onplane
-
Posts
432 -
Joined
-
Last visited
Content Type
Profiles
Forums
Events
Posts posted by onplane
-
-
On 4/16/2018 at 12:02 PM, genek said:
No. I went looking for a 3-way acoustic suspension speaker one could add a 12" subwoofer to, and that Yamaha bookshelf box seems to be the only one there is.
Gene, is there any reason you did not chose this option?
Now, I felt the unit went too low and would overlap too much the SVS sealed 12 inch sub.
Regards,
Jerry
-
4 hours ago, Aadams said:
There has been a lot of talk in this thread. Has anyone actually done anything with new speakers to achieve the "AR sound"? I get the feeling this board is mostly geezers, to whom this is not problem, because the expected life of working ARs at this point is longer than that of the owner.
Adams
Adams, you just might be right about that.
Another possibility is that board members rather than seeking high performance speaker systems, are spending big $'s on high performance hearing aids.
Regards,
Jerry
'
-
29 minutes ago, genek said:
This is pretty much the way subwoofers used to work in the olden days before home theater, and if the goal is to make the new speaker stack sound more like a "classic" bookshelf or floor standing AR, it's probably still the way you want to go. The AVR's subwoofer out would just not be used at all.
And if the LFE setting on the SVS is the bypass for its low pass, then you'd need an external crossover.
Gene, your point about AVR LFE output being a summed signal is on the mark. It would be of no value with two subs where we wish to maintain imaging. I did mention in my post above about an external xover, but that would NOT be my goal.
I just wish NHT published the frequency response graphs of their units. I suspect that 4.5 inch NHT unit begins to roll off somewhere in the 150Hz to 100Hz range. This natural roll off could be complemented quite well by the sub.
As for the low pass defeat, SVS is not the only manufacturer that provides for a complete by-pass. The idea is to let systems like Audseey take complete control of satellites and sub.
Regards,
Jerry
-
On 3/24/2018 at 7:40 PM, Aadams said:
The SVS is a nice unit. Even though it extends to 260hz It appears the only way you can cross it over above 160hz is to use the LFE circuitry in an AV amp/receiver. My old 5.1 will cut LFE as high as 200hz and front satellites starting at 200hz down. I have never seen a stereo amp with this kind of built in capability.
Adams
Adams, it looks like you are correct that the LFE setting is the only way to cross the SVS sealed sub above 160Hz. That is, the actual crossing must be done outside the sub. AVR is one way to do this, but so is an external electronic xover.
In both cases, IF YOU CROSS THIS HIGH, you must also make certain that you limit these frequencies from the bookshelf (i.e. the other speaker in the stack). With the NHT unit I choose, I suspect crossing at 100 to 120Hz would be ideal. That is, assuming the NHT bookshelf does a decent job in the 100 to 200Hz range. Now bear in mind, it is "rated" down to 85Hz.
Regards,
Jerry
-
7 hours ago, Aadams said:
Onplane
This is your thread and we have not heard from you. Now that a few of us have tossed out ideas, what are your thoughts at this point?
Adams
Well, Adams, it certainly gets confusing, especially when you bring in AVR units. I don't have a lot of experience with these. I do own a Marantz 5.1 AVR with Koss mains, KLH rears and an AR sub. For movies, it is great!
For music... not so hot. I much prefer my AR's powered by a rather standard two channel amp. (Actually my unit has two full range amps in a single box allowing bi-amping with just the three terminals AR provided.)
Anyhow, when my AR's finally succumb, I know I would never be happy with a single sub for music. I simply must have a sub for each channel. Further, I want sealed units, because I enjoy the bass delivered by the AS system. I can hear the difference over ported systems and I simply prefer the AS sound.
So with the "heavy lifting" being done by the subs, and having found in SVS sealed units capable of being driven by speaker level inputs, my next problem is to find AS units to handle the mids and highs. (I believe Rel is correct that integrating subs into music systems works better when the subs "see" exactly the same signal as the mains with any and all phase shifts introduced in the power amps. Next the SVS unit can easily go to 200Hz, which is another plus.)
So to reiterate, the remaining problem would be to achieve the dispersion of the domed mid and that is NOT easy. My "gut feel" is that the NHT unit with the 4 inch "mid/woofer" would do this better than units with larger drivers. My fear is that larger drivers would just become far too directional at and near the xover with the tweeters. Thus giving up dispersion to gain... what?
So I am back to where I started. Clearly, the SVS/NHT stack is not perfect, but it still might be the closet you can get with modern components. My only real fear is with the NHT SuperZero and will it really get down to the range of 200 to 150Hz smoothly. Possibly members who have them can comment.
Regards,
Jerry
-
Supposing you really enjoy that acoustic suspension sound "invented" by AR and supposing you no longer wished to "struggle" keeping those 40 to 50 year old speakers running and properly tuned. How would you achieve that "AR sound" with devices in today's audio market?
There is a current thread about the resurgence of KLH started by Frank, but I did not see any AS offerings in that new line. (It's possible that AS speakers will be included, but as I said, I did NOT see any.)
Thanks, Frank, for that thread as it is interesting to see an American company ... trying!
Anyhow, I have been giving this subject some thought and given that I would be willing to spend some $'s, but NOT mortgage my house, I think stacking something like these:
On a pair of these:
https://www.svsound.com/collections/1000-series/products/sb-1000
Just might yield acceptable results. The SVS 12 inch, front firing sub is a sealed box and the NHT unit is also sealed. The specs on the NHT rate it down to 85Hz, but my suspicion is that around 120 is more realistic. At the same time the SVS is rated up to 260Hz, but again looking at the actual graph, 200 is more realistic. My point is there should be adequate "room" to merge these units using the variable xover on the sub.
