My Realistic Mach One Restoration

[Freewillisdead112]

Im not going anywhere. I am starting to understand why these are not getting such high accolades. I am watching a movie as we speak and I'm hearing nothing but tweater and midrange distortion. I think im going to get rid of them as soon as possible. Kinda upset I fell for a couple good reviews.

Is this my integrated amp or the speakers or the crossover caps?

Once again, I'm sorry about my spelling. I honestly did not think It was a big deal.

I am here like everyone else to learn. And learning takes time, mistakes and wasted money.

And my Integrated amp 50x2

[Luvin Da Blues]

Once again, I'm sorry about my spelling. I honestly did not think It was a big deal.

I am here like everyone else to learn. And learning takes time, mistakes and wasted money

Take it all in context. A lot of us are nearing or are at our "Arctic Blonde" stage of life and we were raised a bit differently. Stick around, lots of very knowledgeable people here. I came here a couple years back with a very mediocre system, many thousands of dollars later and still not completely content.

[JoeE SP9]

Im not going anywhere. I am starting to understand why these are not getting such high accolades. I am watching a movie as we speak and I'm hearing nothing but tweater and midrange distortion. I think im going to get rid of them as soon as possible. Kinda upset I fell for a couple good reviews.

Is this my integrated amp or the speakers or the crossover caps?

Once again, I'm sorry about my spelling. I honestly did not think It was a big deal.

I am here like everyone else to learn. And learning takes time, mistakes and wasted money.

And my Integrated amp 50x2

When you get an almost unanimous "diss" of a speaker it should tell you something. Over at AK the response is completely different. As I said earlier, many of the members over there are more interested in vintage than sound quality.
Yes, it's probably the capacitors in the crossovers.They are old and are probably failing or have failed. Rebuilding them would definitely improve the sound. Since you already have them you might consider doing a direct replacement of the crossover parts. It would not be expensive, would improve the sound and would be good practice if you are going the vintage route speaker wise.
Most of us have made mistakes with speakers and other gear. That's why we were so adamant about Mach speakers. It's gratifying to know that you are hearing why most of us think they don't sound very good. We're just trying to save you money!
Ported or horn type speakers tend to be more efficient than sealed box (acoustic suspension) speakers. 50 WPC should be more than sufficient for efficient speakers in a small to medium sized room. Of course, if you are listening at "head banging" levels 50 WPC may not be enough.

[3LB]

I'm hearing nothing but tweater and midrange distortion.
Is this my integrated amp or the speakers or the crossover caps?

I guess if you can unload them fast, then I'd do so, but if you can't, don't trash 'em, crack them open and use them as a learning tool. It's best not to fuss with something if yer afraid of breaking it.

It could be the caps in your x-over, it could be the drivers, it could be the L-pads. Old drivers tend to dry out and are more prone to distortion that before. If the sound of the horn presentation suits you, then by all means, keep the large horn - surely the driver is replacable. The smaller tweeter may have a replaceble diaphram, but I doubt it. It may even be a simple piezo (I'd have to see it). The woofer is easily replaced with a "budget woofer" or a slight upgrade, but it should be replaced by a woofer that will operate under optimum performance that cabinet. Take those drivers out and take pictures of those and lets have a look at them.

The L-pads are usually speayed with a lubricating oil from the factory and over a period of years, will turn to something similar to varnish. This will cause poor conductivity resulting in dropouts and distortion. Take that panel off and see if the pots have a tiny hole or opening anywhere - spray some electrical contact cleaner in them a work the control knob(Ratshack used to carry it). *try this first*

Most x-over caps are rated to around 60v to 70v, giving them an effective wattage rating of 100watts. That supposed to mean that that cap will maintain its effective crossover property at 100watts, even with a new electrolytic caps, rated at 100v, can still lose effectivness at high volumes, resulting in distortion. You can keep it simple, as I'm sure RS did, and stay with the -6db x-over, but use at least a 400v poly cap, which will never break down at high volumes and in my experience, introduces no significant artifact.

