The AM Forum

I know that this is potentially a loaded question, but, what kinds of speakers do you have hooked up to that tube receiver?

Thanks, Roland

A 12 inch, in the top case, from a 60's high school gym class mono record player
A 16 inch Jensen coaxial with center mounted 4 inch..both have paper cones.... the big one has repairs made with fingernail polish....
An 8 inch 8 ohm RCA 70's stereo speaker with an 8/600 ohm transformer on a 600ohm output....
     Some other receivers have diode outputs switched into a solid state amp that drives a set of 80's Pioneer stereo speakers
  I have an RBC Navy rx that only has a headphone jack designed to drive multiple sets of headphones...Like 25 sets...I plugged in an old 8 ohm stereo speaker when I was testing the receiver 10 years ago and it is still working....I don't question why....The RBC is my mainstay 20M AM rx.......
    All but one are boat anchor receivers and I don't hear as well as I used to and this works for me....I just rig up the best I can with the junk that comes my way..Good Luck to you  and I am interested to see what others are using...

Several large Hallicrafters (multiple R-12T's , PM-23's, R-42's, R-46/46A's) and National 10" speakers hooked to all brands, they sound better than most other factory options. Exceptions are a 75A3 with matching speaker which is shared with a 75A2, and a HQ-180 with its 6x9 SP-200 matching one

I also have a 12" military speaker (LS-12 I believe) being beat upon by a couple of older Super Pros.

Carl

Mainly Hallicrafters,  R42, PM23 and R12.  
 
I use matching speakers when I can.  All national HRO's are hooked to the correct national speaker.  

For R390 and SP600, I dont use the internal audio.  I use a Diode load take off to an RCA jack to any small audio amp I could find.

C

Halli R42 is a decent all-purpose speaker you can move from set to set pretty easily, and it sounds reasonably good. I've got one here, it works well. Also a 10 inch Jensen plain jane cone in a 312A speaker hooked to the A-4.

Others are the big 1950s 15" EV TRX-something in a corner enclosure used for the SP-100 and a pair of '40s-'50s vintage Jensen JHP-52 15" coaxials in Collins lobby cabinets courtesy of Long Island Radio WA2PJP. Recently hooked one up to the SX-62B, sure sounds nice.

Other than the EV, I think they're all 500-600 ohm.

Hi Roland ... interesting that you brought up this question .... most hams will spend plenty $$ on the gear and then the minimum $ on the reproducer (loudsqueaker or microphonium)

since most boatanchor receivers have limited audio power out before onset of distortion, it is important to use an efficient speaker ... the specification is db spl / Watt at a distance of usually 1 meter ...  looking for at least say 95 db spl for 1 Watt input power ... this will give you loud sound in a small room with cleanest possible audio

I tend to prefer coaxial speakers used in sound reinforcement as they tend to meet this criteria in a compact size

73 .... John

Roland your question is one of personal preference, and worth discussing as you consider the range of choices for yourself.

John has put it well, above, in suggesting many stations shortchange their ability to obtain the best quality of reception that their receiver(s) can deliver.

And I also agree with him that something from the category of sound reinforcement speakers is best suited to deliver the full fidelity available from many stations we talk with.

What I use is a pair of Avid 102,  a two-way loudspeaker that was quite popular for home stereos about 30 years ago.  They don't take much audio power (high efficiency) and deliver full tonal response without a lot of equalization.  To provide the most driving power, I connect the output of my receiver to an external audio amplifier (McIntosh tube amp, total overkill), with the volume level still adjusted at the receiver.  

(http://www.oaktreevintage.com/web_photos/Stereo_Speakers/Avid_Model-102_Speakers_web.jpg)

Muting, when transmitting, is a simple relay system that puts a shunt resistor in the audio path, in addition to the customary muting of RF amplification at the receiver. This dual-step method completely eliminates any feedback heard while transmitting.

I use an Altec "Voice of the Theater" horn on the R-390A, and a ROKIT-5 (built-in amp) off the diode load on the R-390.

Polk 4a on the NC300.

Thanks for all the great information. I'm going to make a guess that speakers for communication equipment don't need a very wide frequency response. What would be a good spread for AM (no just BCB) listening?

