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lodoc
03-20-2005, 09:32 PM
I'll try not to make it a long story but...
I have a pair of JBL L-65's with some HK equipment in the house. Have had L-100's as well.
I have a 2000 sq ft pole barn for car restoration with a McIntosh MC 60 amp and some tired Bozak speakers from the early 60's. The Bozaks are as big as a small refrigerator. They are so 'unidirectional' you have to be right in front of them to appreciate the one speaker that is still working fairly well. I would like to move up to some JBL's for the shop as I am able to spend more and more time out there. I don't mind spending the $ but want to get something that does a good job in the large space with the relatively small amp generally with an FM receiver playing. Any thoughts on what JBL's I should seek out?

lodoc
03-25-2005, 11:36 AM
oops, sorry...
checked the amp and it's a MC 240. still would like some input on JBL's that would sound reasonably good with this relatively small tube amp in a larger space.
my experience with tube amps is quite limited...

Mr. Widget
03-25-2005, 12:04 PM
This is for a work space right? Generally poor acoustics and all?

I would use the SS amp of the receiver and take the 240 indoors and use it as a mid frequency amp in a tri-amped setup... the MC-240s have very nice mids but are soggy on the bottom and a bit weak up top.

That said, back to the original question.... hmmm, I guess I would try a pair of 4430s if space and money aren't an issue. A local pro sound company has a pair in their barn and they sound pretty good in their large live space. You might also try 4 4425s or even 4312s placed roughly in the corners.

Widget

Earl K
03-25-2005, 12:33 PM
I have a 2000 sq ft pole barn for car restoration

Mr. Widgets suggestions/observations are good .

If it was my place, I'd take the opportunity presented by the size of the place to secure a pair of 4530s( or 4520s ) loaded with 2225h woofs, crossed over to a pair of 2445j drivers on 2360 or 2365 horns . Xover would be 3105a ? ( 500 hz type with uhf lift ). I'd also move the tube stuff indoors and run this with something a lot more hefty .

:)

mike
03-25-2005, 12:40 PM
An MC240 is far too nice and far too valuable to keep in a workshop.
MC240's were often used with period JBL systems like the Hartsfield and Paragon or more affordable speakers like the C34 or C40 Harkness.

Mike

lodoc
03-25-2005, 10:28 PM
I would venture to say the accoustics are better than most similar buildings because it has a 13 ft vaulted ceiling in the center designed to accomodate an automobile lift - so it's not a 'box'. And the phrase pole barn is somewhat misleading. It's heated, insulated, painted drywall sided, aluminum ceiling, water, phone, compressed air system, 200 amp service, alarm system, refigerator,etc. Really, If my wife throws me out I could live there.

So please don't worry about the MC240. I obtained it fully knowing it was a nice piece and had it refurbished by a certified Mac facility as it had endured some abuse. It is well protected and I leave it on 24/7. I don't have another ss amp/receiver out there. I use an older ss tuner with some asian name. I just want some better-sounding speakers that are compatible with the output of the amp and the accoustic limitations I'm facing.

Thanks for your input and concern for the vintage equipment

speakerdave
03-26-2005, 12:34 AM
I think Earl has the right idea. You need a two-way system with an efficient woofer in a large enclosure and a horn mid/tweeter crossed over fairly low, 500 or 800 cycles. You could also add a super tweeter like the 2405 if you want. A reflex enclosure would go a little lower in the bass than the scoops, with some loss of efficiency, but I don't think that would be a problem--although you have given no indication of your loudness requirements. The 2225 Earl suggests is a musical woofer, though not in production. They are fairly common used, though, as are reusable frames and the recones are reasonable.

You might actually be happy with one of the SR speakers like the 4732 or 33 outfitted with a more sophisticated custom crossover to smooth the response somewhat.

A 2225 or similar woofer can be tuned to 40 Hz or lower in a five cubic foot enclosure or larger. The larger enclosures would begin to involve a compromise of transient response. If you want very low bass you need a different kind of woofer, more drivers and more amp, or a subwoofer.

If it were me I would mate that amp to a pair of very efficient Altec 604-8G's in a five or six cubic foot box. If I wanted more low bass I would put the 604 in a closed 3-foot subenclosure and biamp at 80 or 100 cycles to a big solid state amp driving a pair of the also very efficient 18 inch 2242's in large ported enclosures. That would make the tea breaks more interesting, I think. Or you could use the 2242 up to about 250 cycles and use the top three drivers from the JBL 4350/55--the 12" 2202, the 2441 2" throat compresson driver on the short exponential horn at about 1200 cycles and the 2405 slot diffraction supertweeter cut in at about 9000. With a solid state amp and the 2242's taking care of the lows the Mac 240 would be fine in your application with the other three drivers. If you will be moving around a lot and want the high frequencies everywhere you might consider putting the 2441 on a Smith or Westlake type vaned horn.

You DID say you don't mind spending the money. Well, all right then!