I'd be surprised if that woofer had an inductor (also called a coil or choke) for a x-over. Most manufacturers and designers rely on a woofer's natural rolloff, but if your midbass and/or midrange soounds muddy, that be why. Unless it was a two way and I were crossing in a mid or tweet around 7khz or 8khz, I'd never leave off a coil to aid in woofer rolloff (I'd never do anything like that anyway unless it were a PA speaker). But, i'd use at least a 18g, open aircore coil, and right now, they're a tad pricey, depending on their size (open aircore inductor have the least resistance, and are therefore more efficient).

And this is all contingent on whether or not the cabinet is salvagable. Try cleaning the L-pads and see if they sound more better.

[Freewillisdead112]

I opened the L-pad yesterday and the corners snapped off most of the plastic. Everything think looked clean in there, there was screws holding in the "mid-range" driver so i do think it could be replaceable. My camera Is not here at the moment so I shall tape pictures later.

Everything looked clean and the corner of the speaker is not through the board. This just surface damage. And no, these speakers do not have water damage. Just cup marks and drunken party damage (from what I picked up from the last owner).

I took out the woofer last night, and boy is it light. For how large the surrounds were i figured it would be a monster.

[Freewillisdead112]

today, I hooked them up to a Aiwa mini Hi-Fi Receiver/cd player. This receiver Is 6 ohm. I lost alot of low end boom/slam but cleaned up the highs and mids alot. I am really starting to think that theres something wrong with my Integrated amplifier.

Any thoughts why a garbage stereo would sound better then a stereo I once loved?

[budgetaudio76]

Me time Read?!! Since when do i have time! Of cous=rse i have time, As much i like to say taht i dont have time to do much of any thing because im a single parent. But i like to read about others perspective of music production thru stereos. Hell i take time to do that. negative comments or not. I do the things i do because i enjoy the hobby. Nothing more nothing less.

Take a look in my sig and youll understand. you cant hear what i hear thru my ears when i am listening to music.

[JoeE SP9]

today, I hooked them up to a Aiwa mini Hi-Fi Receiver/cd player. This receiver Is 6 ohm. I lost alot of low end boom/slam but cleaned up the highs and mids alot. I am really starting to think that theres something wrong with my Integrated amplifier.

Any thoughts why a garbage stereo would sound better then a stereo I once loved?

There could be something wrong with your integrated amp. Try the mini speakers on it. If they give the same kind of results, you have found the problem.

[Freewillisdead112]

I don't have the speakers to the mini, It was a garbage day find.

I dont have access to anything really to try and fix this.

[thekid]

Free

Hang in there and chalk these up as a learning experience, I have more than a few learning experiences sitting in my garage....

If you have been bitten by the vintage gear bug you might want to try some of the thrift shops in your area or Craigslist you'd be surprised what you can find. Vintage speakers there often run $20-$25 so you can roll the dice a little w/o spending a lot of coin and enjoy the thrill of the hunt. With a little patience and research you can find some good vintage speakers such as early KLH,Advents or Dynaco's. You can also find vintage gear that can be brought back to life with some cleaning and a few bulb replacements.

Good luck and good hunting!!

[Freewillisdead112]

kls's are on there all the time, not so much advent and dynaco. At least I didnt spend a wazoo!

[Freewillisdead112]

I see those all the time on cl. Ima have to get me a pair. People are greedy here on CL, they wanna charge insane amounts for old, crap things. I am going to pay for audiogons blue book so I can kinda get a jist on what I should be spending.

And I got the jbls for my birthday, so I really didnt loose a penny.

Some guy wants to trade me his mirage M-190i for them?????

[Freewillisdead112]

I have been getting alot of hits on these from CL so I think they shall be gone very soon. For a decent pair of bookshelfs that is!

[Macho_Honcho]