Roland......

I like a cut off of 150 to 7K for an AM only speaker.  The low end cut off is nice for two reasons,  one,  The first minute an AM op gets ahold of an EQ and a studio microphone, they crank the bass to the max. They want to sound like Ted baxter, In reality, IT sounds like shat.. This way, i dont have to listen to all that low end.  Two,  Alot of old tube gear is nearly impossible to get ALL the hum out.  AC filiments and old capacitors,  If you have a speaker that gets super lows down around 60, You get to hear all that hum nice and loud in the shack either from your own receiver or from the station you are listening too.

The High end at 7K is a good balance.  I dont like loud hiss.  Lots of high frequency can cause fatigue to the listener.  5K is even a good place to start.   7K would allow max fidelity without all that hiss...

Hallicrafters used capacitors in the R42 to roll off the frequency.  I put a video up on Youtube showing those caps and the replacement of them.  That system can be used on any speaker to cut the highs down. or, Just unhook the tweeter in a repurposed Stereo hifi speaker.

C

Roland, there are a couple things to keep in mind: as John mentioned, many receivers aren't capable of HiFi or even pleasant audio as they are meant for communications service only. Restricted response and low output. It's easy to use too much speaker in hopes of making up the difference.

OTOH, if you're running a set intended for higher fidelity like an old Super Pro with variable IF and 14 watts or so output, you're missing out if you don't have that amp driving a decent speaker.


Yep, there's certainly plenty of that to go around. I refer to it as 'thumping' since that seems to be the result rather than a fuller sound. That's when the proper description is 'outboard distortion' instead of outboard processing.

But there are plenty of good sounding stations too. Well worth of proper reproduction.

The biggest issue becomes the number of nights you can open up your receiver to enjoy the full fidelity and clean signals some of the big guns have. The further south you go, the shorter the quiet season. But on those night when arm chair listening is possible, nothing beats a big ol' speaker booming away along with reproduction of crisp highs.

Good information. I didn't think about the residual power supply hum. So, high efficiency, ~150 to 7000cps. If you were building one, what kind of enclosure works well, sealed, open back, slots, stuffed, clip leads and no enclosure?
Thanks, Roland....

I wouldn't worry about limiting the frequency response of the speaker. An equalizer on the RX line gives your much more flexibility and allows you to match the audio for any situation/receiver. But that's just me. You should try a number of different speakers and audio arrangements. Everyone's ears and tastes are different.

I use the GE 11-8052A  8 ohm speacker. I found 2 at the side of the road. They are both Black, clean, and do not smell.  The Hamerlund feeds both of them. One sits on a 2X6, the other on a up side down wicker basket. They, like me, have value.


klc

I am a firm believer in having audio stages and speakers/'phones that can exactly reproduce whatever waveform the detector stage provides -- which means they must be capable of extremely high fidelity.

Not only will that allow you to hear precisely whatever the other guy is sending (and, if your ears require restricting or changing the response on some signals, you can always do that with an equalizer), but it will allow you to record it or examine it on a scope or audio spectrum analyzer and know that what you are seeing or recording is as close as possible to what was actually transmitted. Reducing distortion also removes a "veil" that poor quality amplification and reproduction imposes on all signals, which will make intelligibility better.

I have found that most commercial receivers require modification to achieve good fidelity, but it can be done just by following good hi-fi practices such as those laid out in the RCA Tube Manual and other sources. The easy way is to tap off the detector stage (some old receivers have a connector marked "diode load" for just this purpose) and feed the low-level audio into a high fidelity amp and speakers.

If you have good speakers or 'phones on your computer, you can listen to the results possible with a modified Racal RA-6790 on AM here:

http://liberty.3950.net/WA3VJB%207290%2020k%20bw%2020110320%200317PM%20ET.mp3

...and listen to a (slightly) modified SDR-1000 on high quality SSB here:

http://liberty.3950.net/W9AD-KU8R-K9JSP-WB9DNZ-N9BR%203630%20kHz%20LSB%2020120903%20830pm%20et%207500%20Hz%20bw.mp3

Whatever you do, experiment and have fun. There's something magic about getting all the quality and nuances of the human voice to come through the ionosphere.