David

GordonW
03-26-2005, 07:36 AM
Expanding on the idea of the Altec 604-8G... this could be really cool:

Use the 604-8G, in a BI-AMP setup... run it in a SEALED box (it'd only need to be about 2.5 cubic feet, thickly lined with fiberglass), down to 100 Hz. At 100 Hz, cross to a 2245 in a passive-radiator or ported box. For top-end extension, make a little "top-hat" enclosure to go on top, to set back a 2405/077 or 2404 supertweeter, lined up with the acoustic center of the Altec horn.

This entire speaker could be built into a 2x2x3 foot box... with the top 2.5 cubic feet closed off for the 604, and the bottom 8 cubic feet for the 2245. I'd probably use something like the Urei Big Red type crossover topology on the 604-8G, or have someone measure the drivers, in-box, and design a crossover using LMS or Soundeasy or something similar...

Here's a drawing of such a box... I've drawn it, front and side view respecively, spec-ing in a pair of the Parts Express DVC-series 15" passive radiators in the back of the box. Two of these should be able to handle the output of a 2245. The internal baffle for the 604, is literally, just a diagonal board, going from the bottom of the 604 to the top back edge of the cabinet. It'd wind up with almost exactly 2.5 cubic feet up top, and 8 cubic feet in the bottom. Should work great. The passive radiators are a breeze to tune (bolts in back, where you can just bolt on large washers)... should be easy to dial-in the system.

RacerXtreme
03-26-2005, 08:49 AM
How about 2 of these:
http://www.mypages.iparenting.com/webs/racerxtreme/dual18s2.jpg

And two A2's:
http://www.mypages.iparenting.com/webs/racerxtreme/VoiceoftheTheatre.jpg

But lose the Altec horns and go with 2445's on JBL 2365a's and throw in some 2405's or 077's for way up high.

That should be enough for your shop. :blink:


c-ya

Guy

Zilch
03-26-2005, 02:25 PM
Find a pair of JBL Cabaret series 4628B, under $500, and be done with it.

Trust the Zilchster on this, you will NOT be disappointed.

If you MUST, supplement them with a biamped subwoofer. 4625(B) is the matching subwoofer box, though you'll want to put a different driver in them, say 2235H. Just plug one of the ports to retune.... :D

Bernard Wolf
03-27-2005, 05:44 AM
don't worry about the MC240. It is well protected and I leave it on 24/7. I don't have another ss amp/receiver out there.

Why would you leave the Mac on 24/7? Not that I am an authority, but I have never seen that recommended with a tube Amp - a pre-amp perhaps as the small signal tubes might in fact last longer that way, rather than turning them on and off, but not an amp. You will certainly go through output tubes a lot faster that way and according to my 'techie' he does not even like the idea of a vintage amp running without him in the room with it. I myself have been in the room a number of times when a output tube has gone south and started to burn up.... turned it off immediately... would not really want to see what would happen otherwise.

My 2 cents :)

Bernard

lodoc
03-27-2005, 01:56 PM
Why would you leave the Mac on 24/7? ...


The unit is fully functioning with an intact on/off switch. If I have been misinformed I can certainly turn it off when leaving the building. What is the consensus of opinion on this question? I am not a serious audiophile like you folks but do have an ear that requires a certain minimal standard be met.
This is only my second tube amp (the first being a Heathkit my father built in college I used breifly in my own college days until it was stolen).

BTW- I thank all those who have given input on JBL speakers that are compatible with the amp output and building size limitations I'm facing. Some of the responses are beyond my limited technical ability to implement and I realize some are rather 'tongue-in-cheek'. I really want something that is 'plug-and play' considering my other passions. But armed with the given speaker choices that have been presented or other choices that may appear in response to my query I have a shopping list now and will start the search.

karl

HK 100+/ JBL L65's (house)
MC 240 / Bozak B220Y (shop)
67 GTO conv (finished- 300W JL 4 channel speaker amp, 8 boston accoustic
speakers, 250 W JL sub amp JL subs, Alpine head unit)
72 Grand Prix (finished)
67 GTO ht (in progress - almost finished)
67 Firebird sprint conv (just started)
67 GTO conv(s) (waiting their turn)

Mr. Widget
03-27-2005, 02:02 PM
You seem to have a Pontiac problem, much like many of us have JBL or Altec problems...

A picture or two might be nice.:)

Widget

porschedpm
03-27-2005, 04:05 PM
I don't want to tell you what to do but if it was me I would either sell the Mac MC240 or move it into the house to power the L65's. I did a quick check on eBay and Audiogon and the MC240's are averaging between $1200 and $2000 depending on condition. To me, this is too valuable and vintage an amp to be in a workshop environment. Not to mention the tubes do require some periodic maintenance. I think a more fitting environment for the MC240 would be in the house, polished up and displayed proudly and driving the L65's. But if you sell it you could use the proceeds to help buy the speakers and amp you want. If it's Mac equipment you like I would suggest their MA6200 integrated amp. They produce a clean 75w/ch into 8 ohms, are solid state, sturdy and have switching to drive 3 pairs of speakers. These sell for around $800 on eBay. If you need more power later you can tie in a separate power amp and use the 6200 as a preamp.

