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cowboy99

BA T1000's AND T1030's

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Recently scored a nice pair of T1030's. Nice shape and recently professionally 're-foamed. Was asking $170.....I gave him $200 feeling almost guilty.

Two weeks later by dumb luck I inherited another pair of BA, a beautiful set of T1000's that had been stored/unused for 20+ years with original surrounds in excellent shape.......Unbelievable !

Have looked at the T1030 crossovers to consider which electrolytic caps to replace and I understand the difference in them and the T1000.

Does anyone have the manuals or copies for these two models?

Anyone one with schematics of the crossovers or freq specs?

I was somewhat surprised to see that the 6" & 8" were different units from model to model, I'd read several times that they both used the same speakers??

I've been in the process of building a multichannel BuffaloIII DAC with Aleph J amps for the primary 4 channels. So these towers are a real blessing towards that goal.

A question for Gerry S. (if he would honor me) Any recommendations on recapping or replacing the HF cap with a more modern type or maybe modifying the T1000 x-overs to be more inline with the improved T1030 version for simultaneous use? Or would they interfere with each other as is?

Don't believe replacing any of the mid & low freq cutoff caps with non-electrolytic would be a good idea, but unsure.

I guess I could reverse-engineer a schematic and attempt to calculate the designed freq cutoffs......But it certainly would be nice to have factory data.

As for the queries comparing the actual 'sound' differences between these models...after recapping I'll get a better opinion. They both sound really nice as is, but different.

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Please refer to: Boston T1000 vs T1030 Started by morkys, Mar 16 2009 10:01 AM

The driver alignment difference alone would make replicating the T1030 "sound" on the T1000 difficult (if not impossible) in the "near field".

The T1000 and T1030 use identical drivers and enclosure volumes, but the crossovers are NOT interchangeable.

That's because the two systems have different physical driver alignments, requiring a different approach to crossover design.

As far as specifics, the T1000 crossover uses three "parallel" networks (one each for the woofer, midrange and tweeter section).

The T1030 uses a "quasi-second series" network between the woofer and midrange sections, a parallel network on the tweeter. The crossover frequencies and slopes are also different, resulting in different "near" and "far-field" responses.

As far as replacing caps, I don't think it's necessary. It could actually be detrimental to system performance and reliability (because of changes to the crossover frequencies).

I would not operate both systems in the same room because of likely acoustical interference between the two. Also, each system has an impedance of 4 ohms at low frequencies; operating both systems at once (from the same amp) would tax the amp.

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Thanks Gerry for the detailed response. I was afraid the. Two pair may not match up in a multichannel setup. One of each of larger electrolytic 120mfd caps in both the T1030s show signs of overheating (the leads overlapping body of cap have melted the plastic sheath/label)

Still. It sure would be nice to have some documentation for these. Especially Thiel/Small parameters for the drivers in case I have replace them.

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Well, after a few months listening, I'm much more impressed with the T1030s than my initial opinions.

They amaze me with their separation and the sound stage. Continually hearing definitions that I've never heard from my all time favorite releases. Their really quite nice with all the digital audio I've acquired such as: HQ DVD-A, killer Steven Wilson remixes and various 24bit 96kHz Flac pro rips of vinyl masters & orig pressings (pbthal,DocRob & aksman, etc).Either my 50+yr hearing is getting much better (doubtful) or the crossover design/topology unlike any I've heard before. Comparisons are to some of better XO's I have used for years: EV X8/X36 even JBL N1200. And that's unmodded with orginial electrolytics . Although,hifreq side isn't near my hiend JBL N7000 w/pair of 077 prisms. The mid-low side is impressive. (Gerry, I took your advice & left as is).

Quote:"The T1030 uses a "quasi-second series" network between the woofer and midrange sections, a parallel network on the tweeter. The crossover frequencies and slopes are also different, resulting in different "near" and "far-field" responses."

Quasi-2nd series..... Unfamiliar with this type my interest is keen, and I plan to rev-eng circuit/schematic to understand the math/physics of your X0 design, if that's OK Gerry. I like what I'm hearing.....intend it as a compliment to your achievement.

FWIW... Agree the T1000 can't be even compared to the audiophile T1030s

Edited by cowboy99

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HELP!!

I have a Boston Acoustics T1000 crossover but I do not know how to wire it to the drivers or to the input from the driving amplifier. (I also have all the drivers)

This late 1980's 3-way speaker system has two 8 inch woofers, a 6.5 inch mid and 1 inch dome tweeter. Obviously they all have to be wired to the crossover and the whole business needs to have a + and a - terminal for connection to a driving amplifier. 

I wrote Boston Acoustics and they could offer no guidance.

Can someone help me figure out how to wire this up?

