00 PM

I am getting a pair of AR-303a speakers and I was interested to hear comments from those that
own these type of speakers or similar, regarding the type of receiver and power required to drive
adequately these speakers. I know that they are rated at 85db, which makes them not as efficient
as more modern speakers, but I would like to know what to expect or may need. Would a 110 watt per
channel receiver suffice? Any recommendations?

DeanC

#2 Mexicomike

Mexicomike

    Advanced Member

  • Members
  • PipPipPip
  • 315 posts
  • Gender:Male
  • Location:Mexico City/Chester, MD
  • Interests:Too many to list but include...<br />Audiophile since I was around 14 - first amp was an Eico 4WPC kit!<br />Build Harpsichords<br />Photography<br />Play Flamenco Guitar/piano/started learning violin 2 years ago.<br />Built/owned/operated small recording studio for 10 years <br />Motorcycles - raced in my 20's; still own a Norton Commando I raced...<br />Built auto high performance and competition engines; still do it for friends<br /><br />

Posted 26 January 2011 - 10:15 PM

110 RMS watts per channel would be fine as long as you don't push them to insane levels. Once an amp goes into clipping it will fry the tweeters pretty easily. I blew AR tweeters twice with a 40WPC amp (totally covered by the AR warranty). When I went to a 200WPC Phase Linear 400 amp, I never had another problem.

The more good RMS power the better as far the possibility of clipping is concerned. Also remember that it takes double the amp power to make a noticeable increase (3db) in volume. So a 200WPC amp can only drive a speaker to just noticeably louder than a 100 WPC amp. The real advantage of that higher power is the better clipping" headroom associated with the power.








#3 Steve F

Steve F

    Advanced Member

  • Members
  • PipPipPip
  • 908 posts

Posted 27 January 2011 - 05:11 PM

I am getting a pair of AR-303a speakers and I was interested to hear comments from those that
own these type of speakers or similar, regarding the type of receiver and power required to drive
adequately these speakers. I know that they are rated at 85db, which makes them not as efficient
as more modern speakers, but I would like to know what to expect or may need. Would a 110 watt per
channel receiver suffice? Any recommendations?

DeanC


110 watts per channel in a smallish room will drive the 303 just fine to any sane loudness level you want.

I have AR-3a’s in a small 11 x 13 room. First, consider that the sensitivity specification, as measured one meter on axis for a 1-watt input, will yield a figure of about 86dB for an AR-3a. That’s considered “inefficient.”

But 86dB is really a pretty healthy level, more than background listening. It may not be loud enough in a dealer showroom, but in your quiet listening room, you’d have to turn it down to answer the phone.

Now, you've got two speakers, so there’s some addition to the 86 SPL figure because of that. You are also about 8-10 feet away from the two speakers (and somewhat off axis, to boot), so there’s some reduction because of that (the inverse square law, which says that SPL reduces by -6 dB as the distance doubles). Throw in your room’s absorptive characteristics, any open walls that lead to the next room, etc, and what you’re left with is that the raw sensitivity figure for one speaker is a pretty decent number to work with as to how loud two speakers will sound from your listening position with a one-watt input. There are a LOT of variables, obviously, but 86dB for 1 watt for a pair of 3a’s from your listening chair is not a bad estimate. The 303 will be very similar, within a few dB.

Every doubling of power is another 3dB of loudness. So:

2 w = 89 dB
4 w = 92 dB
8 w = 95 dB
16 w = 98 dB
32 w = 101 dB
64 w = 104 dB
128 w = 107 dB
256 w = 110 dB

I’m not even sure how cleanly the 3a can play at or above 110dB, but any competent amp has enough juice to push the 3a or 303 to 95-100dB in a normal listening room. And that is very loud. As mentioned in previous posts, make sure you’re using a good amp that’s not apt to be driven into distortion. The 303 has a ferrofluid-cooled tweeter (the 3a did not), so the 303’s tweeter will be more tolerant of a little abuse here and there than the 3a’s tweeter.


Steve F.

#4 mluong303

mluong303

    Advanced Member

  • Members
  • PipPipPip
  • 385 posts
  • Gender:Male
  • Location:New York

Posted 27 January 2011 - 09:37 PM

I am getting a pair of AR-303a speakers and I was interested to hear comments from those that
own these type of speakers or similar, regarding the type of receiver and power required to drive
adequately these speakers. I know that they are rated at 85db, which makes them not as efficient
as more modern speakers, but I would like to know what to expect or may need. Would a 110 watt per
channel receiver suffice? Any recommendations?