Two questions:
1. What do you think of this stack?
2. How would you achieve that AR sound with modern components?
Regards,
Jerry
PS: Just happened to think that for Frank and his LST's, you could get 4 of the NHT units and wire them two units for each channel in parallel.
-
20 hours ago, Ray O said:
So, this brings another question. What vintage receivers would drive the two pair of AR3a? Maybe I should seek an external amplifier. Any suggestions?
RAY, not vintage, but the Sherwood RX-5502 (see datasheet attached) would handle 4 AR-3a's. Reason for this is this unit has 4 full range amps (i.e. 2 stereo amps) in a single box. Each amp is rated 100 wpc at 4 ohms.
Beauty of this scheme is you get two independent volume controls so you can balance the two set of speakers to get similar volume in spite of room placement. With a single amp, one speaker set with dominant the other just due to its position in your room.
Regards,
Jerry
-
4 hours ago, Steve F said:
For the 2ax (new), 5 and 3a, there is the tweeter issue: those three little blobs that constitute the tweeter ‘surround’ simply degrade and stiffen, reducing the tweeter’s output far below its already “reticent, too-polite” level. When brand new, the 2ax’s/3a’s on-axis tweeter level was 5-6 dB below the woofer level. AR’s own system curves show this. A 40-year-old tweeter with output reduced even farther below that level results in a speaker with barely-audible highs.
The pots. Enough said.
Steve, your observations are spot on! Below is an example of that original AR frequency response graph.
My 3a's still sound fairly decent (I am the original owner), and I did NOT spend a fortune restoring. I by passed both pots, and added a padding resistor to the mid to drop it further behind the woofer. Finally, I bi-amp using just the 3 terminals AR provided.
Then to bring everything back into balance, I simply provide more voltage to the mids/tweeters via the volume control on their dedicated amp. In short, I have moved "voice control" from those pots behind the speakers to the volume controls on my amps. Further, on my latest amp the volume controls exist on a single remote, so altering voice is now a matter of remote clicks.
This was done on my 3a's ten years ago and I have experienced zero problems with this setup. Now, in all fairness, Roy cautioned me ten years ago about the eminent demise of the tweeters. He felt the additional power they now see, will kill them off. The 3a's are in my den, a very small room, so keeping Roy's advice in mind, I rarely apply more than a watt of power. At that level the voltage across those tweeters ... well, it isn't very much ... NOT very much at all! They really aren't being "pushed" that hard and I suspect that is why almost 50 years later they still work and sound better than the original "muted" setup.
Regards,
Jerry
-
On 8/19/2017 at 5:52 PM, barryjo said:
Applying a signal to the normal terminals gives no sound. It might be that the capacitors are open.
If I apply a small signal directly to the tweeters I can tell if they are working . I will be careful
I understand that you get no sound, but the whole idea of using a scope is to see where the failure exists. If you get "no sound", but you can see voltage exists across the tweeter, then the tweeter is most likely dead.
On the other hand, if you apply voltage to the main speaker terminals and can not see anything across the tweeter, then this explains why you get no sound. It also means the failure is in those damn pots or not as likely in the cap.
Regards,
Jerry
-
9 hours ago, barryjo said:
I am going to use my computer and amplifier as a signal generator. I can go to the Internet and enter "online tone generator" and get a program that allows me to make tones of different frequency. I have the computer output routed to my amplifier. I think I can then carefully put the speaker output directly across the tweeter terminals to see if I can hear the high frequency tone. I will do this at low level of course to make sure I don't damage anything. I hope this works.
I see that I can get tot e tweeter and mid range terminals easily using the terminals on the front panel of the speakers with the grill removed.
There is no need to connect direct to the tweeters. Just connect your amp to the normal speaker terminals. Those high frequencies should be passed directly to the tweeters. Also be very careful of those wires on the front. They are very delicate and some would say brittle.
Also do NOT apply any significant voltage to the tweeters. You will fry them. You should start at 1000Hz and make certain that you are not over driving.
Once you can get a modest sound out of the mids at 1000, then you can try 7000Hz and put your scope across the tweeter wires very carefully. If you can't see anything on the scope, you know no voltage is getting to the tweeters.
Regards,
Jerry
-
16 hours ago, barryjo said:
Since both speakers act the same, i.e. no high freq sound I gather the best thing to do is to remove the woofers, then the stuffing, then troubleshoot the pots and capacitors. Moving the pots does not cause any sound or scratching at all. I do see that there are very small wires connecting the tweeter and midrange voice coils to the terminals on the front panel. Using my oscilloscope, I should be able to connect my amplifier to the speakers and then look for a signal on those fine wires. That should tell me a lot.
Hey, I really appreciate all of the good advice I am getting here.
With your scope you can see whether any voltage is getting to the tweeters.
Now bear in mind that there isn't much music in these ultra high frequencies. You must look for tracks full of cymbals like a jazz trio. Also to even hear working AR tweeters requires a toilet paper tube over the tweeter at one end and near your ear at the other end.
If you hear anything, they are working.
Those pots are notorious for corroding and significantly reducing voltage. I by-passed mine nine years ago and they haven't given me any problems since.
Regards,
Jerry
-
I found the pic below on AK and it's supposed to be the xover of an A-25. I've seen written many times that the A-25 has no coil in the woofer xover, yet there clearly is one in this pic.
Any guesses as to what's going on here?
Regards,
Jerry
How would you achieve that AR sound modern components?
in Acoustic Research
Posted
Well, Gene, that is exactly the problem and why I choose the SuperZero - in hopes that its natural roll off would NOT overlap the SVS unit in the LOWEST frequencies.
I don't know, but my gut feel is a single low frequency driver would yield the clearest, cleanest bass.
Regards,
Jerry