As far as speakers, There have already been a number of good suggestions. My vote goes to:

two 4430's
two or four 4628b's
four 4425's
or four 4412's

GordonW
03-27-2005, 07:24 PM
Didn't initially think of the 4628... but it's a very good speaker, made up of very good parts. I'd think it should match up very well with an amp such as a MC240.

While we're in JBL Cabaret Series mode... how about one last suggestion: A pair of 4612s, plus a pair of powered subwoofers? That might be a bit easier to find... I see 4612 listings fairly regularly, on various web sites. Add a pair of beefy powered subs of your choice (since you seem to be a Boston Acoustics fan, might I suggest a pair of PV700s or PV900s, as one possibility?), and you'd have a system that could definitely rock the house. Just run the 4612s directly from the MC240, and either Y-adapt the RCA cables from the preamp to both the MC240 and the subwoofers (one sub on left, one on right), or even simpler... since 4612s have dual 1/4" jacks on the back, you could just come into the 4612 from the MC240, then out of the other 1/4" jack with a cable into the speaker-level inputs on the subwoofers. All you'd need, would be to get AC power from an outlet to the subwoofers... and you'd be in business.

Regards,
Gordon.

lodoc
03-28-2005, 05:08 PM
You seem to have a Pontiac problem, much like many of us have JBL or Altec problems...
A picture or two might be nice


Glad to oblige. Hope you're referring to a Pontiac rather than the Mac equipment and I'm not in violation of forum rules... so I'll keep it to one.
btw-You guys are giving me second thoughts on the Mac equipment in the shop. I guess I'll have to haul the MC240 and the MX110 inside to try them with the L-65's. If the combo sounds good I could demote the HK to the shop. This could cut into my welding...

porschedpm
03-28-2005, 07:58 PM
Nice goat! :coolness:

I likes em when they look stock.

Charley Rummel
03-30-2005, 07:24 PM
With all that space, I would think you're not overly concerned about size. So, I recommend the following classics (from the bottom up):

4520's stocked with 2205's

2441/2395 combo's for the mids

2405's for the highs

3152 and 3105 crossover networks

The MC240 would work very nicely with this arrangement.

Regards,
Charley

lodoc
08-03-2005, 08:02 AM
I want to update those contributing to my knowledge base and express a special word of thanks to Gordon W and Zilch. I aggressively pursued 4628's and 4612's after hearing their views and doing some of my own research. I came very close to obtaining a pair of 4628's but the gentleman wouldn't turn them loose even though they have been in storage for 10 yrs. Picked up a pair of 4612's and am glad I did. The first weekend here my son loaded them up for an outdoor graduation party. Between his receiver, sub and laptop computer they really rocked the joint. He received many compliments on the quality of their sound playing music from 50's rockabilly thru kid rock.

Now they are in the shop and sound great for my application with the MC 240. They even make FM radio sound good but I have noted the two tuners I'm using (Mac MX 110 tube and Akai transistor) are quite susceptible to distortion with lower signal strength so I'm looking for a new FM antennae.

But I'm also in the market for subs. Gordon suggested the PV series from boston acoustics but having trouble finding in the used/aftermarket.
I'm thinking subs with their own internal amps would be the easiest and be the most versatile for future travels, parties etc.

MY question(s): What other brand/model subs should I consider that would be compatible with this set-up? Do I really need a pair of them for each channel or would one that is somewhat more powerful be better? Is the 35-100 Hz signal generally in stereo from FM, CD, iPOd sources necessitating a pair or dual channel feed into one sub? I'm most certainly going to obtain the sub(s) used as they don't need to be pretty covered with shop dust.

Zilch
08-03-2005, 11:26 AM
Do I really need a pair of them for each channel or would one that is somewhat more powerful be better? Is the 35-100 Hz signal generally in stereo from FM, CD, iPOd sources necessitating a pair or dual channel feed into one sub?I am pleased our suggestions worked out for you. 4612's don't have the power that 4628's do for parties, but, as you discovered, they're by no means wimpy. :D

There IS stereo information in the 35-100 Hz range, so the best approach for real listening is a separate sub for each channel. Don't know why you're suggesting two per channel, though.

That said, for the shop and parties, a single dual-channel sub will do fine. If you're up to it, build a B380 and power it with a Parts Express plate amp, built in. If you find you want more, you can always build another.... :p

lodoc
08-03-2005, 10:01 PM
"Don't know why you're suggesting two per channel, though"



The grammar may have been confusing. I was inquiring regarding obtaining ONE sub vs a PAIR - one for each channel. I like the concept of bi-channel input to one sub. That's what I built for my goat with a pair of 6" JL subs in a narrow/wide space behind the rear seat back in front of the folding top. Nothing 'off the shelf' would fit and I was told it couldn't be done - so I built one. And I could certainly build another one. Subs seem rather easy compared to car restoration. But I wouldn't mind just buying if I could be assured of quality in a plug and play unit that would be a reasonable match with my other components.

Zilch
08-03-2005, 10:41 PM
http://www.lansingheritage.org/html/jbl/reference/technical/1983-subs.htm

OR, find a 4625 (or two), put 2235H in it, and plug one of the ports:

http://audioheritage.org/vbulletin/showthread.php?t=2731