73,

Kevin, WB4AIO.

Is that ESSB on the second clip?

Ive modified a TS-950SD for 3300 Hz on SSB and AM, the next step is being able to TX thru the 12KHz LC filter.

Look forward to hearing it!

I suppose you'd call the second recording ESSB -- just another name for high quality on SSB, which was once so rare you could go years between hearing it in a QSO. Now it's easy to hear it several times a week. I credit the AM gang with keeping the audio quality flame alive in ham radio, and the attitude we embody is now being used to improve another mode.

73,

Kevin, WB4AIO.

Ive heard that ESSB doesnt sound well on a regular SSB radio?

I suppose that's a matter of opinion. You'd definitely be missing part of the transmitted signal when listening in a more restricted bandwidth. And ESSBers, like Amers, have varied philosophies on how to tailor their transmitted audio. Some prefer an even energy response, octave for octave (which can be achieved with multiband processing set for "flat," and which sounds wideband but quite bright, like a top-40 broadcast station), while others prefer no upper range emphasis at all (which makes them sound bassier, to which some add bass boost). So they're all over the map -- as they should be, I suppose, since we're an experimental service.

Some stock SSB rigs (like some stock AM receivers, too, even ones considered "classic") severely roll off the high frequency audio response, so the only stations that don't sound muddy on them are stations with heavily boosted midrange or a severe lack of bass response.

Getting back to the topic of speakers, a relatively cheap (I got mine at Staples for $70 a few years ago) amplified computer speaker set that has very good performance for its price is the Altec Lansing VS-4121. I also really liked my old Acoustic Research AR-3 for amateur radio use.

73,

Kevin, WB4AIO.

I prefer to use old paper cone speakers.

If you look at what was used in the higher quality "console hi-fi" units from the 50's and 60's that had tube stuff in them - the tuner and record player with a flip up lid - they had 12" or 15" woofers and then some 5-6" paper cone mids and some paper cone tweeters. Often Jensen stuff or similar. Low power and high sensitivity. I like the woofers full range and a cap in series with the sealed back mids... skip the tweeters.

I'd advise to skip the tweeters if ur using cone speakers... go with a wide range mid if you run a two way.

But actually hooked up to my R388 now is an old Altec 12" coax monitor speaker, it's in a small stage monitor box, which is how it was used for years. The HF section is padded down a bit for better midrange balance. It doesn't reproduce very low in this small box. What I get is very natural, clear voices, effortless sounding.

I use a single JBL D208 "fullrange" 8" driver with the TS440s and that sounds wonderful actually.

Unless you want to use a giant box like that Altec Voice Of The Theater mentioned before, and you want big bass (some do) I'd suggest using an external amplifier and then putting on appropriate speakers for that.

In general it's my feeling that most "consumer grade" hi-fi/stereo speakers make poor speakers for listening to voices (unless you modify them and maybe not then). The reason is that they tend to be set up for excess highs, and some "boom" on the bottom. There are exceptions of course.

Everyone has different preferences and hearing, so what you like to hear is what sounds best to you. :)

                      _-_-bear

The other night, after loading the latest version of Flex software for the Flex 5000, I was sliding around 75 meters and found 3 wide-body SSB stations in QSO. Two were about 10 to 20 db over S9 while the third was about S8. Opening up the bandwidth a bit caused the weaker station to be peppered more by the prevailing evening atmospheric static making reception annoying and cumbersome to listen to. The highlight was that, with the amount of bass they all had coming through the 3-way speakers with 10 inch woofers, they all sounded like singer Al Greene. I half expected one or more to break out in song each time they transmitted.

They are amusing though. One year, while driving from home to Dayton, I listened to two guys on 20 meters spend roughly 3 hours diddling with their knobs and sliders on their multiple daisy-chained boxes between their microphone and the rig trying to find their audio "sweet spot". I never laughed so hard; finally had to switch over to Channel 19 to listen to some manly jabbering.