Hi all. Okay.. I know this thread is a several days old.. But it is still smoldering enough to warrant MY two cents. After reading this thread it seems that there are questions pertaining to the Radio Shack Mach One speakers that need answering, and hopefully someone will find this interesting. The ORIGINAL Thompson Electronics version of the Mach One, RS model 4024a, after thirty two years with no attention paid to the dried up ELECTROLYTIC capacitors in the crossovers, does and should sound like crap. Later the same box dimensions were used to produce similar looking 4029s in various countries for much less. Fewer screws, inferior drivers, much CHEAPER.. (Not to be confused with less expensive.) I digress.. So you have, or had a model "4024(a)" Mach One .. FYI, Without changing model numbers, Radio Shack (Tandy Corp.) slowly and quietly "de-contented" these 4024 speakers between '77 and '79. Yes, they all had the same model number.. 4024.. The original Mach Ones actually had veneer on the BOTTOM of the cabinet. (check yours?) By mid '78 the bottoms were spray painted brown .. to cut costs? Of course we all know what happened later with the cheaper drivers, and x-over parts. I am here to tell anyone that gives a hoot, that you need to hear an original pair of 4024's complete with the veneer on the bottom, and the original drivers. I have a pair.. here's what I did to get them into shape for actual LISTENING. New MUNDORF 10 watt resistors, to replace the cheapie sand filled wire wounds. New CLARITY CAPS for the signal path into the horn and tweeter, and SOLEN caps everywhere else. I left the original air core inductors intact. Yes the inductors are cheap, and I may replace them eventually, but so far this simple upgrade has taken these speakers from "FRAT HOUSE" to actually being very listenable. This was just a project.. I am always tinkering.. I have owned these speakers for decades. I actually have two pairs. Yes pairs, .. there are two of them. They are just for display.. they see some use when I am feeling sentiMENTAL. They are pushed by a Sony TA-N77ES for power, and they can really SOAK it up. The tweeters and horns are Phenolic dome compression drivers. Much like police sirens. Amazing that the tweeters can get all the way up to beyond 20Khz! I did spend a bit more on the crossover parts (Madisound.com) than $50, but every penny was money well spent. I would put them up against ANY consumer grade big box store speaker at ANY price. They of course will not hold a candle to my line arrays, and will never be for really critical listening.. Sometimes you drive the restored '65 Stingray, instead of the new Porsche 'cause you like the feel of a big V-8. I do not like Cerwin Vega, and never will. Sloppy , greasy , muddy, kid stuff. Not even in the same league with the original RS Mach one. Trust me, I know. .. .. On another "note".. I just finished going through a $4000 pair of Salk Sound V3's. You would think that for that much money, not only would they sound GREAT, (unimpressed) but the crossovers wouldn't be mounted on masonite peg board with components siliconed and wire tied into place.. You would think that for $4000, the screws holding the drivers in place would be tightened into threaded inserts of some kind.. T-nuts anyone? Wood screws, just tightened down into bare wood? (PARTICLE BOARD) Are you kidding me? My Mach Ones are certainly more well made than that! Even if they are also particle board boxes. BTW.. The horn section is completely sealed.. pry off the back panel, and take a deep breath of some thirty year old asian air! This concludes my CRAZY rant! Comments? Are I usin' bad words and stuff and junk? All in fun! Cheers!

[JoeE SP9]

Mundorf resistors, Solen and Clarity caps is a lot of money to try to make a silk purse out of a sows ear. In they end they are still sows ears.

[Sir Terrence the Terrible]

