Don your help here is really outstanding, and so useful to me.
> Cori, were you planning on running them as BiAmp or single amp. There is still the issue of low impedance.
It will be a single amp setup. As far as I can tell, the amp has a 6 ohm minimum impedance.
Thank you so much Don!
> Cori, were you planning on running them as BiAmp or single amp. There is still the issue of low impedance.
It will be a single amp setup. As far as I can tell, the amp has a 6 ohm minimum impedance.
Thank you so much Don!
Tuning
Hi Cori,
I realized I mis-spoke on the tuning in the earlier post. The graphs are correct for a 10cm long tuning port. You measured the Image6T and its has 20cm long tuning ports. I've included the hornresp data file as well if you want to try it.
So I don't know how easy it is to replace or cut those port pipes. I provided the comparison graphs for both the 10cm and 20cm port lengths. Unfortunately the sim shows the bass will be worse if the ports are left at 20cm.
Hi Cori,
I realized I mis-spoke on the tuning in the earlier post. The graphs are correct for a 10cm long tuning port. You measured the Image6T and its has 20cm long tuning ports. I've included the hornresp data file as well if you want to try it.
So I don't know how easy it is to replace or cut those port pipes. I provided the comparison graphs for both the 10cm and 20cm port lengths. Unfortunately the sim shows the bass will be worse if the ports are left at 20cm.
Attachments
Impedance corrections
Cori, did you have a tweeter in mind?
I have a suggestion to get the impedance closer to 6ohm min for your amp to drive. This option keeps your speaker a 2.5 way design. It's most likely the original drivers were higher impedance. Keep in mind that for a given voltage the lower impedance woofer will output more than a high impedance woofer. You can install all 3 woofers but only drive 2 of them. The bottom woofer would not be driven.
I've updated the XO schematic that rebalances the system for 2 woofers. Two resistors are added (after the XO board) to match the midbass and tweeter levels to a single woofer. I should add that the effect of the ported woofers and baffle has not been included yet but it will not change the min impedance. The system impedance dips to 5 ohm at 2 points with the changes. In reality it will be a little higher due to speaker wires and various losses. That should be close enough to meet the 6 Ohm min drive requirement of your amp.
The other ways 1) find drivers that are higher impedance, or b) bi-amp the system, or c) use an amp that can drive 3ohm speaker.
Cori, did you have a tweeter in mind?
I have a suggestion to get the impedance closer to 6ohm min for your amp to drive. This option keeps your speaker a 2.5 way design. It's most likely the original drivers were higher impedance. Keep in mind that for a given voltage the lower impedance woofer will output more than a high impedance woofer. You can install all 3 woofers but only drive 2 of them. The bottom woofer would not be driven.
I've updated the XO schematic that rebalances the system for 2 woofers. Two resistors are added (after the XO board) to match the midbass and tweeter levels to a single woofer. I should add that the effect of the ported woofers and baffle has not been included yet but it will not change the min impedance. The system impedance dips to 5 ohm at 2 points with the changes. In reality it will be a little higher due to speaker wires and various losses. That should be close enough to meet the 6 Ohm min drive requirement of your amp.
The other ways 1) find drivers that are higher impedance, or b) bi-amp the system, or c) use an amp that can drive 3ohm speaker.
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Don this is really excellent stuff, and very helpful to me.
It's fascinating to me that such a small change could have such a large impact on sound quality. Yes, it will be possible for me to cut the ports to size, but I'll leave that until I know how to proceed with the crossovers and tweeters. Thank you so much for this observation!
There are two candidates, which should fit with the speaker's mounting bracket and curved fascia. I can see it'll come down to impedance.
1. BC25SC08-04 (4 ohms, possibly with a 2 ohm resistor - easier to find)
BC25SC08-04 - Tymphany
2. BC25SC08-08 (8 ohms)
BC25SC08-08 - Tymphany
Reading through the forum, and following your calculations, Don, it's clear that the 4 ohm tweeters will bring the impedance down too far. So here are my calculations (and I'm aware that I'm being very naive and possibly wrong here):
A) 4 x series, 4 x 8 Ohms: 32 Ohms
B) 4 x series, 1 x 4 Ohms + 3 x 8 Ohms: 28 Ohms
C) 4 x parallel, 4 x 8 Ohms: 2 Ohms
D) 4 x parallel, 1 x 4 Ohms + 3 x 8 Ohms: 1.6 Ohms
E) 2 series x 2 parallel, 4 x 8 Ohms: 8 Ohms
F) 2 series x 2 parallel, 1 x 4 Ohms + 3 x 8 Ohms: 6.8 Ohms
G) 2 parallel x 2 parallel, 4 x 8 Ohms: 8 Ohms
H) 2 parallel x 2 parallel, 1 x 4 Ohms + 3 x 8 Ohms: 6.6 Ohms
Options A through D are either too high or too low. So that leaves options E through H - though I'm thinking there is something really big I haven't seen here. I know that each of these options means that whatever's on the same series line as the tweeter (I assume the bass driver) will get the same power as the tweeter. This may screw things up because the tweeter and the woofer will have different SPL sensitivity (i.e. 94.1dB for the 8 Ohm tweeter vs. 89dB for the woofer).