ESSB is just another part of the hobby to keep us engineers busy.  There is a popular ESSB freq here.  One night I listened on my Icom 756 Pro.  I keyed up to answer a question on the STOCK HAND mic and was told I had wonderfull articulate audio and was asked what my audio rack setup and microphone was!  BAHABABABA

That's why I enjoy the 15 inch Jensen JHP coaxials. I figure they knew what they were doing when they designed and produced them some 60+ years ago. No need to consult the audiophool community today for advice. They sound perfect, provided one has a receiver capable of driving them properly.


This is the part that confuses me. The advantage to using SSB is its ability to transmit a signal more efficiently. Works great for DX and so on. So why would you want to bend over backward trying to make it sound like AM instead of just flipping the mode switch to AM?  ::)


Yep, stupidity is not exclusive to one particular radio service. According to some of the ancient (20s-30s) QST columns from T.O.M., this has always been the case despite disparaging remarks about the more recent Citizens Band.

There's plenty of comedy to go around. ;D

I have several of the new Jensen speakers here.  I just put one into my R12 speaker as I needed an 8 ohm.  They are dirt cheap and sound realy nice.  The Vintage ceramic in "R" trim which means 25 watts max is a real bargain.  I also have some of the "MOD" model speakers used as replacements for some halli and national companion speakers.

The website is neat as you can listen and view the audio response graphs for each model.

http://www.jensentone.com/

C

One of my SX-62A's is hooked to a 1955 RCA AM/FM/Phono console audio system which has a pair of 12" plus a pair of 5" driven by PP 6V6's. Everything sounds great on it including ham AM but since it is in the FR it is mostly used for everything else for family and company. The other one up in the BR gets one of the R-42's.

They also like the Scott 800B with the 6550's (was 6L6G's) driving the stock 15" coaxial Jensen and thats in the DR.

Bet that sounds sweet!

Probably the simple answer from "them" is because "I want to do it" although there might be some underlying reason(s) that drive them to try a mimic an AM broadcast quality station on SSB. Maybe the mind says, "I don't get no respect" operating regular SSB. Or, maybe it's, "I don't like carrier" or maybe it's "2 sidebands and carrier are hard to manage and confusing". Who knows; maybe it's an ego thing; say I sound good enough times and many in the fold will believe it.

Generally, when I'm working casual SSB, the filter is set at 2.4 or 2.8 KHz, so anything beyond that just gets crunched in the electrons. When I'm contesting on SSB, I generally run the filter at 2.1 or 1.8 KHz. Don't need much for contest info like 59-### or 59-USA.

My first transceivers were TS-930's just as I was getting serious about contesting. The stock 2.7KHz filters were too wide for crowded bands and I installed a set of International 2.1's using sticky tape and some diodes rigged up so I could TX thru the stock filters and listen with either set. It kept those trying to squeeze in far enough away to be generally tolerable. ;D and soon became a widely used method that was often whined about in contest rags ::)

Another trick with stacks was to rotate the lower pair at the stateside QRM for  transmit on all 4 and listen with just the upper pair. It didnt take long to get a clear frequency and I doubt if most had a clue what I was doing and thought it was just propagation.

More power to 'em for trying things out and all that, it just seems like a more roundabout, difficult/expensive way to sound reasonably decent. Would be similar to adding 4 or 5 underpowered engines to a Yugo hatchback to go faster instead of just one larger engine or a different car actually built for speed.


It's tough to beat the old push-pull tube receivers for pleasant audio with minimal effort or complications like external amps, equalizers and so on. The SX-62B drives that big 15 inch Jensen JHP-52 like they were made for each other. Not CD-quality, just warm, full sound like an old console HiFi or floor model radio. The old Super Pros are my favorites. National made a few nice sets as well, like the NC-240 series. I think the HRO-60 was the last in the line.

