Your electronics appear to be SS, so a ~5.86 ft^3 tuned to ~38 Hz for max flat, but with them in the corners would personally use the whole space and tune to Fs the old fashioned way (match up the two impedance peaks) with just a baffle thickness vent and if switched to tubes, then all the better; i.e. classic driver, classic alignment = win-win IME, not to mention a lot less work. 👍
Thanks for your response. I like the sound of "win-win", but the rest of your message went over my head, lol. So it looks like I've got some homework to do to try and make sense of the rest of it. I did some searching here and found the pinned topic, So you want to design your own speaker from scratch!, and will try and read through it tonight.
If you have any other advice about how I can learn how to "tune to Fs the old fashioned way (match up the two impedance peaks) with just a baffle thickness vent" I would really appreciate it. And, I am on the look out for a tube amp now that I have the 604s, but I am on a tight budget and may to use the SS gear I have now until I find something affordable.
Thanks again. Cheers.
👍 😎 Forgot I posted that, but the current one is for me a close second if at least SET tubes and preferably with one of the pioneer's (pre) amps that have variable DF tone controls.
You're welcome!
https://archive.org/details/HowToBuildSpeakerEnclosuresByAlexixBadmaieffDonDavis/page/n63/mode/2up
That's OK, just recommend critically damping the vent or at least to 'taste' if it sounds too 'boomy' or can hear any mid bass/mids at the listening position.
That said, in retrospect it might be best to start auditioning with sealed as the room may provide sufficient bass, lower mids with your music, etc..
Thanks for the link and the advice. I've been doing some reading and have a better understanding of speaker parameters like "Fs" and some of the other things you're talking about. Starting with a sealed baffle sounds like a good idea to me and would certainly be the easiest way to get started.
I was also reading the Altec publication "Loudspeaker Enclosures - Their Design and Use (1975 version)" and it describes Infinite Baffles and Wall Baffles:
"The use of the wall baffle requires following some simple general rules. The rear wave must be easily dissipated into the space behind the transducer—generally a minimum cubic volume of 12 to 15 cubic feet. The transducer should be mounted on a sturdy speaker baffle of at least 3/4-inch thickness, and the baffle appropriately mounted in the wall. There should be no air leaks around the edge of the mounting baffle, and effort should be made to insure there are no resonances set up in adjacent panels of wall board or wood paneling."
My cabinets each have a volume of around 23 cubic feet, so it sounds like I should have ample room to dissipate the rear wave.
Baltic Birch plywood seems to be the preferred material here for baffles and cabinets, but I may buy a 4x8 sheet of 3/4 OSB to start testing whether this idea will even work. I can make two baffles out of one sheet and it is only $30CAD. Additional bracing can be added as needed.
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Well, the experimenting has begun. I had a sheet of 3/4" particle board in the garage, so decided to make a couple quick baffles just to get a better feeling about whether this is an idea worth pursuing or not.
My expectations were pretty low since I've added no additional bracing or damping to the cabinets or baffles yet, the speakers are firing straight ahead with no toe-in, one driver needs a new surround, my SS amplification is a poor match for the Altecs, and the room is empty at the moment, since I removed the old carpet and started refinishing the hardwood floors. So there are a lot of reasons why this should sound like crap, but I have to say I was pleasantly surprised. 🙂
There is obviously room for improvement, but I can certainly hear the potential and could almost live with the sound the way it is. So I'm definitely going to pursue this project further. Any suggestions on how to proceed with bracing, insulation, etc, would be much appreciated. I think I could add some toe-in by setting the inside edge of the baffle back a couple inches, but not sure if angling the speakers in relation to the rear and side walls is a good idea or not.
I'm also thinking about ways to make the giant baffles more visually appealing and have posted a couple photos below of big speakers with decorative grills that might work. I have a fair bit of wood working experience and a shop full of tools, so I'm not too worried about constructing anything I need. In the end, I want this to sound good, but I also want it to look good and compliment the cabinets my dad built.
Thanks for any advice.
Here's a couple photos with decorative grills that I find appealing.
My expectations were pretty low since I've added no additional bracing or damping to the cabinets or baffles yet, the speakers are firing straight ahead with no toe-in, one driver needs a new surround, my SS amplification is a poor match for the Altecs, and the room is empty at the moment, since I removed the old carpet and started refinishing the hardwood floors. So there are a lot of reasons why this should sound like crap, but I have to say I was pleasantly surprised. 🙂
There is obviously room for improvement, but I can certainly hear the potential and could almost live with the sound the way it is. So I'm definitely going to pursue this project further. Any suggestions on how to proceed with bracing, insulation, etc, would be much appreciated. I think I could add some toe-in by setting the inside edge of the baffle back a couple inches, but not sure if angling the speakers in relation to the rear and side walls is a good idea or not.
I'm also thinking about ways to make the giant baffles more visually appealing and have posted a couple photos below of big speakers with decorative grills that might work. I have a fair bit of wood working experience and a shop full of tools, so I'm not too worried about constructing anything I need. In the end, I want this to sound good, but I also want it to look good and compliment the cabinets my dad built.
Thanks for any advice.
Here's a couple photos with decorative grills that I find appealing.
Pleased to hear that. It looks like you've just about made the best of the situation.
From here I guess I'd do a little equalising and look at hanging drapes along part of the side walls.
From here I guess I'd do a little equalising and look at hanging drapes along part of the side walls.