DeanC



I would recommend at least 150w/ch of better Amplifier(not vintage Crown or Phase Linear) to drive the AR-303a speakers. I got decent result with Acurus A200 and Adcom GFA 5500 power amps both rated 200w/ch@8ohms and close to doubled @4 ohms. The bottom line is higher power/high current will make the AR-303a speakers sound better. The spider is so hard and stiff and the rubber surround is so thick that make the AR-303 woofer much harder to push compare to the original AR-3a woofer. To the people who complain about Tonegen woofer spider is too hard, wait until you see and feel the spider and rubber surround of the AR-303 woofer! One good thing about the AR-303a speakers is you can bi-amp them to make them sound the way they should.

Minh Luong

Attached Thumbnails

  • AR Ltd 3 & 303 woofers.jpg


#5 RoyC

RoyC

    Advanced Member

  • Members
  • PipPipPip
  • 1,696 posts
  • Gender:Male
  • Location:Latham, NY

Posted 28 January 2011 - 12:13 AM

I would recommend at least 150w/ch of better Amplifier(not vintage Crown or Phase Linear) to drive the AR-303a speakers. I got decent result with Acurus A200 and Adcom GFA 5500 power amps both rated 200w/ch@8ohms and close to doubled @4 ohms. The bottom line is higher power/high current will make the AR-303a speakers sound better. The spider is so hard and stiff and the rubber surround is so thick that make the AR-303 woofer much harder to push compare to the original AR-3a woofer. To the people who complain about Tonegen woofer spider is too hard, wait until you see and feel the spider and rubber surround of the AR-303 woofer! One good thing about the AR-303a speakers is you can bi-amp them to make them sound the way they should.

Minh Luong


Hi Minh,

I recently measured new old stock AR 303 woofers (sent to me by Tom Tyson). The 303 woofers had a slightly lower fs...22hz vs 25hz measured for the Tonegen woofer. This suggests that the 303 woofer is actually a tiny bit more compliant than the Tonegen. Sensitivity is about the same. I really don't see the 303 woofer requiring more power.

I listened to a friend's pair of AR 303's through an old 75 watt/channel receiver last summer in a rather large room. They easily filled the room, and sounded very good.

Roy
Roy Champagne

#6 mluong303

mluong303

    Advanced Member

  • Members
  • PipPipPip
  • 385 posts
  • Gender:Male
  • Location:New York

Posted 30 January 2011 - 02:03 PM

Hi Minh,

I recently measured new old stock AR 303 woofers (sent to me by Tom Tyson). The 303 woofers had a slightly lower fs...22hz vs 25hz measured for the Tonegen woofer. This suggests that the 303 woofer is actually a tiny bit more compliant than the Tonegen. Sensitivity is about the same. I really don't see the 303 woofer requiring more power.

I listened to a friend's pair of AR 303's through an old 75 watt/channel receiver last summer in a rather large room. They easily filled the room, and sounded very good.

Roy



Hi Roy

If 75w/ch receiver made the AR-303 speakers sound good to you then that is wonderful. You are a lucky man!

I love the AR-303a speakers a great deal among many other AR speakers that I had owned and collect over the years. Just like the AR Limited 3 woofer with rubber surround and stiff spider, both the AR-303a and AR Limited 3 speakers sound better to my ears with higher power amps from Adcom, Acurus, Aragon and Nakamichi Stasis(Threshold). If I can afford more and have the money to spend, I would definitely try Krell, Bryston and Pass Lab amplifiers to drive my AR speakers. Crown I like but only the Crown Reference 1 amplifier which cost $4000 when they first came out!

Some people insist on Tube amps mate better with AR speakers and if you have the knowledge to choose the right vintage, brands and batches of tubes in different era and have the time to wait for the tubes to warm up half an hour before listening then by all mean... go for tube!

HiFi is a very personal hobby so whatever please your ears and sound great in your listening room then be happy with your set up and "Enjoy the Music".