I'm very impressed with the amount of knowledge on this forum - especially the level of technical expertise that members have for what is essentially the beauty of listening to music. It's really humbling.
I really appreciate your lateral solution here! I do think it is a very clever solution but I think I should try as hard as I can to build a unit that sounds good and has all 3 main drivers firing. I know I'm going to have to replace the original crossovers anyway - and I'm not sure how well that's going to go - but I'd like to try if I can.
So based on your comment here, I spent some time trying to hunt down details of the original drivers. The only impedance rating I can find is 9.5 Ohms for the W6-14PP 12S/P drivers! You were right Don!
It's fascinating to me that such a small change could have such a large impact on sound quality. Yes, it will be possible for me to cut the ports to size, but I'll leave that until I know how to proceed with the crossovers and tweeters. Thank you so much for this observation!
There are two candidates, which should fit with the speaker's mounting bracket and curved fascia. I can see it'll come down to impedance.
1. BC25SC08-04 (4 ohms, possibly with a 2 ohm resistor - easier to find)
BC25SC08-04 - Tymphany
2. BC25SC08-08 (8 ohms)
BC25SC08-08 - Tymphany
Reading through the forum, and following your calculations, Don, it's clear that the 4 ohm tweeters will bring the impedance down too far. So here are my calculations (and I'm aware that I'm being very naive and possibly wrong here):
A) 4 x series, 4 x 8 Ohms: 32 Ohms
B) 4 x series, 1 x 4 Ohms + 3 x 8 Ohms: 28 Ohms
C) 4 x parallel, 4 x 8 Ohms: 2 Ohms
D) 4 x parallel, 1 x 4 Ohms + 3 x 8 Ohms: 1.6 Ohms
E) 2 series x 2 parallel, 4 x 8 Ohms: 8 Ohms
F) 2 series x 2 parallel, 1 x 4 Ohms + 3 x 8 Ohms: 6.8 Ohms
G) 2 parallel x 2 parallel, 4 x 8 Ohms: 8 Ohms
H) 2 parallel x 2 parallel, 1 x 4 Ohms + 3 x 8 Ohms: 6.6 Ohms
Options A through D are either too high or too low. So that leaves options E through H - though I'm thinking there is something really big I haven't seen here. I know that each of these options means that whatever's on the same series line as the tweeter (I assume the bass driver) will get the same power as the tweeter. This may screw things up because the tweeter and the woofer will have different SPL sensitivity (i.e. 94.1dB for the 8 Ohm tweeter vs. 89dB for the woofer).
I'm very impressed with the amount of knowledge on this forum - especially the level of technical expertise that members have for what is essentially the beauty of listening to music. It's really humbling.
I really appreciate your lateral solution here! I do think it is a very clever solution but I think I should try as hard as I can to build a unit that sounds good and has all 3 main drivers firing. I know I'm going to have to replace the original crossovers anyway - and I'm not sure how well that's going to go - but I'd like to try if I can.
So based on your comment here, I spent some time trying to hunt down details of the original drivers. The only impedance rating I can find is 9.5 Ohms for the W6-14PP 12S/P drivers! You were right Don!
3-way
How about modifying the crossover to make it a true 3 way. That way only 2 woofers are active at low freq where the impedance problem is. The midrange only comes in later on when its needed and it keeps the speaker impedance higher. These changes could be easily done with minimal cost.
The impedance is still around 5 ohm min and will probably be a bit higher when wires are included. I've attached a screen shot from Xsim.
The issue with trying to create series connections of drivers is that the inductance increases and that limits high frequency. So you can't put a tweeter in series with a woofer. The drivers are effectively all in parallel but they are individually active in different frequency ranges and so you need to consider the complex impedance (R,L,C) rather than just DC resistance (R).
