Speaker Identification Help!

[VintageVill]

Hello all,

I recently came across this pair of speakers, and I have no idea what they are. They are branded GTR and the model is the R 5000. A google search reveals nothing about this model. The cabinets measure 14" x 8.5" x 26.5". On the back it has no binding posts, rather it is wired directly to the drivers. It's 3 way - 12" Woofer, 5" Mid and 4" Tweeter. I unscrewed the drivers, all of which are Pioneers, and there's no crossover board inside . The speaker wire is wired directly onto the woofers, and then there are wires going off to the tweeter and mid from there, with a single inline capacitor to each. The one going to the tweeter is rated 4.7uf 50V, and the one to the mid is rated 6.8uf 50V. All of the drivers seem to be rated 8 Ohm, but i don't know the wattage of the whole speaker. Sadly the information on the back of the Woofer is pretty much entirely obscured or rubbed off.

I took photos of everything in hopes that someone may be able to tell me what I've got and what they're worth.

 

[Markoneswift]

Junk and not a lot They look like 'white van' type units IMO using a Pioneer driver load in generic cabs. The absence of an 'actual' crossover also points to their junky nature. They do have a crossover network, it's just done via capacitors soldered directly inline with the drivers.

The double porting on the front and 'frequency response curve' also hint at the fact these are not very good.

 

[turboyam]

I would say, pass.

 

[Markoneswift]

Welcome to AK by the way

 

[KingBubba]

The model is right in front of your face. Pioneer C77A.

 

[VintageVill]

Junk and not a lot They look like 'white van' type units IMO using a Pioneer driver load in generic cabs. The absence of an 'actual' crossover also points to their junky nature. They do have a crossover network, it's just done via capacitors soldered directly inline with the drivers.

The double porting on the front and 'frequency response curve' also hint at the fact these are not very good.

Oh, damn. Well thanks for saving me the trouble.

 

[gdmoore28]

The model is right in front of your face. Pioneer C77A.

Where do you see that, Bubba? The Pioneer Cs77A is an older model with an elaborate grill.

Are you referring to the drivers themselves having come from a CS77A? That would certainly be feasible.

Pioneer C77A is an amp.

The GTR speakers show up regularly around here at flea markets, pawn shops, garage sales, etc.. From my experience with them, they are as close to white van speakers as any other generic speaker. This pair being populated with Pioneer drivers is a bit puzzling, but I doubt that GTR sourcing from Pioneer's gigantic output of speakers is not out of the question.

The capacitor-only crossover puts the nail in the coffin as to the manufacturer's intent: build a consumer speaker as cheaply as possible. It's rare for me to outright dismiss a speaker, but that would be the case with GTR. I've heard a bunch of them around here, and not a single one has been impressive.

But, if they are $5 for the pair and the OP needs a garage speaker, then we could talk. But, for elements in a nice listening system - no way. Keep looking. You will run across some gold-standard speaks at some point.

A big welcome to AK, too!!!!!! Great to have you here.

GeeDeeEmm

 

[bowtie427ss]

Pioneer CS-77:

Early CS-77's had a vented dust cap and a smooth cone.

Pioneer CS-77A:

 

[Markoneswift]

Kingbubba was referring to the model numbers of the drivers, clearly seen in the pics. C77a. There's no 'S' in it, so the driver load is clearly a newer generation than the classic CS-77. Presumably the drivers in the older speaker would be made in Japan also, rather than Taiwan (could be wrong though)

 

[toxcrusadr]

The woofer having C77 as part of a much larger part number does not seem to me to be evidence of any connection to the CS-77a.

Lots of signs that these are a cheaply built, maybe regional or house brand speaker. BTW for the OP, a single cap in line with the tweeter is not unusual, although good speakers often have an inductor across the tweeter leads. The mid in a good speaker almost always has an inductor in line so that the signal is limited to the midrange. In this speaker the mid is getting a share of the treble as well. I bet they do not sound very good.

 

[KingBubba]

I don't even know if there is a Model C77A enclosure. It just seemed obvious due to the driver markings. Apologies for being a smart ass.

 

[toxcrusadr]

Off with his head!

 

[GlenGC]

brand: junk
model: rubbish MKII
value: farts

 

[RW Oliver]

I think these were made by Huron Acoustics out of Toronto. The owner was "Fast Eddy Gretsch" He had 13 v-groovers and turned out tons of private label speakers for large audio retailers.
The fact that the speakers are Pioneer should not be too surprising ,they are the largest oem in the world.
As a side note I had a single v-groover and could make 300 speaker cabinets in a day , by myself.

 

[toxcrusadr]

What is a v-groover? I want one.

 

[RW Oliver]

Meet Vera

 

[toxcrusadr]

As a woodworker I think I should have known about this machine. Admittedly it's an industrial machine and not something that shows up in Bob Vila's shop though.

I can see how you could crank out mitered boxes like wieners with one of these.

 

[VintageVill]

Would it be possible to make dedicated crossover boards for each of them? Should increase the audio quality maybe? What if I were to plug the ports there on the front? I’d love to make em sound as best they can.

 

[toxcrusadr]

Same question came up just yesterday related to another pair of speakers with only a couple of caps. Yes it may sound better IF done scientifically, but problems abound trying to do that.

Crossover points are determined by the actual impedance curve of the driver. This is why selecting prebuilt crossovers (i.e. Parts Express) is a crapshoot. Normally when engineering a speaker, drivers are tested and those parameters used to design a crossover for those drivers in that box. To do this right you would need some driver test equipment ($100 for a simple PC based gadget) and some crossover modeling software (downloadable for free). It's a fair amount of trouble.

The semi scientific way to do it is to assume the impedance is the nominal value, then look at those caps and consult some charts to estimate the two crossover frequencies. Then see if you can find a premade 2d order crossover close to those values.

There are, however, very good sounding speakers with very simple crossovers that were designed that way on purpose. For now I would keep it simple and replace those old caps with some new 5% Dayton metallized polyprop caps from PE. It's pretty cheap and usually improves the mid and upper end.

As for plugging the port: the driver is likely a type that prefers a ported cabinet rather than a sealed one. You can try it and it may reduce the bass 'hump' at the port tuning frequency and extend the response a bit lower. It's less risky doing this than putting a port in a sealed cabinet - that can overextend a driver and damage it.

 

[VintageVill]

See, the thing is, they have like no low end whatsoever, the frequency response chart on the front of the cabinets is accurate in that regard. Knowing the model drivers that I have and basing off the response I get from the current crossover network, would it be possible to reengineer it for a different frequency response with a more present low end? Currently all my listening is done with the loudness switch of my receiver turned on, and the speakers sound pretty good that way.