Minh Luong

Attached Thumbnails

  • AR-303 woofer-1.jpg
  • AR-303 woofer-2.jpg
  • AR-303 woofer part# & measurement.png


#7 RoyC

RoyC

    Advanced Member

  • Members
  • PipPipPip
  • 1,696 posts
  • Gender:Male
  • Location:Latham, NY

Posted 30 January 2011 - 05:02 PM

Hi Roy

If 75w/ch receiver made the AR-303 speakers sound good to you then that is wonderful. You are a lucky man!

I love the AR-303a speakers a great deal among many other AR speakers that I had owned and collect over the years. Just like the AR Limited 3 woofer with rubber surround and stiff spider, both the AR-303a and AR Limited 3 speakers sound better to my ears with higher power amps from Adcom, Acurus, Aragon and Nakamichi Stasis(Threshold). If I can afford more and have the money to spend, I would definitely try Krell, Bryston and Pass Lab amplifiers to drive my AR speakers. Crown I like but only the Crown Reference 1 amplifier which cost $4000 when they first came out!

Some people insist on Tube amps mate better with AR speakers and if you have the knowledge to choose the right vintage, brands and batches of tubes in different era and have the time to wait for the tubes to warm up half an hour before listening then by all mean... go for tube!

HiFi is a very personal hobby so whatever please your ears and sound great in your listening room then be happy with your set up and "Enjoy the Music".

Minh Luong


Hi Minh,

I agree, those are wonderful amplifier recommendations, and it is advantageous to use the best possible amplifier. I just didn't want folks to think that they need to spend alot of money for the the 303's to be satisfying.

The WT3 measurements you posted of the AR 303 woofer are very close to my results, and supports my contention that the Tonegen woofer is not more compliant than the 303 woofer. The 303 woofer also has the advantage of operating in a slightly larger cabinet.

Roy
Roy Champagne

#8 AR303 and classic 18 user

AR303 and classic 18 user

    Member

  • Members
  • PipPip
  • 20 posts

Posted 13 February 2011 - 08:05 PM

I drive my 303s as right and left mains in a 5.1 setup powered by a sunfire signature 400 seven. (Theater Grand IV as pre amp) Never any problems. At typical volumes with music, movies conatining < 25-32 Hz content expect around 50-60 watts. I agree with the 100+ watt recomendation for the clipping reasons mentioned previously. The AR suggested range printed on the back of the speaker is from 50 watts min to 250 max.

Attached Thumbnails

  • 303Logo.jpg


#9 soundminded

soundminded

    Advanced Member

  • Members
  • PipPipPip
  • 1,617 posts

Posted 13 February 2011 - 08:45 PM

I am getting a pair of AR-303a speakers and I was interested to hear comments from those that
own these type of speakers or similar, regarding the type of receiver and power required to drive
adequately these speakers. I know that they are rated at 85db, which makes them not as efficient
as more modern speakers, but I would like to know what to expect or may need. Would a 110 watt per
channel receiver suffice? Any recommendations?

DeanC


The issue for amplifiers driving AR 12" speaker systems isn't the power levels like it once was in the early days of AR3 and AR3a when 25 watts RMS was a large amplifier. It is the low impedence and power bandwidth/frequency response.

AR 12" speakers present a nominal 4 ohm impedence to amplifiers and at some frequencies are even lower. This is a problem for many modern HT receivers. I tried a Sherwood with my AR9s with the woofers disconnected and it still shut down to protect itself. These speakers require amplifiers that are stable at very low impedences. Many HT receivers warn not to connect speakers of less than 8 ohms, some not less than 6 ohms and they mean it.

The other problem is that some HT receivers only have a power bandwidth that extends down to 50 hz. This is not enough to take full advantage of the low frequency capabilities of these systems, a characteristic which distinguishes them from most other speakers. A receiver or amplifier for use with them should have a power bandwidth and frequency response that extends down to 20 hz. An alternative to a low cost HT receiver would be a fine used receiver from the 1970s or 1980s such as a Marantz 2270 or 2285. These receivers have ample power, stability, and the ability to handle low impedences to do an excellent job. Other alternatives are separate amplifiers, practically anything produced by Adcom has proven satisfactory. SET amplifiers and the inexpensive amplifier boards being offered by Parts Express that appear to have high nominal output would not be on my list of choices either.

Among HT receivers I'd look at are high end Harman Kardon receivers. I'm not sure but I think they'd have some candidates among them. The problem is that they can get expensive.