Hi all. Okay.. I know this thread is a several days old.. But it is still smoldering enough to warrant MY two cents. After reading this thread it seems that there are questions pertaining to the Radio Shack Mach One speakers that need answering, and hopefully someone will find this interesting. The ORIGINAL Thompson Electronics version of the Mach One, RS model 4024a, after thirty two years with no attention paid to the dried up ELECTROLYTIC capacitors in the crossovers, does and should sound like crap. Later the same box dimensions were used to produce similar looking 4029s in various countries for much less. Fewer screws, inferior drivers, much CHEAPER.. (Not to be confused with less expensive.) I digress.. So you have, or had a model "4024(a)" Mach One .. FYI, Without changing model numbers, Radio Shack (Tandy Corp.) slowly and quietly "de-contented" these 4024 speakers between '77 and '79. Yes, they all had the same model number.. 4024.. The original Mach Ones actually had veneer on the BOTTOM of the cabinet. (check yours?) By mid '78 the bottoms were spray painted brown .. to cut costs? Of course we all know what happened later with the cheaper drivers, and x-over parts. I am here to tell anyone that gives a hoot, that you need to hear an original pair of 4024's complete with the veneer on the bottom, and the original drivers. I have a pair.. here's what I did to get them into shape for actual LISTENING. New MUNDORF 10 watt resistors, to replace the cheapie sand filled wire wounds. New CLARITY CAPS for the signal path into the horn and tweeter, and SOLEN caps everywhere else. I left the original air core inductors intact. Yes the inductors are cheap, and I may replace them eventually, but so far this simple upgrade has taken these speakers from "FRAT HOUSE" to actually being very listenable. This was just a project.. I am always tinkering.. I have owned these speakers for decades. I actually have two pairs. Yes pairs, .. there are two of them. They are just for display.. they see some use when I am feeling sentiMENTAL. They are pushed by a Sony TA-N77ES for power, and they can really SOAK it up. The tweeters and horns are Phenolic dome compression drivers. Much like police sirens. Amazing that the tweeters can get all the way up to beyond 20Khz! I did spend a bit more on the crossover parts (Madisound.com) than $50, but every penny was money well spent. I would put them up against ANY consumer grade big box store speaker at ANY price. They of course will not hold a candle to my line arrays, and will never be for really critical listening.. Sometimes you drive the restored '65 Stingray, instead of the new Porsche 'cause you like the feel of a big V-8. I do not like Cerwin Vega, and never will. Sloppy , greasy , muddy, kid stuff. Not even in the same league with the original RS Mach one. Trust me, I know. .. .. On another "note".. I just finished going through a $4000 pair of Salk Sound V3's. You would think that for that much money, not only would they sound GREAT, (unimpressed) but the crossovers wouldn't be mounted on masonite peg board with components siliconed and wire tied into place.. You would think that for $4000, the screws holding the drivers in place would be tightened into threaded inserts of some kind.. T-nuts anyone? Wood screws, just tightened down into bare wood? (PARTICLE BOARD) Are you kidding me? My Mach Ones are certainly more well made than that! Even if they are also particle board boxes. BTW.. The horn section is completely sealed.. pry off the back panel, and take a deep breath of some thirty year old asian air! This concludes my CRAZY rant! Comments? Are I usin' bad words and stuff and junk? All in fun! Cheers!

Holy ****aki mushrooms, somebody with some real knowledge and history of the Mach One speaker. I still have 3 pairs the original 4024(originally purchased 4 pair) model built in 77 with the veneer unsprayed bottoms. They sounded significantly better than the later incarnations and are very listenable even when compared with some speakers produced today. Back in the day Stereo Review ranked these speakers the second best sounding of its time, as it had more strengths than weaknesses. I replaced the same exact parts as you did include the air core inductors. I loved these speakers so much that later I had the mids and tweeters upgraded with new drivers, and purchased a new crossover system that time aligned the drivers. By the time I finished, I almost had a new speaker sans the cabinet and woofer. The original woofer complete with rubber surrounds was so good, I never replaced it. From what I understand (from the RS engineers at the time) they began downgrading the speaker to control costs, and make them manufactureable for the masses. The real originals were hand built, and used high quality parts, and were well tuned(this took awhile to do) which made them VERY expensive and difficult to reproduce in large quantities. There were also was not a lot of them built or sold until the cheaper lesser quality ones came on the market. They are an extremely rare find now, as they have been abused and neglected too much to sell.

I am of strong belief that Freewillisdead has the later incarnation of the 4024. I gave my son one pair of the real originals that I took extremely good care of, and left them unaltered from its original form. They still sound pretty darn good, but not nearly as good as my upgraded ones. The thing I liked about them is that they did not have the horn coloration that the later models had, and actually had a very sweet airy high end. The bass was clean, went deep(it was really flat to 20hz) and a very good driver to driver balance - something that was very difficult to achieve at the time. The later models sounded dirty and rolled off in comparison, so I completely understand why many folks here dislike their sound. Like all things their internal part do degrade over time, and require replacing if you want them to sound good. Freewillisdead, unless you have the woofer with the rubber surround you will have to ditch the woofer. There are no more original woofer drivers because according to RS I bought the last six they had in stock many, many years ago(and I still have them just in case the others fail). You will also have to replace all of the parts that Macho Honcho mentions in his post. If you are willing to make the investment of money and time, those speakers will sound significantly better than they do now.