I'm still assuming you want to use the Jaycar woofers you bought. It's possible to put two 4 ohm woofers in series as well, but you'd need to buy 4 more woofers.
How about modifying the crossover to make it a true 3 way. That way only 2 woofers are active at low freq where the impedance problem is. The midrange only comes in later on when its needed and it keeps the speaker impedance higher. These changes could be easily done with minimal cost.
The impedance is still around 5 ohm min and will probably be a bit higher when wires are included. I've attached a screen shot from Xsim.
The issue with trying to create series connections of drivers is that the inductance increases and that limits high frequency. So you can't put a tweeter in series with a woofer. The drivers are effectively all in parallel but they are individually active in different frequency ranges and so you need to consider the complex impedance (R,L,C) rather than just DC resistance (R).
I'm still assuming you want to use the Jaycar woofers you bought. It's possible to put two 4 ohm woofers in series as well, but you'd need to buy 4 more woofers.
Attachments
Jumping in late here. Do you have 4 or 6 of the Jaycar drivers?
Did you buy them because they fit in the original holes?
I ask because my personal opinion of these is not great where the midrange is concerned.
I echo the above comment that making these a true 3-Way or a 3.5 would be better where the midrange is concerned
There should be a moderately priced mid-range suitable driver around that will fit the hole
Did you buy them because they fit in the original holes?
I ask because my personal opinion of these is not great where the midrange is concerned.
I echo the above comment that making these a true 3-Way or a 3.5 would be better where the midrange is concerned
There should be a moderately priced mid-range suitable driver around that will fit the hole
That is an enlightened idea!
I also very much appreciate the explanation for the woofer/tweeter problem. That makes a lot of sense. I'm very grateful for your sage advice, Don.
I've thought about your comments here, Don, and those of Moondog55 below (Hi Moondog55!) and I'm seeing a lot of upside to swapping out the Jaycar woofers for something that might sound better, be easier to engineer impedance-wise, but hopefully won't break the bank.
I have 6, to replace the original 6 PSB drivers.
I did
but also because they were accessible at the time, and because I don't think I really knew what I was doing. I realise I should have come here first before I made a move.I guessed that might be the case. Hmmm. How bad is not great? I don't really want to buy new drivers, but then again I don't want the speakers to sound awful after all this. Which drivers would you recommend?
I don't know which drivers might also alleviate this impedance problem. I think being able to use the original crossover would be, well, terrific.
As a woofer I think they are OK although I do hope you got the bulk discount.
I also assume that there is a limited budget .
There is a cheap Peerless driver that has a better midrange and a round frame
831916 - PEERLESS 61/2" MID-WOOFER POLY-NYLON - Peerless
Should work to 3k, maybe 3.5k if that made the tweeter easier to use
I've not used it myself tho, only listened once.
If you have the skills to fill in the big hole and go to a smaller driver for the midrange then there is a cheap but good Peerless driver or simply use one of the truncated frame Peerless and fill in the gap
6.5"
830657 - PEERLESS 61/2" MID-WOOFER SDS PAPER - Peerless
5"
830656 - PEERLESS 5" MID-WOOFER SDS - Peerless
The paper coned Peerless 830657 is the one used in Paul Carmodys "Tarkus"
I also assume that there is a limited budget .
There is a cheap Peerless driver that has a better midrange and a round frame
831916 - PEERLESS 61/2" MID-WOOFER POLY-NYLON - Peerless
Should work to 3k, maybe 3.5k if that made the tweeter easier to use
I've not used it myself tho, only listened once.
If you have the skills to fill in the big hole and go to a smaller driver for the midrange then there is a cheap but good Peerless driver or simply use one of the truncated frame Peerless and fill in the gap
6.5"
830657 - PEERLESS 61/2" MID-WOOFER SDS PAPER - Peerless
5"
830656 - PEERLESS 5" MID-WOOFER SDS - Peerless
The paper coned Peerless 830657 is the one used in Paul Carmodys "Tarkus"
If only it were possible to do this and still sound good, but most times it can't be done.
There might be a work-around if there was a spare stereo amplifier sitting around.
Use the subwoofer out on the HT amplifer to send LF to the woofers and set the speaker selector to Small and just drive the midbass and tweeter using the HT amplifer
Might work better with the Jaycar woofers in sealed boxes too
This way all you should need is a simple by comparison 2-way cross-over
The original crossover (or a replacement stock one) will have to be modified in all cases because you can't get exact replacement drivers. The Xsim schematic shows the additional parts required. I have tried to place the additions either before or after the existing crossover parts to make the modifications easy.