I've drawn the schematic and taken a photo of the crossover. Some wires were still connected to the crossover - these wires lead to drivers and to the speaker systems's pair of input terminals, one + and one -. I've indicated these connection points on the schematic, and the labeled points' letter correspond T1000xover.pngBostonXover.jpg between schematic and photo.

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Pretty sure I can help you.

1) I took full set of pictures of my partially disassembled T1000 without diconnecting any wiring for the main purpose of re-capping the x-overs.

2) Hand drew a schematic of the entire wiring hookup.

Give me the day to gather it all.

Charles

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mike66 posted this on AK in response to your question:

A 3 red wires, two woofer +, one to speaker in + terminal
B 2 black wires woofer -, brown/white to midrange -
C yellow to tweeter -, black to - input terminal
D white wire to midrange +
E brown to tweeter +
I think that covers it. Good luck!
 
And gave these values:
 
Ferrite inductor is 2.75mH, yellow inductor is 0.42, and the red is 0.51.
 

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Edit:  The 2uF cap C3 in my schematic below looks too small, it is in the bottom left corner and

is large, is that actually 42 uF?  Anyone?

I posted this:

I never heard these but always wanted to after reading the excellent review
of them in Audio. I redrew the schematic in SPICE.
The woofer to mid crossover is a series type that employs a fairly low parts count
and is first order. I first saw it used in the DQ-10, it is also used in some AR speakers such
as the AR-48s as I documented here: http://baselaudiolab.com/AR48s.html
Starting with the woofers it can be seen that the positive inputs are wired directly to the
main system input. Low frequency signals including DC pass through the 2.75 mH inductor
L2 and 80 uF C2 acts to shunt highs away from the woofer rolling it off and providing a path for
highs to the midrange. R3 and C3 appear to be roughly a Zobel for the woofer.
R5 provides attenuation for the midrange and L3 is a low pass to the mid rolling off the
high end to it. 16 uF C4 makes the low pass XO to the mid 2nd order. R4 and C5 provide
a Zoble for the midrange. C1 and L1 form a 2nd order highpass to the tweeter with the
total attenuation to the tweeter controlled by the total resistance of R1 plus R2 and the
ratio controlling the Q or shape the that rolloff.

T1000-XO-CP.jpg.64a88df0e1c2ed333357420444791605.jpg

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Very curious to see the T1030 schematic if anyone has it.

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This is excellent, thanks.  This is much farther than I went into this.  Very complete.

Actually, I removed the drivers from the cabinet in 2005 when I noticed that the woofer surrounds were shot, and have used the cabinets for experiments since then.  If you are interested in the experiments, you can see http://www.diyaudio.com/forums/multi-way/256074-road-3-active-speaker.html )  And then recently I cleaned out some storage space and came across the drivers and crossovers. I hated to just toss them away, so I refoamed the woofers and sold the whole lot on eBay at auction. This didn't result in very much income- about enough to ship them and then have a couple of coffees and a bagel- but now the drivers and xover will get a new life  in someone else's hands and they will have the pleasure of tinkering, building and listening.  The buyer needed more information about connecting the drivers than I had, and I noticed others over the years looking for crossover info on the T1000, so I started a few threads here and there thread and now we have all the answers.  

 

HAHAHA the only thing I personally was able to figure out from this crossover is that one side of the tweeter probably connected to the brown wire at "E"  -   but now greater minds have considered the matter and the answers are known!

 

Just a great job here.

 

A few last notes - each 8 inch woofer is mounted in it's own sealed enclosure, 1 cu ft in volume and with some poly stuffing in it- not tightly stuffed or packed, but not a "sparse" amount of fiberfill  either.  Moderate stuffing.  The 6.5 inch mid has perhaps a 0.15~0.25 cu ft of sealed volume behind it.  Also, this crossover is designed for the original T1000 system with woofers on the bottom of the cabinet's face, the midrange in the middle, and the tweeter at the top.  Some subsequent T1000 version had the tweeter in the middle with the mid up top, that would have a different crossover design.

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I agree, great job Pete. Don't have either of the official schematics. All I have is the 'chicken scratch' ones I've created myself. What you've posted matches what I drew up on the T1000.

As far as the T1030 I feel it best to run any schematic that might be posted on it by Gerry S. and of course ask his blessing to post it first. That x-over is his baby!

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I updated the schematic with corrections.

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Thanks Pete,

Got to appreciate a man finishining what he started.

I've got an extra T1030 XO that is just waiting for me to pick it up one day soon. If you have any interest in documenting it. I'm not sure I.ll ever get around to it, plus your work would outclass any thing I would draw up.

Charles

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Again many thanks to Pete B for his expertise and time.  Now, this schematic is available to anyone who needs it - worldwide!  If I come across a T1000 thread on Audio Karma, DIY Audio etc  I will link to this thread here.