I still own those three pairs of upgraded Mach Ones and use them in a hometheater in my vacation get away. I converted two of them into subwoofers by just removing the drivers, L-pads and crossover, and sealing the front panel. They still have the original woofer, and it plays back extremely loud and clean. Three are used for the front channels behind a woven acoustically transparent woven 110" screen. One sits idle and carefully packed to keep dust away - I have not figured out what to do with it. While this hometheater is not my besting sounding one, it has a very good sound to it(minus the annoying horn colorations), and when mated with with a fairly decent 100 watt per channel stereo amps(they don't need this much power to achieve theatrical levels), and combined with six custom designed and built speakers with horn loaded tweeters (incorporating the same tweeter drivers as my fronts) makes for a very authentic sounding big movie theater sound.

[Sir Terrence the Terrible]

Mundorf resistors, Solen and Clarity caps is a lot of money to try to make a silk purse out of a sows ear. In they end they are still sows ears.

Upgrading to them makes a pretty good sounding sows ears. You really need to hear them with their internal parts upgraded before calling them sows ears. I suspect you have never really heard the original models, just their later incarnation. The first original models were not sows ears, but they were not a silk purse either. But neither were a lot of speakers manufacturered during that period. They definitely sounded better than many speakers of their time.

[thekid]

Sir T

Glad to see a regular weigh in on these a bit on the positive side. A lot people and some here are quick to dismiss RS gear. Many audio people think of the RS of today was the same as RS of 30+ years ago and that is just not the case. RS was probably the largest electronic/audio retailer back in the 60's-70's and as such was able to get a lot of quality manufacturer's to produce quality gear under the RS brand names. I am not saying all of their was great or that they produced quality speakers as consistently back then as AR,Advent etc who were the big speaker names back then but there are some quality RS speakers out there that are more than listenable to for those into vintage gear. Do a little research and learn abouth those that are worth picking up at the right price. Older RS gear consistently flies under the radar of your average "audiophile" and hopefully it will stay that way for those of us who like to buy on the cheap.....

[Worf101]

Rat Shack?!!!1 Hell I go back to "Lafayette Electronics"!!!!

Da Worfster

[thekid]

Rat Shack?!!!1 Hell I go back to "Lafayette Electronics"!!!!

Da Worfster

Well I was going to mention Lafayette in my rant but I figured most people here would not know what the heck I was talking about. Lafayette receivers though often fall into the same trap as RS gear. Do not get alot of respect from the the high end crowd but based on what some of their gear goes for on the Bay I'd say someone appreciates them. My Gladding-Claricon reciever is the same as a Layette LR-4000 or 5000 I think. Built in Japan and then rebadged by Lafayette.

[JoeE SP9]

Like Worf101, I go back to Lafayette Electronics. Worf, wasn't Criterion their in house speaker line? I heard Mach One's when TRS was major in the stereo business. I didn't like them then. I'm almost 62 now and still don't like them. I've been using planars since I got some MG-1's in 1976.

[Boatman1]

Don't let them bully you, show me another set of speakers that look as cool, I also have a pair hooked up to a Realistic sta 2000 and they sound good listening to 70s Rock on a Album. Everyone has there own taste, just be you.

[JoeE SP9]

No bullying is necessary. Doing a listening comparison is all that's necessary. HPM-100's sound better than Mach One's. I don't like them either.

[Sir Terrence the Terrible]

No bullying is necessary. Doing a listening comparison is all that's necessary. HPM-100's sound better than Mach One's. I don't like them either.

Isn't this a personal opinion Joe? Were the Mach Ones you heard the originals from 77-79, or the ratchet down ones? Regardless, you probably do not care for horn loaded speakers, and that is something I can understand. However, the originals were the most non horn sounding horn loaded speakers I have heard up to that time. I have since heard many custom designed horn loaded speakers that didn't have the traditional "honkiness" that most horn loaded speakers have, and now I am a lover of this design(at least one designers design anyway!)

From what I remember of the HPM-100, they didn't sound any better than the original Mach Ones. I think the HPM-1100 got in the same ballpark in the bass, and both speakers reach 25khz. I know the HPM-100's could not keep up with the original Mach Ones in maximum output with low distortion. Keep in mind, not a lot of original Mach Ones were sold. Far more of the later designs were sold than the original. There were few chances to hear the originals back then, and next to none of them have survived over time.

[Freewillisdead112]

They are the original with no straypaint here. I never sold them. Alot of peope interested till they saw the condition. Will It make that much of a change if I replace the parts in the crossover?