I use a pair of KRK Rockit 5 two way biamped studio monitors fed from an audio switch matrix that
I built and is sourced from all of my receivers mounted in the rack. I can simultaneously switch the
audio feeds to my monitors, and the antenna feeds to the receivers.
Mainly, I use the R-390 as it's my favorite receiver, but I also use the 51J-4 and SP-600 JX-17.
The KRK's are very great sounding inexpensive studio monitors and can fill the
room with distortion free audio. They can be fed with any source impedance and offer three types of
connections. TRS 1/4", RCA & XLR. Balanced and unbalanced @-10 or +4. Provision for High frequency
level and input level. While I may end up using larger format speakers at some point, I think these are
more than adequate and certainly kick the snot out of the old Jensen's, of which I have many.
Another important aspect of this choice is physical size. They are approximately 10" tall and 7" wide,
8" deep. Hook up a powered sup woofer and you're in for a real treat. ;)

Some people like a challenge. And they like good-sounding audio, whatever the mode. (Myself, I have always loathed "communications quality audio" and I don't think the premises behind its promotion are valid, but that's a subject for another day.)

I had a Hell of a lot of fun back in 1987 modifying my TS-440 for good sound on both AM and SSB transmit and receive.

And the SDR-1000 I am using now can achieve even better quality in both modes. In fact, the mods I am doing to it involve mostly stabilizing the DDS reference, and using an external eq and limiter because they're (somewhat) superior to the internal processing.

But the rigs based on PowerSDR are basically broadcast quality right out of the box. That's an amazing thing to me -- and it means the 3885 hi-fi guys from 1968 have essentially won.

With my best,

Kevin, WB4AIO.

"hi-fi guys from 1968 have essentially won"
Won what?? I don't see the connection. SSB stations trying to achieve wide-body audio sounds more like an oxymoron.

Hey, I think anybody on any voice mode trying to achieve good audio is great.

I think that nobody in 1968 -- or 1978 -- or 1988 -- or 1998 -- would have believed that amateur rigs would ever be developed and sold that could transmit and receive broadcast quality audio right out the box. That kind of audio was what the then-rebellious young guys wanted, treasured, and developed in '68. It looked like a losing battle. The League, and just about all the manufacturers and publishers, were against it and firmly in favor of narrow, restricted, clipped audio.

But the 3885 guys have won. I don't mean they've forced anyone to stop running or liking narrow audio. I mean they've won the right to exist, and their specialty is now an established, growing niche in the hobby as a whole. Better quality audio (both for AM and SSB) is now built in to the PowerSDR rigs, and other manufacturers have followed suit.

Bravo, I say. Some of the central figures in making this happen from the AM side are WA1HLR, K4KYV, and WA3VJB. From the SSB side, NU9N. There are others too.

All the best,


Kevin, WB4AIO.

Close to BC quality out of the box on SSB goes back to the first phasing rig and those that followed which the SDR is based on. Aint nothing new about that and I get BC quality reports with a 1959 CE-100V.

DUQ was hi-fi in the 50's.

True. They were excellent, the best of their day.

But by 1970, CE was gone and the powers in ham radio were totally opposed to good audio on the ham bands.

A few rebellious free-thinkers, most of them young AMers who operated on 3885 and environs, went against the trend. They believed in and practiced the art and science of achieving excellent quality sound on HF ham radio.

It seemed liked a lost cause to many.

But now they've won. Though still hated by a few, their niche is now respected by many amateur operators -- and even catered to by manufacturers. Let's hope the trend continues.

All the best,

Kevin, WB4AIO.

I use the speaker that came with the TCS. It has a Jensen. Am I missing the timbre in some signals?

Jensen is just a brand name, not all were created equal.

Carl

For ham AM and SWL, which benefit from some audio fidelity, a small 2-way hi-fi speaker is my favorite.

They can be had for almost nothing when the receivers go bad - and be sure to check the high class neighborhood alleys after Christmas. Maybe someone got a new stereo. The bookshelf speakers thrown out will be nicely broken in!

A contender for the all time worst sounding receiver speaker is the LS-116?  - the weather resistant 4" mylar cone job in the cast aluminum green box. If the tinny sounding mylar isn't bad enough, the little 600:8 Ohm transformer inside is there to help.

The only excuse today for listening through a poor-sounding speaker is to experience the original "cone in a metal can" item or a restored one.

The Hallicrafters SSB mobile speaker is no gem either. Its hard to believe but it was also listed as an option for the SX-115!