 

The T1000 and T1030 were / are decent speakers. Lots of them were sold.  I imagine a good many are still out there, and I can imagine a number of scenarios where someone ends up with just the drivers, or just the drivers and a disconnected xover, and this schematic can help them sort  things out.

FYI, the re-foam kits available on Ebay, Parts Express, etc, are actually easier to use than you'd think on the T1000's 8 inch woofers and the midrange driver, worth it especially if you find a kit that's not too expensive.  I bought a kit for $19 with 4 woofer and 2 midrange surrounds, plus glue, it worked just fine.

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On 3/20/2018 at 5:37 PM, cowboy99 said:

Thanks Pete,

Got to appreciate a man finishining what he started.

I've got an extra T1030 XO that is just waiting for me to pick it up one day soon. If you have any interest in documenting it. I'm not sure I.ll ever get around to it, plus your work would outclass any thing I would draw up.

Charles

Thanks Charles, but if you can believe it I just bought a pair of T1030 XO's on ebay a few hours ago,

wish I'd seen your offer. 

I notice that the T830, T930 have series II and III versions were these aligned with the T1030 logically or T1000?

Next question of course is if there were series II and III of the T1030?

 

Picture of T1030  AC001494 from ebay advertisement, I traced it out from the pictures but need the XO to measure the inductors:

T1030-XO4.jpg

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Dam nit Pete,

That was YOU I was bidding against. I was going to grab them to update my T1000's as an experiment. But the seller wouldn't do a break on shipping both of them .... which made me hesitate too long. Glad they went to the right home though cuz now we.ll all get a schematic for the T1030. Plus I've got bigger projects needing focus. See links, thats a cherry pair of JBL  L65A and a serious 200W x2 amp to drive em ....Heathkit AA-1800 ..the old Leach Super Amp

Did you notice the caps are different between the two?

https://drive.google.com/file/d/1-z5urNCCOy-4rRymUYgoLFWaMeD9CtrV/view?usp=drivesdk

https://drive.google.com/file/d/1senj9hU4OTcmytK3YRBGEa_4AsQhkCJd/view?usp=drivesdk

30lb trans

https://drive.google.com/file/d/1eOldw4f__yCVQsqhT1nhL9M1QGw3KQ90/view?usp=drivesdk

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Don't think the T1030 had a series II.

But again, Gerry S would be the man to ask. I.d certainly run any final results past him, he.s designed that XO

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On 11/19/2015 at 11:50 PM, cowboy99 said:

Thanks Gerry for the detailed response. I was afraid the. Two pair may not match up in a multichannel setup. One of each of larger electrolytic 120mfd caps in both the T1030s show signs of overheating (the leads overlapping body of cap have melted the plastic sheath/label)

Still. It sure would be nice to have some documentation for these. Especially Thiel/Small parameters for the drivers in case I have replace them.

I'd use Bennic NPE caps to replace all of the NPE types, the film cap is probably fine.

I can measure T&S parameters but I don't have any of the drivers.

Gerry says that the drivers are the same, yet they don't look the same?

The T1000 woofers and mids look like Peerless (maybe the old CC line) and those in the T1030 

look custom to BA, perhaps they cloned the performance?

There's a pair of T1030's for sale in FL that I want, anyone making a trip from FL to the North East 

any time soon who can pony express them for me, LOL?

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Charles,  I bought both of the T1030 crossovers figuring that the circuit is common

to one that I use and the inductors are probably close to what I use - I can wind them 

up or down for whatever I need.  But if you want them I'll measure them and then we

can work out a deal.

One thing I noticed about the T1000 XO is that zobels are used where most designers

are able to avoid them, the T1030 doesn't use them.  I like the T1030 XO better.

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The T1030 crossover pictured above is a genuine BA part. It is a "quasi-second order"  SERIES network between the woofer and midrange. With this type of network, any change in X-O values affect both the woofer AND the midrange  SIMULTAINIOUSLY (because the drivers are effectively in series). It is much harder to "voice" because of this inter-dependent relationship.  Note that If you disconnect either the midrange or woofer from the crossover, you will get no sound from either!

The T930 Series 2 also used this "quasi-second order" configuration. I'm pretty sure the T830 Series 2 also used a quasi-second order network.

The midrange and tweeters should be identical for the T930, T930 Series 2, T1000, T1000 Series 2 and T1030.

There is NO "Series 2" T1030 (probably because it's hard to "improve" the T1030).

Lessons learned from the  T1030 development work resulted in the Series Two versions of the T930 and T830.

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Gerry,  I think you got those flipped, the T1000 that I have drawn above is series between the

woofer and midrange.  I've already traced out the T1030 pictured and it is not series.  I don't

like the series connection due to the interaction that you mention.

Nice work by the way, I really admire the updated versions that compete with much more 

expensive speakers.

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