The crossover additions are relatively low cost, and you have the Jaycar drivers already (sunk cost). Why not give them a try. If you don't like the sound, you can swap out the midrange driver later and see if you prefer the new sound.
The crossover additions are relatively low cost, and you have the Jaycar drivers already (sunk cost). Why not give them a try. If you don't like the sound, you can swap out the midrange driver later and see if you prefer the new sound.
Yes I realised my stupidity on this comment last night in bed.
Of course the crossover will have to be modified because I can't get the identical drivers as in the original cab, and the response will be different. I don't know what I was thinking. 
I think this is good advice. I'll gather my thoughts and post a plan for the way forward in the next day. I'm really very grateful for all the help!
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OK here's the plan.
1. Order the following parts from Parts Express or similar
3. Solder the new components on to the board.
4. Reassemble crossover and test with multimeter.
5. Soft install crossover and connect to drivers. Test. Jump for joy if it works.
6. Repeat for second speaker.
My only question is whether it would be worth my trying to find 8 Ohm tweeters rather than the 4 Ohm versions listed above. Otherwise, I think I'm good to go!
1. Order the following parts from Parts Express or similar
- 2 x BC25SC08-04 (4 Ohm) tweeters
- 2 x Resistor 22 Ohm
- 2 x Capacitor 33μF
- 2 x Capacitor 3.9μF
3. Solder the new components on to the board.
4. Reassemble crossover and test with multimeter.
5. Soft install crossover and connect to drivers. Test. Jump for joy if it works.
6. Repeat for second speaker.
My only question is whether it would be worth my trying to find 8 Ohm tweeters rather than the 4 Ohm versions listed above. Otherwise, I think I'm good to go!
Suggested parts 3way mod
A suggested parts list, based on schematic V4 post #25, making a 3way using Jaycar drivers. The midrange driver does not require a ported cabinet and you can seal the pipe at inside opening (paper towel plug wrapped in plastic).
R2=2.2R (2.2 ohm)
this 5w or the 10w below : 2.2 Ohm 5 Watt Wire Wound Resistor | Jaycar Electronics
R3=R4= 1.5R or 2.2ohm and Jaycar does not have 1.5R in 10W
only Jaycar option : 2.2 Ohm 10 Watt Wire Wound Resistor | Jaycar Electronics
C2=3.3uF bipolar 100v
better : 3.3uF 100V Electrolytic Crossover Capacitor | Jaycar Electronics
acceptable : 3.3uF 50V Bipolar Electrolytic Capacitor | Jaycar Electronics
C3=33uF bipolar 100v,
better : 33uF 100V Electrolytic Crossover Capacitor | Jaycar Electronics
acceptable : https://www.jaycar.com.au/33uf-50v-bipolar-electrolytic-capacitor/p/RY6818
Recommended to use quick disconnect spade M+F same size as your new speakers or crossover. Like these, but check your sizes.
https://www.jaycar.com.au/female-spade-red-pk-8/p/PT4507
https://www.jaycar.com.au/male-spade-red-pk-8/p/PT4509
The modifications can be done by inserting the mod resistor or cap with M/F spade lugs between the a) speaker wire and crossover board or b) speaker wire and speaker terminal. This allows you to make adjustments easily when you listen (or measure preferred) and need to correct a problem. When you are happy then try to find room on the board and make it more permanent if you want.
A suggested parts list, based on schematic V4 post #25, making a 3way using Jaycar drivers. The midrange driver does not require a ported cabinet and you can seal the pipe at inside opening (paper towel plug wrapped in plastic).
R2=2.2R (2.2 ohm)
this 5w or the 10w below : 2.2 Ohm 5 Watt Wire Wound Resistor | Jaycar Electronics
R3=R4= 1.5R or 2.2ohm and Jaycar does not have 1.5R in 10W
only Jaycar option : 2.2 Ohm 10 Watt Wire Wound Resistor | Jaycar Electronics
C2=3.3uF bipolar 100v
better : 3.3uF 100V Electrolytic Crossover Capacitor | Jaycar Electronics
acceptable : 3.3uF 50V Bipolar Electrolytic Capacitor | Jaycar Electronics
C3=33uF bipolar 100v,
better : 33uF 100V Electrolytic Crossover Capacitor | Jaycar Electronics
acceptable : https://www.jaycar.com.au/33uf-50v-bipolar-electrolytic-capacitor/p/RY6818
Recommended to use quick disconnect spade M+F same size as your new speakers or crossover. Like these, but check your sizes.
https://www.jaycar.com.au/female-spade-red-pk-8/p/PT4507
https://www.jaycar.com.au/male-spade-red-pk-8/p/PT4509
The modifications can be done by inserting the mod resistor or cap with M/F spade lugs between the a) speaker wire and crossover board or b) speaker wire and speaker terminal. This allows you to make adjustments easily when you listen (or measure preferred) and need to correct a problem. When you are happy then try to find room on the board and make it more permanent if you want.
