ltank

7 hours ago, agedhorse said:

Sorry, I wasn’t feeling well for a couple of days and missed this.

 

First, a professional service technician that made that kind of mistake (substituting a 4 ohm driver for an 8 ohm driver in a 410 needs to hand in any credentials he may (or may not) have. That’s a bone-head error in judgement, just like choosing a BP-102 which is about the worst driver I can think of for that application. 
 

The original vendor for the earlier PH cabinets went out of business, the parts for those drivers are no longer available. The closest match to the drivers in your cabinet is the Legend CA-10 (8 ohm), and the drivers are wired series-parallel. Note that wiring so the polarities are correct is essential. If you need a diagram, message me and I will get it for you. 
 

This is why I always recommend verifying that the cabinet you are buying used is really what you think it is, I see folks get burned all the time. 

Pm send!

5 hours ago, Hellzero said:

I would buy 4 Eminence CA10-8 200 Watts as they are the replacement suggested by Mesa Boogie and change the 4 of them, but that's a lot of money...

Why change all four? The two speakers on the right side are fine to my knowledge.

5 hours ago, Hellzero said:

By the way, where do you live as Northern Europe is quite vague...

Sorry, Denmark.

21 minutes ago, Hellzero said:

8 ohms, if it's an 8 Ohms cabinet.

Regarding wattage, is it essential to stick to 150 watts per speaker, or is there some flexibility?

In the meantime, if I were to switch out the two speakers (the broken one and the one that the technician incorrectly installed), what would then be the correct ohm to buy? I live in Northern Europe, so I don't have access to US markets.

I'm truly appreciative of your prompt responses! Currently, the cabinet isn't at my place, it's situated at our studio. But I'll swing by, give some of your ideas a try, and gather some more info so I can answer your questions better.

13 hours ago, BigRedX said:

Is it the replacement speaker that has blown?

 

For the cab to have an overall impedance of 8Ω the speakers should all be 8Ω each and wired in series/parallel pairs. If this replacement speaker really is 4Ω then the impedance of the whole cab will be under 8Ω (6.86Ω approx) which could also damage you amp if it isn't rated for loads under 8Ω, or it's valve amp and you are using the wrong transferee tap output.

 

Also what is that bit of orange tape doing on the white wire? Is it just for identification purposes or is it covering a join? If it's a join I'd be looking at that as a possible source of any unwanted noises, and replacing it with single continuous wire.

The original speaker placed above the new one has given out. I'm not sure what the tape is doing there, but I'll get back to you on that one.

13 hours ago, Hellzero said:

Do you have a multimeter @ltank?

 

When yes, unconnect an official "Mesa Boogie" speaker and measure it, then give us the resistance reading.

 

You won't have the exact impedance of the speaker (which is a way more complicated process), but you could know it by this reading.

 

If it's an 8 Ohms cabinet, why the heck is there one 4 Ohms speaker in it?

 

Are you sure it's an 8 Ohms cabinet?

That's a good point, I wish I had thought of it earlier. I currently don't own a multimeter, but I will acquire one soon and then share the findings with you here.
 

13 hours ago, warwickhunt said:

A professional repair technician put a 4 ohm driver in a cab rated at 8 ohms and populated by all 8 ohm drivers... you've had a lucky escape that he is busy!    

 

If you have a valve amp you really need to get the ohmage sorted.  If you have a solid state amp it is less of an immediate issue as your amp is likely to go down to 4 ohms but it is not good for the drivers to be mismatched like that.  

Fortunately I use a GK1001RB which is solid state and can take 4 and 8 ohms.

Hello wizards,
As an absolute beginner to cabinet repair and musical equipment maintenance, I'm venturing into uncharted waters here, so please bear with me.
I need advice on removing glued speakers and on identifying suitable replacement speakers.



I am the proud owner of an exceptional Mesa Boogie PH410, which I believe is top-notch. However, following our recent performance, I suspect that one of the four speakers has blown. It's begun to sound noticeably distorted compared to the others, and it also seems to vibrate more intensively. I purchased it second-hand, and the previous owner had one of the speakers replaced by a professional repair technician who has experience with this specific model. However, he is currently unable to service it within an acceptable timeline, hence he suggested that I simply purchase the same type of speaker he had installed earlier.

When I tried removing the faulty speaker, I found it firmly glued in place. Can anyone suggest a reliable method to handle this? I own a heat gun; would that be an appropriate tool to use in this situation?

To assist with identifying the right replacement, I've attached a photo of the speaker that was recently replaced.

To my limited understanding, the speaker indicates 4ohms. But if the total cabinet impedance is 8ohms, shouldn't each speaker, when wired in parallel, be 32ohms?

Interestingly, on the Mesa Boogie's official website, it's mentioned that the original PH custom Eminence speakers are no longer in production. They recommend using Eminence Legend CA10 as a suitable replacement. However, I am unsure of the impedance I should opt for. Can anyone provide guidance on this?
https://store.mesaboogie.com/products/speaker-10-eminence-legend-ca10-8-200-watt-8-ohm-1.html

The original speakers don't have any discernible markings on them.
 

I sincerely hope some of you can provide me with some guidance. My apologies for the lengthy narrative, but I am genuinely in need of assistance.

Thank you.

On 18/06/2023 at 15:56, funkle said:

I would, if I were doing this all again, now choose the Wal pickup casing/mounting over the MM shape. The MM shape is cooler, but I can achieve a much wider range of pickup heights more easily using the Wal design than the MM shape/present mounting method. Live and learn! 

I guess you could get the mounting ring from Chris turner. I recently bought a pair of SEP multicoils from him and I got the mounting rings along with them. It seems like you could fit any MM style pickup in it, but I don't know if slot depth could become a problem. But I could be very wrong..

Following this whole adventure is incredibly addictive.

I'm really curious about what will be the factor that pulls out the 600k and 800k spikes on the spectrum.