#10 genek

genek

    Advanced Member

  • Administrators
  • PipPipPip
  • 1,607 posts
  • Gender:Male
  • Location:San Marcos, CA

Posted 13 February 2011 - 09:35 PM

I consulted HK about driving speakers with impedances as low as 2 ohms when I was shopping for a new amp a few years ago, and they said although all their HT units were 8 ohm rated their top models could do it if they were provided with really good ventilation. I eventually ended up with a pair of Sherwood separates that were rated at 4 ohms after Sherwood assured me that 2 ohms or lower were no problem for the power amp, and so far it hasn't been.

#11 Mexicomike

Mexicomike

    Advanced Member

  • Members
  • PipPipPip
  • 315 posts
  • Gender:Male
  • Location:Mexico City/Chester, MD
  • Interests:Too many to list but include...<br />Audiophile since I was around 14 - first amp was an Eico 4WPC kit!<br />Build Harpsichords<br />Photography<br />Play Flamenco Guitar/piano/started learning violin 2 years ago.<br />Built/owned/operated small recording studio for 10 years <br />Motorcycles - raced in my 20's; still own a Norton Commando I raced...<br />Built auto high performance and competition engines; still do it for friends<br /><br />

Posted 13 February 2011 - 10:58 PM

That is one neat thing about the McIntosh power amps - they commonly had speaker taps for 4, 8 and 16 ohm. Another neat thing was the power-guard circuit that they incorporated in the 70's which makes the amps incapable of clipping. It's a nice safety "system" for speakers and has no effect on the sound of the amplifier. If it activates, it just limits the power output. Mc power amps are, IMO, essentially bulletproof. I'm less a fan of the Mc preamps after they went to multiple circuit boards and eliminated point-to point wiring. I have had frequent channel dropouts that require opening up the preamp and breaking/cleaning/remaking the connections on the circuit boards. It's not hard to "fix" but I have to do it once or twice a year on my C34.

#12 JeffS

JeffS

    Advanced Member

  • Members
  • PipPipPip
  • 39 posts

Posted 03 April 2011 - 02:28 PM

I am getting a pair of AR-303a speakers and I was interested to hear comments from those that
own these type of speakers or similar, regarding the type of receiver and power required to drive
adequately these speakers. I know that they are rated at 85db, which makes them not as efficient
as more modern speakers, but I would like to know what to expect or may need. Would a 110 watt per
channel receiver suffice? Any recommendations?

DeanC


I'm very late to this, but hopefully can still be of help. I've been using a pair of 303's for over 10 years now. Currently they are being used with a modern HK stereo receiver with 120 W/ch @ 8 ohms in a relatively live 400 sq ft room. That seems to work very well. You're power requirements will depend largely on room size and furnishings. A few years ago I had the 303's in a 200 sg ft room that had an 8' open doorway next to one speaker. With wall-to wall carpet, I was driving them with a Carver amp that had ~ 350 W/ch. Having that much power with wide dynamic material was handy but I found that after replacing the wall-to-wall carpet with a smaller area rug, I could get by with ~ 100 W/ch.

JeffS

#13 Seabert

Seabert

    Member

  • Members
  • PipPip
  • 13 posts

Posted 05 April 2011 - 02:52 AM

I have a pair of AR2ax. So far I tried Cary SLI-80 (80W)/all tube system, Naim 180 (35W), HK630 (30W)/vintage reciever/ and a Haffler SE-240 (120W) w/carver preamp. They all sounded great and I never had any problems. For the money, the HK630 was perhaps one of the sweatest amps with the ARs in spite of its low power output. I liked the bass response/contol from the Naim. The SLI80 had no problems driving the ARs at 40W triode or 80W ultralinear. I am now trying the Hafler which is rated at about 120W. At first, the Hafler which has the most power I tried so far sounded a bit harsh but after a few days i don't notice that anymore. No matter what i do, the ARs still sound like ARs but I never tried 200W or more. My guess is that a good tube preamp with a decent B&K (200W) amp would probably be one of the best combos for the ARs. Well that is what I want to try next. Anyhow, it always seems to me the ARs are very lacking in the mid and high frequencies which is were may of the amps i like excel. I have been thinking about upgrading the drivers but i am also worry about loosing the AR sound. We will see what happens but the mix of tremendous base with more airy highs could be pretty magical.