I've got a little update and I'm not a happy camper right now. I took the Altec's to my local speaker guy to repair the surround, but I'm worried he messed them up. Before I took them over I sent several pics showing the damaged surround on the one speaker and asked him if he wanted me to purchase the recone kits. He said no need for a full recone and he could "replace the surrounds and repair the cones" for $75. He's been doing speaker repairs for more than 40 years, and has done a few other speakers for me, so I trusted him to do it right.
Well, he just emailed me saying they're ready to pickup and included the below photo of the "repaired" speakers. I could tell immediately the surrounds he used are different than the originals and they look like foam, not cloth. Now I'm worried I'm going to be boxing these up and sending them to Great Plains Audio to be repaired properly. I'm in Canada, so shipping alone is going to be expensive. The other option is to order the recone kits and try doing it myself. What a disappointment 😢
Here's the pic he sent me. Any feedback or suggestions on next steps would be much appreciated.
Well, he just emailed me saying they're ready to pickup and included the below photo of the "repaired" speakers. I could tell immediately the surrounds he used are different than the originals and they look like foam, not cloth. Now I'm worried I'm going to be boxing these up and sending them to Great Plains Audio to be repaired properly. I'm in Canada, so shipping alone is going to be expensive. The other option is to order the recone kits and try doing it myself. What a disappointment 😢
Here's the pic he sent me. Any feedback or suggestions on next steps would be much appreciated.
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They are treated paper surrounds similar to the originals, Santon Audio has reconed over 200,000 speakers over 40 years - maybe thats your repair place, they know what their doing - rest easy unless you want exact originals. ( and it will cost you both for the recone and the shipping. You could possibly get the cone kits to recone locally - cheaper, but still won’t be cheap
Thanks for reply. It wasn't Stanton, but maybe that's where my speaker guy got the parts. I hope you're right about them being close to the originals. I just wish he had told me what he using and that they would look different.
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The originals should have been treated cloth surrounds but it's hard to say what you have now. I am leaning toward ticknpop's suggestion that those are paper. The important part is to have the same, or very similar compliance, which one must assume that your guy cross referenced to ensure they are correct. You don't take a classic driver like that and throw any old thing at it. Perhaps ask gently about the difference. I say gently because the speaker guys can be an ornery bunch when poked or prodded. 🙂
Looking further the new surrounds they could be cloth
You might consider to replacing the caps in the crossover with polypropylene like Solen, Clarity, Mundorf - or your favorite.
There are also aftermarket crossovers, but thats a whole new discussion.
You might consider to replacing the caps in the crossover with polypropylene like Solen, Clarity, Mundorf - or your favorite.
There are also aftermarket crossovers, but thats a whole new discussion.
I haven't picked them up yet, but I messaged him and he said "cloth surrounds all perform the same, almost no movement".
That's why I reacted the way I did when I saw the picture. Given the choice, I would have been happy to pay more money to get the correct surrounds installed. Hopefully, he took compliance into consideration and the performance is not impacted, but I do think the resale value has been reduced just based on the appearance. I don't plan to sell them now, but I don't know if this built-in speaker experiment is going to work. So they could be up for sale in the future . Anyone who knows anything about these speakers will be able to tell the surrounds are not correct. I also know I'll have lingering concerns about whether I'm getting the most out of these speakers and whether the repairs where done right.
Got the speakers home and surrounds are cloth. He was pretty adamant that they will be the same as originals, but will require some break in time. I asked where he got them, and he said he ordered them from the states and didn't elaborate. He's a nice guy who does good work at reasonable prices, and he's also only guy in town that I know of. So I didn't want to poke or prod too much 😉They definitely look better, that's for sure. He said he had to completely disassemble them and cleaned up some corrosion and other crap around the voice coil.
Not sure why he went with what's known as an "M-roll" (two rounded bumps) instead of a standard pleated/corrugated cloth surround, like the originals. Those surrounds are available in the USA, probably just as easily as the ones used there. I have repaired quite a few 416s, 604s and such, with these surrounds.
Those M-roll surrounds are usually stiffer (which raises the Fs a bit), and have different damping behavior, compared to the originals. I don't know if it will be a detriment, an improvement, or a wash (not better or worse), but it definitely will result in a different frequency response than the original surrounds.
Regards,
Gordon.
Those M-roll surrounds are usually stiffer (which raises the Fs a bit), and have different damping behavior, compared to the originals. I don't know if it will be a detriment, an improvement, or a wash (not better or worse), but it definitely will result in a different frequency response than the original surrounds.
Regards,
Gordon.
Yeah, I wish he told me what he was doing and why. I would have definitely preferred the original pleated style and offered to order the Speaker Exchange recone kits for him. He said a complete recone wasn't necessary and I trusted his expertize. But then today he told me the cones were different sizes because one had been reconed previously and they also had two different spiders. So it sounds like recone kits would have been a good idea.
I definitely learned a lesson here and will ask more questions next time. Thankfully, nothing he did is irreversible and I could always have then redone again in the future if I really like them. I paid $225 for the speakers and $120 for the repairs. So I've only got $345CAD into them now.
I definitely learned a lesson here and will ask more questions next time. Thankfully, nothing he did is irreversible and I could always have then redone again in the future if I really like them. I paid $225 for the speakers and $120 for the repairs. So I've only got $345CAD into them now.
I emailed Great Plains this morning to ask about cost of a makeover. Their service center is in California now, so jsut the back and forth shipping cost would be pretty expensive since I'm in Ontario.