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schematic v5
Well, I missed by edit window so I'll add the updates here. I noticed you want the 4 ohm tweeter. So I included a 4 ohm tweeter in a quick sim using a Dayton RST28a-4 to see the effect. Your BC25SC08-04 seems like it's a bit more sensitive than RST28, and you may decide to tone it down once you listen to it. The speaker impedance is still good.
R2 = 4.7ohm 4.7 Ohm 5 Watt Wire Wound Resistor | Jaycar Electronics
Well, I missed by edit window so I'll add the updates here. I noticed you want the 4 ohm tweeter. So I included a 4 ohm tweeter in a quick sim using a Dayton RST28a-4 to see the effect. Your BC25SC08-04 seems like it's a bit more sensitive than RST28, and you may decide to tone it down once you listen to it. The speaker impedance is still good.
R2 = 4.7ohm 4.7 Ohm 5 Watt Wire Wound Resistor | Jaycar Electronics
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Hi everybody
First, I really am ever so thankful for the advice and help in building these speakers. It took me quite a few months, in the end, but I eventually finished everything. I was very proud to have completed them.
I've now heard them running in two different rooms, I find I'm bugged by the sound. Every time I hear them it sounds to me like there are frequencies 'missing': maybe not enough bass? Maybe not enough treble? I just don't know enough to tell. Overall, despite the size of the speakers, they sound thin. I don't think it's an out of phase issue. This is the first time I've ever encountered this problem with any speakers so I'm not sure how to describe it. They're being powered through a a Pioneer VSX-523 amplifier.
I took a sound reading with the Spectroid app on my phone - this is 'Airbag' by Radiohead (source is CD):
Edit, I also took a reading through my floorstanding speakers at home, powered by a Pioneer SCLX56, which I think sound excellent:
...but I don't know if this helps me to diagnose the problems. Hence, humbly, I am back before you for your advice. I'd be grateful for any advice on what this look like, and what might be happening.
First, I really am ever so thankful for the advice and help in building these speakers. It took me quite a few months, in the end, but I eventually finished everything. I was very proud to have completed them.
I've now heard them running in two different rooms, I find I'm bugged by the sound. Every time I hear them it sounds to me like there are frequencies 'missing': maybe not enough bass? Maybe not enough treble? I just don't know enough to tell. Overall, despite the size of the speakers, they sound thin. I don't think it's an out of phase issue. This is the first time I've ever encountered this problem with any speakers so I'm not sure how to describe it. They're being powered through a a Pioneer VSX-523 amplifier.
I took a sound reading with the Spectroid app on my phone - this is 'Airbag' by Radiohead (source is CD):
Edit, I also took a reading through my floorstanding speakers at home, powered by a Pioneer SCLX56, which I think sound excellent:
...but I don't know if this helps me to diagnose the problems. Hence, humbly, I am back before you for your advice. I'd be grateful for any advice on what this look like, and what might be happening.
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When someone says their speakers have a thin sound (and the driver complement indicates they probably shouldn't sound thin) it suggests the crossover needs to be tweaked to account for baffle diffraction losses. If you Google 'baffle step compensation' there is a fair bit of info about it. However, it can be quite involved to remedy it in the crossover...although with multiple woofers it can be easier than when you have a single woofer.
Welcome back @Cori . Can you provide an update on what you eventually built?
The curves you provided do not provide enough information to determine what could be the problem. You would need a known test sweep from something like REW, rather than an RTA of a song. If they sound "thin" then bass or midbass may be lacking with a number of possible causes. One step at a time.
The curves you provided do not provide enough information to determine what could be the problem. You would need a known test sweep from something like REW, rather than an RTA of a song. If they sound "thin" then bass or midbass may be lacking with a number of possible causes. One step at a time.
Hi you two! 
First, let me say that I do not attribute the sound to anything other than what I have done. I'm very grateful indeed for all the help.