#14 genek

genek

    Advanced Member

  • Administrators
  • PipPipPip
  • 1,607 posts
  • Gender:Male
  • Location:San Marcos, CA

Posted 05 April 2011 - 04:27 PM

Any change you make in the drivers will change the sound, especially the "airy" nature of the highs, which are produced by the wide-dispersion MR and HF domes. Replace those with modern drivers and you will get boosted MR and HF and tighter imaging at the cost of that "airy," because modern drivers are not designed to produce that sound.

Maybe what you really need is an amp with a midrange tone control, or an equalizer?

#15 Pete B

Pete B

    Advanced Member

  • Members
  • PipPipPip
  • 1,557 posts
  • Gender:Male
  • Location:Connecticut, NE USA
  • Interests:Interest in Audio for over 30 years, got started early
    Electrical Engineer (see my web site link)

Posted 05 April 2011 - 11:23 PM

Hi Minh,

I recently measured new old stock AR 303 woofers (sent to me by Tom Tyson). The 303 woofers had a slightly lower fs...22hz vs 25hz measured for the Tonegen woofer. This suggests that the 303 woofer is actually a tiny bit more compliant than the Tonegen. Sensitivity is about the same. I really don't see the 303 woofer requiring more power.

I listened to a friend's pair of AR 303's through an old 75 watt/channel receiver last summer in a rather large room. They easily filled the room, and sounded very good.

Roy


Hi Roy,

You really can't be sure if a lower Fs is due to higher compliance
unless you know that the moving mass is the same. The 303 woofer
has higher cone mass than the typical AR 3a woofer which is also
in line with it having lower efficiency. I do recall some of the
design info on the 303 indicating that it was a few dB less
efficient than the 3a. Moving mass is the significant parameter
since once the compliance is high the box volume is the dominant
parameter with regard to the closed box resonance (Fc).

#16 Mexicomike

Mexicomike

    Advanced Member

  • Members
  • PipPipPip
  • 315 posts
  • Gender:Male
  • Location:Mexico City/Chester, MD
  • Interests:Too many to list but include...<br />Audiophile since I was around 14 - first amp was an Eico 4WPC kit!<br />Build Harpsichords<br />Photography<br />Play Flamenco Guitar/piano/started learning violin 2 years ago.<br />Built/owned/operated small recording studio for 10 years <br />Motorcycles - raced in my 20's; still own a Norton Commando I raced...<br />Built auto high performance and competition engines; still do it for friends<br /><br />

Posted 06 April 2011 - 03:12 AM

" do recall some of the
design info on the 303 indicating that it was a few dB less
efficient than the 3a."



I didn't realize ANYTHING was less efficient than a 3a! :)

#17 genek

genek

    Advanced Member

  • Administrators
  • PipPipPip
  • 1,607 posts
  • Gender:Male
  • Location:San Marcos, CA

Posted 06 April 2011 - 03:46 AM

Back in the 90's I "test drove" a pair of 303s using my old AR amplifier, and they worked fine together. Just couldn't wrap myself around the idea of two big, all-black boxes (still can't, really). Got distracted from audio for a while and didn't find out about the cherry and rosewood versions until long after the model had been discontinued. :(

#18 RoyC

RoyC

    Advanced Member

  • Members
  • PipPipPip
  • 1,696 posts
  • Gender:Male
  • Location:Latham, NY

Posted 06 April 2011 - 04:26 AM

Hi Roy,

You really can't be sure if a lower Fs is due to higher compliance
unless you know that the moving mass is the same. The 303 woofer
has higher cone mass than the typical AR 3a woofer which is also
in line with it having lower efficiency. I do recall some of the
design info on the 303 indicating that it was a few dB less
efficient than the 3a. Moving mass is the significant parameter
since once the compliance is high the box volume is the dominant
parameter with regard to the closed box resonance (Fc).


Hey Pete,

Good points...I just dug out the 1995 Stereo Review comparison, and Julian Hirsch measured the 303 to be 2db less sensitive than the 3a. I believe the 303 also had the advantage of a very slightly larger cabinet volume.

With that said, I was able to compare 303's and 3a's head to head last summer, and subjectively did not find the sensitivity to be much of an issue relative to bass response. There were more obvious differences at higher frequencies. When compared outside the cabinets, the 303 woofer suspension (spider and surround) softness was similar to the 3a Tonegen replacement woofer, but a bit stiffer than several original 3a woofers I had on hand.

Roy
Roy Champagne




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users