So I used Jaycar CW2194 6.5" (8Ω) drivers instead for each of the originals. I did find exact replacements for the original tweeters, using Tymphany Peerless BC25SC08-04 1" units (at 4Ω) which I ordered from the US. For completeness, this is the plan of the circuit I used:
After I completed the work, I tested them in my garage and I thought they sounded pretty good. I used a Yamaha RX-450 Natural Sound receiver to drive them. It seemed a detailed, full sound. A little bright, maybe, but a very suitable overall response indeed.
When I connected them to my friend's receiver, the sound was not impressive. My nagging and persistent feeling is that the speakers' sound quality is somehow now not very good. Specifically, I feel some frequencies are missing, particularly around the bass. I feel the midrange lacks detail and the top range is harsh. But the big thing is the bass presence - it feels like it's missing. And I have no idea what's wrong.
I first thought it might be an equalizer issue but I'm now not convinced that targeting individual frequencies would really solve the problem. Then I'm wondering if it might be a power issue - i.e. the crossover design may be basically expecting to be bi-amped, which isn't currently the case. I remember that when I tested them using the Yamaha receiver (which wasn't bi-amped either), I did have to crank up the volume dial because that receiver only supplies 45 watts per channel at 8Ω (the VSX-523 will do 80 watts).
Of course, it might also (and more simply) be that I somehow screwed the soldering or made a bad choice about driver selection. Also, I know that cabs and drivers are symbiotic, and it may be that in changing the drivers I created an unsuitable environment. I recall the original simulation did take the cab dimensions into account but maybe there's an oversight somewhere. One thing I did not do, that I was advised to do, was to cut the ports on both cabs down from 20cm to 10cm.
I guess it could all be my imagination. But I just can't tell for sure. I've now heard those speakers with that receiver in two different rooms in two different buildings (in one, a small, carpeted living room, and in the second, a larger, high ceiling living room). These are two very different room configurations and spaces, but my impression of the speakers is just about identical in both.
So this is where I'm at. Is this all in my head? I can see I'll need to take a good sweeping reading.
@Stuey - thanks for the tip! It's really amazing how deep this hobby is!
@DonVK - one slow step at a time, definitely! I'll see if I can get a test sweep some time in the next few weeks. I can see that that would be useful.
First, let me say that I do not attribute the sound to anything other than what I have done. I'm very grateful indeed for all the help.
So I used Jaycar CW2194 6.5" (8Ω) drivers instead for each of the originals. I did find exact replacements for the original tweeters, using Tymphany Peerless BC25SC08-04 1" units (at 4Ω) which I ordered from the US. For completeness, this is the plan of the circuit I used:
After I completed the work, I tested them in my garage and I thought they sounded pretty good. I used a Yamaha RX-450 Natural Sound receiver to drive them. It seemed a detailed, full sound. A little bright, maybe, but a very suitable overall response indeed.
When I connected them to my friend's receiver, the sound was not impressive. My nagging and persistent feeling is that the speakers' sound quality is somehow now not very good. Specifically, I feel some frequencies are missing, particularly around the bass. I feel the midrange lacks detail and the top range is harsh. But the big thing is the bass presence - it feels like it's missing. And I have no idea what's wrong.
I first thought it might be an equalizer issue but I'm now not convinced that targeting individual frequencies would really solve the problem. Then I'm wondering if it might be a power issue - i.e. the crossover design may be basically expecting to be bi-amped, which isn't currently the case. I remember that when I tested them using the Yamaha receiver (which wasn't bi-amped either), I did have to crank up the volume dial because that receiver only supplies 45 watts per channel at 8Ω (the VSX-523 will do 80 watts).
Of course, it might also (and more simply) be that I somehow screwed the soldering or made a bad choice about driver selection. Also, I know that cabs and drivers are symbiotic, and it may be that in changing the drivers I created an unsuitable environment. I recall the original simulation did take the cab dimensions into account but maybe there's an oversight somewhere. One thing I did not do, that I was advised to do, was to cut the ports on both cabs down from 20cm to 10cm.
I guess it could all be my imagination. But I just can't tell for sure. I've now heard those speakers with that receiver in two different rooms in two different buildings (in one, a small, carpeted living room, and in the second, a larger, high ceiling living room). These are two very different room configurations and spaces, but my impression of the speakers is just about identical in both.
So this is where I'm at. Is this all in my head? I can see I'll need to take a good sweeping reading.
@Stuey - thanks for the tip! It's really amazing how deep this hobby is!
@DonVK - one slow step at a time, definitely! I'll see if I can get a test sweep some time in the next few weeks. I can see that that would be useful.
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